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+/*-------------------------------------------------------------------------
+ *
+ * numeric.c
+ * An exact numeric data type for the Postgres database system
+ *
+ * Original coding 1998, Jan Wieck. Heavily revised 2003, Tom Lane.
+ *
+ * Many of the algorithmic ideas are borrowed from David M. Smith's "FM"
+ * multiple-precision math library, most recently published as Algorithm
+ * 786: Multiple-Precision Complex Arithmetic and Functions, ACM
+ * Transactions on Mathematical Software, Vol. 24, No. 4, December 1998,
+ * pages 359-367.
+ *
+ * Copyright (c) 1998-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/backend/utils/adt/numeric.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include <ctype.h>
+#include <float.h>
+#include <limits.h>
+#include <math.h>
+
+#include "catalog/pg_type.h"
+#include "common/hashfn.h"
+#include "common/int.h"
+#include "funcapi.h"
+#include "lib/hyperloglog.h"
+#include "libpq/pqformat.h"
+#include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/supportnodes.h"
+#include "utils/array.h"
+#include "utils/builtins.h"
+#include "utils/float.h"
+#include "utils/guc.h"
+#include "utils/int8.h"
+#include "utils/numeric.h"
+#include "utils/pg_lsn.h"
+#include "utils/sortsupport.h"
+
+/* ----------
+ * Uncomment the following to enable compilation of dump_numeric()
+ * and dump_var() and to get a dump of any result produced by make_result().
+ * ----------
+#define NUMERIC_DEBUG
+ */
+
+
+/* ----------
+ * Local data types
+ *
+ * Numeric values are represented in a base-NBASE floating point format.
+ * Each "digit" ranges from 0 to NBASE-1. The type NumericDigit is signed
+ * and wide enough to store a digit. We assume that NBASE*NBASE can fit in
+ * an int. Although the purely calculational routines could handle any even
+ * NBASE that's less than sqrt(INT_MAX), in practice we are only interested
+ * in NBASE a power of ten, so that I/O conversions and decimal rounding
+ * are easy. Also, it's actually more efficient if NBASE is rather less than
+ * sqrt(INT_MAX), so that there is "headroom" for mul_var and div_var_fast to
+ * postpone processing carries.
+ *
+ * Values of NBASE other than 10000 are considered of historical interest only
+ * and are no longer supported in any sense; no mechanism exists for the client
+ * to discover the base, so every client supporting binary mode expects the
+ * base-10000 format. If you plan to change this, also note the numeric
+ * abbreviation code, which assumes NBASE=10000.
+ * ----------
+ */
+
+#if 0
+#define NBASE 10
+#define HALF_NBASE 5
+#define DEC_DIGITS 1 /* decimal digits per NBASE digit */
+#define MUL_GUARD_DIGITS 4 /* these are measured in NBASE digits */
+#define DIV_GUARD_DIGITS 8
+
+typedef signed char NumericDigit;
+#endif
+
+#if 0
+#define NBASE 100
+#define HALF_NBASE 50
+#define DEC_DIGITS 2 /* decimal digits per NBASE digit */
+#define MUL_GUARD_DIGITS 3 /* these are measured in NBASE digits */
+#define DIV_GUARD_DIGITS 6
+
+typedef signed char NumericDigit;
+#endif
+
+#if 1
+#define NBASE 10000
+#define HALF_NBASE 5000
+#define DEC_DIGITS 4 /* decimal digits per NBASE digit */
+#define MUL_GUARD_DIGITS 2 /* these are measured in NBASE digits */
+#define DIV_GUARD_DIGITS 4
+
+typedef int16 NumericDigit;
+#endif
+
+/*
+ * The Numeric type as stored on disk.
+ *
+ * If the high bits of the first word of a NumericChoice (n_header, or
+ * n_short.n_header, or n_long.n_sign_dscale) are NUMERIC_SHORT, then the
+ * numeric follows the NumericShort format; if they are NUMERIC_POS or
+ * NUMERIC_NEG, it follows the NumericLong format. If they are NUMERIC_SPECIAL,
+ * the value is a NaN or Infinity. We currently always store SPECIAL values
+ * using just two bytes (i.e. only n_header), but previous releases used only
+ * the NumericLong format, so we might find 4-byte NaNs (though not infinities)
+ * on disk if a database has been migrated using pg_upgrade. In either case,
+ * the low-order bits of a special value's header are reserved and currently
+ * should always be set to zero.
+ *
+ * In the NumericShort format, the remaining 14 bits of the header word
+ * (n_short.n_header) are allocated as follows: 1 for sign (positive or
+ * negative), 6 for dynamic scale, and 7 for weight. In practice, most
+ * commonly-encountered values can be represented this way.
+ *
+ * In the NumericLong format, the remaining 14 bits of the header word
+ * (n_long.n_sign_dscale) represent the display scale; and the weight is
+ * stored separately in n_weight.
+ *
+ * NOTE: by convention, values in the packed form have been stripped of
+ * all leading and trailing zero digits (where a "digit" is of base NBASE).
+ * In particular, if the value is zero, there will be no digits at all!
+ * The weight is arbitrary in that case, but we normally set it to zero.
+ */
+
+struct NumericShort
+{
+ uint16 n_header; /* Sign + display scale + weight */
+ NumericDigit n_data[FLEXIBLE_ARRAY_MEMBER]; /* Digits */
+};
+
+struct NumericLong
+{
+ uint16 n_sign_dscale; /* Sign + display scale */
+ int16 n_weight; /* Weight of 1st digit */
+ NumericDigit n_data[FLEXIBLE_ARRAY_MEMBER]; /* Digits */
+};
+
+union NumericChoice
+{
+ uint16 n_header; /* Header word */
+ struct NumericLong n_long; /* Long form (4-byte header) */
+ struct NumericShort n_short; /* Short form (2-byte header) */
+};
+
+struct NumericData
+{
+ int32 vl_len_; /* varlena header (do not touch directly!) */
+ union NumericChoice choice; /* choice of format */
+};
+
+
+/*
+ * Interpretation of high bits.
+ */
+
+#define NUMERIC_SIGN_MASK 0xC000
+#define NUMERIC_POS 0x0000
+#define NUMERIC_NEG 0x4000
+#define NUMERIC_SHORT 0x8000
+#define NUMERIC_SPECIAL 0xC000
+
+#define NUMERIC_FLAGBITS(n) ((n)->choice.n_header & NUMERIC_SIGN_MASK)
+#define NUMERIC_IS_SHORT(n) (NUMERIC_FLAGBITS(n) == NUMERIC_SHORT)
+#define NUMERIC_IS_SPECIAL(n) (NUMERIC_FLAGBITS(n) == NUMERIC_SPECIAL)
+
+#define NUMERIC_HDRSZ (VARHDRSZ + sizeof(uint16) + sizeof(int16))
+#define NUMERIC_HDRSZ_SHORT (VARHDRSZ + sizeof(uint16))
+
+/*
+ * If the flag bits are NUMERIC_SHORT or NUMERIC_SPECIAL, we want the short
+ * header; otherwise, we want the long one. Instead of testing against each
+ * value, we can just look at the high bit, for a slight efficiency gain.
+ */
+#define NUMERIC_HEADER_IS_SHORT(n) (((n)->choice.n_header & 0x8000) != 0)
+#define NUMERIC_HEADER_SIZE(n) \
+ (VARHDRSZ + sizeof(uint16) + \
+ (NUMERIC_HEADER_IS_SHORT(n) ? 0 : sizeof(int16)))
+
+/*
+ * Definitions for special values (NaN, positive infinity, negative infinity).
+ *
+ * The two bits after the NUMERIC_SPECIAL bits are 00 for NaN, 01 for positive
+ * infinity, 11 for negative infinity. (This makes the sign bit match where
+ * it is in a short-format value, though we make no use of that at present.)
+ * We could mask off the remaining bits before testing the active bits, but
+ * currently those bits must be zeroes, so masking would just add cycles.
+ */
+#define NUMERIC_EXT_SIGN_MASK 0xF000 /* high bits plus NaN/Inf flag bits */
+#define NUMERIC_NAN 0xC000
+#define NUMERIC_PINF 0xD000
+#define NUMERIC_NINF 0xF000
+#define NUMERIC_INF_SIGN_MASK 0x2000
+
+#define NUMERIC_EXT_FLAGBITS(n) ((n)->choice.n_header & NUMERIC_EXT_SIGN_MASK)
+#define NUMERIC_IS_NAN(n) ((n)->choice.n_header == NUMERIC_NAN)
+#define NUMERIC_IS_PINF(n) ((n)->choice.n_header == NUMERIC_PINF)
+#define NUMERIC_IS_NINF(n) ((n)->choice.n_header == NUMERIC_NINF)
+#define NUMERIC_IS_INF(n) \
+ (((n)->choice.n_header & ~NUMERIC_INF_SIGN_MASK) == NUMERIC_PINF)
+
+/*
+ * Short format definitions.
+ */
+
+#define NUMERIC_SHORT_SIGN_MASK 0x2000
+#define NUMERIC_SHORT_DSCALE_MASK 0x1F80
+#define NUMERIC_SHORT_DSCALE_SHIFT 7
+#define NUMERIC_SHORT_DSCALE_MAX \
+ (NUMERIC_SHORT_DSCALE_MASK >> NUMERIC_SHORT_DSCALE_SHIFT)
+#define NUMERIC_SHORT_WEIGHT_SIGN_MASK 0x0040
+#define NUMERIC_SHORT_WEIGHT_MASK 0x003F
+#define NUMERIC_SHORT_WEIGHT_MAX NUMERIC_SHORT_WEIGHT_MASK
+#define NUMERIC_SHORT_WEIGHT_MIN (-(NUMERIC_SHORT_WEIGHT_MASK+1))
+
+/*
+ * Extract sign, display scale, weight. These macros extract field values
+ * suitable for the NumericVar format from the Numeric (on-disk) format.
+ *
+ * Note that we don't trouble to ensure that dscale and weight read as zero
+ * for an infinity; however, that doesn't matter since we never convert
+ * "special" numerics to NumericVar form. Only the constants defined below
+ * (const_nan, etc) ever represent a non-finite value as a NumericVar.
+ */
+
+#define NUMERIC_DSCALE_MASK 0x3FFF
+#define NUMERIC_DSCALE_MAX NUMERIC_DSCALE_MASK
+
+#define NUMERIC_SIGN(n) \
+ (NUMERIC_IS_SHORT(n) ? \
+ (((n)->choice.n_short.n_header & NUMERIC_SHORT_SIGN_MASK) ? \
+ NUMERIC_NEG : NUMERIC_POS) : \
+ (NUMERIC_IS_SPECIAL(n) ? \
+ NUMERIC_EXT_FLAGBITS(n) : NUMERIC_FLAGBITS(n)))
+#define NUMERIC_DSCALE(n) (NUMERIC_HEADER_IS_SHORT((n)) ? \
+ ((n)->choice.n_short.n_header & NUMERIC_SHORT_DSCALE_MASK) \
+ >> NUMERIC_SHORT_DSCALE_SHIFT \
+ : ((n)->choice.n_long.n_sign_dscale & NUMERIC_DSCALE_MASK))
+#define NUMERIC_WEIGHT(n) (NUMERIC_HEADER_IS_SHORT((n)) ? \
+ (((n)->choice.n_short.n_header & NUMERIC_SHORT_WEIGHT_SIGN_MASK ? \
+ ~NUMERIC_SHORT_WEIGHT_MASK : 0) \
+ | ((n)->choice.n_short.n_header & NUMERIC_SHORT_WEIGHT_MASK)) \
+ : ((n)->choice.n_long.n_weight))
+
+/* ----------
+ * NumericVar is the format we use for arithmetic. The digit-array part
+ * is the same as the NumericData storage format, but the header is more
+ * complex.
+ *
+ * The value represented by a NumericVar is determined by the sign, weight,
+ * ndigits, and digits[] array. If it is a "special" value (NaN or Inf)
+ * then only the sign field matters; ndigits should be zero, and the weight
+ * and dscale fields are ignored.
+ *
+ * Note: the first digit of a NumericVar's value is assumed to be multiplied
+ * by NBASE ** weight. Another way to say it is that there are weight+1
+ * digits before the decimal point. It is possible to have weight < 0.
+ *
+ * buf points at the physical start of the palloc'd digit buffer for the
+ * NumericVar. digits points at the first digit in actual use (the one
+ * with the specified weight). We normally leave an unused digit or two
+ * (preset to zeroes) between buf and digits, so that there is room to store
+ * a carry out of the top digit without reallocating space. We just need to
+ * decrement digits (and increment weight) to make room for the carry digit.
+ * (There is no such extra space in a numeric value stored in the database,
+ * only in a NumericVar in memory.)
+ *
+ * If buf is NULL then the digit buffer isn't actually palloc'd and should
+ * not be freed --- see the constants below for an example.
+ *
+ * dscale, or display scale, is the nominal precision expressed as number
+ * of digits after the decimal point (it must always be >= 0 at present).
+ * dscale may be more than the number of physically stored fractional digits,
+ * implying that we have suppressed storage of significant trailing zeroes.
+ * It should never be less than the number of stored digits, since that would
+ * imply hiding digits that are present. NOTE that dscale is always expressed
+ * in *decimal* digits, and so it may correspond to a fractional number of
+ * base-NBASE digits --- divide by DEC_DIGITS to convert to NBASE digits.
+ *
+ * rscale, or result scale, is the target precision for a computation.
+ * Like dscale it is expressed as number of *decimal* digits after the decimal
+ * point, and is always >= 0 at present.
+ * Note that rscale is not stored in variables --- it's figured on-the-fly
+ * from the dscales of the inputs.
+ *
+ * While we consistently use "weight" to refer to the base-NBASE weight of
+ * a numeric value, it is convenient in some scale-related calculations to
+ * make use of the base-10 weight (ie, the approximate log10 of the value).
+ * To avoid confusion, such a decimal-units weight is called a "dweight".
+ *
+ * NB: All the variable-level functions are written in a style that makes it
+ * possible to give one and the same variable as argument and destination.
+ * This is feasible because the digit buffer is separate from the variable.
+ * ----------
+ */
+typedef struct NumericVar
+{
+ int ndigits; /* # of digits in digits[] - can be 0! */
+ int weight; /* weight of first digit */
+ int sign; /* NUMERIC_POS, _NEG, _NAN, _PINF, or _NINF */
+ int dscale; /* display scale */
+ NumericDigit *buf; /* start of palloc'd space for digits[] */
+ NumericDigit *digits; /* base-NBASE digits */
+} NumericVar;
+
+
+/* ----------
+ * Data for generate_series
+ * ----------
+ */
+typedef struct
+{
+ NumericVar current;
+ NumericVar stop;
+ NumericVar step;
+} generate_series_numeric_fctx;
+
+
+/* ----------
+ * Sort support.
+ * ----------
+ */
+typedef struct
+{
+ void *buf; /* buffer for short varlenas */
+ int64 input_count; /* number of non-null values seen */
+ bool estimating; /* true if estimating cardinality */
+
+ hyperLogLogState abbr_card; /* cardinality estimator */
+} NumericSortSupport;
+
+
+/* ----------
+ * Fast sum accumulator.
+ *
+ * NumericSumAccum is used to implement SUM(), and other standard aggregates
+ * that track the sum of input values. It uses 32-bit integers to store the
+ * digits, instead of the normal 16-bit integers (with NBASE=10000). This
+ * way, we can safely accumulate up to NBASE - 1 values without propagating
+ * carry, before risking overflow of any of the digits. 'num_uncarried'
+ * tracks how many values have been accumulated without propagating carry.
+ *
+ * Positive and negative values are accumulated separately, in 'pos_digits'
+ * and 'neg_digits'. This is simpler and faster than deciding whether to add
+ * or subtract from the current value, for each new value (see sub_var() for
+ * the logic we avoid by doing this). Both buffers are of same size, and
+ * have the same weight and scale. In accum_sum_final(), the positive and
+ * negative sums are added together to produce the final result.
+ *
+ * When a new value has a larger ndigits or weight than the accumulator
+ * currently does, the accumulator is enlarged to accommodate the new value.
+ * We normally have one zero digit reserved for carry propagation, and that
+ * is indicated by the 'have_carry_space' flag. When accum_sum_carry() uses
+ * up the reserved digit, it clears the 'have_carry_space' flag. The next
+ * call to accum_sum_add() will enlarge the buffer, to make room for the
+ * extra digit, and set the flag again.
+ *
+ * To initialize a new accumulator, simply reset all fields to zeros.
+ *
+ * The accumulator does not handle NaNs.
+ * ----------
+ */
+typedef struct NumericSumAccum
+{
+ int ndigits;
+ int weight;
+ int dscale;
+ int num_uncarried;
+ bool have_carry_space;
+ int32 *pos_digits;
+ int32 *neg_digits;
+} NumericSumAccum;
+
+
+/*
+ * We define our own macros for packing and unpacking abbreviated-key
+ * representations for numeric values in order to avoid depending on
+ * USE_FLOAT8_BYVAL. The type of abbreviation we use is based only on
+ * the size of a datum, not the argument-passing convention for float8.
+ *
+ * The range of abbreviations for finite values is from +PG_INT64/32_MAX
+ * to -PG_INT64/32_MAX. NaN has the abbreviation PG_INT64/32_MIN, and we
+ * define the sort ordering to make that work out properly (see further
+ * comments below). PINF and NINF share the abbreviations of the largest
+ * and smallest finite abbreviation classes.
+ */
+#define NUMERIC_ABBREV_BITS (SIZEOF_DATUM * BITS_PER_BYTE)
+#if SIZEOF_DATUM == 8
+#define NumericAbbrevGetDatum(X) ((Datum) (X))
+#define DatumGetNumericAbbrev(X) ((int64) (X))
+#define NUMERIC_ABBREV_NAN NumericAbbrevGetDatum(PG_INT64_MIN)
+#define NUMERIC_ABBREV_PINF NumericAbbrevGetDatum(-PG_INT64_MAX)
+#define NUMERIC_ABBREV_NINF NumericAbbrevGetDatum(PG_INT64_MAX)
+#else
+#define NumericAbbrevGetDatum(X) ((Datum) (X))
+#define DatumGetNumericAbbrev(X) ((int32) (X))
+#define NUMERIC_ABBREV_NAN NumericAbbrevGetDatum(PG_INT32_MIN)
+#define NUMERIC_ABBREV_PINF NumericAbbrevGetDatum(-PG_INT32_MAX)
+#define NUMERIC_ABBREV_NINF NumericAbbrevGetDatum(PG_INT32_MAX)
+#endif
+
+
+/* ----------
+ * Some preinitialized constants
+ * ----------
+ */
+static const NumericDigit const_zero_data[1] = {0};
+static const NumericVar const_zero =
+{0, 0, NUMERIC_POS, 0, NULL, (NumericDigit *) const_zero_data};
+
+static const NumericDigit const_one_data[1] = {1};
+static const NumericVar const_one =
+{1, 0, NUMERIC_POS, 0, NULL, (NumericDigit *) const_one_data};
+
+static const NumericVar const_minus_one =
+{1, 0, NUMERIC_NEG, 0, NULL, (NumericDigit *) const_one_data};
+
+static const NumericDigit const_two_data[1] = {2};
+static const NumericVar const_two =
+{1, 0, NUMERIC_POS, 0, NULL, (NumericDigit *) const_two_data};
+
+#if DEC_DIGITS == 4
+static const NumericDigit const_zero_point_nine_data[1] = {9000};
+#elif DEC_DIGITS == 2
+static const NumericDigit const_zero_point_nine_data[1] = {90};
+#elif DEC_DIGITS == 1
+static const NumericDigit const_zero_point_nine_data[1] = {9};
+#endif
+static const NumericVar const_zero_point_nine =
+{1, -1, NUMERIC_POS, 1, NULL, (NumericDigit *) const_zero_point_nine_data};
+
+#if DEC_DIGITS == 4
+static const NumericDigit const_one_point_one_data[2] = {1, 1000};
+#elif DEC_DIGITS == 2
+static const NumericDigit const_one_point_one_data[2] = {1, 10};
+#elif DEC_DIGITS == 1
+static const NumericDigit const_one_point_one_data[2] = {1, 1};
+#endif
+static const NumericVar const_one_point_one =
+{2, 0, NUMERIC_POS, 1, NULL, (NumericDigit *) const_one_point_one_data};
+
+static const NumericVar const_nan =
+{0, 0, NUMERIC_NAN, 0, NULL, NULL};
+
+static const NumericVar const_pinf =
+{0, 0, NUMERIC_PINF, 0, NULL, NULL};
+
+static const NumericVar const_ninf =
+{0, 0, NUMERIC_NINF, 0, NULL, NULL};
+
+#if DEC_DIGITS == 4
+static const int round_powers[4] = {0, 1000, 100, 10};
+#endif
+
+
+/* ----------
+ * Local functions
+ * ----------
+ */
+
+#ifdef NUMERIC_DEBUG
+static void dump_numeric(const char *str, Numeric num);
+static void dump_var(const char *str, NumericVar *var);
+#else
+#define dump_numeric(s,n)
+#define dump_var(s,v)
+#endif
+
+#define digitbuf_alloc(ndigits) \
+ ((NumericDigit *) palloc((ndigits) * sizeof(NumericDigit)))
+#define digitbuf_free(buf) \
+ do { \
+ if ((buf) != NULL) \
+ pfree(buf); \
+ } while (0)
+
+#define init_var(v) memset(v, 0, sizeof(NumericVar))
+
+#define NUMERIC_DIGITS(num) (NUMERIC_HEADER_IS_SHORT(num) ? \
+ (num)->choice.n_short.n_data : (num)->choice.n_long.n_data)
+#define NUMERIC_NDIGITS(num) \
+ ((VARSIZE(num) - NUMERIC_HEADER_SIZE(num)) / sizeof(NumericDigit))
+#define NUMERIC_CAN_BE_SHORT(scale,weight) \
+ ((scale) <= NUMERIC_SHORT_DSCALE_MAX && \
+ (weight) <= NUMERIC_SHORT_WEIGHT_MAX && \
+ (weight) >= NUMERIC_SHORT_WEIGHT_MIN)
+
+static void alloc_var(NumericVar *var, int ndigits);
+static void free_var(NumericVar *var);
+static void zero_var(NumericVar *var);
+
+static const char *set_var_from_str(const char *str, const char *cp,
+ NumericVar *dest);
+static void set_var_from_num(Numeric value, NumericVar *dest);
+static void init_var_from_num(Numeric num, NumericVar *dest);
+static void set_var_from_var(const NumericVar *value, NumericVar *dest);
+static char *get_str_from_var(const NumericVar *var);
+static char *get_str_from_var_sci(const NumericVar *var, int rscale);
+
+static Numeric duplicate_numeric(Numeric num);
+static Numeric make_result(const NumericVar *var);
+static Numeric make_result_opt_error(const NumericVar *var, bool *error);
+
+static void apply_typmod(NumericVar *var, int32 typmod);
+static void apply_typmod_special(Numeric num, int32 typmod);
+
+static bool numericvar_to_int32(const NumericVar *var, int32 *result);
+static bool numericvar_to_int64(const NumericVar *var, int64 *result);
+static void int64_to_numericvar(int64 val, NumericVar *var);
+static bool numericvar_to_uint64(const NumericVar *var, uint64 *result);
+#ifdef HAVE_INT128
+static bool numericvar_to_int128(const NumericVar *var, int128 *result);
+static void int128_to_numericvar(int128 val, NumericVar *var);
+#endif
+static double numericvar_to_double_no_overflow(const NumericVar *var);
+
+static Datum numeric_abbrev_convert(Datum original_datum, SortSupport ssup);
+static bool numeric_abbrev_abort(int memtupcount, SortSupport ssup);
+static int numeric_fast_cmp(Datum x, Datum y, SortSupport ssup);
+static int numeric_cmp_abbrev(Datum x, Datum y, SortSupport ssup);
+
+static Datum numeric_abbrev_convert_var(const NumericVar *var,
+ NumericSortSupport *nss);
+
+static int cmp_numerics(Numeric num1, Numeric num2);
+static int cmp_var(const NumericVar *var1, const NumericVar *var2);
+static int cmp_var_common(const NumericDigit *var1digits, int var1ndigits,
+ int var1weight, int var1sign,
+ const NumericDigit *var2digits, int var2ndigits,
+ int var2weight, int var2sign);
+static void add_var(const NumericVar *var1, const NumericVar *var2,
+ NumericVar *result);
+static void sub_var(const NumericVar *var1, const NumericVar *var2,
+ NumericVar *result);
+static void mul_var(const NumericVar *var1, const NumericVar *var2,
+ NumericVar *result,
+ int rscale);
+static void div_var(const NumericVar *var1, const NumericVar *var2,
+ NumericVar *result,
+ int rscale, bool round);
+static void div_var_fast(const NumericVar *var1, const NumericVar *var2,
+ NumericVar *result, int rscale, bool round);
+static int select_div_scale(const NumericVar *var1, const NumericVar *var2);
+static void mod_var(const NumericVar *var1, const NumericVar *var2,
+ NumericVar *result);
+static void div_mod_var(const NumericVar *var1, const NumericVar *var2,
+ NumericVar *quot, NumericVar *rem);
+static void ceil_var(const NumericVar *var, NumericVar *result);
+static void floor_var(const NumericVar *var, NumericVar *result);
+
+static void gcd_var(const NumericVar *var1, const NumericVar *var2,
+ NumericVar *result);
+static void sqrt_var(const NumericVar *arg, NumericVar *result, int rscale);
+static void exp_var(const NumericVar *arg, NumericVar *result, int rscale);
+static int estimate_ln_dweight(const NumericVar *var);
+static void ln_var(const NumericVar *arg, NumericVar *result, int rscale);
+static void log_var(const NumericVar *base, const NumericVar *num,
+ NumericVar *result);
+static void power_var(const NumericVar *base, const NumericVar *exp,
+ NumericVar *result);
+static void power_var_int(const NumericVar *base, int exp, NumericVar *result,
+ int rscale);
+static void power_ten_int(int exp, NumericVar *result);
+
+static int cmp_abs(const NumericVar *var1, const NumericVar *var2);
+static int cmp_abs_common(const NumericDigit *var1digits, int var1ndigits,
+ int var1weight,
+ const NumericDigit *var2digits, int var2ndigits,
+ int var2weight);
+static void add_abs(const NumericVar *var1, const NumericVar *var2,
+ NumericVar *result);
+static void sub_abs(const NumericVar *var1, const NumericVar *var2,
+ NumericVar *result);
+static void round_var(NumericVar *var, int rscale);
+static void trunc_var(NumericVar *var, int rscale);
+static void strip_var(NumericVar *var);
+static void compute_bucket(Numeric operand, Numeric bound1, Numeric bound2,
+ const NumericVar *count_var, bool reversed_bounds,
+ NumericVar *result_var);
+
+static void accum_sum_add(NumericSumAccum *accum, const NumericVar *var1);
+static void accum_sum_rescale(NumericSumAccum *accum, const NumericVar *val);
+static void accum_sum_carry(NumericSumAccum *accum);
+static void accum_sum_reset(NumericSumAccum *accum);
+static void accum_sum_final(NumericSumAccum *accum, NumericVar *result);
+static void accum_sum_copy(NumericSumAccum *dst, NumericSumAccum *src);
+static void accum_sum_combine(NumericSumAccum *accum, NumericSumAccum *accum2);
+
+
+/* ----------------------------------------------------------------------
+ *
+ * Input-, output- and rounding-functions
+ *
+ * ----------------------------------------------------------------------
+ */
+
+
+/*
+ * numeric_in() -
+ *
+ * Input function for numeric data type
+ */
+Datum
+numeric_in(PG_FUNCTION_ARGS)
+{
+ char *str = PG_GETARG_CSTRING(0);
+
+#ifdef NOT_USED
+ Oid typelem = PG_GETARG_OID(1);
+#endif
+ int32 typmod = PG_GETARG_INT32(2);
+ Numeric res;
+ const char *cp;
+
+ /* Skip leading spaces */
+ cp = str;
+ while (*cp)
+ {
+ if (!isspace((unsigned char) *cp))
+ break;
+ cp++;
+ }
+
+ /*
+ * Check for NaN and infinities. We recognize the same strings allowed by
+ * float8in().
+ */
+ if (pg_strncasecmp(cp, "NaN", 3) == 0)
+ {
+ res = make_result(&const_nan);
+ cp += 3;
+ }
+ else if (pg_strncasecmp(cp, "Infinity", 8) == 0)
+ {
+ res = make_result(&const_pinf);
+ cp += 8;
+ }
+ else if (pg_strncasecmp(cp, "+Infinity", 9) == 0)
+ {
+ res = make_result(&const_pinf);
+ cp += 9;
+ }
+ else if (pg_strncasecmp(cp, "-Infinity", 9) == 0)
+ {
+ res = make_result(&const_ninf);
+ cp += 9;
+ }
+ else if (pg_strncasecmp(cp, "inf", 3) == 0)
+ {
+ res = make_result(&const_pinf);
+ cp += 3;
+ }
+ else if (pg_strncasecmp(cp, "+inf", 4) == 0)
+ {
+ res = make_result(&const_pinf);
+ cp += 4;
+ }
+ else if (pg_strncasecmp(cp, "-inf", 4) == 0)
+ {
+ res = make_result(&const_ninf);
+ cp += 4;
+ }
+ else
+ {
+ /*
+ * Use set_var_from_str() to parse a normal numeric value
+ */
+ NumericVar value;
+
+ init_var(&value);
+
+ cp = set_var_from_str(str, cp, &value);
+
+ /*
+ * We duplicate a few lines of code here because we would like to
+ * throw any trailing-junk syntax error before any semantic error
+ * resulting from apply_typmod. We can't easily fold the two cases
+ * together because we mustn't apply apply_typmod to a NaN/Inf.
+ */
+ while (*cp)
+ {
+ if (!isspace((unsigned char) *cp))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ errmsg("invalid input syntax for type %s: \"%s\"",
+ "numeric", str)));
+ cp++;
+ }
+
+ apply_typmod(&value, typmod);
+
+ res = make_result(&value);
+ free_var(&value);
+
+ PG_RETURN_NUMERIC(res);
+ }
+
+ /* Should be nothing left but spaces */
+ while (*cp)
+ {
+ if (!isspace((unsigned char) *cp))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ errmsg("invalid input syntax for type %s: \"%s\"",
+ "numeric", str)));
+ cp++;
+ }
+
+ /* As above, throw any typmod error after finishing syntax check */
+ apply_typmod_special(res, typmod);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_out() -
+ *
+ * Output function for numeric data type
+ */
+Datum
+numeric_out(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ NumericVar x;
+ char *str;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ if (NUMERIC_IS_PINF(num))
+ PG_RETURN_CSTRING(pstrdup("Infinity"));
+ else if (NUMERIC_IS_NINF(num))
+ PG_RETURN_CSTRING(pstrdup("-Infinity"));
+ else
+ PG_RETURN_CSTRING(pstrdup("NaN"));
+ }
+
+ /*
+ * Get the number in the variable format.
+ */
+ init_var_from_num(num, &x);
+
+ str = get_str_from_var(&x);
+
+ PG_RETURN_CSTRING(str);
+}
+
+/*
+ * numeric_is_nan() -
+ *
+ * Is Numeric value a NaN?
+ */
+bool
+numeric_is_nan(Numeric num)
+{
+ return NUMERIC_IS_NAN(num);
+}
+
+/*
+ * numeric_is_inf() -
+ *
+ * Is Numeric value an infinity?
+ */
+bool
+numeric_is_inf(Numeric num)
+{
+ return NUMERIC_IS_INF(num);
+}
+
+/*
+ * numeric_is_integral() -
+ *
+ * Is Numeric value integral?
+ */
+static bool
+numeric_is_integral(Numeric num)
+{
+ NumericVar arg;
+
+ /* Reject NaN, but infinities are considered integral */
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ if (NUMERIC_IS_NAN(num))
+ return false;
+ return true;
+ }
+
+ /* Integral if there are no digits to the right of the decimal point */
+ init_var_from_num(num, &arg);
+
+ return (arg.ndigits == 0 || arg.ndigits <= arg.weight + 1);
+}
+
+/*
+ * numeric_maximum_size() -
+ *
+ * Maximum size of a numeric with given typmod, or -1 if unlimited/unknown.
+ */
+int32
+numeric_maximum_size(int32 typmod)
+{
+ int precision;
+ int numeric_digits;
+
+ if (typmod < (int32) (VARHDRSZ))
+ return -1;
+
+ /* precision (ie, max # of digits) is in upper bits of typmod */
+ precision = ((typmod - VARHDRSZ) >> 16) & 0xffff;
+
+ /*
+ * This formula computes the maximum number of NumericDigits we could need
+ * in order to store the specified number of decimal digits. Because the
+ * weight is stored as a number of NumericDigits rather than a number of
+ * decimal digits, it's possible that the first NumericDigit will contain
+ * only a single decimal digit. Thus, the first two decimal digits can
+ * require two NumericDigits to store, but it isn't until we reach
+ * DEC_DIGITS + 2 decimal digits that we potentially need a third
+ * NumericDigit.
+ */
+ numeric_digits = (precision + 2 * (DEC_DIGITS - 1)) / DEC_DIGITS;
+
+ /*
+ * In most cases, the size of a numeric will be smaller than the value
+ * computed below, because the varlena header will typically get toasted
+ * down to a single byte before being stored on disk, and it may also be
+ * possible to use a short numeric header. But our job here is to compute
+ * the worst case.
+ */
+ return NUMERIC_HDRSZ + (numeric_digits * sizeof(NumericDigit));
+}
+
+/*
+ * numeric_out_sci() -
+ *
+ * Output function for numeric data type in scientific notation.
+ */
+char *
+numeric_out_sci(Numeric num, int scale)
+{
+ NumericVar x;
+ char *str;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ if (NUMERIC_IS_PINF(num))
+ return pstrdup("Infinity");
+ else if (NUMERIC_IS_NINF(num))
+ return pstrdup("-Infinity");
+ else
+ return pstrdup("NaN");
+ }
+
+ init_var_from_num(num, &x);
+
+ str = get_str_from_var_sci(&x, scale);
+
+ return str;
+}
+
+/*
+ * numeric_normalize() -
+ *
+ * Output function for numeric data type, suppressing insignificant trailing
+ * zeroes and then any trailing decimal point. The intent of this is to
+ * produce strings that are equal if and only if the input numeric values
+ * compare equal.
+ */
+char *
+numeric_normalize(Numeric num)
+{
+ NumericVar x;
+ char *str;
+ int last;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ if (NUMERIC_IS_PINF(num))
+ return pstrdup("Infinity");
+ else if (NUMERIC_IS_NINF(num))
+ return pstrdup("-Infinity");
+ else
+ return pstrdup("NaN");
+ }
+
+ init_var_from_num(num, &x);
+
+ str = get_str_from_var(&x);
+
+ /* If there's no decimal point, there's certainly nothing to remove. */
+ if (strchr(str, '.') != NULL)
+ {
+ /*
+ * Back up over trailing fractional zeroes. Since there is a decimal
+ * point, this loop will terminate safely.
+ */
+ last = strlen(str) - 1;
+ while (str[last] == '0')
+ last--;
+
+ /* We want to get rid of the decimal point too, if it's now last. */
+ if (str[last] == '.')
+ last--;
+
+ /* Delete whatever we backed up over. */
+ str[last + 1] = '\0';
+ }
+
+ return str;
+}
+
+/*
+ * numeric_recv - converts external binary format to numeric
+ *
+ * External format is a sequence of int16's:
+ * ndigits, weight, sign, dscale, NumericDigits.
+ */
+Datum
+numeric_recv(PG_FUNCTION_ARGS)
+{
+ StringInfo buf = (StringInfo) PG_GETARG_POINTER(0);
+
+#ifdef NOT_USED
+ Oid typelem = PG_GETARG_OID(1);
+#endif
+ int32 typmod = PG_GETARG_INT32(2);
+ NumericVar value;
+ Numeric res;
+ int len,
+ i;
+
+ init_var(&value);
+
+ len = (uint16) pq_getmsgint(buf, sizeof(uint16));
+
+ alloc_var(&value, len);
+
+ value.weight = (int16) pq_getmsgint(buf, sizeof(int16));
+ /* we allow any int16 for weight --- OK? */
+
+ value.sign = (uint16) pq_getmsgint(buf, sizeof(uint16));
+ if (!(value.sign == NUMERIC_POS ||
+ value.sign == NUMERIC_NEG ||
+ value.sign == NUMERIC_NAN ||
+ value.sign == NUMERIC_PINF ||
+ value.sign == NUMERIC_NINF))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
+ errmsg("invalid sign in external \"numeric\" value")));
+
+ value.dscale = (uint16) pq_getmsgint(buf, sizeof(uint16));
+ if ((value.dscale & NUMERIC_DSCALE_MASK) != value.dscale)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
+ errmsg("invalid scale in external \"numeric\" value")));
+
+ for (i = 0; i < len; i++)
+ {
+ NumericDigit d = pq_getmsgint(buf, sizeof(NumericDigit));
+
+ if (d < 0 || d >= NBASE)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
+ errmsg("invalid digit in external \"numeric\" value")));
+ value.digits[i] = d;
+ }
+
+ /*
+ * If the given dscale would hide any digits, truncate those digits away.
+ * We could alternatively throw an error, but that would take a bunch of
+ * extra code (about as much as trunc_var involves), and it might cause
+ * client compatibility issues. Be careful not to apply trunc_var to
+ * special values, as it could do the wrong thing; we don't need it
+ * anyway, since make_result will ignore all but the sign field.
+ *
+ * After doing that, be sure to check the typmod restriction.
+ */
+ if (value.sign == NUMERIC_POS ||
+ value.sign == NUMERIC_NEG)
+ {
+ trunc_var(&value, value.dscale);
+
+ apply_typmod(&value, typmod);
+
+ res = make_result(&value);
+ }
+ else
+ {
+ /* apply_typmod_special wants us to make the Numeric first */
+ res = make_result(&value);
+
+ apply_typmod_special(res, typmod);
+ }
+
+ free_var(&value);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+/*
+ * numeric_send - converts numeric to binary format
+ */
+Datum
+numeric_send(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ NumericVar x;
+ StringInfoData buf;
+ int i;
+
+ init_var_from_num(num, &x);
+
+ pq_begintypsend(&buf);
+
+ pq_sendint16(&buf, x.ndigits);
+ pq_sendint16(&buf, x.weight);
+ pq_sendint16(&buf, x.sign);
+ pq_sendint16(&buf, x.dscale);
+ for (i = 0; i < x.ndigits; i++)
+ pq_sendint16(&buf, x.digits[i]);
+
+ PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+}
+
+
+/*
+ * numeric_support()
+ *
+ * Planner support function for the numeric() length coercion function.
+ *
+ * Flatten calls that solely represent increases in allowable precision.
+ * Scale changes mutate every datum, so they are unoptimizable. Some values,
+ * e.g. 1E-1001, can only fit into an unconstrained numeric, so a change from
+ * an unconstrained numeric to any constrained numeric is also unoptimizable.
+ */
+Datum
+numeric_support(PG_FUNCTION_ARGS)
+{
+ Node *rawreq = (Node *) PG_GETARG_POINTER(0);
+ Node *ret = NULL;
+
+ if (IsA(rawreq, SupportRequestSimplify))
+ {
+ SupportRequestSimplify *req = (SupportRequestSimplify *) rawreq;
+ FuncExpr *expr = req->fcall;
+ Node *typmod;
+
+ Assert(list_length(expr->args) >= 2);
+
+ typmod = (Node *) lsecond(expr->args);
+
+ if (IsA(typmod, Const) && !((Const *) typmod)->constisnull)
+ {
+ Node *source = (Node *) linitial(expr->args);
+ int32 old_typmod = exprTypmod(source);
+ int32 new_typmod = DatumGetInt32(((Const *) typmod)->constvalue);
+ int32 old_scale = (old_typmod - VARHDRSZ) & 0xffff;
+ int32 new_scale = (new_typmod - VARHDRSZ) & 0xffff;
+ int32 old_precision = (old_typmod - VARHDRSZ) >> 16 & 0xffff;
+ int32 new_precision = (new_typmod - VARHDRSZ) >> 16 & 0xffff;
+
+ /*
+ * If new_typmod < VARHDRSZ, the destination is unconstrained;
+ * that's always OK. If old_typmod >= VARHDRSZ, the source is
+ * constrained, and we're OK if the scale is unchanged and the
+ * precision is not decreasing. See further notes in function
+ * header comment.
+ */
+ if (new_typmod < (int32) VARHDRSZ ||
+ (old_typmod >= (int32) VARHDRSZ &&
+ new_scale == old_scale && new_precision >= old_precision))
+ ret = relabel_to_typmod(source, new_typmod);
+ }
+ }
+
+ PG_RETURN_POINTER(ret);
+}
+
+/*
+ * numeric() -
+ *
+ * This is a special function called by the Postgres database system
+ * before a value is stored in a tuple's attribute. The precision and
+ * scale of the attribute have to be applied on the value.
+ */
+Datum
+numeric (PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ int32 typmod = PG_GETARG_INT32(1);
+ Numeric new;
+ int32 tmp_typmod;
+ int precision;
+ int scale;
+ int ddigits;
+ int maxdigits;
+ NumericVar var;
+
+ /*
+ * Handle NaN and infinities: if apply_typmod_special doesn't complain,
+ * just return a copy of the input.
+ */
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ apply_typmod_special(num, typmod);
+ PG_RETURN_NUMERIC(duplicate_numeric(num));
+ }
+
+ /*
+ * If the value isn't a valid type modifier, simply return a copy of the
+ * input value
+ */
+ if (typmod < (int32) (VARHDRSZ))
+ PG_RETURN_NUMERIC(duplicate_numeric(num));
+
+ /*
+ * Get the precision and scale out of the typmod value
+ */
+ tmp_typmod = typmod - VARHDRSZ;
+ precision = (tmp_typmod >> 16) & 0xffff;
+ scale = tmp_typmod & 0xffff;
+ maxdigits = precision - scale;
+
+ /*
+ * If the number is certainly in bounds and due to the target scale no
+ * rounding could be necessary, just make a copy of the input and modify
+ * its scale fields, unless the larger scale forces us to abandon the
+ * short representation. (Note we assume the existing dscale is
+ * honest...)
+ */
+ ddigits = (NUMERIC_WEIGHT(num) + 1) * DEC_DIGITS;
+ if (ddigits <= maxdigits && scale >= NUMERIC_DSCALE(num)
+ && (NUMERIC_CAN_BE_SHORT(scale, NUMERIC_WEIGHT(num))
+ || !NUMERIC_IS_SHORT(num)))
+ {
+ new = duplicate_numeric(num);
+ if (NUMERIC_IS_SHORT(num))
+ new->choice.n_short.n_header =
+ (num->choice.n_short.n_header & ~NUMERIC_SHORT_DSCALE_MASK)
+ | (scale << NUMERIC_SHORT_DSCALE_SHIFT);
+ else
+ new->choice.n_long.n_sign_dscale = NUMERIC_SIGN(new) |
+ ((uint16) scale & NUMERIC_DSCALE_MASK);
+ PG_RETURN_NUMERIC(new);
+ }
+
+ /*
+ * We really need to fiddle with things - unpack the number into a
+ * variable and let apply_typmod() do it.
+ */
+ init_var(&var);
+
+ set_var_from_num(num, &var);
+ apply_typmod(&var, typmod);
+ new = make_result(&var);
+
+ free_var(&var);
+
+ PG_RETURN_NUMERIC(new);
+}
+
+Datum
+numerictypmodin(PG_FUNCTION_ARGS)
+{
+ ArrayType *ta = PG_GETARG_ARRAYTYPE_P(0);
+ int32 *tl;
+ int n;
+ int32 typmod;
+
+ tl = ArrayGetIntegerTypmods(ta, &n);
+
+ if (n == 2)
+ {
+ if (tl[0] < 1 || tl[0] > NUMERIC_MAX_PRECISION)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("NUMERIC precision %d must be between 1 and %d",
+ tl[0], NUMERIC_MAX_PRECISION)));
+ if (tl[1] < 0 || tl[1] > tl[0])
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("NUMERIC scale %d must be between 0 and precision %d",
+ tl[1], tl[0])));
+ typmod = ((tl[0] << 16) | tl[1]) + VARHDRSZ;
+ }
+ else if (n == 1)
+ {
+ if (tl[0] < 1 || tl[0] > NUMERIC_MAX_PRECISION)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("NUMERIC precision %d must be between 1 and %d",
+ tl[0], NUMERIC_MAX_PRECISION)));
+ /* scale defaults to zero */
+ typmod = (tl[0] << 16) + VARHDRSZ;
+ }
+ else
+ {
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("invalid NUMERIC type modifier")));
+ typmod = 0; /* keep compiler quiet */
+ }
+
+ PG_RETURN_INT32(typmod);
+}
+
+Datum
+numerictypmodout(PG_FUNCTION_ARGS)
+{
+ int32 typmod = PG_GETARG_INT32(0);
+ char *res = (char *) palloc(64);
+
+ if (typmod >= 0)
+ snprintf(res, 64, "(%d,%d)",
+ ((typmod - VARHDRSZ) >> 16) & 0xffff,
+ (typmod - VARHDRSZ) & 0xffff);
+ else
+ *res = '\0';
+
+ PG_RETURN_CSTRING(res);
+}
+
+
+/* ----------------------------------------------------------------------
+ *
+ * Sign manipulation, rounding and the like
+ *
+ * ----------------------------------------------------------------------
+ */
+
+Datum
+numeric_abs(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ Numeric res;
+
+ /*
+ * Do it the easy way directly on the packed format
+ */
+ res = duplicate_numeric(num);
+
+ if (NUMERIC_IS_SHORT(num))
+ res->choice.n_short.n_header =
+ num->choice.n_short.n_header & ~NUMERIC_SHORT_SIGN_MASK;
+ else if (NUMERIC_IS_SPECIAL(num))
+ {
+ /* This changes -Inf to Inf, and doesn't affect NaN */
+ res->choice.n_short.n_header =
+ num->choice.n_short.n_header & ~NUMERIC_INF_SIGN_MASK;
+ }
+ else
+ res->choice.n_long.n_sign_dscale = NUMERIC_POS | NUMERIC_DSCALE(num);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+Datum
+numeric_uminus(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ Numeric res;
+
+ /*
+ * Do it the easy way directly on the packed format
+ */
+ res = duplicate_numeric(num);
+
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ /* Flip the sign, if it's Inf or -Inf */
+ if (!NUMERIC_IS_NAN(num))
+ res->choice.n_short.n_header =
+ num->choice.n_short.n_header ^ NUMERIC_INF_SIGN_MASK;
+ }
+
+ /*
+ * The packed format is known to be totally zero digit trimmed always. So
+ * once we've eliminated specials, we can identify a zero by the fact that
+ * there are no digits at all. Do nothing to a zero.
+ */
+ else if (NUMERIC_NDIGITS(num) != 0)
+ {
+ /* Else, flip the sign */
+ if (NUMERIC_IS_SHORT(num))
+ res->choice.n_short.n_header =
+ num->choice.n_short.n_header ^ NUMERIC_SHORT_SIGN_MASK;
+ else if (NUMERIC_SIGN(num) == NUMERIC_POS)
+ res->choice.n_long.n_sign_dscale =
+ NUMERIC_NEG | NUMERIC_DSCALE(num);
+ else
+ res->choice.n_long.n_sign_dscale =
+ NUMERIC_POS | NUMERIC_DSCALE(num);
+ }
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+Datum
+numeric_uplus(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+
+ PG_RETURN_NUMERIC(duplicate_numeric(num));
+}
+
+
+/*
+ * numeric_sign_internal() -
+ *
+ * Returns -1 if the argument is less than 0, 0 if the argument is equal
+ * to 0, and 1 if the argument is greater than zero. Caller must have
+ * taken care of the NaN case, but we can handle infinities here.
+ */
+static int
+numeric_sign_internal(Numeric num)
+{
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ Assert(!NUMERIC_IS_NAN(num));
+ /* Must be Inf or -Inf */
+ if (NUMERIC_IS_PINF(num))
+ return 1;
+ else
+ return -1;
+ }
+
+ /*
+ * The packed format is known to be totally zero digit trimmed always. So
+ * once we've eliminated specials, we can identify a zero by the fact that
+ * there are no digits at all.
+ */
+ else if (NUMERIC_NDIGITS(num) == 0)
+ return 0;
+ else if (NUMERIC_SIGN(num) == NUMERIC_NEG)
+ return -1;
+ else
+ return 1;
+}
+
+/*
+ * numeric_sign() -
+ *
+ * returns -1 if the argument is less than 0, 0 if the argument is equal
+ * to 0, and 1 if the argument is greater than zero.
+ */
+Datum
+numeric_sign(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+
+ /*
+ * Handle NaN (infinities can be handled normally)
+ */
+ if (NUMERIC_IS_NAN(num))
+ PG_RETURN_NUMERIC(make_result(&const_nan));
+
+ switch (numeric_sign_internal(num))
+ {
+ case 0:
+ PG_RETURN_NUMERIC(make_result(&const_zero));
+ case 1:
+ PG_RETURN_NUMERIC(make_result(&const_one));
+ case -1:
+ PG_RETURN_NUMERIC(make_result(&const_minus_one));
+ }
+
+ Assert(false);
+ return (Datum) 0;
+}
+
+
+/*
+ * numeric_round() -
+ *
+ * Round a value to have 'scale' digits after the decimal point.
+ * We allow negative 'scale', implying rounding before the decimal
+ * point --- Oracle interprets rounding that way.
+ */
+Datum
+numeric_round(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ int32 scale = PG_GETARG_INT32(1);
+ Numeric res;
+ NumericVar arg;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num))
+ PG_RETURN_NUMERIC(duplicate_numeric(num));
+
+ /*
+ * Limit the scale value to avoid possible overflow in calculations
+ */
+ scale = Max(scale, -NUMERIC_MAX_RESULT_SCALE);
+ scale = Min(scale, NUMERIC_MAX_RESULT_SCALE);
+
+ /*
+ * Unpack the argument and round it at the proper digit position
+ */
+ init_var(&arg);
+ set_var_from_num(num, &arg);
+
+ round_var(&arg, scale);
+
+ /* We don't allow negative output dscale */
+ if (scale < 0)
+ arg.dscale = 0;
+
+ /*
+ * Return the rounded result
+ */
+ res = make_result(&arg);
+
+ free_var(&arg);
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_trunc() -
+ *
+ * Truncate a value to have 'scale' digits after the decimal point.
+ * We allow negative 'scale', implying a truncation before the decimal
+ * point --- Oracle interprets truncation that way.
+ */
+Datum
+numeric_trunc(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ int32 scale = PG_GETARG_INT32(1);
+ Numeric res;
+ NumericVar arg;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num))
+ PG_RETURN_NUMERIC(duplicate_numeric(num));
+
+ /*
+ * Limit the scale value to avoid possible overflow in calculations
+ */
+ scale = Max(scale, -NUMERIC_MAX_RESULT_SCALE);
+ scale = Min(scale, NUMERIC_MAX_RESULT_SCALE);
+
+ /*
+ * Unpack the argument and truncate it at the proper digit position
+ */
+ init_var(&arg);
+ set_var_from_num(num, &arg);
+
+ trunc_var(&arg, scale);
+
+ /* We don't allow negative output dscale */
+ if (scale < 0)
+ arg.dscale = 0;
+
+ /*
+ * Return the truncated result
+ */
+ res = make_result(&arg);
+
+ free_var(&arg);
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_ceil() -
+ *
+ * Return the smallest integer greater than or equal to the argument
+ */
+Datum
+numeric_ceil(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ Numeric res;
+ NumericVar result;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num))
+ PG_RETURN_NUMERIC(duplicate_numeric(num));
+
+ init_var_from_num(num, &result);
+ ceil_var(&result, &result);
+
+ res = make_result(&result);
+ free_var(&result);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_floor() -
+ *
+ * Return the largest integer equal to or less than the argument
+ */
+Datum
+numeric_floor(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ Numeric res;
+ NumericVar result;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num))
+ PG_RETURN_NUMERIC(duplicate_numeric(num));
+
+ init_var_from_num(num, &result);
+ floor_var(&result, &result);
+
+ res = make_result(&result);
+ free_var(&result);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * generate_series_numeric() -
+ *
+ * Generate series of numeric.
+ */
+Datum
+generate_series_numeric(PG_FUNCTION_ARGS)
+{
+ return generate_series_step_numeric(fcinfo);
+}
+
+Datum
+generate_series_step_numeric(PG_FUNCTION_ARGS)
+{
+ generate_series_numeric_fctx *fctx;
+ FuncCallContext *funcctx;
+ MemoryContext oldcontext;
+
+ if (SRF_IS_FIRSTCALL())
+ {
+ Numeric start_num = PG_GETARG_NUMERIC(0);
+ Numeric stop_num = PG_GETARG_NUMERIC(1);
+ NumericVar steploc = const_one;
+
+ /* Reject NaN and infinities in start and stop values */
+ if (NUMERIC_IS_SPECIAL(start_num))
+ {
+ if (NUMERIC_IS_NAN(start_num))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("start value cannot be NaN")));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("start value cannot be infinity")));
+ }
+ if (NUMERIC_IS_SPECIAL(stop_num))
+ {
+ if (NUMERIC_IS_NAN(stop_num))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("stop value cannot be NaN")));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("stop value cannot be infinity")));
+ }
+
+ /* see if we were given an explicit step size */
+ if (PG_NARGS() == 3)
+ {
+ Numeric step_num = PG_GETARG_NUMERIC(2);
+
+ if (NUMERIC_IS_SPECIAL(step_num))
+ {
+ if (NUMERIC_IS_NAN(step_num))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("step size cannot be NaN")));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("step size cannot be infinity")));
+ }
+
+ init_var_from_num(step_num, &steploc);
+
+ if (cmp_var(&steploc, &const_zero) == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("step size cannot equal zero")));
+ }
+
+ /* create a function context for cross-call persistence */
+ funcctx = SRF_FIRSTCALL_INIT();
+
+ /*
+ * Switch to memory context appropriate for multiple function calls.
+ */
+ oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+ /* allocate memory for user context */
+ fctx = (generate_series_numeric_fctx *)
+ palloc(sizeof(generate_series_numeric_fctx));
+
+ /*
+ * Use fctx to keep state from call to call. Seed current with the
+ * original start value. We must copy the start_num and stop_num
+ * values rather than pointing to them, since we may have detoasted
+ * them in the per-call context.
+ */
+ init_var(&fctx->current);
+ init_var(&fctx->stop);
+ init_var(&fctx->step);
+
+ set_var_from_num(start_num, &fctx->current);
+ set_var_from_num(stop_num, &fctx->stop);
+ set_var_from_var(&steploc, &fctx->step);
+
+ funcctx->user_fctx = fctx;
+ MemoryContextSwitchTo(oldcontext);
+ }
+
+ /* stuff done on every call of the function */
+ funcctx = SRF_PERCALL_SETUP();
+
+ /*
+ * Get the saved state and use current state as the result of this
+ * iteration.
+ */
+ fctx = funcctx->user_fctx;
+
+ if ((fctx->step.sign == NUMERIC_POS &&
+ cmp_var(&fctx->current, &fctx->stop) <= 0) ||
+ (fctx->step.sign == NUMERIC_NEG &&
+ cmp_var(&fctx->current, &fctx->stop) >= 0))
+ {
+ Numeric result = make_result(&fctx->current);
+
+ /* switch to memory context appropriate for iteration calculation */
+ oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+ /* increment current in preparation for next iteration */
+ add_var(&fctx->current, &fctx->step, &fctx->current);
+ MemoryContextSwitchTo(oldcontext);
+
+ /* do when there is more left to send */
+ SRF_RETURN_NEXT(funcctx, NumericGetDatum(result));
+ }
+ else
+ /* do when there is no more left */
+ SRF_RETURN_DONE(funcctx);
+}
+
+
+/*
+ * Implements the numeric version of the width_bucket() function
+ * defined by SQL2003. See also width_bucket_float8().
+ *
+ * 'bound1' and 'bound2' are the lower and upper bounds of the
+ * histogram's range, respectively. 'count' is the number of buckets
+ * in the histogram. width_bucket() returns an integer indicating the
+ * bucket number that 'operand' belongs to in an equiwidth histogram
+ * with the specified characteristics. An operand smaller than the
+ * lower bound is assigned to bucket 0. An operand greater than the
+ * upper bound is assigned to an additional bucket (with number
+ * count+1). We don't allow "NaN" for any of the numeric arguments.
+ */
+Datum
+width_bucket_numeric(PG_FUNCTION_ARGS)
+{
+ Numeric operand = PG_GETARG_NUMERIC(0);
+ Numeric bound1 = PG_GETARG_NUMERIC(1);
+ Numeric bound2 = PG_GETARG_NUMERIC(2);
+ int32 count = PG_GETARG_INT32(3);
+ NumericVar count_var;
+ NumericVar result_var;
+ int32 result;
+
+ if (count <= 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_WIDTH_BUCKET_FUNCTION),
+ errmsg("count must be greater than zero")));
+
+ if (NUMERIC_IS_SPECIAL(operand) ||
+ NUMERIC_IS_SPECIAL(bound1) ||
+ NUMERIC_IS_SPECIAL(bound2))
+ {
+ if (NUMERIC_IS_NAN(operand) ||
+ NUMERIC_IS_NAN(bound1) ||
+ NUMERIC_IS_NAN(bound2))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_WIDTH_BUCKET_FUNCTION),
+ errmsg("operand, lower bound, and upper bound cannot be NaN")));
+ /* We allow "operand" to be infinite; cmp_numerics will cope */
+ if (NUMERIC_IS_INF(bound1) || NUMERIC_IS_INF(bound2))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_WIDTH_BUCKET_FUNCTION),
+ errmsg("lower and upper bounds must be finite")));
+ }
+
+ init_var(&result_var);
+ init_var(&count_var);
+
+ /* Convert 'count' to a numeric, for ease of use later */
+ int64_to_numericvar((int64) count, &count_var);
+
+ switch (cmp_numerics(bound1, bound2))
+ {
+ case 0:
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_WIDTH_BUCKET_FUNCTION),
+ errmsg("lower bound cannot equal upper bound")));
+ break;
+
+ /* bound1 < bound2 */
+ case -1:
+ if (cmp_numerics(operand, bound1) < 0)
+ set_var_from_var(&const_zero, &result_var);
+ else if (cmp_numerics(operand, bound2) >= 0)
+ add_var(&count_var, &const_one, &result_var);
+ else
+ compute_bucket(operand, bound1, bound2, &count_var, false,
+ &result_var);
+ break;
+
+ /* bound1 > bound2 */
+ case 1:
+ if (cmp_numerics(operand, bound1) > 0)
+ set_var_from_var(&const_zero, &result_var);
+ else if (cmp_numerics(operand, bound2) <= 0)
+ add_var(&count_var, &const_one, &result_var);
+ else
+ compute_bucket(operand, bound1, bound2, &count_var, true,
+ &result_var);
+ break;
+ }
+
+ /* if result exceeds the range of a legal int4, we ereport here */
+ if (!numericvar_to_int32(&result_var, &result))
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("integer out of range")));
+
+ free_var(&count_var);
+ free_var(&result_var);
+
+ PG_RETURN_INT32(result);
+}
+
+/*
+ * If 'operand' is not outside the bucket range, determine the correct
+ * bucket for it to go. The calculations performed by this function
+ * are derived directly from the SQL2003 spec. Note however that we
+ * multiply by count before dividing, to avoid unnecessary roundoff error.
+ */
+static void
+compute_bucket(Numeric operand, Numeric bound1, Numeric bound2,
+ const NumericVar *count_var, bool reversed_bounds,
+ NumericVar *result_var)
+{
+ NumericVar bound1_var;
+ NumericVar bound2_var;
+ NumericVar operand_var;
+
+ init_var_from_num(bound1, &bound1_var);
+ init_var_from_num(bound2, &bound2_var);
+ init_var_from_num(operand, &operand_var);
+
+ if (!reversed_bounds)
+ {
+ sub_var(&operand_var, &bound1_var, &operand_var);
+ sub_var(&bound2_var, &bound1_var, &bound2_var);
+ }
+ else
+ {
+ sub_var(&bound1_var, &operand_var, &operand_var);
+ sub_var(&bound1_var, &bound2_var, &bound2_var);
+ }
+
+ mul_var(&operand_var, count_var, &operand_var,
+ operand_var.dscale + count_var->dscale);
+ div_var(&operand_var, &bound2_var, result_var,
+ select_div_scale(&operand_var, &bound2_var), true);
+ add_var(result_var, &const_one, result_var);
+ floor_var(result_var, result_var);
+
+ free_var(&bound1_var);
+ free_var(&bound2_var);
+ free_var(&operand_var);
+}
+
+/* ----------------------------------------------------------------------
+ *
+ * Comparison functions
+ *
+ * Note: btree indexes need these routines not to leak memory; therefore,
+ * be careful to free working copies of toasted datums. Most places don't
+ * need to be so careful.
+ *
+ * Sort support:
+ *
+ * We implement the sortsupport strategy routine in order to get the benefit of
+ * abbreviation. The ordinary numeric comparison can be quite slow as a result
+ * of palloc/pfree cycles (due to detoasting packed values for alignment);
+ * while this could be worked on itself, the abbreviation strategy gives more
+ * speedup in many common cases.
+ *
+ * Two different representations are used for the abbreviated form, one in
+ * int32 and one in int64, whichever fits into a by-value Datum. In both cases
+ * the representation is negated relative to the original value, because we use
+ * the largest negative value for NaN, which sorts higher than other values. We
+ * convert the absolute value of the numeric to a 31-bit or 63-bit positive
+ * value, and then negate it if the original number was positive.
+ *
+ * We abort the abbreviation process if the abbreviation cardinality is below
+ * 0.01% of the row count (1 per 10k non-null rows). The actual break-even
+ * point is somewhat below that, perhaps 1 per 30k (at 1 per 100k there's a
+ * very small penalty), but we don't want to build up too many abbreviated
+ * values before first testing for abort, so we take the slightly pessimistic
+ * number. We make no attempt to estimate the cardinality of the real values,
+ * since it plays no part in the cost model here (if the abbreviation is equal,
+ * the cost of comparing equal and unequal underlying values is comparable).
+ * We discontinue even checking for abort (saving us the hashing overhead) if
+ * the estimated cardinality gets to 100k; that would be enough to support many
+ * billions of rows while doing no worse than breaking even.
+ *
+ * ----------------------------------------------------------------------
+ */
+
+/*
+ * Sort support strategy routine.
+ */
+Datum
+numeric_sortsupport(PG_FUNCTION_ARGS)
+{
+ SortSupport ssup = (SortSupport) PG_GETARG_POINTER(0);
+
+ ssup->comparator = numeric_fast_cmp;
+
+ if (ssup->abbreviate)
+ {
+ NumericSortSupport *nss;
+ MemoryContext oldcontext = MemoryContextSwitchTo(ssup->ssup_cxt);
+
+ nss = palloc(sizeof(NumericSortSupport));
+
+ /*
+ * palloc a buffer for handling unaligned packed values in addition to
+ * the support struct
+ */
+ nss->buf = palloc(VARATT_SHORT_MAX + VARHDRSZ + 1);
+
+ nss->input_count = 0;
+ nss->estimating = true;
+ initHyperLogLog(&nss->abbr_card, 10);
+
+ ssup->ssup_extra = nss;
+
+ ssup->abbrev_full_comparator = ssup->comparator;
+ ssup->comparator = numeric_cmp_abbrev;
+ ssup->abbrev_converter = numeric_abbrev_convert;
+ ssup->abbrev_abort = numeric_abbrev_abort;
+
+ MemoryContextSwitchTo(oldcontext);
+ }
+
+ PG_RETURN_VOID();
+}
+
+/*
+ * Abbreviate a numeric datum, handling NaNs and detoasting
+ * (must not leak memory!)
+ */
+static Datum
+numeric_abbrev_convert(Datum original_datum, SortSupport ssup)
+{
+ NumericSortSupport *nss = ssup->ssup_extra;
+ void *original_varatt = PG_DETOAST_DATUM_PACKED(original_datum);
+ Numeric value;
+ Datum result;
+
+ nss->input_count += 1;
+
+ /*
+ * This is to handle packed datums without needing a palloc/pfree cycle;
+ * we keep and reuse a buffer large enough to handle any short datum.
+ */
+ if (VARATT_IS_SHORT(original_varatt))
+ {
+ void *buf = nss->buf;
+ Size sz = VARSIZE_SHORT(original_varatt) - VARHDRSZ_SHORT;
+
+ Assert(sz <= VARATT_SHORT_MAX - VARHDRSZ_SHORT);
+
+ SET_VARSIZE(buf, VARHDRSZ + sz);
+ memcpy(VARDATA(buf), VARDATA_SHORT(original_varatt), sz);
+
+ value = (Numeric) buf;
+ }
+ else
+ value = (Numeric) original_varatt;
+
+ if (NUMERIC_IS_SPECIAL(value))
+ {
+ if (NUMERIC_IS_PINF(value))
+ result = NUMERIC_ABBREV_PINF;
+ else if (NUMERIC_IS_NINF(value))
+ result = NUMERIC_ABBREV_NINF;
+ else
+ result = NUMERIC_ABBREV_NAN;
+ }
+ else
+ {
+ NumericVar var;
+
+ init_var_from_num(value, &var);
+
+ result = numeric_abbrev_convert_var(&var, nss);
+ }
+
+ /* should happen only for external/compressed toasts */
+ if ((Pointer) original_varatt != DatumGetPointer(original_datum))
+ pfree(original_varatt);
+
+ return result;
+}
+
+/*
+ * Consider whether to abort abbreviation.
+ *
+ * We pay no attention to the cardinality of the non-abbreviated data. There is
+ * no reason to do so: unlike text, we have no fast check for equal values, so
+ * we pay the full overhead whenever the abbreviations are equal regardless of
+ * whether the underlying values are also equal.
+ */
+static bool
+numeric_abbrev_abort(int memtupcount, SortSupport ssup)
+{
+ NumericSortSupport *nss = ssup->ssup_extra;
+ double abbr_card;
+
+ if (memtupcount < 10000 || nss->input_count < 10000 || !nss->estimating)
+ return false;
+
+ abbr_card = estimateHyperLogLog(&nss->abbr_card);
+
+ /*
+ * If we have >100k distinct values, then even if we were sorting many
+ * billion rows we'd likely still break even, and the penalty of undoing
+ * that many rows of abbrevs would probably not be worth it. Stop even
+ * counting at that point.
+ */
+ if (abbr_card > 100000.0)
+ {
+#ifdef TRACE_SORT
+ if (trace_sort)
+ elog(LOG,
+ "numeric_abbrev: estimation ends at cardinality %f"
+ " after " INT64_FORMAT " values (%d rows)",
+ abbr_card, nss->input_count, memtupcount);
+#endif
+ nss->estimating = false;
+ return false;
+ }
+
+ /*
+ * Target minimum cardinality is 1 per ~10k of non-null inputs. (The
+ * break even point is somewhere between one per 100k rows, where
+ * abbreviation has a very slight penalty, and 1 per 10k where it wins by
+ * a measurable percentage.) We use the relatively pessimistic 10k
+ * threshold, and add a 0.5 row fudge factor, because it allows us to
+ * abort earlier on genuinely pathological data where we've had exactly
+ * one abbreviated value in the first 10k (non-null) rows.
+ */
+ if (abbr_card < nss->input_count / 10000.0 + 0.5)
+ {
+#ifdef TRACE_SORT
+ if (trace_sort)
+ elog(LOG,
+ "numeric_abbrev: aborting abbreviation at cardinality %f"
+ " below threshold %f after " INT64_FORMAT " values (%d rows)",
+ abbr_card, nss->input_count / 10000.0 + 0.5,
+ nss->input_count, memtupcount);
+#endif
+ return true;
+ }
+
+#ifdef TRACE_SORT
+ if (trace_sort)
+ elog(LOG,
+ "numeric_abbrev: cardinality %f"
+ " after " INT64_FORMAT " values (%d rows)",
+ abbr_card, nss->input_count, memtupcount);
+#endif
+
+ return false;
+}
+
+/*
+ * Non-fmgr interface to the comparison routine to allow sortsupport to elide
+ * the fmgr call. The saving here is small given how slow numeric comparisons
+ * are, but it is a required part of the sort support API when abbreviations
+ * are performed.
+ *
+ * Two palloc/pfree cycles could be saved here by using persistent buffers for
+ * aligning short-varlena inputs, but this has not so far been considered to
+ * be worth the effort.
+ */
+static int
+numeric_fast_cmp(Datum x, Datum y, SortSupport ssup)
+{
+ Numeric nx = DatumGetNumeric(x);
+ Numeric ny = DatumGetNumeric(y);
+ int result;
+
+ result = cmp_numerics(nx, ny);
+
+ if ((Pointer) nx != DatumGetPointer(x))
+ pfree(nx);
+ if ((Pointer) ny != DatumGetPointer(y))
+ pfree(ny);
+
+ return result;
+}
+
+/*
+ * Compare abbreviations of values. (Abbreviations may be equal where the true
+ * values differ, but if the abbreviations differ, they must reflect the
+ * ordering of the true values.)
+ */
+static int
+numeric_cmp_abbrev(Datum x, Datum y, SortSupport ssup)
+{
+ /*
+ * NOTE WELL: this is intentionally backwards, because the abbreviation is
+ * negated relative to the original value, to handle NaN/infinity cases.
+ */
+ if (DatumGetNumericAbbrev(x) < DatumGetNumericAbbrev(y))
+ return 1;
+ if (DatumGetNumericAbbrev(x) > DatumGetNumericAbbrev(y))
+ return -1;
+ return 0;
+}
+
+/*
+ * Abbreviate a NumericVar according to the available bit size.
+ *
+ * The 31-bit value is constructed as:
+ *
+ * 0 + 7bits digit weight + 24 bits digit value
+ *
+ * where the digit weight is in single decimal digits, not digit words, and
+ * stored in excess-44 representation[1]. The 24-bit digit value is the 7 most
+ * significant decimal digits of the value converted to binary. Values whose
+ * weights would fall outside the representable range are rounded off to zero
+ * (which is also used to represent actual zeros) or to 0x7FFFFFFF (which
+ * otherwise cannot occur). Abbreviation therefore fails to gain any advantage
+ * where values are outside the range 10^-44 to 10^83, which is not considered
+ * to be a serious limitation, or when values are of the same magnitude and
+ * equal in the first 7 decimal digits, which is considered to be an
+ * unavoidable limitation given the available bits. (Stealing three more bits
+ * to compare another digit would narrow the range of representable weights by
+ * a factor of 8, which starts to look like a real limiting factor.)
+ *
+ * (The value 44 for the excess is essentially arbitrary)
+ *
+ * The 63-bit value is constructed as:
+ *
+ * 0 + 7bits weight + 4 x 14-bit packed digit words
+ *
+ * The weight in this case is again stored in excess-44, but this time it is
+ * the original weight in digit words (i.e. powers of 10000). The first four
+ * digit words of the value (if present; trailing zeros are assumed as needed)
+ * are packed into 14 bits each to form the rest of the value. Again,
+ * out-of-range values are rounded off to 0 or 0x7FFFFFFFFFFFFFFF. The
+ * representable range in this case is 10^-176 to 10^332, which is considered
+ * to be good enough for all practical purposes, and comparison of 4 words
+ * means that at least 13 decimal digits are compared, which is considered to
+ * be a reasonable compromise between effectiveness and efficiency in computing
+ * the abbreviation.
+ *
+ * (The value 44 for the excess is even more arbitrary here, it was chosen just
+ * to match the value used in the 31-bit case)
+ *
+ * [1] - Excess-k representation means that the value is offset by adding 'k'
+ * and then treated as unsigned, so the smallest representable value is stored
+ * with all bits zero. This allows simple comparisons to work on the composite
+ * value.
+ */
+
+#if NUMERIC_ABBREV_BITS == 64
+
+static Datum
+numeric_abbrev_convert_var(const NumericVar *var, NumericSortSupport *nss)
+{
+ int ndigits = var->ndigits;
+ int weight = var->weight;
+ int64 result;
+
+ if (ndigits == 0 || weight < -44)
+ {
+ result = 0;
+ }
+ else if (weight > 83)
+ {
+ result = PG_INT64_MAX;
+ }
+ else
+ {
+ result = ((int64) (weight + 44) << 56);
+
+ switch (ndigits)
+ {
+ default:
+ result |= ((int64) var->digits[3]);
+ /* FALLTHROUGH */
+ case 3:
+ result |= ((int64) var->digits[2]) << 14;
+ /* FALLTHROUGH */
+ case 2:
+ result |= ((int64) var->digits[1]) << 28;
+ /* FALLTHROUGH */
+ case 1:
+ result |= ((int64) var->digits[0]) << 42;
+ break;
+ }
+ }
+
+ /* the abbrev is negated relative to the original */
+ if (var->sign == NUMERIC_POS)
+ result = -result;
+
+ if (nss->estimating)
+ {
+ uint32 tmp = ((uint32) result
+ ^ (uint32) ((uint64) result >> 32));
+
+ addHyperLogLog(&nss->abbr_card, DatumGetUInt32(hash_uint32(tmp)));
+ }
+
+ return NumericAbbrevGetDatum(result);
+}
+
+#endif /* NUMERIC_ABBREV_BITS == 64 */
+
+#if NUMERIC_ABBREV_BITS == 32
+
+static Datum
+numeric_abbrev_convert_var(const NumericVar *var, NumericSortSupport *nss)
+{
+ int ndigits = var->ndigits;
+ int weight = var->weight;
+ int32 result;
+
+ if (ndigits == 0 || weight < -11)
+ {
+ result = 0;
+ }
+ else if (weight > 20)
+ {
+ result = PG_INT32_MAX;
+ }
+ else
+ {
+ NumericDigit nxt1 = (ndigits > 1) ? var->digits[1] : 0;
+
+ weight = (weight + 11) * 4;
+
+ result = var->digits[0];
+
+ /*
+ * "result" now has 1 to 4 nonzero decimal digits. We pack in more
+ * digits to make 7 in total (largest we can fit in 24 bits)
+ */
+
+ if (result > 999)
+ {
+ /* already have 4 digits, add 3 more */
+ result = (result * 1000) + (nxt1 / 10);
+ weight += 3;
+ }
+ else if (result > 99)
+ {
+ /* already have 3 digits, add 4 more */
+ result = (result * 10000) + nxt1;
+ weight += 2;
+ }
+ else if (result > 9)
+ {
+ NumericDigit nxt2 = (ndigits > 2) ? var->digits[2] : 0;
+
+ /* already have 2 digits, add 5 more */
+ result = (result * 100000) + (nxt1 * 10) + (nxt2 / 1000);
+ weight += 1;
+ }
+ else
+ {
+ NumericDigit nxt2 = (ndigits > 2) ? var->digits[2] : 0;
+
+ /* already have 1 digit, add 6 more */
+ result = (result * 1000000) + (nxt1 * 100) + (nxt2 / 100);
+ }
+
+ result = result | (weight << 24);
+ }
+
+ /* the abbrev is negated relative to the original */
+ if (var->sign == NUMERIC_POS)
+ result = -result;
+
+ if (nss->estimating)
+ {
+ uint32 tmp = (uint32) result;
+
+ addHyperLogLog(&nss->abbr_card, DatumGetUInt32(hash_uint32(tmp)));
+ }
+
+ return NumericAbbrevGetDatum(result);
+}
+
+#endif /* NUMERIC_ABBREV_BITS == 32 */
+
+/*
+ * Ordinary (non-sortsupport) comparisons follow.
+ */
+
+Datum
+numeric_cmp(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ int result;
+
+ result = cmp_numerics(num1, num2);
+
+ PG_FREE_IF_COPY(num1, 0);
+ PG_FREE_IF_COPY(num2, 1);
+
+ PG_RETURN_INT32(result);
+}
+
+
+Datum
+numeric_eq(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ bool result;
+
+ result = cmp_numerics(num1, num2) == 0;
+
+ PG_FREE_IF_COPY(num1, 0);
+ PG_FREE_IF_COPY(num2, 1);
+
+ PG_RETURN_BOOL(result);
+}
+
+Datum
+numeric_ne(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ bool result;
+
+ result = cmp_numerics(num1, num2) != 0;
+
+ PG_FREE_IF_COPY(num1, 0);
+ PG_FREE_IF_COPY(num2, 1);
+
+ PG_RETURN_BOOL(result);
+}
+
+Datum
+numeric_gt(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ bool result;
+
+ result = cmp_numerics(num1, num2) > 0;
+
+ PG_FREE_IF_COPY(num1, 0);
+ PG_FREE_IF_COPY(num2, 1);
+
+ PG_RETURN_BOOL(result);
+}
+
+Datum
+numeric_ge(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ bool result;
+
+ result = cmp_numerics(num1, num2) >= 0;
+
+ PG_FREE_IF_COPY(num1, 0);
+ PG_FREE_IF_COPY(num2, 1);
+
+ PG_RETURN_BOOL(result);
+}
+
+Datum
+numeric_lt(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ bool result;
+
+ result = cmp_numerics(num1, num2) < 0;
+
+ PG_FREE_IF_COPY(num1, 0);
+ PG_FREE_IF_COPY(num2, 1);
+
+ PG_RETURN_BOOL(result);
+}
+
+Datum
+numeric_le(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ bool result;
+
+ result = cmp_numerics(num1, num2) <= 0;
+
+ PG_FREE_IF_COPY(num1, 0);
+ PG_FREE_IF_COPY(num2, 1);
+
+ PG_RETURN_BOOL(result);
+}
+
+static int
+cmp_numerics(Numeric num1, Numeric num2)
+{
+ int result;
+
+ /*
+ * We consider all NANs to be equal and larger than any non-NAN (including
+ * Infinity). This is somewhat arbitrary; the important thing is to have
+ * a consistent sort order.
+ */
+ if (NUMERIC_IS_SPECIAL(num1))
+ {
+ if (NUMERIC_IS_NAN(num1))
+ {
+ if (NUMERIC_IS_NAN(num2))
+ result = 0; /* NAN = NAN */
+ else
+ result = 1; /* NAN > non-NAN */
+ }
+ else if (NUMERIC_IS_PINF(num1))
+ {
+ if (NUMERIC_IS_NAN(num2))
+ result = -1; /* PINF < NAN */
+ else if (NUMERIC_IS_PINF(num2))
+ result = 0; /* PINF = PINF */
+ else
+ result = 1; /* PINF > anything else */
+ }
+ else /* num1 must be NINF */
+ {
+ if (NUMERIC_IS_NINF(num2))
+ result = 0; /* NINF = NINF */
+ else
+ result = -1; /* NINF < anything else */
+ }
+ }
+ else if (NUMERIC_IS_SPECIAL(num2))
+ {
+ if (NUMERIC_IS_NINF(num2))
+ result = 1; /* normal > NINF */
+ else
+ result = -1; /* normal < NAN or PINF */
+ }
+ else
+ {
+ result = cmp_var_common(NUMERIC_DIGITS(num1), NUMERIC_NDIGITS(num1),
+ NUMERIC_WEIGHT(num1), NUMERIC_SIGN(num1),
+ NUMERIC_DIGITS(num2), NUMERIC_NDIGITS(num2),
+ NUMERIC_WEIGHT(num2), NUMERIC_SIGN(num2));
+ }
+
+ return result;
+}
+
+/*
+ * in_range support function for numeric.
+ */
+Datum
+in_range_numeric_numeric(PG_FUNCTION_ARGS)
+{
+ Numeric val = PG_GETARG_NUMERIC(0);
+ Numeric base = PG_GETARG_NUMERIC(1);
+ Numeric offset = PG_GETARG_NUMERIC(2);
+ bool sub = PG_GETARG_BOOL(3);
+ bool less = PG_GETARG_BOOL(4);
+ bool result;
+
+ /*
+ * Reject negative (including -Inf) or NaN offset. Negative is per spec,
+ * and NaN is because appropriate semantics for that seem non-obvious.
+ */
+ if (NUMERIC_IS_NAN(offset) ||
+ NUMERIC_IS_NINF(offset) ||
+ NUMERIC_SIGN(offset) == NUMERIC_NEG)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
+ errmsg("invalid preceding or following size in window function")));
+
+ /*
+ * Deal with cases where val and/or base is NaN, following the rule that
+ * NaN sorts after non-NaN (cf cmp_numerics). The offset cannot affect
+ * the conclusion.
+ */
+ if (NUMERIC_IS_NAN(val))
+ {
+ if (NUMERIC_IS_NAN(base))
+ result = true; /* NAN = NAN */
+ else
+ result = !less; /* NAN > non-NAN */
+ }
+ else if (NUMERIC_IS_NAN(base))
+ {
+ result = less; /* non-NAN < NAN */
+ }
+
+ /*
+ * Deal with infinite offset (necessarily +Inf, at this point).
+ */
+ else if (NUMERIC_IS_SPECIAL(offset))
+ {
+ Assert(NUMERIC_IS_PINF(offset));
+ if (sub ? NUMERIC_IS_PINF(base) : NUMERIC_IS_NINF(base))
+ {
+ /*
+ * base +/- offset would produce NaN, so return true for any val
+ * (see in_range_float8_float8() for reasoning).
+ */
+ result = true;
+ }
+ else if (sub)
+ {
+ /* base - offset must be -inf */
+ if (less)
+ result = NUMERIC_IS_NINF(val); /* only -inf is <= sum */
+ else
+ result = true; /* any val is >= sum */
+ }
+ else
+ {
+ /* base + offset must be +inf */
+ if (less)
+ result = true; /* any val is <= sum */
+ else
+ result = NUMERIC_IS_PINF(val); /* only +inf is >= sum */
+ }
+ }
+
+ /*
+ * Deal with cases where val and/or base is infinite. The offset, being
+ * now known finite, cannot affect the conclusion.
+ */
+ else if (NUMERIC_IS_SPECIAL(val))
+ {
+ if (NUMERIC_IS_PINF(val))
+ {
+ if (NUMERIC_IS_PINF(base))
+ result = true; /* PINF = PINF */
+ else
+ result = !less; /* PINF > any other non-NAN */
+ }
+ else /* val must be NINF */
+ {
+ if (NUMERIC_IS_NINF(base))
+ result = true; /* NINF = NINF */
+ else
+ result = less; /* NINF < anything else */
+ }
+ }
+ else if (NUMERIC_IS_SPECIAL(base))
+ {
+ if (NUMERIC_IS_NINF(base))
+ result = !less; /* normal > NINF */
+ else
+ result = less; /* normal < PINF */
+ }
+ else
+ {
+ /*
+ * Otherwise go ahead and compute base +/- offset. While it's
+ * possible for this to overflow the numeric format, it's unlikely
+ * enough that we don't take measures to prevent it.
+ */
+ NumericVar valv;
+ NumericVar basev;
+ NumericVar offsetv;
+ NumericVar sum;
+
+ init_var_from_num(val, &valv);
+ init_var_from_num(base, &basev);
+ init_var_from_num(offset, &offsetv);
+ init_var(&sum);
+
+ if (sub)
+ sub_var(&basev, &offsetv, &sum);
+ else
+ add_var(&basev, &offsetv, &sum);
+
+ if (less)
+ result = (cmp_var(&valv, &sum) <= 0);
+ else
+ result = (cmp_var(&valv, &sum) >= 0);
+
+ free_var(&sum);
+ }
+
+ PG_FREE_IF_COPY(val, 0);
+ PG_FREE_IF_COPY(base, 1);
+ PG_FREE_IF_COPY(offset, 2);
+
+ PG_RETURN_BOOL(result);
+}
+
+Datum
+hash_numeric(PG_FUNCTION_ARGS)
+{
+ Numeric key = PG_GETARG_NUMERIC(0);
+ Datum digit_hash;
+ Datum result;
+ int weight;
+ int start_offset;
+ int end_offset;
+ int i;
+ int hash_len;
+ NumericDigit *digits;
+
+ /* If it's NaN or infinity, don't try to hash the rest of the fields */
+ if (NUMERIC_IS_SPECIAL(key))
+ PG_RETURN_UINT32(0);
+
+ weight = NUMERIC_WEIGHT(key);
+ start_offset = 0;
+ end_offset = 0;
+
+ /*
+ * Omit any leading or trailing zeros from the input to the hash. The
+ * numeric implementation *should* guarantee that leading and trailing
+ * zeros are suppressed, but we're paranoid. Note that we measure the
+ * starting and ending offsets in units of NumericDigits, not bytes.
+ */
+ digits = NUMERIC_DIGITS(key);
+ for (i = 0; i < NUMERIC_NDIGITS(key); i++)
+ {
+ if (digits[i] != (NumericDigit) 0)
+ break;
+
+ start_offset++;
+
+ /*
+ * The weight is effectively the # of digits before the decimal point,
+ * so decrement it for each leading zero we skip.
+ */
+ weight--;
+ }
+
+ /*
+ * If there are no non-zero digits, then the value of the number is zero,
+ * regardless of any other fields.
+ */
+ if (NUMERIC_NDIGITS(key) == start_offset)
+ PG_RETURN_UINT32(-1);
+
+ for (i = NUMERIC_NDIGITS(key) - 1; i >= 0; i--)
+ {
+ if (digits[i] != (NumericDigit) 0)
+ break;
+
+ end_offset++;
+ }
+
+ /* If we get here, there should be at least one non-zero digit */
+ Assert(start_offset + end_offset < NUMERIC_NDIGITS(key));
+
+ /*
+ * Note that we don't hash on the Numeric's scale, since two numerics can
+ * compare equal but have different scales. We also don't hash on the
+ * sign, although we could: since a sign difference implies inequality,
+ * this shouldn't affect correctness.
+ */
+ hash_len = NUMERIC_NDIGITS(key) - start_offset - end_offset;
+ digit_hash = hash_any((unsigned char *) (NUMERIC_DIGITS(key) + start_offset),
+ hash_len * sizeof(NumericDigit));
+
+ /* Mix in the weight, via XOR */
+ result = digit_hash ^ weight;
+
+ PG_RETURN_DATUM(result);
+}
+
+/*
+ * Returns 64-bit value by hashing a value to a 64-bit value, with a seed.
+ * Otherwise, similar to hash_numeric.
+ */
+Datum
+hash_numeric_extended(PG_FUNCTION_ARGS)
+{
+ Numeric key = PG_GETARG_NUMERIC(0);
+ uint64 seed = PG_GETARG_INT64(1);
+ Datum digit_hash;
+ Datum result;
+ int weight;
+ int start_offset;
+ int end_offset;
+ int i;
+ int hash_len;
+ NumericDigit *digits;
+
+ /* If it's NaN or infinity, don't try to hash the rest of the fields */
+ if (NUMERIC_IS_SPECIAL(key))
+ PG_RETURN_UINT64(seed);
+
+ weight = NUMERIC_WEIGHT(key);
+ start_offset = 0;
+ end_offset = 0;
+
+ digits = NUMERIC_DIGITS(key);
+ for (i = 0; i < NUMERIC_NDIGITS(key); i++)
+ {
+ if (digits[i] != (NumericDigit) 0)
+ break;
+
+ start_offset++;
+
+ weight--;
+ }
+
+ if (NUMERIC_NDIGITS(key) == start_offset)
+ PG_RETURN_UINT64(seed - 1);
+
+ for (i = NUMERIC_NDIGITS(key) - 1; i >= 0; i--)
+ {
+ if (digits[i] != (NumericDigit) 0)
+ break;
+
+ end_offset++;
+ }
+
+ Assert(start_offset + end_offset < NUMERIC_NDIGITS(key));
+
+ hash_len = NUMERIC_NDIGITS(key) - start_offset - end_offset;
+ digit_hash = hash_any_extended((unsigned char *) (NUMERIC_DIGITS(key)
+ + start_offset),
+ hash_len * sizeof(NumericDigit),
+ seed);
+
+ result = UInt64GetDatum(DatumGetUInt64(digit_hash) ^ weight);
+
+ PG_RETURN_DATUM(result);
+}
+
+
+/* ----------------------------------------------------------------------
+ *
+ * Basic arithmetic functions
+ *
+ * ----------------------------------------------------------------------
+ */
+
+
+/*
+ * numeric_add() -
+ *
+ * Add two numerics
+ */
+Datum
+numeric_add(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ Numeric res;
+
+ res = numeric_add_opt_error(num1, num2, NULL);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+/*
+ * numeric_add_opt_error() -
+ *
+ * Internal version of numeric_add(). If "*have_error" flag is provided,
+ * on error it's set to true, NULL returned. This is helpful when caller
+ * need to handle errors by itself.
+ */
+Numeric
+numeric_add_opt_error(Numeric num1, Numeric num2, bool *have_error)
+{
+ NumericVar arg1;
+ NumericVar arg2;
+ NumericVar result;
+ Numeric res;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num1) || NUMERIC_IS_SPECIAL(num2))
+ {
+ if (NUMERIC_IS_NAN(num1) || NUMERIC_IS_NAN(num2))
+ return make_result(&const_nan);
+ if (NUMERIC_IS_PINF(num1))
+ {
+ if (NUMERIC_IS_NINF(num2))
+ return make_result(&const_nan); /* Inf + -Inf */
+ else
+ return make_result(&const_pinf);
+ }
+ if (NUMERIC_IS_NINF(num1))
+ {
+ if (NUMERIC_IS_PINF(num2))
+ return make_result(&const_nan); /* -Inf + Inf */
+ else
+ return make_result(&const_ninf);
+ }
+ /* by here, num1 must be finite, so num2 is not */
+ if (NUMERIC_IS_PINF(num2))
+ return make_result(&const_pinf);
+ Assert(NUMERIC_IS_NINF(num2));
+ return make_result(&const_ninf);
+ }
+
+ /*
+ * Unpack the values, let add_var() compute the result and return it.
+ */
+ init_var_from_num(num1, &arg1);
+ init_var_from_num(num2, &arg2);
+
+ init_var(&result);
+ add_var(&arg1, &arg2, &result);
+
+ res = make_result_opt_error(&result, have_error);
+
+ free_var(&result);
+
+ return res;
+}
+
+
+/*
+ * numeric_sub() -
+ *
+ * Subtract one numeric from another
+ */
+Datum
+numeric_sub(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ Numeric res;
+
+ res = numeric_sub_opt_error(num1, num2, NULL);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_sub_opt_error() -
+ *
+ * Internal version of numeric_sub(). If "*have_error" flag is provided,
+ * on error it's set to true, NULL returned. This is helpful when caller
+ * need to handle errors by itself.
+ */
+Numeric
+numeric_sub_opt_error(Numeric num1, Numeric num2, bool *have_error)
+{
+ NumericVar arg1;
+ NumericVar arg2;
+ NumericVar result;
+ Numeric res;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num1) || NUMERIC_IS_SPECIAL(num2))
+ {
+ if (NUMERIC_IS_NAN(num1) || NUMERIC_IS_NAN(num2))
+ return make_result(&const_nan);
+ if (NUMERIC_IS_PINF(num1))
+ {
+ if (NUMERIC_IS_PINF(num2))
+ return make_result(&const_nan); /* Inf - Inf */
+ else
+ return make_result(&const_pinf);
+ }
+ if (NUMERIC_IS_NINF(num1))
+ {
+ if (NUMERIC_IS_NINF(num2))
+ return make_result(&const_nan); /* -Inf - -Inf */
+ else
+ return make_result(&const_ninf);
+ }
+ /* by here, num1 must be finite, so num2 is not */
+ if (NUMERIC_IS_PINF(num2))
+ return make_result(&const_ninf);
+ Assert(NUMERIC_IS_NINF(num2));
+ return make_result(&const_pinf);
+ }
+
+ /*
+ * Unpack the values, let sub_var() compute the result and return it.
+ */
+ init_var_from_num(num1, &arg1);
+ init_var_from_num(num2, &arg2);
+
+ init_var(&result);
+ sub_var(&arg1, &arg2, &result);
+
+ res = make_result_opt_error(&result, have_error);
+
+ free_var(&result);
+
+ return res;
+}
+
+
+/*
+ * numeric_mul() -
+ *
+ * Calculate the product of two numerics
+ */
+Datum
+numeric_mul(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ Numeric res;
+
+ res = numeric_mul_opt_error(num1, num2, NULL);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_mul_opt_error() -
+ *
+ * Internal version of numeric_mul(). If "*have_error" flag is provided,
+ * on error it's set to true, NULL returned. This is helpful when caller
+ * need to handle errors by itself.
+ */
+Numeric
+numeric_mul_opt_error(Numeric num1, Numeric num2, bool *have_error)
+{
+ NumericVar arg1;
+ NumericVar arg2;
+ NumericVar result;
+ Numeric res;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num1) || NUMERIC_IS_SPECIAL(num2))
+ {
+ if (NUMERIC_IS_NAN(num1) || NUMERIC_IS_NAN(num2))
+ return make_result(&const_nan);
+ if (NUMERIC_IS_PINF(num1))
+ {
+ switch (numeric_sign_internal(num2))
+ {
+ case 0:
+ return make_result(&const_nan); /* Inf * 0 */
+ case 1:
+ return make_result(&const_pinf);
+ case -1:
+ return make_result(&const_ninf);
+ }
+ Assert(false);
+ }
+ if (NUMERIC_IS_NINF(num1))
+ {
+ switch (numeric_sign_internal(num2))
+ {
+ case 0:
+ return make_result(&const_nan); /* -Inf * 0 */
+ case 1:
+ return make_result(&const_ninf);
+ case -1:
+ return make_result(&const_pinf);
+ }
+ Assert(false);
+ }
+ /* by here, num1 must be finite, so num2 is not */
+ if (NUMERIC_IS_PINF(num2))
+ {
+ switch (numeric_sign_internal(num1))
+ {
+ case 0:
+ return make_result(&const_nan); /* 0 * Inf */
+ case 1:
+ return make_result(&const_pinf);
+ case -1:
+ return make_result(&const_ninf);
+ }
+ Assert(false);
+ }
+ Assert(NUMERIC_IS_NINF(num2));
+ switch (numeric_sign_internal(num1))
+ {
+ case 0:
+ return make_result(&const_nan); /* 0 * -Inf */
+ case 1:
+ return make_result(&const_ninf);
+ case -1:
+ return make_result(&const_pinf);
+ }
+ Assert(false);
+ }
+
+ /*
+ * Unpack the values, let mul_var() compute the result and return it.
+ * Unlike add_var() and sub_var(), mul_var() will round its result. In the
+ * case of numeric_mul(), which is invoked for the * operator on numerics,
+ * we request exact representation for the product (rscale = sum(dscale of
+ * arg1, dscale of arg2)). If the exact result has more digits after the
+ * decimal point than can be stored in a numeric, we round it. Rounding
+ * after computing the exact result ensures that the final result is
+ * correctly rounded (rounding in mul_var() using a truncated product
+ * would not guarantee this).
+ */
+ init_var_from_num(num1, &arg1);
+ init_var_from_num(num2, &arg2);
+
+ init_var(&result);
+ mul_var(&arg1, &arg2, &result, arg1.dscale + arg2.dscale);
+
+ if (result.dscale > NUMERIC_DSCALE_MAX)
+ round_var(&result, NUMERIC_DSCALE_MAX);
+
+ res = make_result_opt_error(&result, have_error);
+
+ free_var(&result);
+
+ return res;
+}
+
+
+/*
+ * numeric_div() -
+ *
+ * Divide one numeric into another
+ */
+Datum
+numeric_div(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ Numeric res;
+
+ res = numeric_div_opt_error(num1, num2, NULL);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_div_opt_error() -
+ *
+ * Internal version of numeric_div(). If "*have_error" flag is provided,
+ * on error it's set to true, NULL returned. This is helpful when caller
+ * need to handle errors by itself.
+ */
+Numeric
+numeric_div_opt_error(Numeric num1, Numeric num2, bool *have_error)
+{
+ NumericVar arg1;
+ NumericVar arg2;
+ NumericVar result;
+ Numeric res;
+ int rscale;
+
+ if (have_error)
+ *have_error = false;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num1) || NUMERIC_IS_SPECIAL(num2))
+ {
+ if (NUMERIC_IS_NAN(num1) || NUMERIC_IS_NAN(num2))
+ return make_result(&const_nan);
+ if (NUMERIC_IS_PINF(num1))
+ {
+ if (NUMERIC_IS_SPECIAL(num2))
+ return make_result(&const_nan); /* Inf / [-]Inf */
+ switch (numeric_sign_internal(num2))
+ {
+ case 0:
+ if (have_error)
+ {
+ *have_error = true;
+ return NULL;
+ }
+ ereport(ERROR,
+ (errcode(ERRCODE_DIVISION_BY_ZERO),
+ errmsg("division by zero")));
+ break;
+ case 1:
+ return make_result(&const_pinf);
+ case -1:
+ return make_result(&const_ninf);
+ }
+ Assert(false);
+ }
+ if (NUMERIC_IS_NINF(num1))
+ {
+ if (NUMERIC_IS_SPECIAL(num2))
+ return make_result(&const_nan); /* -Inf / [-]Inf */
+ switch (numeric_sign_internal(num2))
+ {
+ case 0:
+ if (have_error)
+ {
+ *have_error = true;
+ return NULL;
+ }
+ ereport(ERROR,
+ (errcode(ERRCODE_DIVISION_BY_ZERO),
+ errmsg("division by zero")));
+ break;
+ case 1:
+ return make_result(&const_ninf);
+ case -1:
+ return make_result(&const_pinf);
+ }
+ Assert(false);
+ }
+ /* by here, num1 must be finite, so num2 is not */
+
+ /*
+ * POSIX would have us return zero or minus zero if num1 is zero, and
+ * otherwise throw an underflow error. But the numeric type doesn't
+ * really do underflow, so let's just return zero.
+ */
+ return make_result(&const_zero);
+ }
+
+ /*
+ * Unpack the arguments
+ */
+ init_var_from_num(num1, &arg1);
+ init_var_from_num(num2, &arg2);
+
+ init_var(&result);
+
+ /*
+ * Select scale for division result
+ */
+ rscale = select_div_scale(&arg1, &arg2);
+
+ /*
+ * If "have_error" is provided, check for division by zero here
+ */
+ if (have_error && (arg2.ndigits == 0 || arg2.digits[0] == 0))
+ {
+ *have_error = true;
+ return NULL;
+ }
+
+ /*
+ * Do the divide and return the result
+ */
+ div_var(&arg1, &arg2, &result, rscale, true);
+
+ res = make_result_opt_error(&result, have_error);
+
+ free_var(&result);
+
+ return res;
+}
+
+
+/*
+ * numeric_div_trunc() -
+ *
+ * Divide one numeric into another, truncating the result to an integer
+ */
+Datum
+numeric_div_trunc(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ NumericVar arg1;
+ NumericVar arg2;
+ NumericVar result;
+ Numeric res;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num1) || NUMERIC_IS_SPECIAL(num2))
+ {
+ if (NUMERIC_IS_NAN(num1) || NUMERIC_IS_NAN(num2))
+ PG_RETURN_NUMERIC(make_result(&const_nan));
+ if (NUMERIC_IS_PINF(num1))
+ {
+ if (NUMERIC_IS_SPECIAL(num2))
+ PG_RETURN_NUMERIC(make_result(&const_nan)); /* Inf / [-]Inf */
+ switch (numeric_sign_internal(num2))
+ {
+ case 0:
+ ereport(ERROR,
+ (errcode(ERRCODE_DIVISION_BY_ZERO),
+ errmsg("division by zero")));
+ break;
+ case 1:
+ PG_RETURN_NUMERIC(make_result(&const_pinf));
+ case -1:
+ PG_RETURN_NUMERIC(make_result(&const_ninf));
+ }
+ Assert(false);
+ }
+ if (NUMERIC_IS_NINF(num1))
+ {
+ if (NUMERIC_IS_SPECIAL(num2))
+ PG_RETURN_NUMERIC(make_result(&const_nan)); /* -Inf / [-]Inf */
+ switch (numeric_sign_internal(num2))
+ {
+ case 0:
+ ereport(ERROR,
+ (errcode(ERRCODE_DIVISION_BY_ZERO),
+ errmsg("division by zero")));
+ break;
+ case 1:
+ PG_RETURN_NUMERIC(make_result(&const_ninf));
+ case -1:
+ PG_RETURN_NUMERIC(make_result(&const_pinf));
+ }
+ Assert(false);
+ }
+ /* by here, num1 must be finite, so num2 is not */
+
+ /*
+ * POSIX would have us return zero or minus zero if num1 is zero, and
+ * otherwise throw an underflow error. But the numeric type doesn't
+ * really do underflow, so let's just return zero.
+ */
+ PG_RETURN_NUMERIC(make_result(&const_zero));
+ }
+
+ /*
+ * Unpack the arguments
+ */
+ init_var_from_num(num1, &arg1);
+ init_var_from_num(num2, &arg2);
+
+ init_var(&result);
+
+ /*
+ * Do the divide and return the result
+ */
+ div_var(&arg1, &arg2, &result, 0, false);
+
+ res = make_result(&result);
+
+ free_var(&result);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_mod() -
+ *
+ * Calculate the modulo of two numerics
+ */
+Datum
+numeric_mod(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ Numeric res;
+
+ res = numeric_mod_opt_error(num1, num2, NULL);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_mod_opt_error() -
+ *
+ * Internal version of numeric_mod(). If "*have_error" flag is provided,
+ * on error it's set to true, NULL returned. This is helpful when caller
+ * need to handle errors by itself.
+ */
+Numeric
+numeric_mod_opt_error(Numeric num1, Numeric num2, bool *have_error)
+{
+ Numeric res;
+ NumericVar arg1;
+ NumericVar arg2;
+ NumericVar result;
+
+ if (have_error)
+ *have_error = false;
+
+ /*
+ * Handle NaN and infinities. We follow POSIX fmod() on this, except that
+ * POSIX treats x-is-infinite and y-is-zero identically, raising EDOM and
+ * returning NaN. We choose to throw error only for y-is-zero.
+ */
+ if (NUMERIC_IS_SPECIAL(num1) || NUMERIC_IS_SPECIAL(num2))
+ {
+ if (NUMERIC_IS_NAN(num1) || NUMERIC_IS_NAN(num2))
+ return make_result(&const_nan);
+ if (NUMERIC_IS_INF(num1))
+ {
+ if (numeric_sign_internal(num2) == 0)
+ {
+ if (have_error)
+ {
+ *have_error = true;
+ return NULL;
+ }
+ ereport(ERROR,
+ (errcode(ERRCODE_DIVISION_BY_ZERO),
+ errmsg("division by zero")));
+ }
+ /* Inf % any nonzero = NaN */
+ return make_result(&const_nan);
+ }
+ /* num2 must be [-]Inf; result is num1 regardless of sign of num2 */
+ return duplicate_numeric(num1);
+ }
+
+ init_var_from_num(num1, &arg1);
+ init_var_from_num(num2, &arg2);
+
+ init_var(&result);
+
+ /*
+ * If "have_error" is provided, check for division by zero here
+ */
+ if (have_error && (arg2.ndigits == 0 || arg2.digits[0] == 0))
+ {
+ *have_error = true;
+ return NULL;
+ }
+
+ mod_var(&arg1, &arg2, &result);
+
+ res = make_result_opt_error(&result, NULL);
+
+ free_var(&result);
+
+ return res;
+}
+
+
+/*
+ * numeric_inc() -
+ *
+ * Increment a number by one
+ */
+Datum
+numeric_inc(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ NumericVar arg;
+ Numeric res;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num))
+ PG_RETURN_NUMERIC(duplicate_numeric(num));
+
+ /*
+ * Compute the result and return it
+ */
+ init_var_from_num(num, &arg);
+
+ add_var(&arg, &const_one, &arg);
+
+ res = make_result(&arg);
+
+ free_var(&arg);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_smaller() -
+ *
+ * Return the smaller of two numbers
+ */
+Datum
+numeric_smaller(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+
+ /*
+ * Use cmp_numerics so that this will agree with the comparison operators,
+ * particularly as regards comparisons involving NaN.
+ */
+ if (cmp_numerics(num1, num2) < 0)
+ PG_RETURN_NUMERIC(num1);
+ else
+ PG_RETURN_NUMERIC(num2);
+}
+
+
+/*
+ * numeric_larger() -
+ *
+ * Return the larger of two numbers
+ */
+Datum
+numeric_larger(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+
+ /*
+ * Use cmp_numerics so that this will agree with the comparison operators,
+ * particularly as regards comparisons involving NaN.
+ */
+ if (cmp_numerics(num1, num2) > 0)
+ PG_RETURN_NUMERIC(num1);
+ else
+ PG_RETURN_NUMERIC(num2);
+}
+
+
+/* ----------------------------------------------------------------------
+ *
+ * Advanced math functions
+ *
+ * ----------------------------------------------------------------------
+ */
+
+/*
+ * numeric_gcd() -
+ *
+ * Calculate the greatest common divisor of two numerics
+ */
+Datum
+numeric_gcd(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ NumericVar arg1;
+ NumericVar arg2;
+ NumericVar result;
+ Numeric res;
+
+ /*
+ * Handle NaN and infinities: we consider the result to be NaN in all such
+ * cases.
+ */
+ if (NUMERIC_IS_SPECIAL(num1) || NUMERIC_IS_SPECIAL(num2))
+ PG_RETURN_NUMERIC(make_result(&const_nan));
+
+ /*
+ * Unpack the arguments
+ */
+ init_var_from_num(num1, &arg1);
+ init_var_from_num(num2, &arg2);
+
+ init_var(&result);
+
+ /*
+ * Find the GCD and return the result
+ */
+ gcd_var(&arg1, &arg2, &result);
+
+ res = make_result(&result);
+
+ free_var(&result);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_lcm() -
+ *
+ * Calculate the least common multiple of two numerics
+ */
+Datum
+numeric_lcm(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ NumericVar arg1;
+ NumericVar arg2;
+ NumericVar result;
+ Numeric res;
+
+ /*
+ * Handle NaN and infinities: we consider the result to be NaN in all such
+ * cases.
+ */
+ if (NUMERIC_IS_SPECIAL(num1) || NUMERIC_IS_SPECIAL(num2))
+ PG_RETURN_NUMERIC(make_result(&const_nan));
+
+ /*
+ * Unpack the arguments
+ */
+ init_var_from_num(num1, &arg1);
+ init_var_from_num(num2, &arg2);
+
+ init_var(&result);
+
+ /*
+ * Compute the result using lcm(x, y) = abs(x / gcd(x, y) * y), returning
+ * zero if either input is zero.
+ *
+ * Note that the division is guaranteed to be exact, returning an integer
+ * result, so the LCM is an integral multiple of both x and y. A display
+ * scale of Min(x.dscale, y.dscale) would be sufficient to represent it,
+ * but as with other numeric functions, we choose to return a result whose
+ * display scale is no smaller than either input.
+ */
+ if (arg1.ndigits == 0 || arg2.ndigits == 0)
+ set_var_from_var(&const_zero, &result);
+ else
+ {
+ gcd_var(&arg1, &arg2, &result);
+ div_var(&arg1, &result, &result, 0, false);
+ mul_var(&arg2, &result, &result, arg2.dscale);
+ result.sign = NUMERIC_POS;
+ }
+
+ result.dscale = Max(arg1.dscale, arg2.dscale);
+
+ res = make_result(&result);
+
+ free_var(&result);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_fac()
+ *
+ * Compute factorial
+ */
+Datum
+numeric_fac(PG_FUNCTION_ARGS)
+{
+ int64 num = PG_GETARG_INT64(0);
+ Numeric res;
+ NumericVar fact;
+ NumericVar result;
+
+ if (num < 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("factorial of a negative number is undefined")));
+ if (num <= 1)
+ {
+ res = make_result(&const_one);
+ PG_RETURN_NUMERIC(res);
+ }
+ /* Fail immediately if the result would overflow */
+ if (num > 32177)
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("value overflows numeric format")));
+
+ init_var(&fact);
+ init_var(&result);
+
+ int64_to_numericvar(num, &result);
+
+ for (num = num - 1; num > 1; num--)
+ {
+ /* this loop can take awhile, so allow it to be interrupted */
+ CHECK_FOR_INTERRUPTS();
+
+ int64_to_numericvar(num, &fact);
+
+ mul_var(&result, &fact, &result, 0);
+ }
+
+ res = make_result(&result);
+
+ free_var(&fact);
+ free_var(&result);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_sqrt() -
+ *
+ * Compute the square root of a numeric.
+ */
+Datum
+numeric_sqrt(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ Numeric res;
+ NumericVar arg;
+ NumericVar result;
+ int sweight;
+ int rscale;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ /* error should match that in sqrt_var() */
+ if (NUMERIC_IS_NINF(num))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_POWER_FUNCTION),
+ errmsg("cannot take square root of a negative number")));
+ /* For NAN or PINF, just duplicate the input */
+ PG_RETURN_NUMERIC(duplicate_numeric(num));
+ }
+
+ /*
+ * Unpack the argument and determine the result scale. We choose a scale
+ * to give at least NUMERIC_MIN_SIG_DIGITS significant digits; but in any
+ * case not less than the input's dscale.
+ */
+ init_var_from_num(num, &arg);
+
+ init_var(&result);
+
+ /* Assume the input was normalized, so arg.weight is accurate */
+ sweight = (arg.weight + 1) * DEC_DIGITS / 2 - 1;
+
+ rscale = NUMERIC_MIN_SIG_DIGITS - sweight;
+ rscale = Max(rscale, arg.dscale);
+ rscale = Max(rscale, NUMERIC_MIN_DISPLAY_SCALE);
+ rscale = Min(rscale, NUMERIC_MAX_DISPLAY_SCALE);
+
+ /*
+ * Let sqrt_var() do the calculation and return the result.
+ */
+ sqrt_var(&arg, &result, rscale);
+
+ res = make_result(&result);
+
+ free_var(&result);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_exp() -
+ *
+ * Raise e to the power of x
+ */
+Datum
+numeric_exp(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ Numeric res;
+ NumericVar arg;
+ NumericVar result;
+ int rscale;
+ double val;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ /* Per POSIX, exp(-Inf) is zero */
+ if (NUMERIC_IS_NINF(num))
+ PG_RETURN_NUMERIC(make_result(&const_zero));
+ /* For NAN or PINF, just duplicate the input */
+ PG_RETURN_NUMERIC(duplicate_numeric(num));
+ }
+
+ /*
+ * Unpack the argument and determine the result scale. We choose a scale
+ * to give at least NUMERIC_MIN_SIG_DIGITS significant digits; but in any
+ * case not less than the input's dscale.
+ */
+ init_var_from_num(num, &arg);
+
+ init_var(&result);
+
+ /* convert input to float8, ignoring overflow */
+ val = numericvar_to_double_no_overflow(&arg);
+
+ /*
+ * log10(result) = num * log10(e), so this is approximately the decimal
+ * weight of the result:
+ */
+ val *= 0.434294481903252;
+
+ /* limit to something that won't cause integer overflow */
+ val = Max(val, -NUMERIC_MAX_RESULT_SCALE);
+ val = Min(val, NUMERIC_MAX_RESULT_SCALE);
+
+ rscale = NUMERIC_MIN_SIG_DIGITS - (int) val;
+ rscale = Max(rscale, arg.dscale);
+ rscale = Max(rscale, NUMERIC_MIN_DISPLAY_SCALE);
+ rscale = Min(rscale, NUMERIC_MAX_DISPLAY_SCALE);
+
+ /*
+ * Let exp_var() do the calculation and return the result.
+ */
+ exp_var(&arg, &result, rscale);
+
+ res = make_result(&result);
+
+ free_var(&result);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_ln() -
+ *
+ * Compute the natural logarithm of x
+ */
+Datum
+numeric_ln(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ Numeric res;
+ NumericVar arg;
+ NumericVar result;
+ int ln_dweight;
+ int rscale;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ if (NUMERIC_IS_NINF(num))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_LOG),
+ errmsg("cannot take logarithm of a negative number")));
+ /* For NAN or PINF, just duplicate the input */
+ PG_RETURN_NUMERIC(duplicate_numeric(num));
+ }
+
+ init_var_from_num(num, &arg);
+ init_var(&result);
+
+ /* Estimated dweight of logarithm */
+ ln_dweight = estimate_ln_dweight(&arg);
+
+ rscale = NUMERIC_MIN_SIG_DIGITS - ln_dweight;
+ rscale = Max(rscale, arg.dscale);
+ rscale = Max(rscale, NUMERIC_MIN_DISPLAY_SCALE);
+ rscale = Min(rscale, NUMERIC_MAX_DISPLAY_SCALE);
+
+ ln_var(&arg, &result, rscale);
+
+ res = make_result(&result);
+
+ free_var(&result);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_log() -
+ *
+ * Compute the logarithm of x in a given base
+ */
+Datum
+numeric_log(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ Numeric res;
+ NumericVar arg1;
+ NumericVar arg2;
+ NumericVar result;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num1) || NUMERIC_IS_SPECIAL(num2))
+ {
+ int sign1,
+ sign2;
+
+ if (NUMERIC_IS_NAN(num1) || NUMERIC_IS_NAN(num2))
+ PG_RETURN_NUMERIC(make_result(&const_nan));
+ /* fail on negative inputs including -Inf, as log_var would */
+ sign1 = numeric_sign_internal(num1);
+ sign2 = numeric_sign_internal(num2);
+ if (sign1 < 0 || sign2 < 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_LOG),
+ errmsg("cannot take logarithm of a negative number")));
+ /* fail on zero inputs, as log_var would */
+ if (sign1 == 0 || sign2 == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_LOG),
+ errmsg("cannot take logarithm of zero")));
+ if (NUMERIC_IS_PINF(num1))
+ {
+ /* log(Inf, Inf) reduces to Inf/Inf, so it's NaN */
+ if (NUMERIC_IS_PINF(num2))
+ PG_RETURN_NUMERIC(make_result(&const_nan));
+ /* log(Inf, finite-positive) is zero (we don't throw underflow) */
+ PG_RETURN_NUMERIC(make_result(&const_zero));
+ }
+ Assert(NUMERIC_IS_PINF(num2));
+ /* log(finite-positive, Inf) is Inf */
+ PG_RETURN_NUMERIC(make_result(&const_pinf));
+ }
+
+ /*
+ * Initialize things
+ */
+ init_var_from_num(num1, &arg1);
+ init_var_from_num(num2, &arg2);
+ init_var(&result);
+
+ /*
+ * Call log_var() to compute and return the result; note it handles scale
+ * selection itself.
+ */
+ log_var(&arg1, &arg2, &result);
+
+ res = make_result(&result);
+
+ free_var(&result);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/*
+ * numeric_power() -
+ *
+ * Raise x to the power of y
+ */
+Datum
+numeric_power(PG_FUNCTION_ARGS)
+{
+ Numeric num1 = PG_GETARG_NUMERIC(0);
+ Numeric num2 = PG_GETARG_NUMERIC(1);
+ Numeric res;
+ NumericVar arg1;
+ NumericVar arg2;
+ NumericVar result;
+ int sign1,
+ sign2;
+
+ /*
+ * Handle NaN and infinities
+ */
+ if (NUMERIC_IS_SPECIAL(num1) || NUMERIC_IS_SPECIAL(num2))
+ {
+ /*
+ * We follow the POSIX spec for pow(3), which says that NaN ^ 0 = 1,
+ * and 1 ^ NaN = 1, while all other cases with NaN inputs yield NaN
+ * (with no error).
+ */
+ if (NUMERIC_IS_NAN(num1))
+ {
+ if (!NUMERIC_IS_SPECIAL(num2))
+ {
+ init_var_from_num(num2, &arg2);
+ if (cmp_var(&arg2, &const_zero) == 0)
+ PG_RETURN_NUMERIC(make_result(&const_one));
+ }
+ PG_RETURN_NUMERIC(make_result(&const_nan));
+ }
+ if (NUMERIC_IS_NAN(num2))
+ {
+ if (!NUMERIC_IS_SPECIAL(num1))
+ {
+ init_var_from_num(num1, &arg1);
+ if (cmp_var(&arg1, &const_one) == 0)
+ PG_RETURN_NUMERIC(make_result(&const_one));
+ }
+ PG_RETURN_NUMERIC(make_result(&const_nan));
+ }
+ /* At least one input is infinite, but error rules still apply */
+ sign1 = numeric_sign_internal(num1);
+ sign2 = numeric_sign_internal(num2);
+ if (sign1 == 0 && sign2 < 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_POWER_FUNCTION),
+ errmsg("zero raised to a negative power is undefined")));
+ if (sign1 < 0 && !numeric_is_integral(num2))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_POWER_FUNCTION),
+ errmsg("a negative number raised to a non-integer power yields a complex result")));
+
+ /*
+ * POSIX gives this series of rules for pow(3) with infinite inputs:
+ *
+ * For any value of y, if x is +1, 1.0 shall be returned.
+ */
+ if (!NUMERIC_IS_SPECIAL(num1))
+ {
+ init_var_from_num(num1, &arg1);
+ if (cmp_var(&arg1, &const_one) == 0)
+ PG_RETURN_NUMERIC(make_result(&const_one));
+ }
+
+ /*
+ * For any value of x, if y is [-]0, 1.0 shall be returned.
+ */
+ if (sign2 == 0)
+ PG_RETURN_NUMERIC(make_result(&const_one));
+
+ /*
+ * For any odd integer value of y > 0, if x is [-]0, [-]0 shall be
+ * returned. For y > 0 and not an odd integer, if x is [-]0, +0 shall
+ * be returned. (Since we don't deal in minus zero, we need not
+ * distinguish these two cases.)
+ */
+ if (sign1 == 0 && sign2 > 0)
+ PG_RETURN_NUMERIC(make_result(&const_zero));
+
+ /*
+ * If x is -1, and y is [-]Inf, 1.0 shall be returned.
+ *
+ * For |x| < 1, if y is -Inf, +Inf shall be returned.
+ *
+ * For |x| > 1, if y is -Inf, +0 shall be returned.
+ *
+ * For |x| < 1, if y is +Inf, +0 shall be returned.
+ *
+ * For |x| > 1, if y is +Inf, +Inf shall be returned.
+ */
+ if (NUMERIC_IS_INF(num2))
+ {
+ bool abs_x_gt_one;
+
+ if (NUMERIC_IS_SPECIAL(num1))
+ abs_x_gt_one = true; /* x is either Inf or -Inf */
+ else
+ {
+ init_var_from_num(num1, &arg1);
+ if (cmp_var(&arg1, &const_minus_one) == 0)
+ PG_RETURN_NUMERIC(make_result(&const_one));
+ arg1.sign = NUMERIC_POS; /* now arg1 = abs(x) */
+ abs_x_gt_one = (cmp_var(&arg1, &const_one) > 0);
+ }
+ if (abs_x_gt_one == (sign2 > 0))
+ PG_RETURN_NUMERIC(make_result(&const_pinf));
+ else
+ PG_RETURN_NUMERIC(make_result(&const_zero));
+ }
+
+ /*
+ * For y < 0, if x is +Inf, +0 shall be returned.
+ *
+ * For y > 0, if x is +Inf, +Inf shall be returned.
+ */
+ if (NUMERIC_IS_PINF(num1))
+ {
+ if (sign2 > 0)
+ PG_RETURN_NUMERIC(make_result(&const_pinf));
+ else
+ PG_RETURN_NUMERIC(make_result(&const_zero));
+ }
+
+ Assert(NUMERIC_IS_NINF(num1));
+
+ /*
+ * For y an odd integer < 0, if x is -Inf, -0 shall be returned. For
+ * y < 0 and not an odd integer, if x is -Inf, +0 shall be returned.
+ * (Again, we need not distinguish these two cases.)
+ */
+ if (sign2 < 0)
+ PG_RETURN_NUMERIC(make_result(&const_zero));
+
+ /*
+ * For y an odd integer > 0, if x is -Inf, -Inf shall be returned. For
+ * y > 0 and not an odd integer, if x is -Inf, +Inf shall be returned.
+ */
+ init_var_from_num(num2, &arg2);
+ if (arg2.ndigits > 0 && arg2.ndigits == arg2.weight + 1 &&
+ (arg2.digits[arg2.ndigits - 1] & 1))
+ PG_RETURN_NUMERIC(make_result(&const_ninf));
+ else
+ PG_RETURN_NUMERIC(make_result(&const_pinf));
+ }
+
+ /*
+ * The SQL spec requires that we emit a particular SQLSTATE error code for
+ * certain error conditions. Specifically, we don't return a
+ * divide-by-zero error code for 0 ^ -1. Raising a negative number to a
+ * non-integer power must produce the same error code, but that case is
+ * handled in power_var().
+ */
+ sign1 = numeric_sign_internal(num1);
+ sign2 = numeric_sign_internal(num2);
+
+ if (sign1 == 0 && sign2 < 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_POWER_FUNCTION),
+ errmsg("zero raised to a negative power is undefined")));
+
+ /*
+ * Initialize things
+ */
+ init_var(&result);
+ init_var_from_num(num1, &arg1);
+ init_var_from_num(num2, &arg2);
+
+ /*
+ * Call power_var() to compute and return the result; note it handles
+ * scale selection itself.
+ */
+ power_var(&arg1, &arg2, &result);
+
+ res = make_result(&result);
+
+ free_var(&result);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+/*
+ * numeric_scale() -
+ *
+ * Returns the scale, i.e. the count of decimal digits in the fractional part
+ */
+Datum
+numeric_scale(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+
+ if (NUMERIC_IS_SPECIAL(num))
+ PG_RETURN_NULL();
+
+ PG_RETURN_INT32(NUMERIC_DSCALE(num));
+}
+
+/*
+ * Calculate minimum scale for value.
+ */
+static int
+get_min_scale(NumericVar *var)
+{
+ int min_scale;
+ int last_digit_pos;
+
+ /*
+ * Ordinarily, the input value will be "stripped" so that the last
+ * NumericDigit is nonzero. But we don't want to get into an infinite
+ * loop if it isn't, so explicitly find the last nonzero digit.
+ */
+ last_digit_pos = var->ndigits - 1;
+ while (last_digit_pos >= 0 &&
+ var->digits[last_digit_pos] == 0)
+ last_digit_pos--;
+
+ if (last_digit_pos >= 0)
+ {
+ /* compute min_scale assuming that last ndigit has no zeroes */
+ min_scale = (last_digit_pos - var->weight) * DEC_DIGITS;
+
+ /*
+ * We could get a negative result if there are no digits after the
+ * decimal point. In this case the min_scale must be zero.
+ */
+ if (min_scale > 0)
+ {
+ /*
+ * Reduce min_scale if trailing digit(s) in last NumericDigit are
+ * zero.
+ */
+ NumericDigit last_digit = var->digits[last_digit_pos];
+
+ while (last_digit % 10 == 0)
+ {
+ min_scale--;
+ last_digit /= 10;
+ }
+ }
+ else
+ min_scale = 0;
+ }
+ else
+ min_scale = 0; /* result if input is zero */
+
+ return min_scale;
+}
+
+/*
+ * Returns minimum scale required to represent supplied value without loss.
+ */
+Datum
+numeric_min_scale(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ NumericVar arg;
+ int min_scale;
+
+ if (NUMERIC_IS_SPECIAL(num))
+ PG_RETURN_NULL();
+
+ init_var_from_num(num, &arg);
+ min_scale = get_min_scale(&arg);
+ free_var(&arg);
+
+ PG_RETURN_INT32(min_scale);
+}
+
+/*
+ * Reduce scale of numeric value to represent supplied value without loss.
+ */
+Datum
+numeric_trim_scale(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ Numeric res;
+ NumericVar result;
+
+ if (NUMERIC_IS_SPECIAL(num))
+ PG_RETURN_NUMERIC(duplicate_numeric(num));
+
+ init_var_from_num(num, &result);
+ result.dscale = get_min_scale(&result);
+ res = make_result(&result);
+ free_var(&result);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+/* ----------------------------------------------------------------------
+ *
+ * Type conversion functions
+ *
+ * ----------------------------------------------------------------------
+ */
+
+Numeric
+int64_to_numeric(int64 val)
+{
+ Numeric res;
+ NumericVar result;
+
+ init_var(&result);
+
+ int64_to_numericvar(val, &result);
+
+ res = make_result(&result);
+
+ free_var(&result);
+
+ return res;
+}
+
+/*
+ * Convert val1/(10**val2) to numeric. This is much faster than normal
+ * numeric division.
+ */
+Numeric
+int64_div_fast_to_numeric(int64 val1, int log10val2)
+{
+ Numeric res;
+ NumericVar result;
+ int64 saved_val1 = val1;
+ int w;
+ int m;
+
+ /* how much to decrease the weight by */
+ w = log10val2 / DEC_DIGITS;
+ /* how much is left */
+ m = log10val2 % DEC_DIGITS;
+
+ /*
+ * If there is anything left, multiply the dividend by what's left, then
+ * shift the weight by one more.
+ */
+ if (m > 0)
+ {
+ static int pow10[] = {1, 10, 100, 1000};
+
+ StaticAssertStmt(lengthof(pow10) == DEC_DIGITS, "mismatch with DEC_DIGITS");
+ if (unlikely(pg_mul_s64_overflow(val1, pow10[DEC_DIGITS - m], &val1)))
+ {
+ /*
+ * If it doesn't fit, do the whole computation in numeric the slow
+ * way. Note that va1l may have been overwritten, so use
+ * saved_val1 instead.
+ */
+ int val2 = 1;
+
+ for (int i = 0; i < log10val2; i++)
+ val2 *= 10;
+ res = numeric_div_opt_error(int64_to_numeric(saved_val1), int64_to_numeric(val2), NULL);
+ res = DatumGetNumeric(DirectFunctionCall2(numeric_round,
+ NumericGetDatum(res),
+ Int32GetDatum(log10val2)));
+ return res;
+ }
+ w++;
+ }
+
+ init_var(&result);
+
+ int64_to_numericvar(val1, &result);
+
+ result.weight -= w;
+ result.dscale += w * DEC_DIGITS - (DEC_DIGITS - m);
+
+ res = make_result(&result);
+
+ free_var(&result);
+
+ return res;
+}
+
+Datum
+int4_numeric(PG_FUNCTION_ARGS)
+{
+ int32 val = PG_GETARG_INT32(0);
+
+ PG_RETURN_NUMERIC(int64_to_numeric(val));
+}
+
+int32
+numeric_int4_opt_error(Numeric num, bool *have_error)
+{
+ NumericVar x;
+ int32 result;
+
+ if (have_error)
+ *have_error = false;
+
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ if (have_error)
+ {
+ *have_error = true;
+ return 0;
+ }
+ else
+ {
+ if (NUMERIC_IS_NAN(num))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot convert NaN to %s", "integer")));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot convert infinity to %s", "integer")));
+ }
+ }
+
+ /* Convert to variable format, then convert to int4 */
+ init_var_from_num(num, &x);
+
+ if (!numericvar_to_int32(&x, &result))
+ {
+ if (have_error)
+ {
+ *have_error = true;
+ return 0;
+ }
+ else
+ {
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("integer out of range")));
+ }
+ }
+
+ return result;
+}
+
+Datum
+numeric_int4(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+
+ PG_RETURN_INT32(numeric_int4_opt_error(num, NULL));
+}
+
+/*
+ * Given a NumericVar, convert it to an int32. If the NumericVar
+ * exceeds the range of an int32, false is returned, otherwise true is returned.
+ * The input NumericVar is *not* free'd.
+ */
+static bool
+numericvar_to_int32(const NumericVar *var, int32 *result)
+{
+ int64 val;
+
+ if (!numericvar_to_int64(var, &val))
+ return false;
+
+ if (unlikely(val < PG_INT32_MIN) || unlikely(val > PG_INT32_MAX))
+ return false;
+
+ /* Down-convert to int4 */
+ *result = (int32) val;
+
+ return true;
+}
+
+Datum
+int8_numeric(PG_FUNCTION_ARGS)
+{
+ int64 val = PG_GETARG_INT64(0);
+
+ PG_RETURN_NUMERIC(int64_to_numeric(val));
+}
+
+
+Datum
+numeric_int8(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ NumericVar x;
+ int64 result;
+
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ if (NUMERIC_IS_NAN(num))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot convert NaN to %s", "bigint")));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot convert infinity to %s", "bigint")));
+ }
+
+ /* Convert to variable format and thence to int8 */
+ init_var_from_num(num, &x);
+
+ if (!numericvar_to_int64(&x, &result))
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("bigint out of range")));
+
+ PG_RETURN_INT64(result);
+}
+
+
+Datum
+int2_numeric(PG_FUNCTION_ARGS)
+{
+ int16 val = PG_GETARG_INT16(0);
+
+ PG_RETURN_NUMERIC(int64_to_numeric(val));
+}
+
+
+Datum
+numeric_int2(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ NumericVar x;
+ int64 val;
+ int16 result;
+
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ if (NUMERIC_IS_NAN(num))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot convert NaN to %s", "smallint")));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot convert infinity to %s", "smallint")));
+ }
+
+ /* Convert to variable format and thence to int8 */
+ init_var_from_num(num, &x);
+
+ if (!numericvar_to_int64(&x, &val))
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("smallint out of range")));
+
+ if (unlikely(val < PG_INT16_MIN) || unlikely(val > PG_INT16_MAX))
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("smallint out of range")));
+
+ /* Down-convert to int2 */
+ result = (int16) val;
+
+ PG_RETURN_INT16(result);
+}
+
+
+Datum
+float8_numeric(PG_FUNCTION_ARGS)
+{
+ float8 val = PG_GETARG_FLOAT8(0);
+ Numeric res;
+ NumericVar result;
+ char buf[DBL_DIG + 100];
+
+ if (isnan(val))
+ PG_RETURN_NUMERIC(make_result(&const_nan));
+
+ if (isinf(val))
+ {
+ if (val < 0)
+ PG_RETURN_NUMERIC(make_result(&const_ninf));
+ else
+ PG_RETURN_NUMERIC(make_result(&const_pinf));
+ }
+
+ snprintf(buf, sizeof(buf), "%.*g", DBL_DIG, val);
+
+ init_var(&result);
+
+ /* Assume we need not worry about leading/trailing spaces */
+ (void) set_var_from_str(buf, buf, &result);
+
+ res = make_result(&result);
+
+ free_var(&result);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+Datum
+numeric_float8(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ char *tmp;
+ Datum result;
+
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ if (NUMERIC_IS_PINF(num))
+ PG_RETURN_FLOAT8(get_float8_infinity());
+ else if (NUMERIC_IS_NINF(num))
+ PG_RETURN_FLOAT8(-get_float8_infinity());
+ else
+ PG_RETURN_FLOAT8(get_float8_nan());
+ }
+
+ tmp = DatumGetCString(DirectFunctionCall1(numeric_out,
+ NumericGetDatum(num)));
+
+ result = DirectFunctionCall1(float8in, CStringGetDatum(tmp));
+
+ pfree(tmp);
+
+ PG_RETURN_DATUM(result);
+}
+
+
+/*
+ * Convert numeric to float8; if out of range, return +/- HUGE_VAL
+ *
+ * (internal helper function, not directly callable from SQL)
+ */
+Datum
+numeric_float8_no_overflow(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ double val;
+
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ if (NUMERIC_IS_PINF(num))
+ val = HUGE_VAL;
+ else if (NUMERIC_IS_NINF(num))
+ val = -HUGE_VAL;
+ else
+ val = get_float8_nan();
+ }
+ else
+ {
+ NumericVar x;
+
+ init_var_from_num(num, &x);
+ val = numericvar_to_double_no_overflow(&x);
+ }
+
+ PG_RETURN_FLOAT8(val);
+}
+
+Datum
+float4_numeric(PG_FUNCTION_ARGS)
+{
+ float4 val = PG_GETARG_FLOAT4(0);
+ Numeric res;
+ NumericVar result;
+ char buf[FLT_DIG + 100];
+
+ if (isnan(val))
+ PG_RETURN_NUMERIC(make_result(&const_nan));
+
+ if (isinf(val))
+ {
+ if (val < 0)
+ PG_RETURN_NUMERIC(make_result(&const_ninf));
+ else
+ PG_RETURN_NUMERIC(make_result(&const_pinf));
+ }
+
+ snprintf(buf, sizeof(buf), "%.*g", FLT_DIG, val);
+
+ init_var(&result);
+
+ /* Assume we need not worry about leading/trailing spaces */
+ (void) set_var_from_str(buf, buf, &result);
+
+ res = make_result(&result);
+
+ free_var(&result);
+
+ PG_RETURN_NUMERIC(res);
+}
+
+
+Datum
+numeric_float4(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ char *tmp;
+ Datum result;
+
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ if (NUMERIC_IS_PINF(num))
+ PG_RETURN_FLOAT4(get_float4_infinity());
+ else if (NUMERIC_IS_NINF(num))
+ PG_RETURN_FLOAT4(-get_float4_infinity());
+ else
+ PG_RETURN_FLOAT4(get_float4_nan());
+ }
+
+ tmp = DatumGetCString(DirectFunctionCall1(numeric_out,
+ NumericGetDatum(num)));
+
+ result = DirectFunctionCall1(float4in, CStringGetDatum(tmp));
+
+ pfree(tmp);
+
+ PG_RETURN_DATUM(result);
+}
+
+
+Datum
+numeric_pg_lsn(PG_FUNCTION_ARGS)
+{
+ Numeric num = PG_GETARG_NUMERIC(0);
+ NumericVar x;
+ XLogRecPtr result;
+
+ if (NUMERIC_IS_SPECIAL(num))
+ {
+ if (NUMERIC_IS_NAN(num))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot convert NaN to %s", "pg_lsn")));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot convert infinity to %s", "pg_lsn")));
+ }
+
+ /* Convert to variable format and thence to pg_lsn */
+ init_var_from_num(num, &x);
+
+ if (!numericvar_to_uint64(&x, (uint64 *) &result))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("pg_lsn out of range")));
+
+ PG_RETURN_LSN(result);
+}
+
+
+/* ----------------------------------------------------------------------
+ *
+ * Aggregate functions
+ *
+ * The transition datatype for all these aggregates is declared as INTERNAL.
+ * Actually, it's a pointer to a NumericAggState allocated in the aggregate
+ * context. The digit buffers for the NumericVars will be there too.
+ *
+ * On platforms which support 128-bit integers some aggregates instead use a
+ * 128-bit integer based transition datatype to speed up calculations.
+ *
+ * ----------------------------------------------------------------------
+ */
+
+typedef struct NumericAggState
+{
+ bool calcSumX2; /* if true, calculate sumX2 */
+ MemoryContext agg_context; /* context we're calculating in */
+ int64 N; /* count of processed numbers */
+ NumericSumAccum sumX; /* sum of processed numbers */
+ NumericSumAccum sumX2; /* sum of squares of processed numbers */
+ int maxScale; /* maximum scale seen so far */
+ int64 maxScaleCount; /* number of values seen with maximum scale */
+ /* These counts are *not* included in N! Use NA_TOTAL_COUNT() as needed */
+ int64 NaNcount; /* count of NaN values */
+ int64 pInfcount; /* count of +Inf values */
+ int64 nInfcount; /* count of -Inf values */
+} NumericAggState;
+
+#define NA_TOTAL_COUNT(na) \
+ ((na)->N + (na)->NaNcount + (na)->pInfcount + (na)->nInfcount)
+
+/*
+ * Prepare state data for a numeric aggregate function that needs to compute
+ * sum, count and optionally sum of squares of the input.
+ */
+static NumericAggState *
+makeNumericAggState(FunctionCallInfo fcinfo, bool calcSumX2)
+{
+ NumericAggState *state;
+ MemoryContext agg_context;
+ MemoryContext old_context;
+
+ if (!AggCheckCallContext(fcinfo, &agg_context))
+ elog(ERROR, "aggregate function called in non-aggregate context");
+
+ old_context = MemoryContextSwitchTo(agg_context);
+
+ state = (NumericAggState *) palloc0(sizeof(NumericAggState));
+ state->calcSumX2 = calcSumX2;
+ state->agg_context = agg_context;
+
+ MemoryContextSwitchTo(old_context);
+
+ return state;
+}
+
+/*
+ * Like makeNumericAggState(), but allocate the state in the current memory
+ * context.
+ */
+static NumericAggState *
+makeNumericAggStateCurrentContext(bool calcSumX2)
+{
+ NumericAggState *state;
+
+ state = (NumericAggState *) palloc0(sizeof(NumericAggState));
+ state->calcSumX2 = calcSumX2;
+ state->agg_context = CurrentMemoryContext;
+
+ return state;
+}
+
+/*
+ * Accumulate a new input value for numeric aggregate functions.
+ */
+static void
+do_numeric_accum(NumericAggState *state, Numeric newval)
+{
+ NumericVar X;
+ NumericVar X2;
+ MemoryContext old_context;
+
+ /* Count NaN/infinity inputs separately from all else */
+ if (NUMERIC_IS_SPECIAL(newval))
+ {
+ if (NUMERIC_IS_PINF(newval))
+ state->pInfcount++;
+ else if (NUMERIC_IS_NINF(newval))
+ state->nInfcount++;
+ else
+ state->NaNcount++;
+ return;
+ }
+
+ /* load processed number in short-lived context */
+ init_var_from_num(newval, &X);
+
+ /*
+ * Track the highest input dscale that we've seen, to support inverse
+ * transitions (see do_numeric_discard).
+ */
+ if (X.dscale > state->maxScale)
+ {
+ state->maxScale = X.dscale;
+ state->maxScaleCount = 1;
+ }
+ else if (X.dscale == state->maxScale)
+ state->maxScaleCount++;
+
+ /* if we need X^2, calculate that in short-lived context */
+ if (state->calcSumX2)
+ {
+ init_var(&X2);
+ mul_var(&X, &X, &X2, X.dscale * 2);
+ }
+
+ /* The rest of this needs to work in the aggregate context */
+ old_context = MemoryContextSwitchTo(state->agg_context);
+
+ state->N++;
+
+ /* Accumulate sums */
+ accum_sum_add(&(state->sumX), &X);
+
+ if (state->calcSumX2)
+ accum_sum_add(&(state->sumX2), &X2);
+
+ MemoryContextSwitchTo(old_context);
+}
+
+/*
+ * Attempt to remove an input value from the aggregated state.
+ *
+ * If the value cannot be removed then the function will return false; the
+ * possible reasons for failing are described below.
+ *
+ * If we aggregate the values 1.01 and 2 then the result will be 3.01.
+ * If we are then asked to un-aggregate the 1.01 then we must fail as we
+ * won't be able to tell what the new aggregated value's dscale should be.
+ * We don't want to return 2.00 (dscale = 2), since the sum's dscale would
+ * have been zero if we'd really aggregated only 2.
+ *
+ * Note: alternatively, we could count the number of inputs with each possible
+ * dscale (up to some sane limit). Not yet clear if it's worth the trouble.
+ */
+static bool
+do_numeric_discard(NumericAggState *state, Numeric newval)
+{
+ NumericVar X;
+ NumericVar X2;
+ MemoryContext old_context;
+
+ /* Count NaN/infinity inputs separately from all else */
+ if (NUMERIC_IS_SPECIAL(newval))
+ {
+ if (NUMERIC_IS_PINF(newval))
+ state->pInfcount--;
+ else if (NUMERIC_IS_NINF(newval))
+ state->nInfcount--;
+ else
+ state->NaNcount--;
+ return true;
+ }
+
+ /* load processed number in short-lived context */
+ init_var_from_num(newval, &X);
+
+ /*
+ * state->sumX's dscale is the maximum dscale of any of the inputs.
+ * Removing the last input with that dscale would require us to recompute
+ * the maximum dscale of the *remaining* inputs, which we cannot do unless
+ * no more non-NaN inputs remain at all. So we report a failure instead,
+ * and force the aggregation to be redone from scratch.
+ */
+ if (X.dscale == state->maxScale)
+ {
+ if (state->maxScaleCount > 1 || state->maxScale == 0)
+ {
+ /*
+ * Some remaining inputs have same dscale, or dscale hasn't gotten
+ * above zero anyway
+ */
+ state->maxScaleCount--;
+ }
+ else if (state->N == 1)
+ {
+ /* No remaining non-NaN inputs at all, so reset maxScale */
+ state->maxScale = 0;
+ state->maxScaleCount = 0;
+ }
+ else
+ {
+ /* Correct new maxScale is uncertain, must fail */
+ return false;
+ }
+ }
+
+ /* if we need X^2, calculate that in short-lived context */
+ if (state->calcSumX2)
+ {
+ init_var(&X2);
+ mul_var(&X, &X, &X2, X.dscale * 2);
+ }
+
+ /* The rest of this needs to work in the aggregate context */
+ old_context = MemoryContextSwitchTo(state->agg_context);
+
+ if (state->N-- > 1)
+ {
+ /* Negate X, to subtract it from the sum */
+ X.sign = (X.sign == NUMERIC_POS ? NUMERIC_NEG : NUMERIC_POS);
+ accum_sum_add(&(state->sumX), &X);
+
+ if (state->calcSumX2)
+ {
+ /* Negate X^2. X^2 is always positive */
+ X2.sign = NUMERIC_NEG;
+ accum_sum_add(&(state->sumX2), &X2);
+ }
+ }
+ else
+ {
+ /* Zero the sums */
+ Assert(state->N == 0);
+
+ accum_sum_reset(&state->sumX);
+ if (state->calcSumX2)
+ accum_sum_reset(&state->sumX2);
+ }
+
+ MemoryContextSwitchTo(old_context);
+
+ return true;
+}
+
+/*
+ * Generic transition function for numeric aggregates that require sumX2.
+ */
+Datum
+numeric_accum(PG_FUNCTION_ARGS)
+{
+ NumericAggState *state;
+
+ state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+ /* Create the state data on the first call */
+ if (state == NULL)
+ state = makeNumericAggState(fcinfo, true);
+
+ if (!PG_ARGISNULL(1))
+ do_numeric_accum(state, PG_GETARG_NUMERIC(1));
+
+ PG_RETURN_POINTER(state);
+}
+
+/*
+ * Generic combine function for numeric aggregates which require sumX2
+ */
+Datum
+numeric_combine(PG_FUNCTION_ARGS)
+{
+ NumericAggState *state1;
+ NumericAggState *state2;
+ MemoryContext agg_context;
+ MemoryContext old_context;
+
+ if (!AggCheckCallContext(fcinfo, &agg_context))
+ elog(ERROR, "aggregate function called in non-aggregate context");
+
+ state1 = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+ state2 = PG_ARGISNULL(1) ? NULL : (NumericAggState *) PG_GETARG_POINTER(1);
+
+ if (state2 == NULL)
+ PG_RETURN_POINTER(state1);
+
+ /* manually copy all fields from state2 to state1 */
+ if (state1 == NULL)
+ {
+ old_context = MemoryContextSwitchTo(agg_context);
+
+ state1 = makeNumericAggStateCurrentContext(true);
+ state1->N = state2->N;
+ state1->NaNcount = state2->NaNcount;
+ state1->pInfcount = state2->pInfcount;
+ state1->nInfcount = state2->nInfcount;
+ state1->maxScale = state2->maxScale;
+ state1->maxScaleCount = state2->maxScaleCount;
+
+ accum_sum_copy(&state1->sumX, &state2->sumX);
+ accum_sum_copy(&state1->sumX2, &state2->sumX2);
+
+ MemoryContextSwitchTo(old_context);
+
+ PG_RETURN_POINTER(state1);
+ }
+
+ state1->N += state2->N;
+ state1->NaNcount += state2->NaNcount;
+ state1->pInfcount += state2->pInfcount;
+ state1->nInfcount += state2->nInfcount;
+
+ if (state2->N > 0)
+ {
+ /*
+ * These are currently only needed for moving aggregates, but let's do
+ * the right thing anyway...
+ */
+ if (state2->maxScale > state1->maxScale)
+ {
+ state1->maxScale = state2->maxScale;
+ state1->maxScaleCount = state2->maxScaleCount;
+ }
+ else if (state2->maxScale == state1->maxScale)
+ state1->maxScaleCount += state2->maxScaleCount;
+
+ /* The rest of this needs to work in the aggregate context */
+ old_context = MemoryContextSwitchTo(agg_context);
+
+ /* Accumulate sums */
+ accum_sum_combine(&state1->sumX, &state2->sumX);
+ accum_sum_combine(&state1->sumX2, &state2->sumX2);
+
+ MemoryContextSwitchTo(old_context);
+ }
+ PG_RETURN_POINTER(state1);
+}
+
+/*
+ * Generic transition function for numeric aggregates that don't require sumX2.
+ */
+Datum
+numeric_avg_accum(PG_FUNCTION_ARGS)
+{
+ NumericAggState *state;
+
+ state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+ /* Create the state data on the first call */
+ if (state == NULL)
+ state = makeNumericAggState(fcinfo, false);
+
+ if (!PG_ARGISNULL(1))
+ do_numeric_accum(state, PG_GETARG_NUMERIC(1));
+
+ PG_RETURN_POINTER(state);
+}
+
+/*
+ * Combine function for numeric aggregates which don't require sumX2
+ */
+Datum
+numeric_avg_combine(PG_FUNCTION_ARGS)
+{
+ NumericAggState *state1;
+ NumericAggState *state2;
+ MemoryContext agg_context;
+ MemoryContext old_context;
+
+ if (!AggCheckCallContext(fcinfo, &agg_context))
+ elog(ERROR, "aggregate function called in non-aggregate context");
+
+ state1 = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+ state2 = PG_ARGISNULL(1) ? NULL : (NumericAggState *) PG_GETARG_POINTER(1);
+
+ if (state2 == NULL)
+ PG_RETURN_POINTER(state1);
+
+ /* manually copy all fields from state2 to state1 */
+ if (state1 == NULL)
+ {
+ old_context = MemoryContextSwitchTo(agg_context);
+
+ state1 = makeNumericAggStateCurrentContext(false);
+ state1->N = state2->N;
+ state1->NaNcount = state2->NaNcount;
+ state1->pInfcount = state2->pInfcount;
+ state1->nInfcount = state2->nInfcount;
+ state1->maxScale = state2->maxScale;
+ state1->maxScaleCount = state2->maxScaleCount;
+
+ accum_sum_copy(&state1->sumX, &state2->sumX);
+
+ MemoryContextSwitchTo(old_context);
+
+ PG_RETURN_POINTER(state1);
+ }
+
+ state1->N += state2->N;
+ state1->NaNcount += state2->NaNcount;
+ state1->pInfcount += state2->pInfcount;
+ state1->nInfcount += state2->nInfcount;
+
+ if (state2->N > 0)
+ {
+ /*
+ * These are currently only needed for moving aggregates, but let's do
+ * the right thing anyway...
+ */
+ if (state2->maxScale > state1->maxScale)
+ {
+ state1->maxScale = state2->maxScale;
+ state1->maxScaleCount = state2->maxScaleCount;
+ }
+ else if (state2->maxScale == state1->maxScale)
+ state1->maxScaleCount += state2->maxScaleCount;
+
+ /* The rest of this needs to work in the aggregate context */
+ old_context = MemoryContextSwitchTo(agg_context);
+
+ /* Accumulate sums */
+ accum_sum_combine(&state1->sumX, &state2->sumX);
+
+ MemoryContextSwitchTo(old_context);
+ }
+ PG_RETURN_POINTER(state1);
+}
+
+/*
+ * numeric_avg_serialize
+ * Serialize NumericAggState for numeric aggregates that don't require
+ * sumX2.
+ */
+Datum
+numeric_avg_serialize(PG_FUNCTION_ARGS)
+{
+ NumericAggState *state;
+ StringInfoData buf;
+ Datum temp;
+ bytea *sumX;
+ bytea *result;
+ NumericVar tmp_var;
+
+ /* Ensure we disallow calling when not in aggregate context */
+ if (!AggCheckCallContext(fcinfo, NULL))
+ elog(ERROR, "aggregate function called in non-aggregate context");
+
+ state = (NumericAggState *) PG_GETARG_POINTER(0);
+
+ /*
+ * This is a little wasteful since make_result converts the NumericVar
+ * into a Numeric and numeric_send converts it back again. Is it worth
+ * splitting the tasks in numeric_send into separate functions to stop
+ * this? Doing so would also remove the fmgr call overhead.
+ */
+ init_var(&tmp_var);
+ accum_sum_final(&state->sumX, &tmp_var);
+
+ temp = DirectFunctionCall1(numeric_send,
+ NumericGetDatum(make_result(&tmp_var)));
+ sumX = DatumGetByteaPP(temp);
+ free_var(&tmp_var);
+
+ pq_begintypsend(&buf);
+
+ /* N */
+ pq_sendint64(&buf, state->N);
+
+ /* sumX */
+ pq_sendbytes(&buf, VARDATA_ANY(sumX), VARSIZE_ANY_EXHDR(sumX));
+
+ /* maxScale */
+ pq_sendint32(&buf, state->maxScale);
+
+ /* maxScaleCount */
+ pq_sendint64(&buf, state->maxScaleCount);
+
+ /* NaNcount */
+ pq_sendint64(&buf, state->NaNcount);
+
+ /* pInfcount */
+ pq_sendint64(&buf, state->pInfcount);
+
+ /* nInfcount */
+ pq_sendint64(&buf, state->nInfcount);
+
+ result = pq_endtypsend(&buf);
+
+ PG_RETURN_BYTEA_P(result);
+}
+
+/*
+ * numeric_avg_deserialize
+ * Deserialize bytea into NumericAggState for numeric aggregates that
+ * don't require sumX2.
+ */
+Datum
+numeric_avg_deserialize(PG_FUNCTION_ARGS)
+{
+ bytea *sstate;
+ NumericAggState *result;
+ Datum temp;
+ NumericVar tmp_var;
+ StringInfoData buf;
+
+ if (!AggCheckCallContext(fcinfo, NULL))
+ elog(ERROR, "aggregate function called in non-aggregate context");
+
+ sstate = PG_GETARG_BYTEA_PP(0);
+
+ /*
+ * Copy the bytea into a StringInfo so that we can "receive" it using the
+ * standard recv-function infrastructure.
+ */
+ initStringInfo(&buf);
+ appendBinaryStringInfo(&buf,
+ VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
+
+ result = makeNumericAggStateCurrentContext(false);
+
+ /* N */
+ result->N = pq_getmsgint64(&buf);
+
+ /* sumX */
+ temp = DirectFunctionCall3(numeric_recv,
+ PointerGetDatum(&buf),
+ ObjectIdGetDatum(InvalidOid),
+ Int32GetDatum(-1));
+ init_var_from_num(DatumGetNumeric(temp), &tmp_var);
+ accum_sum_add(&(result->sumX), &tmp_var);
+
+ /* maxScale */
+ result->maxScale = pq_getmsgint(&buf, 4);
+
+ /* maxScaleCount */
+ result->maxScaleCount = pq_getmsgint64(&buf);
+
+ /* NaNcount */
+ result->NaNcount = pq_getmsgint64(&buf);
+
+ /* pInfcount */
+ result->pInfcount = pq_getmsgint64(&buf);
+
+ /* nInfcount */
+ result->nInfcount = pq_getmsgint64(&buf);
+
+ pq_getmsgend(&buf);
+ pfree(buf.data);
+
+ PG_RETURN_POINTER(result);
+}
+
+/*
+ * numeric_serialize
+ * Serialization function for NumericAggState for numeric aggregates that
+ * require sumX2.
+ */
+Datum
+numeric_serialize(PG_FUNCTION_ARGS)
+{
+ NumericAggState *state;
+ StringInfoData buf;
+ Datum temp;
+ bytea *sumX;
+ NumericVar tmp_var;
+ bytea *sumX2;
+ bytea *result;
+
+ /* Ensure we disallow calling when not in aggregate context */
+ if (!AggCheckCallContext(fcinfo, NULL))
+ elog(ERROR, "aggregate function called in non-aggregate context");
+
+ state = (NumericAggState *) PG_GETARG_POINTER(0);
+
+ /*
+ * This is a little wasteful since make_result converts the NumericVar
+ * into a Numeric and numeric_send converts it back again. Is it worth
+ * splitting the tasks in numeric_send into separate functions to stop
+ * this? Doing so would also remove the fmgr call overhead.
+ */
+ init_var(&tmp_var);
+
+ accum_sum_final(&state->sumX, &tmp_var);
+ temp = DirectFunctionCall1(numeric_send,
+ NumericGetDatum(make_result(&tmp_var)));
+ sumX = DatumGetByteaPP(temp);
+
+ accum_sum_final(&state->sumX2, &tmp_var);
+ temp = DirectFunctionCall1(numeric_send,
+ NumericGetDatum(make_result(&tmp_var)));
+ sumX2 = DatumGetByteaPP(temp);
+
+ free_var(&tmp_var);
+
+ pq_begintypsend(&buf);
+
+ /* N */
+ pq_sendint64(&buf, state->N);
+
+ /* sumX */
+ pq_sendbytes(&buf, VARDATA_ANY(sumX), VARSIZE_ANY_EXHDR(sumX));
+
+ /* sumX2 */
+ pq_sendbytes(&buf, VARDATA_ANY(sumX2), VARSIZE_ANY_EXHDR(sumX2));
+
+ /* maxScale */
+ pq_sendint32(&buf, state->maxScale);
+
+ /* maxScaleCount */
+ pq_sendint64(&buf, state->maxScaleCount);
+
+ /* NaNcount */
+ pq_sendint64(&buf, state->NaNcount);
+
+ /* pInfcount */
+ pq_sendint64(&buf, state->pInfcount);
+
+ /* nInfcount */
+ pq_sendint64(&buf, state->nInfcount);
+
+ result = pq_endtypsend(&buf);
+
+ PG_RETURN_BYTEA_P(result);
+}
+
+/*
+ * numeric_deserialize
+ * Deserialization function for NumericAggState for numeric aggregates that
+ * require sumX2.
+ */
+Datum
+numeric_deserialize(PG_FUNCTION_ARGS)
+{
+ bytea *sstate;
+ NumericAggState *result;
+ Datum temp;
+ NumericVar sumX_var;
+ NumericVar sumX2_var;
+ StringInfoData buf;
+
+ if (!AggCheckCallContext(fcinfo, NULL))
+ elog(ERROR, "aggregate function called in non-aggregate context");
+
+ sstate = PG_GETARG_BYTEA_PP(0);
+
+ /*
+ * Copy the bytea into a StringInfo so that we can "receive" it using the
+ * standard recv-function infrastructure.
+ */
+ initStringInfo(&buf);
+ appendBinaryStringInfo(&buf,
+ VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
+
+ result = makeNumericAggStateCurrentContext(false);
+
+ /* N */
+ result->N = pq_getmsgint64(&buf);
+
+ /* sumX */
+ temp = DirectFunctionCall3(numeric_recv,
+ PointerGetDatum(&buf),
+ ObjectIdGetDatum(InvalidOid),
+ Int32GetDatum(-1));
+ init_var_from_num(DatumGetNumeric(temp), &sumX_var);
+ accum_sum_add(&(result->sumX), &sumX_var);
+
+ /* sumX2 */
+ temp = DirectFunctionCall3(numeric_recv,
+ PointerGetDatum(&buf),
+ ObjectIdGetDatum(InvalidOid),
+ Int32GetDatum(-1));
+ init_var_from_num(DatumGetNumeric(temp), &sumX2_var);
+ accum_sum_add(&(result->sumX2), &sumX2_var);
+
+ /* maxScale */
+ result->maxScale = pq_getmsgint(&buf, 4);
+
+ /* maxScaleCount */
+ result->maxScaleCount = pq_getmsgint64(&buf);
+
+ /* NaNcount */
+ result->NaNcount = pq_getmsgint64(&buf);
+
+ /* pInfcount */
+ result->pInfcount = pq_getmsgint64(&buf);
+
+ /* nInfcount */
+ result->nInfcount = pq_getmsgint64(&buf);
+
+ pq_getmsgend(&buf);
+ pfree(buf.data);
+
+ PG_RETURN_POINTER(result);
+}
+
+/*
+ * Generic inverse transition function for numeric aggregates
+ * (with or without requirement for X^2).
+ */
+Datum
+numeric_accum_inv(PG_FUNCTION_ARGS)
+{
+ NumericAggState *state;
+
+ state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+ /* Should not get here with no state */
+ if (state == NULL)
+ elog(ERROR, "numeric_accum_inv called with NULL state");
+
+ if (!PG_ARGISNULL(1))
+ {
+ /* If we fail to perform the inverse transition, return NULL */
+ if (!do_numeric_discard(state, PG_GETARG_NUMERIC(1)))
+ PG_RETURN_NULL();
+ }
+
+ PG_RETURN_POINTER(state);
+}
+
+
+/*
+ * Integer data types in general use Numeric accumulators to share code
+ * and avoid risk of overflow.
+ *
+ * However for performance reasons optimized special-purpose accumulator
+ * routines are used when possible.
+ *
+ * On platforms with 128-bit integer support, the 128-bit routines will be
+ * used when sum(X) or sum(X*X) fit into 128-bit.
+ *
+ * For 16 and 32 bit inputs, the N and sum(X) fit into 64-bit so the 64-bit
+ * accumulators will be used for SUM and AVG of these data types.
+ */
+
+#ifdef HAVE_INT128
+typedef struct Int128AggState
+{
+ bool calcSumX2; /* if true, calculate sumX2 */
+ int64 N; /* count of processed numbers */
+ int128 sumX; /* sum of processed numbers */
+ int128 sumX2; /* sum of squares of processed numbers */
+} Int128AggState;
+
+/*
+ * Prepare state data for a 128-bit aggregate function that needs to compute
+ * sum, count and optionally sum of squares of the input.
+ */
+static Int128AggState *
+makeInt128AggState(FunctionCallInfo fcinfo, bool calcSumX2)
+{
+ Int128AggState *state;
+ MemoryContext agg_context;
+ MemoryContext old_context;
+
+ if (!AggCheckCallContext(fcinfo, &agg_context))
+ elog(ERROR, "aggregate function called in non-aggregate context");
+
+ old_context = MemoryContextSwitchTo(agg_context);
+
+ state = (Int128AggState *) palloc0(sizeof(Int128AggState));
+ state->calcSumX2 = calcSumX2;
+
+ MemoryContextSwitchTo(old_context);
+
+ return state;
+}
+
+/*
+ * Like makeInt128AggState(), but allocate the state in the current memory
+ * context.
+ */
+static Int128AggState *
+makeInt128AggStateCurrentContext(bool calcSumX2)
+{
+ Int128AggState *state;
+
+ state = (Int128AggState *) palloc0(sizeof(Int128AggState));
+ state->calcSumX2 = calcSumX2;
+
+ return state;
+}
+
+/*
+ * Accumulate a new input value for 128-bit aggregate functions.
+ */
+static void
+do_int128_accum(Int128AggState *state, int128 newval)
+{
+ if (state->calcSumX2)
+ state->sumX2 += newval * newval;
+
+ state->sumX += newval;
+ state->N++;
+}
+
+/*
+ * Remove an input value from the aggregated state.
+ */
+static void
+do_int128_discard(Int128AggState *state, int128 newval)
+{
+ if (state->calcSumX2)
+ state->sumX2 -= newval * newval;
+
+ state->sumX -= newval;
+ state->N--;
+}
+
+typedef Int128AggState PolyNumAggState;
+#define makePolyNumAggState makeInt128AggState
+#define makePolyNumAggStateCurrentContext makeInt128AggStateCurrentContext
+#else
+typedef NumericAggState PolyNumAggState;
+#define makePolyNumAggState makeNumericAggState
+#define makePolyNumAggStateCurrentContext makeNumericAggStateCurrentContext
+#endif
+
+Datum
+int2_accum(PG_FUNCTION_ARGS)
+{
+ PolyNumAggState *state;
+
+ state = PG_ARGISNULL(0) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(0);
+
+ /* Create the state data on the first call */
+ if (state == NULL)
+ state = makePolyNumAggState(fcinfo, true);
+
+ if (!PG_ARGISNULL(1))
+ {
+#ifdef HAVE_INT128
+ do_int128_accum(state, (int128) PG_GETARG_INT16(1));
+#else
+ do_numeric_accum(state, int64_to_numeric(PG_GETARG_INT16(1)));
+#endif
+ }
+
+ PG_RETURN_POINTER(state);
+}
+
+Datum
+int4_accum(PG_FUNCTION_ARGS)
+{
+ PolyNumAggState *state;
+
+ state = PG_ARGISNULL(0) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(0);
+
+ /* Create the state data on the first call */
+ if (state == NULL)
+ state = makePolyNumAggState(fcinfo, true);
+
+ if (!PG_ARGISNULL(1))
+ {
+#ifdef HAVE_INT128
+ do_int128_accum(state, (int128) PG_GETARG_INT32(1));
+#else
+ do_numeric_accum(state, int64_to_numeric(PG_GETARG_INT32(1)));
+#endif
+ }
+
+ PG_RETURN_POINTER(state);
+}
+
+Datum
+int8_accum(PG_FUNCTION_ARGS)
+{
+ NumericAggState *state;
+
+ state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+ /* Create the state data on the first call */
+ if (state == NULL)
+ state = makeNumericAggState(fcinfo, true);
+
+ if (!PG_ARGISNULL(1))
+ do_numeric_accum(state, int64_to_numeric(PG_GETARG_INT64(1)));
+
+ PG_RETURN_POINTER(state);
+}
+
+/*
+ * Combine function for numeric aggregates which require sumX2
+ */
+Datum
+numeric_poly_combine(PG_FUNCTION_ARGS)
+{
+ PolyNumAggState *state1;
+ PolyNumAggState *state2;
+ MemoryContext agg_context;
+ MemoryContext old_context;
+
+ if (!AggCheckCallContext(fcinfo, &agg_context))
+ elog(ERROR, "aggregate function called in non-aggregate context");
+
+ state1 = PG_ARGISNULL(0) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(0);
+ state2 = PG_ARGISNULL(1) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(1);
+
+ if (state2 == NULL)
+ PG_RETURN_POINTER(state1);
+
+ /* manually copy all fields from state2 to state1 */
+ if (state1 == NULL)
+ {
+ old_context = MemoryContextSwitchTo(agg_context);
+
+ state1 = makePolyNumAggState(fcinfo, true);
+ state1->N = state2->N;
+
+#ifdef HAVE_INT128
+ state1->sumX = state2->sumX;
+ state1->sumX2 = state2->sumX2;
+#else
+ accum_sum_copy(&state1->sumX, &state2->sumX);
+ accum_sum_copy(&state1->sumX2, &state2->sumX2);
+#endif
+
+ MemoryContextSwitchTo(old_context);
+
+ PG_RETURN_POINTER(state1);
+ }
+
+ if (state2->N > 0)
+ {
+ state1->N += state2->N;
+
+#ifdef HAVE_INT128
+ state1->sumX += state2->sumX;
+ state1->sumX2 += state2->sumX2;
+#else
+ /* The rest of this needs to work in the aggregate context */
+ old_context = MemoryContextSwitchTo(agg_context);
+
+ /* Accumulate sums */
+ accum_sum_combine(&state1->sumX, &state2->sumX);
+ accum_sum_combine(&state1->sumX2, &state2->sumX2);
+
+ MemoryContextSwitchTo(old_context);
+#endif
+
+ }
+ PG_RETURN_POINTER(state1);
+}
+
+/*
+ * numeric_poly_serialize
+ * Serialize PolyNumAggState into bytea for aggregate functions which
+ * require sumX2.
+ */
+Datum
+numeric_poly_serialize(PG_FUNCTION_ARGS)
+{
+ PolyNumAggState *state;
+ StringInfoData buf;
+ bytea *sumX;
+ bytea *sumX2;
+ bytea *result;
+
+ /* Ensure we disallow calling when not in aggregate context */
+ if (!AggCheckCallContext(fcinfo, NULL))
+ elog(ERROR, "aggregate function called in non-aggregate context");
+
+ state = (PolyNumAggState *) PG_GETARG_POINTER(0);
+
+ /*
+ * If the platform supports int128 then sumX and sumX2 will be a 128 bit
+ * integer type. Here we'll convert that into a numeric type so that the
+ * combine state is in the same format for both int128 enabled machines
+ * and machines which don't support that type. The logic here is that one
+ * day we might like to send these over to another server for further
+ * processing and we want a standard format to work with.
+ */
+ {
+ Datum temp;
+ NumericVar num;
+
+ init_var(&num);
+
+#ifdef HAVE_INT128
+ int128_to_numericvar(state->sumX, &num);
+#else
+ accum_sum_final(&state->sumX, &num);
+#endif
+ temp = DirectFunctionCall1(numeric_send,
+ NumericGetDatum(make_result(&num)));
+ sumX = DatumGetByteaPP(temp);
+
+#ifdef HAVE_INT128
+ int128_to_numericvar(state->sumX2, &num);
+#else
+ accum_sum_final(&state->sumX2, &num);
+#endif
+ temp = DirectFunctionCall1(numeric_send,
+ NumericGetDatum(make_result(&num)));
+ sumX2 = DatumGetByteaPP(temp);
+
+ free_var(&num);
+ }
+
+ pq_begintypsend(&buf);
+
+ /* N */
+ pq_sendint64(&buf, state->N);
+
+ /* sumX */
+ pq_sendbytes(&buf, VARDATA_ANY(sumX), VARSIZE_ANY_EXHDR(sumX));
+
+ /* sumX2 */
+ pq_sendbytes(&buf, VARDATA_ANY(sumX2), VARSIZE_ANY_EXHDR(sumX2));
+
+ result = pq_endtypsend(&buf);
+
+ PG_RETURN_BYTEA_P(result);
+}
+
+/*
+ * numeric_poly_deserialize
+ * Deserialize PolyNumAggState from bytea for aggregate functions which
+ * require sumX2.
+ */
+Datum
+numeric_poly_deserialize(PG_FUNCTION_ARGS)
+{
+ bytea *sstate;
+ PolyNumAggState *result;
+ Datum sumX;
+ NumericVar sumX_var;
+ Datum sumX2;
+ NumericVar sumX2_var;
+ StringInfoData buf;
+
+ if (!AggCheckCallContext(fcinfo, NULL))
+ elog(ERROR, "aggregate function called in non-aggregate context");
+
+ sstate = PG_GETARG_BYTEA_PP(0);
+
+ /*
+ * Copy the bytea into a StringInfo so that we can "receive" it using the
+ * standard recv-function infrastructure.
+ */
+ initStringInfo(&buf);
+ appendBinaryStringInfo(&buf,
+ VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
+
+ result = makePolyNumAggStateCurrentContext(false);
+
+ /* N */
+ result->N = pq_getmsgint64(&buf);
+
+ /* sumX */
+ sumX = DirectFunctionCall3(numeric_recv,
+ PointerGetDatum(&buf),
+ ObjectIdGetDatum(InvalidOid),
+ Int32GetDatum(-1));
+
+ /* sumX2 */
+ sumX2 = DirectFunctionCall3(numeric_recv,
+ PointerGetDatum(&buf),
+ ObjectIdGetDatum(InvalidOid),
+ Int32GetDatum(-1));
+
+ init_var_from_num(DatumGetNumeric(sumX), &sumX_var);
+#ifdef HAVE_INT128
+ numericvar_to_int128(&sumX_var, &result->sumX);
+#else
+ accum_sum_add(&result->sumX, &sumX_var);
+#endif
+
+ init_var_from_num(DatumGetNumeric(sumX2), &sumX2_var);
+#ifdef HAVE_INT128
+ numericvar_to_int128(&sumX2_var, &result->sumX2);
+#else
+ accum_sum_add(&result->sumX2, &sumX2_var);
+#endif
+
+ pq_getmsgend(&buf);
+ pfree(buf.data);
+
+ PG_RETURN_POINTER(result);
+}
+
+/*
+ * Transition function for int8 input when we don't need sumX2.
+ */
+Datum
+int8_avg_accum(PG_FUNCTION_ARGS)
+{
+ PolyNumAggState *state;
+
+ state = PG_ARGISNULL(0) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(0);
+
+ /* Create the state data on the first call */
+ if (state == NULL)
+ state = makePolyNumAggState(fcinfo, false);
+
+ if (!PG_ARGISNULL(1))
+ {
+#ifdef HAVE_INT128
+ do_int128_accum(state, (int128) PG_GETARG_INT64(1));
+#else
+ do_numeric_accum(state, int64_to_numeric(PG_GETARG_INT64(1)));
+#endif
+ }
+
+ PG_RETURN_POINTER(state);
+}
+
+/*
+ * Combine function for PolyNumAggState for aggregates which don't require
+ * sumX2
+ */
+Datum
+int8_avg_combine(PG_FUNCTION_ARGS)
+{
+ PolyNumAggState *state1;
+ PolyNumAggState *state2;
+ MemoryContext agg_context;
+ MemoryContext old_context;
+
+ if (!AggCheckCallContext(fcinfo, &agg_context))
+ elog(ERROR, "aggregate function called in non-aggregate context");
+
+ state1 = PG_ARGISNULL(0) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(0);
+ state2 = PG_ARGISNULL(1) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(1);
+
+ if (state2 == NULL)
+ PG_RETURN_POINTER(state1);
+
+ /* manually copy all fields from state2 to state1 */
+ if (state1 == NULL)
+ {
+ old_context = MemoryContextSwitchTo(agg_context);
+
+ state1 = makePolyNumAggState(fcinfo, false);
+ state1->N = state2->N;
+
+#ifdef HAVE_INT128
+ state1->sumX = state2->sumX;
+#else
+ accum_sum_copy(&state1->sumX, &state2->sumX);
+#endif
+ MemoryContextSwitchTo(old_context);
+
+ PG_RETURN_POINTER(state1);
+ }
+
+ if (state2->N > 0)
+ {
+ state1->N += state2->N;
+
+#ifdef HAVE_INT128
+ state1->sumX += state2->sumX;
+#else
+ /* The rest of this needs to work in the aggregate context */
+ old_context = MemoryContextSwitchTo(agg_context);
+
+ /* Accumulate sums */
+ accum_sum_combine(&state1->sumX, &state2->sumX);
+
+ MemoryContextSwitchTo(old_context);
+#endif
+
+ }
+ PG_RETURN_POINTER(state1);
+}
+
+/*
+ * int8_avg_serialize
+ * Serialize PolyNumAggState into bytea using the standard
+ * recv-function infrastructure.
+ */
+Datum
+int8_avg_serialize(PG_FUNCTION_ARGS)
+{
+ PolyNumAggState *state;
+ StringInfoData buf;
+ bytea *sumX;
+ bytea *result;
+
+ /* Ensure we disallow calling when not in aggregate context */
+ if (!AggCheckCallContext(fcinfo, NULL))
+ elog(ERROR, "aggregate function called in non-aggregate context");
+
+ state = (PolyNumAggState *) PG_GETARG_POINTER(0);
+
+ /*
+ * If the platform supports int128 then sumX will be a 128 integer type.
+ * Here we'll convert that into a numeric type so that the combine state
+ * is in the same format for both int128 enabled machines and machines
+ * which don't support that type. The logic here is that one day we might
+ * like to send these over to another server for further processing and we
+ * want a standard format to work with.
+ */
+ {
+ Datum temp;
+ NumericVar num;
+
+ init_var(&num);
+
+#ifdef HAVE_INT128
+ int128_to_numericvar(state->sumX, &num);
+#else
+ accum_sum_final(&state->sumX, &num);
+#endif
+ temp = DirectFunctionCall1(numeric_send,
+ NumericGetDatum(make_result(&num)));
+ sumX = DatumGetByteaPP(temp);
+
+ free_var(&num);
+ }
+
+ pq_begintypsend(&buf);
+
+ /* N */
+ pq_sendint64(&buf, state->N);
+
+ /* sumX */
+ pq_sendbytes(&buf, VARDATA_ANY(sumX), VARSIZE_ANY_EXHDR(sumX));
+
+ result = pq_endtypsend(&buf);
+
+ PG_RETURN_BYTEA_P(result);
+}
+
+/*
+ * int8_avg_deserialize
+ * Deserialize bytea back into PolyNumAggState.
+ */
+Datum
+int8_avg_deserialize(PG_FUNCTION_ARGS)
+{
+ bytea *sstate;
+ PolyNumAggState *result;
+ StringInfoData buf;
+ Datum temp;
+ NumericVar num;
+
+ if (!AggCheckCallContext(fcinfo, NULL))
+ elog(ERROR, "aggregate function called in non-aggregate context");
+
+ sstate = PG_GETARG_BYTEA_PP(0);
+
+ /*
+ * Copy the bytea into a StringInfo so that we can "receive" it using the
+ * standard recv-function infrastructure.
+ */
+ initStringInfo(&buf);
+ appendBinaryStringInfo(&buf,
+ VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
+
+ result = makePolyNumAggStateCurrentContext(false);
+
+ /* N */
+ result->N = pq_getmsgint64(&buf);
+
+ /* sumX */
+ temp = DirectFunctionCall3(numeric_recv,
+ PointerGetDatum(&buf),
+ ObjectIdGetDatum(InvalidOid),
+ Int32GetDatum(-1));
+ init_var_from_num(DatumGetNumeric(temp), &num);
+#ifdef HAVE_INT128
+ numericvar_to_int128(&num, &result->sumX);
+#else
+ accum_sum_add(&result->sumX, &num);
+#endif
+
+ pq_getmsgend(&buf);
+ pfree(buf.data);
+
+ PG_RETURN_POINTER(result);
+}
+
+/*
+ * Inverse transition functions to go with the above.
+ */
+
+Datum
+int2_accum_inv(PG_FUNCTION_ARGS)
+{
+ PolyNumAggState *state;
+
+ state = PG_ARGISNULL(0) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(0);
+
+ /* Should not get here with no state */
+ if (state == NULL)
+ elog(ERROR, "int2_accum_inv called with NULL state");
+
+ if (!PG_ARGISNULL(1))
+ {
+#ifdef HAVE_INT128
+ do_int128_discard(state, (int128) PG_GETARG_INT16(1));
+#else
+ /* Should never fail, all inputs have dscale 0 */
+ if (!do_numeric_discard(state, int64_to_numeric(PG_GETARG_INT16(1))))
+ elog(ERROR, "do_numeric_discard failed unexpectedly");
+#endif
+ }
+
+ PG_RETURN_POINTER(state);
+}
+
+Datum
+int4_accum_inv(PG_FUNCTION_ARGS)
+{
+ PolyNumAggState *state;
+
+ state = PG_ARGISNULL(0) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(0);
+
+ /* Should not get here with no state */
+ if (state == NULL)
+ elog(ERROR, "int4_accum_inv called with NULL state");
+
+ if (!PG_ARGISNULL(1))
+ {
+#ifdef HAVE_INT128
+ do_int128_discard(state, (int128) PG_GETARG_INT32(1));
+#else
+ /* Should never fail, all inputs have dscale 0 */
+ if (!do_numeric_discard(state, int64_to_numeric(PG_GETARG_INT32(1))))
+ elog(ERROR, "do_numeric_discard failed unexpectedly");
+#endif
+ }
+
+ PG_RETURN_POINTER(state);
+}
+
+Datum
+int8_accum_inv(PG_FUNCTION_ARGS)
+{
+ NumericAggState *state;
+
+ state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+ /* Should not get here with no state */
+ if (state == NULL)
+ elog(ERROR, "int8_accum_inv called with NULL state");
+
+ if (!PG_ARGISNULL(1))
+ {
+ /* Should never fail, all inputs have dscale 0 */
+ if (!do_numeric_discard(state, int64_to_numeric(PG_GETARG_INT64(1))))
+ elog(ERROR, "do_numeric_discard failed unexpectedly");
+ }
+
+ PG_RETURN_POINTER(state);
+}
+
+Datum
+int8_avg_accum_inv(PG_FUNCTION_ARGS)
+{
+ PolyNumAggState *state;
+
+ state = PG_ARGISNULL(0) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(0);
+
+ /* Should not get here with no state */
+ if (state == NULL)
+ elog(ERROR, "int8_avg_accum_inv called with NULL state");
+
+ if (!PG_ARGISNULL(1))
+ {
+#ifdef HAVE_INT128
+ do_int128_discard(state, (int128) PG_GETARG_INT64(1));
+#else
+ /* Should never fail, all inputs have dscale 0 */
+ if (!do_numeric_discard(state, int64_to_numeric(PG_GETARG_INT64(1))))
+ elog(ERROR, "do_numeric_discard failed unexpectedly");
+#endif
+ }
+
+ PG_RETURN_POINTER(state);
+}
+
+Datum
+numeric_poly_sum(PG_FUNCTION_ARGS)
+{
+#ifdef HAVE_INT128
+ PolyNumAggState *state;
+ Numeric res;
+ NumericVar result;
+
+ state = PG_ARGISNULL(0) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(0);
+
+ /* If there were no non-null inputs, return NULL */
+ if (state == NULL || state->N == 0)
+ PG_RETURN_NULL();
+
+ init_var(&result);
+
+ int128_to_numericvar(state->sumX, &result);
+
+ res = make_result(&result);
+
+ free_var(&result);
+
+ PG_RETURN_NUMERIC(res);
+#else
+ return numeric_sum(fcinfo);
+#endif
+}
+
+Datum
+numeric_poly_avg(PG_FUNCTION_ARGS)
+{
+#ifdef HAVE_INT128
+ PolyNumAggState *state;
+ NumericVar result;
+ Datum countd,
+ sumd;
+
+ state = PG_ARGISNULL(0) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(0);
+
+ /* If there were no non-null inputs, return NULL */
+ if (state == NULL || state->N == 0)
+ PG_RETURN_NULL();
+
+ init_var(&result);
+
+ int128_to_numericvar(state->sumX, &result);
+
+ countd = NumericGetDatum(int64_to_numeric(state->N));
+ sumd = NumericGetDatum(make_result(&result));
+
+ free_var(&result);
+
+ PG_RETURN_DATUM(DirectFunctionCall2(numeric_div, sumd, countd));
+#else
+ return numeric_avg(fcinfo);
+#endif
+}
+
+Datum
+numeric_avg(PG_FUNCTION_ARGS)
+{
+ NumericAggState *state;
+ Datum N_datum;
+ Datum sumX_datum;
+ NumericVar sumX_var;
+
+ state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+ /* If there were no non-null inputs, return NULL */
+ if (state == NULL || NA_TOTAL_COUNT(state) == 0)
+ PG_RETURN_NULL();
+
+ if (state->NaNcount > 0) /* there was at least one NaN input */
+ PG_RETURN_NUMERIC(make_result(&const_nan));
+
+ /* adding plus and minus infinities gives NaN */
+ if (state->pInfcount > 0 && state->nInfcount > 0)
+ PG_RETURN_NUMERIC(make_result(&const_nan));
+ if (state->pInfcount > 0)
+ PG_RETURN_NUMERIC(make_result(&const_pinf));
+ if (state->nInfcount > 0)
+ PG_RETURN_NUMERIC(make_result(&const_ninf));
+
+ N_datum = NumericGetDatum(int64_to_numeric(state->N));
+
+ init_var(&sumX_var);
+ accum_sum_final(&state->sumX, &sumX_var);
+ sumX_datum = NumericGetDatum(make_result(&sumX_var));
+ free_var(&sumX_var);
+
+ PG_RETURN_DATUM(DirectFunctionCall2(numeric_div, sumX_datum, N_datum));
+}
+
+Datum
+numeric_sum(PG_FUNCTION_ARGS)
+{
+ NumericAggState *state;
+ NumericVar sumX_var;
+ Numeric result;
+
+ state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+ /* If there were no non-null inputs, return NULL */
+ if (state == NULL || NA_TOTAL_COUNT(state) == 0)
+ PG_RETURN_NULL();
+
+ if (state->NaNcount > 0) /* there was at least one NaN input */
+ PG_RETURN_NUMERIC(make_result(&const_nan));
+
+ /* adding plus and minus infinities gives NaN */
+ if (state->pInfcount > 0 && state->nInfcount > 0)
+ PG_RETURN_NUMERIC(make_result(&const_nan));
+ if (state->pInfcount > 0)
+ PG_RETURN_NUMERIC(make_result(&const_pinf));
+ if (state->nInfcount > 0)
+ PG_RETURN_NUMERIC(make_result(&const_ninf));
+
+ init_var(&sumX_var);
+ accum_sum_final(&state->sumX, &sumX_var);
+ result = make_result(&sumX_var);
+ free_var(&sumX_var);
+
+ PG_RETURN_NUMERIC(result);
+}
+
+/*
+ * Workhorse routine for the standard deviance and variance
+ * aggregates. 'state' is aggregate's transition state.
+ * 'variance' specifies whether we should calculate the
+ * variance or the standard deviation. 'sample' indicates whether the
+ * caller is interested in the sample or the population
+ * variance/stddev.
+ *
+ * If appropriate variance statistic is undefined for the input,
+ * *is_null is set to true and NULL is returned.
+ */
+static Numeric
+numeric_stddev_internal(NumericAggState *state,
+ bool variance, bool sample,
+ bool *is_null)
+{
+ Numeric res;
+ NumericVar vN,
+ vsumX,
+ vsumX2,
+ vNminus1;
+ int64 totCount;
+ int rscale;
+
+ /*
+ * Sample stddev and variance are undefined when N <= 1; population stddev
+ * is undefined when N == 0. Return NULL in either case (note that NaNs
+ * and infinities count as normal inputs for this purpose).
+ */
+ if (state == NULL || (totCount = NA_TOTAL_COUNT(state)) == 0)
+ {
+ *is_null = true;
+ return NULL;
+ }
+
+ if (sample && totCount <= 1)
+ {
+ *is_null = true;
+ return NULL;
+ }
+
+ *is_null = false;
+
+ /*
+ * Deal with NaN and infinity cases. By analogy to the behavior of the
+ * float8 functions, any infinity input produces NaN output.
+ */
+ if (state->NaNcount > 0 || state->pInfcount > 0 || state->nInfcount > 0)
+ return make_result(&const_nan);
+
+ /* OK, normal calculation applies */
+ init_var(&vN);
+ init_var(&vsumX);
+ init_var(&vsumX2);
+
+ int64_to_numericvar(state->N, &vN);
+ accum_sum_final(&(state->sumX), &vsumX);
+ accum_sum_final(&(state->sumX2), &vsumX2);
+
+ init_var(&vNminus1);
+ sub_var(&vN, &const_one, &vNminus1);
+
+ /* compute rscale for mul_var calls */
+ rscale = vsumX.dscale * 2;
+
+ mul_var(&vsumX, &vsumX, &vsumX, rscale); /* vsumX = sumX * sumX */
+ mul_var(&vN, &vsumX2, &vsumX2, rscale); /* vsumX2 = N * sumX2 */
+ sub_var(&vsumX2, &vsumX, &vsumX2); /* N * sumX2 - sumX * sumX */
+
+ if (cmp_var(&vsumX2, &const_zero) <= 0)
+ {
+ /* Watch out for roundoff error producing a negative numerator */
+ res = make_result(&const_zero);
+ }
+ else
+ {
+ if (sample)
+ mul_var(&vN, &vNminus1, &vNminus1, 0); /* N * (N - 1) */
+ else
+ mul_var(&vN, &vN, &vNminus1, 0); /* N * N */
+ rscale = select_div_scale(&vsumX2, &vNminus1);
+ div_var(&vsumX2, &vNminus1, &vsumX, rscale, true); /* variance */
+ if (!variance)
+ sqrt_var(&vsumX, &vsumX, rscale); /* stddev */
+
+ res = make_result(&vsumX);
+ }
+
+ free_var(&vNminus1);
+ free_var(&vsumX);
+ free_var(&vsumX2);
+
+ return res;
+}
+
+Datum
+numeric_var_samp(PG_FUNCTION_ARGS)
+{
+ NumericAggState *state;
+ Numeric res;
+ bool is_null;
+
+ state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+ res = numeric_stddev_internal(state, true, true, &is_null);
+
+ if (is_null)
+ PG_RETURN_NULL();
+ else
+ PG_RETURN_NUMERIC(res);
+}
+
+Datum
+numeric_stddev_samp(PG_FUNCTION_ARGS)
+{
+ NumericAggState *state;
+ Numeric res;
+ bool is_null;
+
+ state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+ res = numeric_stddev_internal(state, false, true, &is_null);
+
+ if (is_null)
+ PG_RETURN_NULL();
+ else
+ PG_RETURN_NUMERIC(res);
+}
+
+Datum
+numeric_var_pop(PG_FUNCTION_ARGS)
+{
+ NumericAggState *state;
+ Numeric res;
+ bool is_null;
+
+ state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+ res = numeric_stddev_internal(state, true, false, &is_null);
+
+ if (is_null)
+ PG_RETURN_NULL();
+ else
+ PG_RETURN_NUMERIC(res);
+}
+
+Datum
+numeric_stddev_pop(PG_FUNCTION_ARGS)
+{
+ NumericAggState *state;
+ Numeric res;
+ bool is_null;
+
+ state = PG_ARGISNULL(0) ? NULL : (NumericAggState *) PG_GETARG_POINTER(0);
+
+ res = numeric_stddev_internal(state, false, false, &is_null);
+
+ if (is_null)
+ PG_RETURN_NULL();
+ else
+ PG_RETURN_NUMERIC(res);
+}
+
+#ifdef HAVE_INT128
+static Numeric
+numeric_poly_stddev_internal(Int128AggState *state,
+ bool variance, bool sample,
+ bool *is_null)
+{
+ NumericAggState numstate;
+ Numeric res;
+
+ /* Initialize an empty agg state */
+ memset(&numstate, 0, sizeof(NumericAggState));
+
+ if (state)
+ {
+ NumericVar tmp_var;
+
+ numstate.N = state->N;
+
+ init_var(&tmp_var);
+
+ int128_to_numericvar(state->sumX, &tmp_var);
+ accum_sum_add(&numstate.sumX, &tmp_var);
+
+ int128_to_numericvar(state->sumX2, &tmp_var);
+ accum_sum_add(&numstate.sumX2, &tmp_var);
+
+ free_var(&tmp_var);
+ }
+
+ res = numeric_stddev_internal(&numstate, variance, sample, is_null);
+
+ if (numstate.sumX.ndigits > 0)
+ {
+ pfree(numstate.sumX.pos_digits);
+ pfree(numstate.sumX.neg_digits);
+ }
+ if (numstate.sumX2.ndigits > 0)
+ {
+ pfree(numstate.sumX2.pos_digits);
+ pfree(numstate.sumX2.neg_digits);
+ }
+
+ return res;
+}
+#endif
+
+Datum
+numeric_poly_var_samp(PG_FUNCTION_ARGS)
+{
+#ifdef HAVE_INT128
+ PolyNumAggState *state;
+ Numeric res;
+ bool is_null;
+
+ state = PG_ARGISNULL(0) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(0);
+
+ res = numeric_poly_stddev_internal(state, true, true, &is_null);
+
+ if (is_null)
+ PG_RETURN_NULL();
+ else
+ PG_RETURN_NUMERIC(res);
+#else
+ return numeric_var_samp(fcinfo);
+#endif
+}
+
+Datum
+numeric_poly_stddev_samp(PG_FUNCTION_ARGS)
+{
+#ifdef HAVE_INT128
+ PolyNumAggState *state;
+ Numeric res;
+ bool is_null;
+
+ state = PG_ARGISNULL(0) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(0);
+
+ res = numeric_poly_stddev_internal(state, false, true, &is_null);
+
+ if (is_null)
+ PG_RETURN_NULL();
+ else
+ PG_RETURN_NUMERIC(res);
+#else
+ return numeric_stddev_samp(fcinfo);
+#endif
+}
+
+Datum
+numeric_poly_var_pop(PG_FUNCTION_ARGS)
+{
+#ifdef HAVE_INT128
+ PolyNumAggState *state;
+ Numeric res;
+ bool is_null;
+
+ state = PG_ARGISNULL(0) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(0);
+
+ res = numeric_poly_stddev_internal(state, true, false, &is_null);
+
+ if (is_null)
+ PG_RETURN_NULL();
+ else
+ PG_RETURN_NUMERIC(res);
+#else
+ return numeric_var_pop(fcinfo);
+#endif
+}
+
+Datum
+numeric_poly_stddev_pop(PG_FUNCTION_ARGS)
+{
+#ifdef HAVE_INT128
+ PolyNumAggState *state;
+ Numeric res;
+ bool is_null;
+
+ state = PG_ARGISNULL(0) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(0);
+
+ res = numeric_poly_stddev_internal(state, false, false, &is_null);
+
+ if (is_null)
+ PG_RETURN_NULL();
+ else
+ PG_RETURN_NUMERIC(res);
+#else
+ return numeric_stddev_pop(fcinfo);
+#endif
+}
+
+/*
+ * SUM transition functions for integer datatypes.
+ *
+ * To avoid overflow, we use accumulators wider than the input datatype.
+ * A Numeric accumulator is needed for int8 input; for int4 and int2
+ * inputs, we use int8 accumulators which should be sufficient for practical
+ * purposes. (The latter two therefore don't really belong in this file,
+ * but we keep them here anyway.)
+ *
+ * Because SQL defines the SUM() of no values to be NULL, not zero,
+ * the initial condition of the transition data value needs to be NULL. This
+ * means we can't rely on ExecAgg to automatically insert the first non-null
+ * data value into the transition data: it doesn't know how to do the type
+ * conversion. The upshot is that these routines have to be marked non-strict
+ * and handle substitution of the first non-null input themselves.
+ *
+ * Note: these functions are used only in plain aggregation mode.
+ * In moving-aggregate mode, we use intX_avg_accum and intX_avg_accum_inv.
+ */
+
+Datum
+int2_sum(PG_FUNCTION_ARGS)
+{
+ int64 newval;
+
+ if (PG_ARGISNULL(0))
+ {
+ /* No non-null input seen so far... */
+ if (PG_ARGISNULL(1))
+ PG_RETURN_NULL(); /* still no non-null */
+ /* This is the first non-null input. */
+ newval = (int64) PG_GETARG_INT16(1);
+ PG_RETURN_INT64(newval);
+ }
+
+ /*
+ * If we're invoked as an aggregate, we can cheat and modify our first
+ * parameter in-place to avoid palloc overhead. If not, we need to return
+ * the new value of the transition variable. (If int8 is pass-by-value,
+ * then of course this is useless as well as incorrect, so just ifdef it
+ * out.)
+ */
+#ifndef USE_FLOAT8_BYVAL /* controls int8 too */
+ if (AggCheckCallContext(fcinfo, NULL))
+ {
+ int64 *oldsum = (int64 *) PG_GETARG_POINTER(0);
+
+ /* Leave the running sum unchanged in the new input is null */
+ if (!PG_ARGISNULL(1))
+ *oldsum = *oldsum + (int64) PG_GETARG_INT16(1);
+
+ PG_RETURN_POINTER(oldsum);
+ }
+ else
+#endif
+ {
+ int64 oldsum = PG_GETARG_INT64(0);
+
+ /* Leave sum unchanged if new input is null. */
+ if (PG_ARGISNULL(1))
+ PG_RETURN_INT64(oldsum);
+
+ /* OK to do the addition. */
+ newval = oldsum + (int64) PG_GETARG_INT16(1);
+
+ PG_RETURN_INT64(newval);
+ }
+}
+
+Datum
+int4_sum(PG_FUNCTION_ARGS)
+{
+ int64 newval;
+
+ if (PG_ARGISNULL(0))
+ {
+ /* No non-null input seen so far... */
+ if (PG_ARGISNULL(1))
+ PG_RETURN_NULL(); /* still no non-null */
+ /* This is the first non-null input. */
+ newval = (int64) PG_GETARG_INT32(1);
+ PG_RETURN_INT64(newval);
+ }
+
+ /*
+ * If we're invoked as an aggregate, we can cheat and modify our first
+ * parameter in-place to avoid palloc overhead. If not, we need to return
+ * the new value of the transition variable. (If int8 is pass-by-value,
+ * then of course this is useless as well as incorrect, so just ifdef it
+ * out.)
+ */
+#ifndef USE_FLOAT8_BYVAL /* controls int8 too */
+ if (AggCheckCallContext(fcinfo, NULL))
+ {
+ int64 *oldsum = (int64 *) PG_GETARG_POINTER(0);
+
+ /* Leave the running sum unchanged in the new input is null */
+ if (!PG_ARGISNULL(1))
+ *oldsum = *oldsum + (int64) PG_GETARG_INT32(1);
+
+ PG_RETURN_POINTER(oldsum);
+ }
+ else
+#endif
+ {
+ int64 oldsum = PG_GETARG_INT64(0);
+
+ /* Leave sum unchanged if new input is null. */
+ if (PG_ARGISNULL(1))
+ PG_RETURN_INT64(oldsum);
+
+ /* OK to do the addition. */
+ newval = oldsum + (int64) PG_GETARG_INT32(1);
+
+ PG_RETURN_INT64(newval);
+ }
+}
+
+/*
+ * Note: this function is obsolete, it's no longer used for SUM(int8).
+ */
+Datum
+int8_sum(PG_FUNCTION_ARGS)
+{
+ Numeric oldsum;
+
+ if (PG_ARGISNULL(0))
+ {
+ /* No non-null input seen so far... */
+ if (PG_ARGISNULL(1))
+ PG_RETURN_NULL(); /* still no non-null */
+ /* This is the first non-null input. */
+ PG_RETURN_NUMERIC(int64_to_numeric(PG_GETARG_INT64(1)));
+ }
+
+ /*
+ * Note that we cannot special-case the aggregate case here, as we do for
+ * int2_sum and int4_sum: numeric is of variable size, so we cannot modify
+ * our first parameter in-place.
+ */
+
+ oldsum = PG_GETARG_NUMERIC(0);
+
+ /* Leave sum unchanged if new input is null. */
+ if (PG_ARGISNULL(1))
+ PG_RETURN_NUMERIC(oldsum);
+
+ /* OK to do the addition. */
+ PG_RETURN_DATUM(DirectFunctionCall2(numeric_add,
+ NumericGetDatum(oldsum),
+ NumericGetDatum(int64_to_numeric(PG_GETARG_INT64(1)))));
+}
+
+
+/*
+ * Routines for avg(int2) and avg(int4). The transition datatype
+ * is a two-element int8 array, holding count and sum.
+ *
+ * These functions are also used for sum(int2) and sum(int4) when
+ * operating in moving-aggregate mode, since for correct inverse transitions
+ * we need to count the inputs.
+ */
+
+typedef struct Int8TransTypeData
+{
+ int64 count;
+ int64 sum;
+} Int8TransTypeData;
+
+Datum
+int2_avg_accum(PG_FUNCTION_ARGS)
+{
+ ArrayType *transarray;
+ int16 newval = PG_GETARG_INT16(1);
+ Int8TransTypeData *transdata;
+
+ /*
+ * If we're invoked as an aggregate, we can cheat and modify our first
+ * parameter in-place to reduce palloc overhead. Otherwise we need to make
+ * a copy of it before scribbling on it.
+ */
+ if (AggCheckCallContext(fcinfo, NULL))
+ transarray = PG_GETARG_ARRAYTYPE_P(0);
+ else
+ transarray = PG_GETARG_ARRAYTYPE_P_COPY(0);
+
+ if (ARR_HASNULL(transarray) ||
+ ARR_SIZE(transarray) != ARR_OVERHEAD_NONULLS(1) + sizeof(Int8TransTypeData))
+ elog(ERROR, "expected 2-element int8 array");
+
+ transdata = (Int8TransTypeData *) ARR_DATA_PTR(transarray);
+ transdata->count++;
+ transdata->sum += newval;
+
+ PG_RETURN_ARRAYTYPE_P(transarray);
+}
+
+Datum
+int4_avg_accum(PG_FUNCTION_ARGS)
+{
+ ArrayType *transarray;
+ int32 newval = PG_GETARG_INT32(1);
+ Int8TransTypeData *transdata;
+
+ /*
+ * If we're invoked as an aggregate, we can cheat and modify our first
+ * parameter in-place to reduce palloc overhead. Otherwise we need to make
+ * a copy of it before scribbling on it.
+ */
+ if (AggCheckCallContext(fcinfo, NULL))
+ transarray = PG_GETARG_ARRAYTYPE_P(0);
+ else
+ transarray = PG_GETARG_ARRAYTYPE_P_COPY(0);
+
+ if (ARR_HASNULL(transarray) ||
+ ARR_SIZE(transarray) != ARR_OVERHEAD_NONULLS(1) + sizeof(Int8TransTypeData))
+ elog(ERROR, "expected 2-element int8 array");
+
+ transdata = (Int8TransTypeData *) ARR_DATA_PTR(transarray);
+ transdata->count++;
+ transdata->sum += newval;
+
+ PG_RETURN_ARRAYTYPE_P(transarray);
+}
+
+Datum
+int4_avg_combine(PG_FUNCTION_ARGS)
+{
+ ArrayType *transarray1;
+ ArrayType *transarray2;
+ Int8TransTypeData *state1;
+ Int8TransTypeData *state2;
+
+ if (!AggCheckCallContext(fcinfo, NULL))
+ elog(ERROR, "aggregate function called in non-aggregate context");
+
+ transarray1 = PG_GETARG_ARRAYTYPE_P(0);
+ transarray2 = PG_GETARG_ARRAYTYPE_P(1);
+
+ if (ARR_HASNULL(transarray1) ||
+ ARR_SIZE(transarray1) != ARR_OVERHEAD_NONULLS(1) + sizeof(Int8TransTypeData))
+ elog(ERROR, "expected 2-element int8 array");
+
+ if (ARR_HASNULL(transarray2) ||
+ ARR_SIZE(transarray2) != ARR_OVERHEAD_NONULLS(1) + sizeof(Int8TransTypeData))
+ elog(ERROR, "expected 2-element int8 array");
+
+ state1 = (Int8TransTypeData *) ARR_DATA_PTR(transarray1);
+ state2 = (Int8TransTypeData *) ARR_DATA_PTR(transarray2);
+
+ state1->count += state2->count;
+ state1->sum += state2->sum;
+
+ PG_RETURN_ARRAYTYPE_P(transarray1);
+}
+
+Datum
+int2_avg_accum_inv(PG_FUNCTION_ARGS)
+{
+ ArrayType *transarray;
+ int16 newval = PG_GETARG_INT16(1);
+ Int8TransTypeData *transdata;
+
+ /*
+ * If we're invoked as an aggregate, we can cheat and modify our first
+ * parameter in-place to reduce palloc overhead. Otherwise we need to make
+ * a copy of it before scribbling on it.
+ */
+ if (AggCheckCallContext(fcinfo, NULL))
+ transarray = PG_GETARG_ARRAYTYPE_P(0);
+ else
+ transarray = PG_GETARG_ARRAYTYPE_P_COPY(0);
+
+ if (ARR_HASNULL(transarray) ||
+ ARR_SIZE(transarray) != ARR_OVERHEAD_NONULLS(1) + sizeof(Int8TransTypeData))
+ elog(ERROR, "expected 2-element int8 array");
+
+ transdata = (Int8TransTypeData *) ARR_DATA_PTR(transarray);
+ transdata->count--;
+ transdata->sum -= newval;
+
+ PG_RETURN_ARRAYTYPE_P(transarray);
+}
+
+Datum
+int4_avg_accum_inv(PG_FUNCTION_ARGS)
+{
+ ArrayType *transarray;
+ int32 newval = PG_GETARG_INT32(1);
+ Int8TransTypeData *transdata;
+
+ /*
+ * If we're invoked as an aggregate, we can cheat and modify our first
+ * parameter in-place to reduce palloc overhead. Otherwise we need to make
+ * a copy of it before scribbling on it.
+ */
+ if (AggCheckCallContext(fcinfo, NULL))
+ transarray = PG_GETARG_ARRAYTYPE_P(0);
+ else
+ transarray = PG_GETARG_ARRAYTYPE_P_COPY(0);
+
+ if (ARR_HASNULL(transarray) ||
+ ARR_SIZE(transarray) != ARR_OVERHEAD_NONULLS(1) + sizeof(Int8TransTypeData))
+ elog(ERROR, "expected 2-element int8 array");
+
+ transdata = (Int8TransTypeData *) ARR_DATA_PTR(transarray);
+ transdata->count--;
+ transdata->sum -= newval;
+
+ PG_RETURN_ARRAYTYPE_P(transarray);
+}
+
+Datum
+int8_avg(PG_FUNCTION_ARGS)
+{
+ ArrayType *transarray = PG_GETARG_ARRAYTYPE_P(0);
+ Int8TransTypeData *transdata;
+ Datum countd,
+ sumd;
+
+ if (ARR_HASNULL(transarray) ||
+ ARR_SIZE(transarray) != ARR_OVERHEAD_NONULLS(1) + sizeof(Int8TransTypeData))
+ elog(ERROR, "expected 2-element int8 array");
+ transdata = (Int8TransTypeData *) ARR_DATA_PTR(transarray);
+
+ /* SQL defines AVG of no values to be NULL */
+ if (transdata->count == 0)
+ PG_RETURN_NULL();
+
+ countd = NumericGetDatum(int64_to_numeric(transdata->count));
+ sumd = NumericGetDatum(int64_to_numeric(transdata->sum));
+
+ PG_RETURN_DATUM(DirectFunctionCall2(numeric_div, sumd, countd));
+}
+
+/*
+ * SUM(int2) and SUM(int4) both return int8, so we can use this
+ * final function for both.
+ */
+Datum
+int2int4_sum(PG_FUNCTION_ARGS)
+{
+ ArrayType *transarray = PG_GETARG_ARRAYTYPE_P(0);
+ Int8TransTypeData *transdata;
+
+ if (ARR_HASNULL(transarray) ||
+ ARR_SIZE(transarray) != ARR_OVERHEAD_NONULLS(1) + sizeof(Int8TransTypeData))
+ elog(ERROR, "expected 2-element int8 array");
+ transdata = (Int8TransTypeData *) ARR_DATA_PTR(transarray);
+
+ /* SQL defines SUM of no values to be NULL */
+ if (transdata->count == 0)
+ PG_RETURN_NULL();
+
+ PG_RETURN_DATUM(Int64GetDatumFast(transdata->sum));
+}
+
+
+/* ----------------------------------------------------------------------
+ *
+ * Debug support
+ *
+ * ----------------------------------------------------------------------
+ */
+
+#ifdef NUMERIC_DEBUG
+
+/*
+ * dump_numeric() - Dump a value in the db storage format for debugging
+ */
+static void
+dump_numeric(const char *str, Numeric num)
+{
+ NumericDigit *digits = NUMERIC_DIGITS(num);
+ int ndigits;
+ int i;
+
+ ndigits = NUMERIC_NDIGITS(num);
+
+ printf("%s: NUMERIC w=%d d=%d ", str,
+ NUMERIC_WEIGHT(num), NUMERIC_DSCALE(num));
+ switch (NUMERIC_SIGN(num))
+ {
+ case NUMERIC_POS:
+ printf("POS");
+ break;
+ case NUMERIC_NEG:
+ printf("NEG");
+ break;
+ case NUMERIC_NAN:
+ printf("NaN");
+ break;
+ case NUMERIC_PINF:
+ printf("Infinity");
+ break;
+ case NUMERIC_NINF:
+ printf("-Infinity");
+ break;
+ default:
+ printf("SIGN=0x%x", NUMERIC_SIGN(num));
+ break;
+ }
+
+ for (i = 0; i < ndigits; i++)
+ printf(" %0*d", DEC_DIGITS, digits[i]);
+ printf("\n");
+}
+
+
+/*
+ * dump_var() - Dump a value in the variable format for debugging
+ */
+static void
+dump_var(const char *str, NumericVar *var)
+{
+ int i;
+
+ printf("%s: VAR w=%d d=%d ", str, var->weight, var->dscale);
+ switch (var->sign)
+ {
+ case NUMERIC_POS:
+ printf("POS");
+ break;
+ case NUMERIC_NEG:
+ printf("NEG");
+ break;
+ case NUMERIC_NAN:
+ printf("NaN");
+ break;
+ case NUMERIC_PINF:
+ printf("Infinity");
+ break;
+ case NUMERIC_NINF:
+ printf("-Infinity");
+ break;
+ default:
+ printf("SIGN=0x%x", var->sign);
+ break;
+ }
+
+ for (i = 0; i < var->ndigits; i++)
+ printf(" %0*d", DEC_DIGITS, var->digits[i]);
+
+ printf("\n");
+}
+#endif /* NUMERIC_DEBUG */
+
+
+/* ----------------------------------------------------------------------
+ *
+ * Local functions follow
+ *
+ * In general, these do not support "special" (NaN or infinity) inputs;
+ * callers should handle those possibilities first.
+ * (There are one or two exceptions, noted in their header comments.)
+ *
+ * ----------------------------------------------------------------------
+ */
+
+
+/*
+ * alloc_var() -
+ *
+ * Allocate a digit buffer of ndigits digits (plus a spare digit for rounding)
+ */
+static void
+alloc_var(NumericVar *var, int ndigits)
+{
+ digitbuf_free(var->buf);
+ var->buf = digitbuf_alloc(ndigits + 1);
+ var->buf[0] = 0; /* spare digit for rounding */
+ var->digits = var->buf + 1;
+ var->ndigits = ndigits;
+}
+
+
+/*
+ * free_var() -
+ *
+ * Return the digit buffer of a variable to the free pool
+ */
+static void
+free_var(NumericVar *var)
+{
+ digitbuf_free(var->buf);
+ var->buf = NULL;
+ var->digits = NULL;
+ var->sign = NUMERIC_NAN;
+}
+
+
+/*
+ * zero_var() -
+ *
+ * Set a variable to ZERO.
+ * Note: its dscale is not touched.
+ */
+static void
+zero_var(NumericVar *var)
+{
+ digitbuf_free(var->buf);
+ var->buf = NULL;
+ var->digits = NULL;
+ var->ndigits = 0;
+ var->weight = 0; /* by convention; doesn't really matter */
+ var->sign = NUMERIC_POS; /* anything but NAN... */
+}
+
+
+/*
+ * set_var_from_str()
+ *
+ * Parse a string and put the number into a variable
+ *
+ * This function does not handle leading or trailing spaces. It returns
+ * the end+1 position parsed, so that caller can check for trailing
+ * spaces/garbage if deemed necessary.
+ *
+ * cp is the place to actually start parsing; str is what to use in error
+ * reports. (Typically cp would be the same except advanced over spaces.)
+ */
+static const char *
+set_var_from_str(const char *str, const char *cp, NumericVar *dest)
+{
+ bool have_dp = false;
+ int i;
+ unsigned char *decdigits;
+ int sign = NUMERIC_POS;
+ int dweight = -1;
+ int ddigits;
+ int dscale = 0;
+ int weight;
+ int ndigits;
+ int offset;
+ NumericDigit *digits;
+
+ /*
+ * We first parse the string to extract decimal digits and determine the
+ * correct decimal weight. Then convert to NBASE representation.
+ */
+ switch (*cp)
+ {
+ case '+':
+ sign = NUMERIC_POS;
+ cp++;
+ break;
+
+ case '-':
+ sign = NUMERIC_NEG;
+ cp++;
+ break;
+ }
+
+ if (*cp == '.')
+ {
+ have_dp = true;
+ cp++;
+ }
+
+ if (!isdigit((unsigned char) *cp))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ errmsg("invalid input syntax for type %s: \"%s\"",
+ "numeric", str)));
+
+ decdigits = (unsigned char *) palloc(strlen(cp) + DEC_DIGITS * 2);
+
+ /* leading padding for digit alignment later */
+ memset(decdigits, 0, DEC_DIGITS);
+ i = DEC_DIGITS;
+
+ while (*cp)
+ {
+ if (isdigit((unsigned char) *cp))
+ {
+ decdigits[i++] = *cp++ - '0';
+ if (!have_dp)
+ dweight++;
+ else
+ dscale++;
+ }
+ else if (*cp == '.')
+ {
+ if (have_dp)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ errmsg("invalid input syntax for type %s: \"%s\"",
+ "numeric", str)));
+ have_dp = true;
+ cp++;
+ }
+ else
+ break;
+ }
+
+ ddigits = i - DEC_DIGITS;
+ /* trailing padding for digit alignment later */
+ memset(decdigits + i, 0, DEC_DIGITS - 1);
+
+ /* Handle exponent, if any */
+ if (*cp == 'e' || *cp == 'E')
+ {
+ long exponent;
+ char *endptr;
+
+ cp++;
+ exponent = strtol(cp, &endptr, 10);
+ if (endptr == cp)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ errmsg("invalid input syntax for type %s: \"%s\"",
+ "numeric", str)));
+ cp = endptr;
+
+ /*
+ * At this point, dweight and dscale can't be more than about
+ * INT_MAX/2 due to the MaxAllocSize limit on string length, so
+ * constraining the exponent similarly should be enough to prevent
+ * integer overflow in this function. If the value is too large to
+ * fit in storage format, make_result() will complain about it later;
+ * for consistency use the same ereport errcode/text as make_result().
+ */
+ if (exponent >= INT_MAX / 2 || exponent <= -(INT_MAX / 2))
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("value overflows numeric format")));
+ dweight += (int) exponent;
+ dscale -= (int) exponent;
+ if (dscale < 0)
+ dscale = 0;
+ }
+
+ /*
+ * Okay, convert pure-decimal representation to base NBASE. First we need
+ * to determine the converted weight and ndigits. offset is the number of
+ * decimal zeroes to insert before the first given digit to have a
+ * correctly aligned first NBASE digit.
+ */
+ if (dweight >= 0)
+ weight = (dweight + 1 + DEC_DIGITS - 1) / DEC_DIGITS - 1;
+ else
+ weight = -((-dweight - 1) / DEC_DIGITS + 1);
+ offset = (weight + 1) * DEC_DIGITS - (dweight + 1);
+ ndigits = (ddigits + offset + DEC_DIGITS - 1) / DEC_DIGITS;
+
+ alloc_var(dest, ndigits);
+ dest->sign = sign;
+ dest->weight = weight;
+ dest->dscale = dscale;
+
+ i = DEC_DIGITS - offset;
+ digits = dest->digits;
+
+ while (ndigits-- > 0)
+ {
+#if DEC_DIGITS == 4
+ *digits++ = ((decdigits[i] * 10 + decdigits[i + 1]) * 10 +
+ decdigits[i + 2]) * 10 + decdigits[i + 3];
+#elif DEC_DIGITS == 2
+ *digits++ = decdigits[i] * 10 + decdigits[i + 1];
+#elif DEC_DIGITS == 1
+ *digits++ = decdigits[i];
+#else
+#error unsupported NBASE
+#endif
+ i += DEC_DIGITS;
+ }
+
+ pfree(decdigits);
+
+ /* Strip any leading/trailing zeroes, and normalize weight if zero */
+ strip_var(dest);
+
+ /* Return end+1 position for caller */
+ return cp;
+}
+
+
+/*
+ * set_var_from_num() -
+ *
+ * Convert the packed db format into a variable
+ */
+static void
+set_var_from_num(Numeric num, NumericVar *dest)
+{
+ int ndigits;
+
+ ndigits = NUMERIC_NDIGITS(num);
+
+ alloc_var(dest, ndigits);
+
+ dest->weight = NUMERIC_WEIGHT(num);
+ dest->sign = NUMERIC_SIGN(num);
+ dest->dscale = NUMERIC_DSCALE(num);
+
+ memcpy(dest->digits, NUMERIC_DIGITS(num), ndigits * sizeof(NumericDigit));
+}
+
+
+/*
+ * init_var_from_num() -
+ *
+ * Initialize a variable from packed db format. The digits array is not
+ * copied, which saves some cycles when the resulting var is not modified.
+ * Also, there's no need to call free_var(), as long as you don't assign any
+ * other value to it (with set_var_* functions, or by using the var as the
+ * destination of a function like add_var())
+ *
+ * CAUTION: Do not modify the digits buffer of a var initialized with this
+ * function, e.g by calling round_var() or trunc_var(), as the changes will
+ * propagate to the original Numeric! It's OK to use it as the destination
+ * argument of one of the calculational functions, though.
+ */
+static void
+init_var_from_num(Numeric num, NumericVar *dest)
+{
+ dest->ndigits = NUMERIC_NDIGITS(num);
+ dest->weight = NUMERIC_WEIGHT(num);
+ dest->sign = NUMERIC_SIGN(num);
+ dest->dscale = NUMERIC_DSCALE(num);
+ dest->digits = NUMERIC_DIGITS(num);
+ dest->buf = NULL; /* digits array is not palloc'd */
+}
+
+
+/*
+ * set_var_from_var() -
+ *
+ * Copy one variable into another
+ */
+static void
+set_var_from_var(const NumericVar *value, NumericVar *dest)
+{
+ NumericDigit *newbuf;
+
+ newbuf = digitbuf_alloc(value->ndigits + 1);
+ newbuf[0] = 0; /* spare digit for rounding */
+ if (value->ndigits > 0) /* else value->digits might be null */
+ memcpy(newbuf + 1, value->digits,
+ value->ndigits * sizeof(NumericDigit));
+
+ digitbuf_free(dest->buf);
+
+ memmove(dest, value, sizeof(NumericVar));
+ dest->buf = newbuf;
+ dest->digits = newbuf + 1;
+}
+
+
+/*
+ * get_str_from_var() -
+ *
+ * Convert a var to text representation (guts of numeric_out).
+ * The var is displayed to the number of digits indicated by its dscale.
+ * Returns a palloc'd string.
+ */
+static char *
+get_str_from_var(const NumericVar *var)
+{
+ int dscale;
+ char *str;
+ char *cp;
+ char *endcp;
+ int i;
+ int d;
+ NumericDigit dig;
+
+#if DEC_DIGITS > 1
+ NumericDigit d1;
+#endif
+
+ dscale = var->dscale;
+
+ /*
+ * Allocate space for the result.
+ *
+ * i is set to the # of decimal digits before decimal point. dscale is the
+ * # of decimal digits we will print after decimal point. We may generate
+ * as many as DEC_DIGITS-1 excess digits at the end, and in addition we
+ * need room for sign, decimal point, null terminator.
+ */
+ i = (var->weight + 1) * DEC_DIGITS;
+ if (i <= 0)
+ i = 1;
+
+ str = palloc(i + dscale + DEC_DIGITS + 2);
+ cp = str;
+
+ /*
+ * Output a dash for negative values
+ */
+ if (var->sign == NUMERIC_NEG)
+ *cp++ = '-';
+
+ /*
+ * Output all digits before the decimal point
+ */
+ if (var->weight < 0)
+ {
+ d = var->weight + 1;
+ *cp++ = '0';
+ }
+ else
+ {
+ for (d = 0; d <= var->weight; d++)
+ {
+ dig = (d < var->ndigits) ? var->digits[d] : 0;
+ /* In the first digit, suppress extra leading decimal zeroes */
+#if DEC_DIGITS == 4
+ {
+ bool putit = (d > 0);
+
+ d1 = dig / 1000;
+ dig -= d1 * 1000;
+ putit |= (d1 > 0);
+ if (putit)
+ *cp++ = d1 + '0';
+ d1 = dig / 100;
+ dig -= d1 * 100;
+ putit |= (d1 > 0);
+ if (putit)
+ *cp++ = d1 + '0';
+ d1 = dig / 10;
+ dig -= d1 * 10;
+ putit |= (d1 > 0);
+ if (putit)
+ *cp++ = d1 + '0';
+ *cp++ = dig + '0';
+ }
+#elif DEC_DIGITS == 2
+ d1 = dig / 10;
+ dig -= d1 * 10;
+ if (d1 > 0 || d > 0)
+ *cp++ = d1 + '0';
+ *cp++ = dig + '0';
+#elif DEC_DIGITS == 1
+ *cp++ = dig + '0';
+#else
+#error unsupported NBASE
+#endif
+ }
+ }
+
+ /*
+ * If requested, output a decimal point and all the digits that follow it.
+ * We initially put out a multiple of DEC_DIGITS digits, then truncate if
+ * needed.
+ */
+ if (dscale > 0)
+ {
+ *cp++ = '.';
+ endcp = cp + dscale;
+ for (i = 0; i < dscale; d++, i += DEC_DIGITS)
+ {
+ dig = (d >= 0 && d < var->ndigits) ? var->digits[d] : 0;
+#if DEC_DIGITS == 4
+ d1 = dig / 1000;
+ dig -= d1 * 1000;
+ *cp++ = d1 + '0';
+ d1 = dig / 100;
+ dig -= d1 * 100;
+ *cp++ = d1 + '0';
+ d1 = dig / 10;
+ dig -= d1 * 10;
+ *cp++ = d1 + '0';
+ *cp++ = dig + '0';
+#elif DEC_DIGITS == 2
+ d1 = dig / 10;
+ dig -= d1 * 10;
+ *cp++ = d1 + '0';
+ *cp++ = dig + '0';
+#elif DEC_DIGITS == 1
+ *cp++ = dig + '0';
+#else
+#error unsupported NBASE
+#endif
+ }
+ cp = endcp;
+ }
+
+ /*
+ * terminate the string and return it
+ */
+ *cp = '\0';
+ return str;
+}
+
+/*
+ * get_str_from_var_sci() -
+ *
+ * Convert a var to a normalised scientific notation text representation.
+ * This function does the heavy lifting for numeric_out_sci().
+ *
+ * This notation has the general form a * 10^b, where a is known as the
+ * "significand" and b is known as the "exponent".
+ *
+ * Because we can't do superscript in ASCII (and because we want to copy
+ * printf's behaviour) we display the exponent using E notation, with a
+ * minimum of two exponent digits.
+ *
+ * For example, the value 1234 could be output as 1.2e+03.
+ *
+ * We assume that the exponent can fit into an int32.
+ *
+ * rscale is the number of decimal digits desired after the decimal point in
+ * the output, negative values will be treated as meaning zero.
+ *
+ * Returns a palloc'd string.
+ */
+static char *
+get_str_from_var_sci(const NumericVar *var, int rscale)
+{
+ int32 exponent;
+ NumericVar tmp_var;
+ size_t len;
+ char *str;
+ char *sig_out;
+
+ if (rscale < 0)
+ rscale = 0;
+
+ /*
+ * Determine the exponent of this number in normalised form.
+ *
+ * This is the exponent required to represent the number with only one
+ * significant digit before the decimal place.
+ */
+ if (var->ndigits > 0)
+ {
+ exponent = (var->weight + 1) * DEC_DIGITS;
+
+ /*
+ * Compensate for leading decimal zeroes in the first numeric digit by
+ * decrementing the exponent.
+ */
+ exponent -= DEC_DIGITS - (int) log10(var->digits[0]);
+ }
+ else
+ {
+ /*
+ * If var has no digits, then it must be zero.
+ *
+ * Zero doesn't technically have a meaningful exponent in normalised
+ * notation, but we just display the exponent as zero for consistency
+ * of output.
+ */
+ exponent = 0;
+ }
+
+ /*
+ * Divide var by 10^exponent to get the significand, rounding to rscale
+ * decimal digits in the process.
+ */
+ init_var(&tmp_var);
+
+ power_ten_int(exponent, &tmp_var);
+ div_var(var, &tmp_var, &tmp_var, rscale, true);
+ sig_out = get_str_from_var(&tmp_var);
+
+ free_var(&tmp_var);
+
+ /*
+ * Allocate space for the result.
+ *
+ * In addition to the significand, we need room for the exponent
+ * decoration ("e"), the sign of the exponent, up to 10 digits for the
+ * exponent itself, and of course the null terminator.
+ */
+ len = strlen(sig_out) + 13;
+ str = palloc(len);
+ snprintf(str, len, "%se%+03d", sig_out, exponent);
+
+ pfree(sig_out);
+
+ return str;
+}
+
+
+/*
+ * duplicate_numeric() - copy a packed-format Numeric
+ *
+ * This will handle NaN and Infinity cases.
+ */
+static Numeric
+duplicate_numeric(Numeric num)
+{
+ Numeric res;
+
+ res = (Numeric) palloc(VARSIZE(num));
+ memcpy(res, num, VARSIZE(num));
+ return res;
+}
+
+/*
+ * make_result_opt_error() -
+ *
+ * Create the packed db numeric format in palloc()'d memory from
+ * a variable. This will handle NaN and Infinity cases.
+ *
+ * If "have_error" isn't NULL, on overflow *have_error is set to true and
+ * NULL is returned. This is helpful when caller needs to handle errors.
+ */
+static Numeric
+make_result_opt_error(const NumericVar *var, bool *have_error)
+{
+ Numeric result;
+ NumericDigit *digits = var->digits;
+ int weight = var->weight;
+ int sign = var->sign;
+ int n;
+ Size len;
+
+ if (have_error)
+ *have_error = false;
+
+ if ((sign & NUMERIC_SIGN_MASK) == NUMERIC_SPECIAL)
+ {
+ /*
+ * Verify valid special value. This could be just an Assert, perhaps,
+ * but it seems worthwhile to expend a few cycles to ensure that we
+ * never write any nonzero reserved bits to disk.
+ */
+ if (!(sign == NUMERIC_NAN ||
+ sign == NUMERIC_PINF ||
+ sign == NUMERIC_NINF))
+ elog(ERROR, "invalid numeric sign value 0x%x", sign);
+
+ result = (Numeric) palloc(NUMERIC_HDRSZ_SHORT);
+
+ SET_VARSIZE(result, NUMERIC_HDRSZ_SHORT);
+ result->choice.n_header = sign;
+ /* the header word is all we need */
+
+ dump_numeric("make_result()", result);
+ return result;
+ }
+
+ n = var->ndigits;
+
+ /* truncate leading zeroes */
+ while (n > 0 && *digits == 0)
+ {
+ digits++;
+ weight--;
+ n--;
+ }
+ /* truncate trailing zeroes */
+ while (n > 0 && digits[n - 1] == 0)
+ n--;
+
+ /* If zero result, force to weight=0 and positive sign */
+ if (n == 0)
+ {
+ weight = 0;
+ sign = NUMERIC_POS;
+ }
+
+ /* Build the result */
+ if (NUMERIC_CAN_BE_SHORT(var->dscale, weight))
+ {
+ len = NUMERIC_HDRSZ_SHORT + n * sizeof(NumericDigit);
+ result = (Numeric) palloc(len);
+ SET_VARSIZE(result, len);
+ result->choice.n_short.n_header =
+ (sign == NUMERIC_NEG ? (NUMERIC_SHORT | NUMERIC_SHORT_SIGN_MASK)
+ : NUMERIC_SHORT)
+ | (var->dscale << NUMERIC_SHORT_DSCALE_SHIFT)
+ | (weight < 0 ? NUMERIC_SHORT_WEIGHT_SIGN_MASK : 0)
+ | (weight & NUMERIC_SHORT_WEIGHT_MASK);
+ }
+ else
+ {
+ len = NUMERIC_HDRSZ + n * sizeof(NumericDigit);
+ result = (Numeric) palloc(len);
+ SET_VARSIZE(result, len);
+ result->choice.n_long.n_sign_dscale =
+ sign | (var->dscale & NUMERIC_DSCALE_MASK);
+ result->choice.n_long.n_weight = weight;
+ }
+
+ Assert(NUMERIC_NDIGITS(result) == n);
+ if (n > 0)
+ memcpy(NUMERIC_DIGITS(result), digits, n * sizeof(NumericDigit));
+
+ /* Check for overflow of int16 fields */
+ if (NUMERIC_WEIGHT(result) != weight ||
+ NUMERIC_DSCALE(result) != var->dscale)
+ {
+ if (have_error)
+ {
+ *have_error = true;
+ return NULL;
+ }
+ else
+ {
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("value overflows numeric format")));
+ }
+ }
+
+ dump_numeric("make_result()", result);
+ return result;
+}
+
+
+/*
+ * make_result() -
+ *
+ * An interface to make_result_opt_error() without "have_error" argument.
+ */
+static Numeric
+make_result(const NumericVar *var)
+{
+ return make_result_opt_error(var, NULL);
+}
+
+
+/*
+ * apply_typmod() -
+ *
+ * Do bounds checking and rounding according to the specified typmod.
+ * Note that this is only applied to normal finite values.
+ */
+static void
+apply_typmod(NumericVar *var, int32 typmod)
+{
+ int precision;
+ int scale;
+ int maxdigits;
+ int ddigits;
+ int i;
+
+ /* Do nothing if we have a default typmod (-1) */
+ if (typmod < (int32) (VARHDRSZ))
+ return;
+
+ typmod -= VARHDRSZ;
+ precision = (typmod >> 16) & 0xffff;
+ scale = typmod & 0xffff;
+ maxdigits = precision - scale;
+
+ /* Round to target scale (and set var->dscale) */
+ round_var(var, scale);
+
+ /*
+ * Check for overflow - note we can't do this before rounding, because
+ * rounding could raise the weight. Also note that the var's weight could
+ * be inflated by leading zeroes, which will be stripped before storage
+ * but perhaps might not have been yet. In any case, we must recognize a
+ * true zero, whose weight doesn't mean anything.
+ */
+ ddigits = (var->weight + 1) * DEC_DIGITS;
+ if (ddigits > maxdigits)
+ {
+ /* Determine true weight; and check for all-zero result */
+ for (i = 0; i < var->ndigits; i++)
+ {
+ NumericDigit dig = var->digits[i];
+
+ if (dig)
+ {
+ /* Adjust for any high-order decimal zero digits */
+#if DEC_DIGITS == 4
+ if (dig < 10)
+ ddigits -= 3;
+ else if (dig < 100)
+ ddigits -= 2;
+ else if (dig < 1000)
+ ddigits -= 1;
+#elif DEC_DIGITS == 2
+ if (dig < 10)
+ ddigits -= 1;
+#elif DEC_DIGITS == 1
+ /* no adjustment */
+#else
+#error unsupported NBASE
+#endif
+ if (ddigits > maxdigits)
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("numeric field overflow"),
+ errdetail("A field with precision %d, scale %d must round to an absolute value less than %s%d.",
+ precision, scale,
+ /* Display 10^0 as 1 */
+ maxdigits ? "10^" : "",
+ maxdigits ? maxdigits : 1
+ )));
+ break;
+ }
+ ddigits -= DEC_DIGITS;
+ }
+ }
+}
+
+/*
+ * apply_typmod_special() -
+ *
+ * Do bounds checking according to the specified typmod, for an Inf or NaN.
+ * For convenience of most callers, the value is presented in packed form.
+ */
+static void
+apply_typmod_special(Numeric num, int32 typmod)
+{
+ int precision;
+ int scale;
+
+ Assert(NUMERIC_IS_SPECIAL(num)); /* caller error if not */
+
+ /*
+ * NaN is allowed regardless of the typmod; that's rather dubious perhaps,
+ * but it's a longstanding behavior. Inf is rejected if we have any
+ * typmod restriction, since an infinity shouldn't be claimed to fit in
+ * any finite number of digits.
+ */
+ if (NUMERIC_IS_NAN(num))
+ return;
+
+ /* Do nothing if we have a default typmod (-1) */
+ if (typmod < (int32) (VARHDRSZ))
+ return;
+
+ typmod -= VARHDRSZ;
+ precision = (typmod >> 16) & 0xffff;
+ scale = typmod & 0xffff;
+
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("numeric field overflow"),
+ errdetail("A field with precision %d, scale %d cannot hold an infinite value.",
+ precision, scale)));
+}
+
+
+/*
+ * Convert numeric to int8, rounding if needed.
+ *
+ * If overflow, return false (no error is raised). Return true if okay.
+ */
+static bool
+numericvar_to_int64(const NumericVar *var, int64 *result)
+{
+ NumericDigit *digits;
+ int ndigits;
+ int weight;
+ int i;
+ int64 val;
+ bool neg;
+ NumericVar rounded;
+
+ /* Round to nearest integer */
+ init_var(&rounded);
+ set_var_from_var(var, &rounded);
+ round_var(&rounded, 0);
+
+ /* Check for zero input */
+ strip_var(&rounded);
+ ndigits = rounded.ndigits;
+ if (ndigits == 0)
+ {
+ *result = 0;
+ free_var(&rounded);
+ return true;
+ }
+
+ /*
+ * For input like 10000000000, we must treat stripped digits as real. So
+ * the loop assumes there are weight+1 digits before the decimal point.
+ */
+ weight = rounded.weight;
+ Assert(weight >= 0 && ndigits <= weight + 1);
+
+ /*
+ * Construct the result. To avoid issues with converting a value
+ * corresponding to INT64_MIN (which can't be represented as a positive 64
+ * bit two's complement integer), accumulate value as a negative number.
+ */
+ digits = rounded.digits;
+ neg = (rounded.sign == NUMERIC_NEG);
+ val = -digits[0];
+ for (i = 1; i <= weight; i++)
+ {
+ if (unlikely(pg_mul_s64_overflow(val, NBASE, &val)))
+ {
+ free_var(&rounded);
+ return false;
+ }
+
+ if (i < ndigits)
+ {
+ if (unlikely(pg_sub_s64_overflow(val, digits[i], &val)))
+ {
+ free_var(&rounded);
+ return false;
+ }
+ }
+ }
+
+ free_var(&rounded);
+
+ if (!neg)
+ {
+ if (unlikely(val == PG_INT64_MIN))
+ return false;
+ val = -val;
+ }
+ *result = val;
+
+ return true;
+}
+
+/*
+ * Convert int8 value to numeric.
+ */
+static void
+int64_to_numericvar(int64 val, NumericVar *var)
+{
+ uint64 uval,
+ newuval;
+ NumericDigit *ptr;
+ int ndigits;
+
+ /* int64 can require at most 19 decimal digits; add one for safety */
+ alloc_var(var, 20 / DEC_DIGITS);
+ if (val < 0)
+ {
+ var->sign = NUMERIC_NEG;
+ uval = -val;
+ }
+ else
+ {
+ var->sign = NUMERIC_POS;
+ uval = val;
+ }
+ var->dscale = 0;
+ if (val == 0)
+ {
+ var->ndigits = 0;
+ var->weight = 0;
+ return;
+ }
+ ptr = var->digits + var->ndigits;
+ ndigits = 0;
+ do
+ {
+ ptr--;
+ ndigits++;
+ newuval = uval / NBASE;
+ *ptr = uval - newuval * NBASE;
+ uval = newuval;
+ } while (uval);
+ var->digits = ptr;
+ var->ndigits = ndigits;
+ var->weight = ndigits - 1;
+}
+
+/*
+ * Convert numeric to uint64, rounding if needed.
+ *
+ * If overflow, return false (no error is raised). Return true if okay.
+ */
+static bool
+numericvar_to_uint64(const NumericVar *var, uint64 *result)
+{
+ NumericDigit *digits;
+ int ndigits;
+ int weight;
+ int i;
+ uint64 val;
+ NumericVar rounded;
+
+ /* Round to nearest integer */
+ init_var(&rounded);
+ set_var_from_var(var, &rounded);
+ round_var(&rounded, 0);
+
+ /* Check for zero input */
+ strip_var(&rounded);
+ ndigits = rounded.ndigits;
+ if (ndigits == 0)
+ {
+ *result = 0;
+ free_var(&rounded);
+ return true;
+ }
+
+ /* Check for negative input */
+ if (rounded.sign == NUMERIC_NEG)
+ {
+ free_var(&rounded);
+ return false;
+ }
+
+ /*
+ * For input like 10000000000, we must treat stripped digits as real. So
+ * the loop assumes there are weight+1 digits before the decimal point.
+ */
+ weight = rounded.weight;
+ Assert(weight >= 0 && ndigits <= weight + 1);
+
+ /* Construct the result */
+ digits = rounded.digits;
+ val = digits[0];
+ for (i = 1; i <= weight; i++)
+ {
+ if (unlikely(pg_mul_u64_overflow(val, NBASE, &val)))
+ {
+ free_var(&rounded);
+ return false;
+ }
+
+ if (i < ndigits)
+ {
+ if (unlikely(pg_add_u64_overflow(val, digits[i], &val)))
+ {
+ free_var(&rounded);
+ return false;
+ }
+ }
+ }
+
+ free_var(&rounded);
+
+ *result = val;
+
+ return true;
+}
+
+#ifdef HAVE_INT128
+/*
+ * Convert numeric to int128, rounding if needed.
+ *
+ * If overflow, return false (no error is raised). Return true if okay.
+ */
+static bool
+numericvar_to_int128(const NumericVar *var, int128 *result)
+{
+ NumericDigit *digits;
+ int ndigits;
+ int weight;
+ int i;
+ int128 val,
+ oldval;
+ bool neg;
+ NumericVar rounded;
+
+ /* Round to nearest integer */
+ init_var(&rounded);
+ set_var_from_var(var, &rounded);
+ round_var(&rounded, 0);
+
+ /* Check for zero input */
+ strip_var(&rounded);
+ ndigits = rounded.ndigits;
+ if (ndigits == 0)
+ {
+ *result = 0;
+ free_var(&rounded);
+ return true;
+ }
+
+ /*
+ * For input like 10000000000, we must treat stripped digits as real. So
+ * the loop assumes there are weight+1 digits before the decimal point.
+ */
+ weight = rounded.weight;
+ Assert(weight >= 0 && ndigits <= weight + 1);
+
+ /* Construct the result */
+ digits = rounded.digits;
+ neg = (rounded.sign == NUMERIC_NEG);
+ val = digits[0];
+ for (i = 1; i <= weight; i++)
+ {
+ oldval = val;
+ val *= NBASE;
+ if (i < ndigits)
+ val += digits[i];
+
+ /*
+ * The overflow check is a bit tricky because we want to accept
+ * INT128_MIN, which will overflow the positive accumulator. We can
+ * detect this case easily though because INT128_MIN is the only
+ * nonzero value for which -val == val (on a two's complement machine,
+ * anyway).
+ */
+ if ((val / NBASE) != oldval) /* possible overflow? */
+ {
+ if (!neg || (-val) != val || val == 0 || oldval < 0)
+ {
+ free_var(&rounded);
+ return false;
+ }
+ }
+ }
+
+ free_var(&rounded);
+
+ *result = neg ? -val : val;
+ return true;
+}
+
+/*
+ * Convert 128 bit integer to numeric.
+ */
+static void
+int128_to_numericvar(int128 val, NumericVar *var)
+{
+ uint128 uval,
+ newuval;
+ NumericDigit *ptr;
+ int ndigits;
+
+ /* int128 can require at most 39 decimal digits; add one for safety */
+ alloc_var(var, 40 / DEC_DIGITS);
+ if (val < 0)
+ {
+ var->sign = NUMERIC_NEG;
+ uval = -val;
+ }
+ else
+ {
+ var->sign = NUMERIC_POS;
+ uval = val;
+ }
+ var->dscale = 0;
+ if (val == 0)
+ {
+ var->ndigits = 0;
+ var->weight = 0;
+ return;
+ }
+ ptr = var->digits + var->ndigits;
+ ndigits = 0;
+ do
+ {
+ ptr--;
+ ndigits++;
+ newuval = uval / NBASE;
+ *ptr = uval - newuval * NBASE;
+ uval = newuval;
+ } while (uval);
+ var->digits = ptr;
+ var->ndigits = ndigits;
+ var->weight = ndigits - 1;
+}
+#endif
+
+/*
+ * Convert a NumericVar to float8; if out of range, return +/- HUGE_VAL
+ */
+static double
+numericvar_to_double_no_overflow(const NumericVar *var)
+{
+ char *tmp;
+ double val;
+ char *endptr;
+
+ tmp = get_str_from_var(var);
+
+ /* unlike float8in, we ignore ERANGE from strtod */
+ val = strtod(tmp, &endptr);
+ if (*endptr != '\0')
+ {
+ /* shouldn't happen ... */
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ errmsg("invalid input syntax for type %s: \"%s\"",
+ "double precision", tmp)));
+ }
+
+ pfree(tmp);
+
+ return val;
+}
+
+
+/*
+ * cmp_var() -
+ *
+ * Compare two values on variable level. We assume zeroes have been
+ * truncated to no digits.
+ */
+static int
+cmp_var(const NumericVar *var1, const NumericVar *var2)
+{
+ return cmp_var_common(var1->digits, var1->ndigits,
+ var1->weight, var1->sign,
+ var2->digits, var2->ndigits,
+ var2->weight, var2->sign);
+}
+
+/*
+ * cmp_var_common() -
+ *
+ * Main routine of cmp_var(). This function can be used by both
+ * NumericVar and Numeric.
+ */
+static int
+cmp_var_common(const NumericDigit *var1digits, int var1ndigits,
+ int var1weight, int var1sign,
+ const NumericDigit *var2digits, int var2ndigits,
+ int var2weight, int var2sign)
+{
+ if (var1ndigits == 0)
+ {
+ if (var2ndigits == 0)
+ return 0;
+ if (var2sign == NUMERIC_NEG)
+ return 1;
+ return -1;
+ }
+ if (var2ndigits == 0)
+ {
+ if (var1sign == NUMERIC_POS)
+ return 1;
+ return -1;
+ }
+
+ if (var1sign == NUMERIC_POS)
+ {
+ if (var2sign == NUMERIC_NEG)
+ return 1;
+ return cmp_abs_common(var1digits, var1ndigits, var1weight,
+ var2digits, var2ndigits, var2weight);
+ }
+
+ if (var2sign == NUMERIC_POS)
+ return -1;
+
+ return cmp_abs_common(var2digits, var2ndigits, var2weight,
+ var1digits, var1ndigits, var1weight);
+}
+
+
+/*
+ * add_var() -
+ *
+ * Full version of add functionality on variable level (handling signs).
+ * result might point to one of the operands too without danger.
+ */
+static void
+add_var(const NumericVar *var1, const NumericVar *var2, NumericVar *result)
+{
+ /*
+ * Decide on the signs of the two variables what to do
+ */
+ if (var1->sign == NUMERIC_POS)
+ {
+ if (var2->sign == NUMERIC_POS)
+ {
+ /*
+ * Both are positive result = +(ABS(var1) + ABS(var2))
+ */
+ add_abs(var1, var2, result);
+ result->sign = NUMERIC_POS;
+ }
+ else
+ {
+ /*
+ * var1 is positive, var2 is negative Must compare absolute values
+ */
+ switch (cmp_abs(var1, var2))
+ {
+ case 0:
+ /* ----------
+ * ABS(var1) == ABS(var2)
+ * result = ZERO
+ * ----------
+ */
+ zero_var(result);
+ result->dscale = Max(var1->dscale, var2->dscale);
+ break;
+
+ case 1:
+ /* ----------
+ * ABS(var1) > ABS(var2)
+ * result = +(ABS(var1) - ABS(var2))
+ * ----------
+ */
+ sub_abs(var1, var2, result);
+ result->sign = NUMERIC_POS;
+ break;
+
+ case -1:
+ /* ----------
+ * ABS(var1) < ABS(var2)
+ * result = -(ABS(var2) - ABS(var1))
+ * ----------
+ */
+ sub_abs(var2, var1, result);
+ result->sign = NUMERIC_NEG;
+ break;
+ }
+ }
+ }
+ else
+ {
+ if (var2->sign == NUMERIC_POS)
+ {
+ /* ----------
+ * var1 is negative, var2 is positive
+ * Must compare absolute values
+ * ----------
+ */
+ switch (cmp_abs(var1, var2))
+ {
+ case 0:
+ /* ----------
+ * ABS(var1) == ABS(var2)
+ * result = ZERO
+ * ----------
+ */
+ zero_var(result);
+ result->dscale = Max(var1->dscale, var2->dscale);
+ break;
+
+ case 1:
+ /* ----------
+ * ABS(var1) > ABS(var2)
+ * result = -(ABS(var1) - ABS(var2))
+ * ----------
+ */
+ sub_abs(var1, var2, result);
+ result->sign = NUMERIC_NEG;
+ break;
+
+ case -1:
+ /* ----------
+ * ABS(var1) < ABS(var2)
+ * result = +(ABS(var2) - ABS(var1))
+ * ----------
+ */
+ sub_abs(var2, var1, result);
+ result->sign = NUMERIC_POS;
+ break;
+ }
+ }
+ else
+ {
+ /* ----------
+ * Both are negative
+ * result = -(ABS(var1) + ABS(var2))
+ * ----------
+ */
+ add_abs(var1, var2, result);
+ result->sign = NUMERIC_NEG;
+ }
+ }
+}
+
+
+/*
+ * sub_var() -
+ *
+ * Full version of sub functionality on variable level (handling signs).
+ * result might point to one of the operands too without danger.
+ */
+static void
+sub_var(const NumericVar *var1, const NumericVar *var2, NumericVar *result)
+{
+ /*
+ * Decide on the signs of the two variables what to do
+ */
+ if (var1->sign == NUMERIC_POS)
+ {
+ if (var2->sign == NUMERIC_NEG)
+ {
+ /* ----------
+ * var1 is positive, var2 is negative
+ * result = +(ABS(var1) + ABS(var2))
+ * ----------
+ */
+ add_abs(var1, var2, result);
+ result->sign = NUMERIC_POS;
+ }
+ else
+ {
+ /* ----------
+ * Both are positive
+ * Must compare absolute values
+ * ----------
+ */
+ switch (cmp_abs(var1, var2))
+ {
+ case 0:
+ /* ----------
+ * ABS(var1) == ABS(var2)
+ * result = ZERO
+ * ----------
+ */
+ zero_var(result);
+ result->dscale = Max(var1->dscale, var2->dscale);
+ break;
+
+ case 1:
+ /* ----------
+ * ABS(var1) > ABS(var2)
+ * result = +(ABS(var1) - ABS(var2))
+ * ----------
+ */
+ sub_abs(var1, var2, result);
+ result->sign = NUMERIC_POS;
+ break;
+
+ case -1:
+ /* ----------
+ * ABS(var1) < ABS(var2)
+ * result = -(ABS(var2) - ABS(var1))
+ * ----------
+ */
+ sub_abs(var2, var1, result);
+ result->sign = NUMERIC_NEG;
+ break;
+ }
+ }
+ }
+ else
+ {
+ if (var2->sign == NUMERIC_NEG)
+ {
+ /* ----------
+ * Both are negative
+ * Must compare absolute values
+ * ----------
+ */
+ switch (cmp_abs(var1, var2))
+ {
+ case 0:
+ /* ----------
+ * ABS(var1) == ABS(var2)
+ * result = ZERO
+ * ----------
+ */
+ zero_var(result);
+ result->dscale = Max(var1->dscale, var2->dscale);
+ break;
+
+ case 1:
+ /* ----------
+ * ABS(var1) > ABS(var2)
+ * result = -(ABS(var1) - ABS(var2))
+ * ----------
+ */
+ sub_abs(var1, var2, result);
+ result->sign = NUMERIC_NEG;
+ break;
+
+ case -1:
+ /* ----------
+ * ABS(var1) < ABS(var2)
+ * result = +(ABS(var2) - ABS(var1))
+ * ----------
+ */
+ sub_abs(var2, var1, result);
+ result->sign = NUMERIC_POS;
+ break;
+ }
+ }
+ else
+ {
+ /* ----------
+ * var1 is negative, var2 is positive
+ * result = -(ABS(var1) + ABS(var2))
+ * ----------
+ */
+ add_abs(var1, var2, result);
+ result->sign = NUMERIC_NEG;
+ }
+ }
+}
+
+
+/*
+ * mul_var() -
+ *
+ * Multiplication on variable level. Product of var1 * var2 is stored
+ * in result. Result is rounded to no more than rscale fractional digits.
+ */
+static void
+mul_var(const NumericVar *var1, const NumericVar *var2, NumericVar *result,
+ int rscale)
+{
+ int res_ndigits;
+ int res_sign;
+ int res_weight;
+ int maxdigits;
+ int *dig;
+ int carry;
+ int maxdig;
+ int newdig;
+ int var1ndigits;
+ int var2ndigits;
+ NumericDigit *var1digits;
+ NumericDigit *var2digits;
+ NumericDigit *res_digits;
+ int i,
+ i1,
+ i2;
+
+ /*
+ * Arrange for var1 to be the shorter of the two numbers. This improves
+ * performance because the inner multiplication loop is much simpler than
+ * the outer loop, so it's better to have a smaller number of iterations
+ * of the outer loop. This also reduces the number of times that the
+ * accumulator array needs to be normalized.
+ */
+ if (var1->ndigits > var2->ndigits)
+ {
+ const NumericVar *tmp = var1;
+
+ var1 = var2;
+ var2 = tmp;
+ }
+
+ /* copy these values into local vars for speed in inner loop */
+ var1ndigits = var1->ndigits;
+ var2ndigits = var2->ndigits;
+ var1digits = var1->digits;
+ var2digits = var2->digits;
+
+ if (var1ndigits == 0 || var2ndigits == 0)
+ {
+ /* one or both inputs is zero; so is result */
+ zero_var(result);
+ result->dscale = rscale;
+ return;
+ }
+
+ /* Determine result sign and (maximum possible) weight */
+ if (var1->sign == var2->sign)
+ res_sign = NUMERIC_POS;
+ else
+ res_sign = NUMERIC_NEG;
+ res_weight = var1->weight + var2->weight + 2;
+
+ /*
+ * Determine the number of result digits to compute. If the exact result
+ * would have more than rscale fractional digits, truncate the computation
+ * with MUL_GUARD_DIGITS guard digits, i.e., ignore input digits that
+ * would only contribute to the right of that. (This will give the exact
+ * rounded-to-rscale answer unless carries out of the ignored positions
+ * would have propagated through more than MUL_GUARD_DIGITS digits.)
+ *
+ * Note: an exact computation could not produce more than var1ndigits +
+ * var2ndigits digits, but we allocate one extra output digit in case
+ * rscale-driven rounding produces a carry out of the highest exact digit.
+ */
+ res_ndigits = var1ndigits + var2ndigits + 1;
+ maxdigits = res_weight + 1 + (rscale + DEC_DIGITS - 1) / DEC_DIGITS +
+ MUL_GUARD_DIGITS;
+ res_ndigits = Min(res_ndigits, maxdigits);
+
+ if (res_ndigits < 3)
+ {
+ /* All input digits will be ignored; so result is zero */
+ zero_var(result);
+ result->dscale = rscale;
+ return;
+ }
+
+ /*
+ * We do the arithmetic in an array "dig[]" of signed int's. Since
+ * INT_MAX is noticeably larger than NBASE*NBASE, this gives us headroom
+ * to avoid normalizing carries immediately.
+ *
+ * maxdig tracks the maximum possible value of any dig[] entry; when this
+ * threatens to exceed INT_MAX, we take the time to propagate carries.
+ * Furthermore, we need to ensure that overflow doesn't occur during the
+ * carry propagation passes either. The carry values could be as much as
+ * INT_MAX/NBASE, so really we must normalize when digits threaten to
+ * exceed INT_MAX - INT_MAX/NBASE.
+ *
+ * To avoid overflow in maxdig itself, it actually represents the max
+ * possible value divided by NBASE-1, ie, at the top of the loop it is
+ * known that no dig[] entry exceeds maxdig * (NBASE-1).
+ */
+ dig = (int *) palloc0(res_ndigits * sizeof(int));
+ maxdig = 0;
+
+ /*
+ * The least significant digits of var1 should be ignored if they don't
+ * contribute directly to the first res_ndigits digits of the result that
+ * we are computing.
+ *
+ * Digit i1 of var1 and digit i2 of var2 are multiplied and added to digit
+ * i1+i2+2 of the accumulator array, so we need only consider digits of
+ * var1 for which i1 <= res_ndigits - 3.
+ */
+ for (i1 = Min(var1ndigits - 1, res_ndigits - 3); i1 >= 0; i1--)
+ {
+ int var1digit = var1digits[i1];
+
+ if (var1digit == 0)
+ continue;
+
+ /* Time to normalize? */
+ maxdig += var1digit;
+ if (maxdig > (INT_MAX - INT_MAX / NBASE) / (NBASE - 1))
+ {
+ /* Yes, do it */
+ carry = 0;
+ for (i = res_ndigits - 1; i >= 0; i--)
+ {
+ newdig = dig[i] + carry;
+ if (newdig >= NBASE)
+ {
+ carry = newdig / NBASE;
+ newdig -= carry * NBASE;
+ }
+ else
+ carry = 0;
+ dig[i] = newdig;
+ }
+ Assert(carry == 0);
+ /* Reset maxdig to indicate new worst-case */
+ maxdig = 1 + var1digit;
+ }
+
+ /*
+ * Add the appropriate multiple of var2 into the accumulator.
+ *
+ * As above, digits of var2 can be ignored if they don't contribute,
+ * so we only include digits for which i1+i2+2 < res_ndigits.
+ *
+ * This inner loop is the performance bottleneck for multiplication,
+ * so we want to keep it simple enough so that it can be
+ * auto-vectorized. Accordingly, process the digits left-to-right
+ * even though schoolbook multiplication would suggest right-to-left.
+ * Since we aren't propagating carries in this loop, the order does
+ * not matter.
+ */
+ {
+ int i2limit = Min(var2ndigits, res_ndigits - i1 - 2);
+ int *dig_i1_2 = &dig[i1 + 2];
+
+ for (i2 = 0; i2 < i2limit; i2++)
+ dig_i1_2[i2] += var1digit * var2digits[i2];
+ }
+ }
+
+ /*
+ * Now we do a final carry propagation pass to normalize the result, which
+ * we combine with storing the result digits into the output. Note that
+ * this is still done at full precision w/guard digits.
+ */
+ alloc_var(result, res_ndigits);
+ res_digits = result->digits;
+ carry = 0;
+ for (i = res_ndigits - 1; i >= 0; i--)
+ {
+ newdig = dig[i] + carry;
+ if (newdig >= NBASE)
+ {
+ carry = newdig / NBASE;
+ newdig -= carry * NBASE;
+ }
+ else
+ carry = 0;
+ res_digits[i] = newdig;
+ }
+ Assert(carry == 0);
+
+ pfree(dig);
+
+ /*
+ * Finally, round the result to the requested precision.
+ */
+ result->weight = res_weight;
+ result->sign = res_sign;
+
+ /* Round to target rscale (and set result->dscale) */
+ round_var(result, rscale);
+
+ /* Strip leading and trailing zeroes */
+ strip_var(result);
+}
+
+
+/*
+ * div_var() -
+ *
+ * Division on variable level. Quotient of var1 / var2 is stored in result.
+ * The quotient is figured to exactly rscale fractional digits.
+ * If round is true, it is rounded at the rscale'th digit; if false, it
+ * is truncated (towards zero) at that digit.
+ */
+static void
+div_var(const NumericVar *var1, const NumericVar *var2, NumericVar *result,
+ int rscale, bool round)
+{
+ int div_ndigits;
+ int res_ndigits;
+ int res_sign;
+ int res_weight;
+ int carry;
+ int borrow;
+ int divisor1;
+ int divisor2;
+ NumericDigit *dividend;
+ NumericDigit *divisor;
+ NumericDigit *res_digits;
+ int i;
+ int j;
+
+ /* copy these values into local vars for speed in inner loop */
+ int var1ndigits = var1->ndigits;
+ int var2ndigits = var2->ndigits;
+
+ /*
+ * First of all division by zero check; we must not be handed an
+ * unnormalized divisor.
+ */
+ if (var2ndigits == 0 || var2->digits[0] == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_DIVISION_BY_ZERO),
+ errmsg("division by zero")));
+
+ /*
+ * Now result zero check
+ */
+ if (var1ndigits == 0)
+ {
+ zero_var(result);
+ result->dscale = rscale;
+ return;
+ }
+
+ /*
+ * Determine the result sign, weight and number of digits to calculate.
+ * The weight figured here is correct if the emitted quotient has no
+ * leading zero digits; otherwise strip_var() will fix things up.
+ */
+ if (var1->sign == var2->sign)
+ res_sign = NUMERIC_POS;
+ else
+ res_sign = NUMERIC_NEG;
+ res_weight = var1->weight - var2->weight;
+ /* The number of accurate result digits we need to produce: */
+ res_ndigits = res_weight + 1 + (rscale + DEC_DIGITS - 1) / DEC_DIGITS;
+ /* ... but always at least 1 */
+ res_ndigits = Max(res_ndigits, 1);
+ /* If rounding needed, figure one more digit to ensure correct result */
+ if (round)
+ res_ndigits++;
+
+ /*
+ * The working dividend normally requires res_ndigits + var2ndigits
+ * digits, but make it at least var1ndigits so we can load all of var1
+ * into it. (There will be an additional digit dividend[0] in the
+ * dividend space, but for consistency with Knuth's notation we don't
+ * count that in div_ndigits.)
+ */
+ div_ndigits = res_ndigits + var2ndigits;
+ div_ndigits = Max(div_ndigits, var1ndigits);
+
+ /*
+ * We need a workspace with room for the working dividend (div_ndigits+1
+ * digits) plus room for the possibly-normalized divisor (var2ndigits
+ * digits). It is convenient also to have a zero at divisor[0] with the
+ * actual divisor data in divisor[1 .. var2ndigits]. Transferring the
+ * digits into the workspace also allows us to realloc the result (which
+ * might be the same as either input var) before we begin the main loop.
+ * Note that we use palloc0 to ensure that divisor[0], dividend[0], and
+ * any additional dividend positions beyond var1ndigits, start out 0.
+ */
+ dividend = (NumericDigit *)
+ palloc0((div_ndigits + var2ndigits + 2) * sizeof(NumericDigit));
+ divisor = dividend + (div_ndigits + 1);
+ memcpy(dividend + 1, var1->digits, var1ndigits * sizeof(NumericDigit));
+ memcpy(divisor + 1, var2->digits, var2ndigits * sizeof(NumericDigit));
+
+ /*
+ * Now we can realloc the result to hold the generated quotient digits.
+ */
+ alloc_var(result, res_ndigits);
+ res_digits = result->digits;
+
+ if (var2ndigits == 1)
+ {
+ /*
+ * If there's only a single divisor digit, we can use a fast path (cf.
+ * Knuth section 4.3.1 exercise 16).
+ */
+ divisor1 = divisor[1];
+ carry = 0;
+ for (i = 0; i < res_ndigits; i++)
+ {
+ carry = carry * NBASE + dividend[i + 1];
+ res_digits[i] = carry / divisor1;
+ carry = carry % divisor1;
+ }
+ }
+ else
+ {
+ /*
+ * The full multiple-place algorithm is taken from Knuth volume 2,
+ * Algorithm 4.3.1D.
+ *
+ * We need the first divisor digit to be >= NBASE/2. If it isn't,
+ * make it so by scaling up both the divisor and dividend by the
+ * factor "d". (The reason for allocating dividend[0] above is to
+ * leave room for possible carry here.)
+ */
+ if (divisor[1] < HALF_NBASE)
+ {
+ int d = NBASE / (divisor[1] + 1);
+
+ carry = 0;
+ for (i = var2ndigits; i > 0; i--)
+ {
+ carry += divisor[i] * d;
+ divisor[i] = carry % NBASE;
+ carry = carry / NBASE;
+ }
+ Assert(carry == 0);
+ carry = 0;
+ /* at this point only var1ndigits of dividend can be nonzero */
+ for (i = var1ndigits; i >= 0; i--)
+ {
+ carry += dividend[i] * d;
+ dividend[i] = carry % NBASE;
+ carry = carry / NBASE;
+ }
+ Assert(carry == 0);
+ Assert(divisor[1] >= HALF_NBASE);
+ }
+ /* First 2 divisor digits are used repeatedly in main loop */
+ divisor1 = divisor[1];
+ divisor2 = divisor[2];
+
+ /*
+ * Begin the main loop. Each iteration of this loop produces the j'th
+ * quotient digit by dividing dividend[j .. j + var2ndigits] by the
+ * divisor; this is essentially the same as the common manual
+ * procedure for long division.
+ */
+ for (j = 0; j < res_ndigits; j++)
+ {
+ /* Estimate quotient digit from the first two dividend digits */
+ int next2digits = dividend[j] * NBASE + dividend[j + 1];
+ int qhat;
+
+ /*
+ * If next2digits are 0, then quotient digit must be 0 and there's
+ * no need to adjust the working dividend. It's worth testing
+ * here to fall out ASAP when processing trailing zeroes in a
+ * dividend.
+ */
+ if (next2digits == 0)
+ {
+ res_digits[j] = 0;
+ continue;
+ }
+
+ if (dividend[j] == divisor1)
+ qhat = NBASE - 1;
+ else
+ qhat = next2digits / divisor1;
+
+ /*
+ * Adjust quotient digit if it's too large. Knuth proves that
+ * after this step, the quotient digit will be either correct or
+ * just one too large. (Note: it's OK to use dividend[j+2] here
+ * because we know the divisor length is at least 2.)
+ */
+ while (divisor2 * qhat >
+ (next2digits - qhat * divisor1) * NBASE + dividend[j + 2])
+ qhat--;
+
+ /* As above, need do nothing more when quotient digit is 0 */
+ if (qhat > 0)
+ {
+ /*
+ * Multiply the divisor by qhat, and subtract that from the
+ * working dividend. "carry" tracks the multiplication,
+ * "borrow" the subtraction (could we fold these together?)
+ */
+ carry = 0;
+ borrow = 0;
+ for (i = var2ndigits; i >= 0; i--)
+ {
+ carry += divisor[i] * qhat;
+ borrow -= carry % NBASE;
+ carry = carry / NBASE;
+ borrow += dividend[j + i];
+ if (borrow < 0)
+ {
+ dividend[j + i] = borrow + NBASE;
+ borrow = -1;
+ }
+ else
+ {
+ dividend[j + i] = borrow;
+ borrow = 0;
+ }
+ }
+ Assert(carry == 0);
+
+ /*
+ * If we got a borrow out of the top dividend digit, then
+ * indeed qhat was one too large. Fix it, and add back the
+ * divisor to correct the working dividend. (Knuth proves
+ * that this will occur only about 3/NBASE of the time; hence,
+ * it's a good idea to test this code with small NBASE to be
+ * sure this section gets exercised.)
+ */
+ if (borrow)
+ {
+ qhat--;
+ carry = 0;
+ for (i = var2ndigits; i >= 0; i--)
+ {
+ carry += dividend[j + i] + divisor[i];
+ if (carry >= NBASE)
+ {
+ dividend[j + i] = carry - NBASE;
+ carry = 1;
+ }
+ else
+ {
+ dividend[j + i] = carry;
+ carry = 0;
+ }
+ }
+ /* A carry should occur here to cancel the borrow above */
+ Assert(carry == 1);
+ }
+ }
+
+ /* And we're done with this quotient digit */
+ res_digits[j] = qhat;
+ }
+ }
+
+ pfree(dividend);
+
+ /*
+ * Finally, round or truncate the result to the requested precision.
+ */
+ result->weight = res_weight;
+ result->sign = res_sign;
+
+ /* Round or truncate to target rscale (and set result->dscale) */
+ if (round)
+ round_var(result, rscale);
+ else
+ trunc_var(result, rscale);
+
+ /* Strip leading and trailing zeroes */
+ strip_var(result);
+}
+
+
+/*
+ * div_var_fast() -
+ *
+ * This has the same API as div_var, but is implemented using the division
+ * algorithm from the "FM" library, rather than Knuth's schoolbook-division
+ * approach. This is significantly faster but can produce inaccurate
+ * results, because it sometimes has to propagate rounding to the left,
+ * and so we can never be entirely sure that we know the requested digits
+ * exactly. We compute DIV_GUARD_DIGITS extra digits, but there is
+ * no certainty that that's enough. We use this only in the transcendental
+ * function calculation routines, where everything is approximate anyway.
+ *
+ * Although we provide a "round" argument for consistency with div_var,
+ * it is unwise to use this function with round=false. In truncation mode
+ * it is possible to get a result with no significant digits, for example
+ * with rscale=0 we might compute 0.99999... and truncate that to 0 when
+ * the correct answer is 1.
+ */
+static void
+div_var_fast(const NumericVar *var1, const NumericVar *var2,
+ NumericVar *result, int rscale, bool round)
+{
+ int div_ndigits;
+ int load_ndigits;
+ int res_sign;
+ int res_weight;
+ int *div;
+ int qdigit;
+ int carry;
+ int maxdiv;
+ int newdig;
+ NumericDigit *res_digits;
+ double fdividend,
+ fdivisor,
+ fdivisorinverse,
+ fquotient;
+ int qi;
+ int i;
+
+ /* copy these values into local vars for speed in inner loop */
+ int var1ndigits = var1->ndigits;
+ int var2ndigits = var2->ndigits;
+ NumericDigit *var1digits = var1->digits;
+ NumericDigit *var2digits = var2->digits;
+
+ /*
+ * First of all division by zero check; we must not be handed an
+ * unnormalized divisor.
+ */
+ if (var2ndigits == 0 || var2digits[0] == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_DIVISION_BY_ZERO),
+ errmsg("division by zero")));
+
+ /*
+ * Now result zero check
+ */
+ if (var1ndigits == 0)
+ {
+ zero_var(result);
+ result->dscale = rscale;
+ return;
+ }
+
+ /*
+ * Determine the result sign, weight and number of digits to calculate
+ */
+ if (var1->sign == var2->sign)
+ res_sign = NUMERIC_POS;
+ else
+ res_sign = NUMERIC_NEG;
+ res_weight = var1->weight - var2->weight + 1;
+ /* The number of accurate result digits we need to produce: */
+ div_ndigits = res_weight + 1 + (rscale + DEC_DIGITS - 1) / DEC_DIGITS;
+ /* Add guard digits for roundoff error */
+ div_ndigits += DIV_GUARD_DIGITS;
+ if (div_ndigits < DIV_GUARD_DIGITS)
+ div_ndigits = DIV_GUARD_DIGITS;
+
+ /*
+ * We do the arithmetic in an array "div[]" of signed int's. Since
+ * INT_MAX is noticeably larger than NBASE*NBASE, this gives us headroom
+ * to avoid normalizing carries immediately.
+ *
+ * We start with div[] containing one zero digit followed by the
+ * dividend's digits (plus appended zeroes to reach the desired precision
+ * including guard digits). Each step of the main loop computes an
+ * (approximate) quotient digit and stores it into div[], removing one
+ * position of dividend space. A final pass of carry propagation takes
+ * care of any mistaken quotient digits.
+ *
+ * Note that div[] doesn't necessarily contain all of the digits from the
+ * dividend --- the desired precision plus guard digits might be less than
+ * the dividend's precision. This happens, for example, in the square
+ * root algorithm, where we typically divide a 2N-digit number by an
+ * N-digit number, and only require a result with N digits of precision.
+ */
+ div = (int *) palloc0((div_ndigits + 1) * sizeof(int));
+ load_ndigits = Min(div_ndigits, var1ndigits);
+ for (i = 0; i < load_ndigits; i++)
+ div[i + 1] = var1digits[i];
+
+ /*
+ * We estimate each quotient digit using floating-point arithmetic, taking
+ * the first four digits of the (current) dividend and divisor. This must
+ * be float to avoid overflow. The quotient digits will generally be off
+ * by no more than one from the exact answer.
+ */
+ fdivisor = (double) var2digits[0];
+ for (i = 1; i < 4; i++)
+ {
+ fdivisor *= NBASE;
+ if (i < var2ndigits)
+ fdivisor += (double) var2digits[i];
+ }
+ fdivisorinverse = 1.0 / fdivisor;
+
+ /*
+ * maxdiv tracks the maximum possible absolute value of any div[] entry;
+ * when this threatens to exceed INT_MAX, we take the time to propagate
+ * carries. Furthermore, we need to ensure that overflow doesn't occur
+ * during the carry propagation passes either. The carry values may have
+ * an absolute value as high as INT_MAX/NBASE + 1, so really we must
+ * normalize when digits threaten to exceed INT_MAX - INT_MAX/NBASE - 1.
+ *
+ * To avoid overflow in maxdiv itself, it represents the max absolute
+ * value divided by NBASE-1, ie, at the top of the loop it is known that
+ * no div[] entry has an absolute value exceeding maxdiv * (NBASE-1).
+ *
+ * Actually, though, that holds good only for div[] entries after div[qi];
+ * the adjustment done at the bottom of the loop may cause div[qi + 1] to
+ * exceed the maxdiv limit, so that div[qi] in the next iteration is
+ * beyond the limit. This does not cause problems, as explained below.
+ */
+ maxdiv = 1;
+
+ /*
+ * Outer loop computes next quotient digit, which will go into div[qi]
+ */
+ for (qi = 0; qi < div_ndigits; qi++)
+ {
+ /* Approximate the current dividend value */
+ fdividend = (double) div[qi];
+ for (i = 1; i < 4; i++)
+ {
+ fdividend *= NBASE;
+ if (qi + i <= div_ndigits)
+ fdividend += (double) div[qi + i];
+ }
+ /* Compute the (approximate) quotient digit */
+ fquotient = fdividend * fdivisorinverse;
+ qdigit = (fquotient >= 0.0) ? ((int) fquotient) :
+ (((int) fquotient) - 1); /* truncate towards -infinity */
+
+ if (qdigit != 0)
+ {
+ /* Do we need to normalize now? */
+ maxdiv += Abs(qdigit);
+ if (maxdiv > (INT_MAX - INT_MAX / NBASE - 1) / (NBASE - 1))
+ {
+ /*
+ * Yes, do it. Note that if var2ndigits is much smaller than
+ * div_ndigits, we can save a significant amount of effort
+ * here by noting that we only need to normalise those div[]
+ * entries touched where prior iterations subtracted multiples
+ * of the divisor.
+ */
+ carry = 0;
+ for (i = Min(qi + var2ndigits - 2, div_ndigits); i > qi; i--)
+ {
+ newdig = div[i] + carry;
+ if (newdig < 0)
+ {
+ carry = -((-newdig - 1) / NBASE) - 1;
+ newdig -= carry * NBASE;
+ }
+ else if (newdig >= NBASE)
+ {
+ carry = newdig / NBASE;
+ newdig -= carry * NBASE;
+ }
+ else
+ carry = 0;
+ div[i] = newdig;
+ }
+ newdig = div[qi] + carry;
+ div[qi] = newdig;
+
+ /*
+ * All the div[] digits except possibly div[qi] are now in the
+ * range 0..NBASE-1. We do not need to consider div[qi] in
+ * the maxdiv value anymore, so we can reset maxdiv to 1.
+ */
+ maxdiv = 1;
+
+ /*
+ * Recompute the quotient digit since new info may have
+ * propagated into the top four dividend digits
+ */
+ fdividend = (double) div[qi];
+ for (i = 1; i < 4; i++)
+ {
+ fdividend *= NBASE;
+ if (qi + i <= div_ndigits)
+ fdividend += (double) div[qi + i];
+ }
+ /* Compute the (approximate) quotient digit */
+ fquotient = fdividend * fdivisorinverse;
+ qdigit = (fquotient >= 0.0) ? ((int) fquotient) :
+ (((int) fquotient) - 1); /* truncate towards -infinity */
+ maxdiv += Abs(qdigit);
+ }
+
+ /*
+ * Subtract off the appropriate multiple of the divisor.
+ *
+ * The digits beyond div[qi] cannot overflow, because we know they
+ * will fall within the maxdiv limit. As for div[qi] itself, note
+ * that qdigit is approximately trunc(div[qi] / vardigits[0]),
+ * which would make the new value simply div[qi] mod vardigits[0].
+ * The lower-order terms in qdigit can change this result by not
+ * more than about twice INT_MAX/NBASE, so overflow is impossible.
+ */
+ if (qdigit != 0)
+ {
+ int istop = Min(var2ndigits, div_ndigits - qi + 1);
+
+ for (i = 0; i < istop; i++)
+ div[qi + i] -= qdigit * var2digits[i];
+ }
+ }
+
+ /*
+ * The dividend digit we are about to replace might still be nonzero.
+ * Fold it into the next digit position.
+ *
+ * There is no risk of overflow here, although proving that requires
+ * some care. Much as with the argument for div[qi] not overflowing,
+ * if we consider the first two terms in the numerator and denominator
+ * of qdigit, we can see that the final value of div[qi + 1] will be
+ * approximately a remainder mod (vardigits[0]*NBASE + vardigits[1]).
+ * Accounting for the lower-order terms is a bit complicated but ends
+ * up adding not much more than INT_MAX/NBASE to the possible range.
+ * Thus, div[qi + 1] cannot overflow here, and in its role as div[qi]
+ * in the next loop iteration, it can't be large enough to cause
+ * overflow in the carry propagation step (if any), either.
+ *
+ * But having said that: div[qi] can be more than INT_MAX/NBASE, as
+ * noted above, which means that the product div[qi] * NBASE *can*
+ * overflow. When that happens, adding it to div[qi + 1] will always
+ * cause a canceling overflow so that the end result is correct. We
+ * could avoid the intermediate overflow by doing the multiplication
+ * and addition in int64 arithmetic, but so far there appears no need.
+ */
+ div[qi + 1] += div[qi] * NBASE;
+
+ div[qi] = qdigit;
+ }
+
+ /*
+ * Approximate and store the last quotient digit (div[div_ndigits])
+ */
+ fdividend = (double) div[qi];
+ for (i = 1; i < 4; i++)
+ fdividend *= NBASE;
+ fquotient = fdividend * fdivisorinverse;
+ qdigit = (fquotient >= 0.0) ? ((int) fquotient) :
+ (((int) fquotient) - 1); /* truncate towards -infinity */
+ div[qi] = qdigit;
+
+ /*
+ * Because the quotient digits might be off by one, some of them might be
+ * -1 or NBASE at this point. The represented value is correct in a
+ * mathematical sense, but it doesn't look right. We do a final carry
+ * propagation pass to normalize the digits, which we combine with storing
+ * the result digits into the output. Note that this is still done at
+ * full precision w/guard digits.
+ */
+ alloc_var(result, div_ndigits + 1);
+ res_digits = result->digits;
+ carry = 0;
+ for (i = div_ndigits; i >= 0; i--)
+ {
+ newdig = div[i] + carry;
+ if (newdig < 0)
+ {
+ carry = -((-newdig - 1) / NBASE) - 1;
+ newdig -= carry * NBASE;
+ }
+ else if (newdig >= NBASE)
+ {
+ carry = newdig / NBASE;
+ newdig -= carry * NBASE;
+ }
+ else
+ carry = 0;
+ res_digits[i] = newdig;
+ }
+ Assert(carry == 0);
+
+ pfree(div);
+
+ /*
+ * Finally, round the result to the requested precision.
+ */
+ result->weight = res_weight;
+ result->sign = res_sign;
+
+ /* Round to target rscale (and set result->dscale) */
+ if (round)
+ round_var(result, rscale);
+ else
+ trunc_var(result, rscale);
+
+ /* Strip leading and trailing zeroes */
+ strip_var(result);
+}
+
+
+/*
+ * Default scale selection for division
+ *
+ * Returns the appropriate result scale for the division result.
+ */
+static int
+select_div_scale(const NumericVar *var1, const NumericVar *var2)
+{
+ int weight1,
+ weight2,
+ qweight,
+ i;
+ NumericDigit firstdigit1,
+ firstdigit2;
+ int rscale;
+
+ /*
+ * The result scale of a division isn't specified in any SQL standard. For
+ * PostgreSQL we select a result scale that will give at least
+ * NUMERIC_MIN_SIG_DIGITS significant digits, so that numeric gives a
+ * result no less accurate than float8; but use a scale not less than
+ * either input's display scale.
+ */
+
+ /* Get the actual (normalized) weight and first digit of each input */
+
+ weight1 = 0; /* values to use if var1 is zero */
+ firstdigit1 = 0;
+ for (i = 0; i < var1->ndigits; i++)
+ {
+ firstdigit1 = var1->digits[i];
+ if (firstdigit1 != 0)
+ {
+ weight1 = var1->weight - i;
+ break;
+ }
+ }
+
+ weight2 = 0; /* values to use if var2 is zero */
+ firstdigit2 = 0;
+ for (i = 0; i < var2->ndigits; i++)
+ {
+ firstdigit2 = var2->digits[i];
+ if (firstdigit2 != 0)
+ {
+ weight2 = var2->weight - i;
+ break;
+ }
+ }
+
+ /*
+ * Estimate weight of quotient. If the two first digits are equal, we
+ * can't be sure, but assume that var1 is less than var2.
+ */
+ qweight = weight1 - weight2;
+ if (firstdigit1 <= firstdigit2)
+ qweight--;
+
+ /* Select result scale */
+ rscale = NUMERIC_MIN_SIG_DIGITS - qweight * DEC_DIGITS;
+ rscale = Max(rscale, var1->dscale);
+ rscale = Max(rscale, var2->dscale);
+ rscale = Max(rscale, NUMERIC_MIN_DISPLAY_SCALE);
+ rscale = Min(rscale, NUMERIC_MAX_DISPLAY_SCALE);
+
+ return rscale;
+}
+
+
+/*
+ * mod_var() -
+ *
+ * Calculate the modulo of two numerics at variable level
+ */
+static void
+mod_var(const NumericVar *var1, const NumericVar *var2, NumericVar *result)
+{
+ NumericVar tmp;
+
+ init_var(&tmp);
+
+ /* ---------
+ * We do this using the equation
+ * mod(x,y) = x - trunc(x/y)*y
+ * div_var can be persuaded to give us trunc(x/y) directly.
+ * ----------
+ */
+ div_var(var1, var2, &tmp, 0, false);
+
+ mul_var(var2, &tmp, &tmp, var2->dscale);
+
+ sub_var(var1, &tmp, result);
+
+ free_var(&tmp);
+}
+
+
+/*
+ * div_mod_var() -
+ *
+ * Calculate the truncated integer quotient and numeric remainder of two
+ * numeric variables. The remainder is precise to var2's dscale.
+ */
+static void
+div_mod_var(const NumericVar *var1, const NumericVar *var2,
+ NumericVar *quot, NumericVar *rem)
+{
+ NumericVar q;
+ NumericVar r;
+
+ init_var(&q);
+ init_var(&r);
+
+ /*
+ * Use div_var_fast() to get an initial estimate for the integer quotient.
+ * This might be inaccurate (per the warning in div_var_fast's comments),
+ * but we can correct it below.
+ */
+ div_var_fast(var1, var2, &q, 0, false);
+
+ /* Compute initial estimate of remainder using the quotient estimate. */
+ mul_var(var2, &q, &r, var2->dscale);
+ sub_var(var1, &r, &r);
+
+ /*
+ * Adjust the results if necessary --- the remainder should have the same
+ * sign as var1, and its absolute value should be less than the absolute
+ * value of var2.
+ */
+ while (r.ndigits != 0 && r.sign != var1->sign)
+ {
+ /* The absolute value of the quotient is too large */
+ if (var1->sign == var2->sign)
+ {
+ sub_var(&q, &const_one, &q);
+ add_var(&r, var2, &r);
+ }
+ else
+ {
+ add_var(&q, &const_one, &q);
+ sub_var(&r, var2, &r);
+ }
+ }
+
+ while (cmp_abs(&r, var2) >= 0)
+ {
+ /* The absolute value of the quotient is too small */
+ if (var1->sign == var2->sign)
+ {
+ add_var(&q, &const_one, &q);
+ sub_var(&r, var2, &r);
+ }
+ else
+ {
+ sub_var(&q, &const_one, &q);
+ add_var(&r, var2, &r);
+ }
+ }
+
+ set_var_from_var(&q, quot);
+ set_var_from_var(&r, rem);
+
+ free_var(&q);
+ free_var(&r);
+}
+
+
+/*
+ * ceil_var() -
+ *
+ * Return the smallest integer greater than or equal to the argument
+ * on variable level
+ */
+static void
+ceil_var(const NumericVar *var, NumericVar *result)
+{
+ NumericVar tmp;
+
+ init_var(&tmp);
+ set_var_from_var(var, &tmp);
+
+ trunc_var(&tmp, 0);
+
+ if (var->sign == NUMERIC_POS && cmp_var(var, &tmp) != 0)
+ add_var(&tmp, &const_one, &tmp);
+
+ set_var_from_var(&tmp, result);
+ free_var(&tmp);
+}
+
+
+/*
+ * floor_var() -
+ *
+ * Return the largest integer equal to or less than the argument
+ * on variable level
+ */
+static void
+floor_var(const NumericVar *var, NumericVar *result)
+{
+ NumericVar tmp;
+
+ init_var(&tmp);
+ set_var_from_var(var, &tmp);
+
+ trunc_var(&tmp, 0);
+
+ if (var->sign == NUMERIC_NEG && cmp_var(var, &tmp) != 0)
+ sub_var(&tmp, &const_one, &tmp);
+
+ set_var_from_var(&tmp, result);
+ free_var(&tmp);
+}
+
+
+/*
+ * gcd_var() -
+ *
+ * Calculate the greatest common divisor of two numerics at variable level
+ */
+static void
+gcd_var(const NumericVar *var1, const NumericVar *var2, NumericVar *result)
+{
+ int res_dscale;
+ int cmp;
+ NumericVar tmp_arg;
+ NumericVar mod;
+
+ res_dscale = Max(var1->dscale, var2->dscale);
+
+ /*
+ * Arrange for var1 to be the number with the greater absolute value.
+ *
+ * This would happen automatically in the loop below, but avoids an
+ * expensive modulo operation.
+ */
+ cmp = cmp_abs(var1, var2);
+ if (cmp < 0)
+ {
+ const NumericVar *tmp = var1;
+
+ var1 = var2;
+ var2 = tmp;
+ }
+
+ /*
+ * Also avoid the taking the modulo if the inputs have the same absolute
+ * value, or if the smaller input is zero.
+ */
+ if (cmp == 0 || var2->ndigits == 0)
+ {
+ set_var_from_var(var1, result);
+ result->sign = NUMERIC_POS;
+ result->dscale = res_dscale;
+ return;
+ }
+
+ init_var(&tmp_arg);
+ init_var(&mod);
+
+ /* Use the Euclidean algorithm to find the GCD */
+ set_var_from_var(var1, &tmp_arg);
+ set_var_from_var(var2, result);
+
+ for (;;)
+ {
+ /* this loop can take a while, so allow it to be interrupted */
+ CHECK_FOR_INTERRUPTS();
+
+ mod_var(&tmp_arg, result, &mod);
+ if (mod.ndigits == 0)
+ break;
+ set_var_from_var(result, &tmp_arg);
+ set_var_from_var(&mod, result);
+ }
+ result->sign = NUMERIC_POS;
+ result->dscale = res_dscale;
+
+ free_var(&tmp_arg);
+ free_var(&mod);
+}
+
+
+/*
+ * sqrt_var() -
+ *
+ * Compute the square root of x using the Karatsuba Square Root algorithm.
+ * NOTE: we allow rscale < 0 here, implying rounding before the decimal
+ * point.
+ */
+static void
+sqrt_var(const NumericVar *arg, NumericVar *result, int rscale)
+{
+ int stat;
+ int res_weight;
+ int res_ndigits;
+ int src_ndigits;
+ int step;
+ int ndigits[32];
+ int blen;
+ int64 arg_int64;
+ int src_idx;
+ int64 s_int64;
+ int64 r_int64;
+ NumericVar s_var;
+ NumericVar r_var;
+ NumericVar a0_var;
+ NumericVar a1_var;
+ NumericVar q_var;
+ NumericVar u_var;
+
+ stat = cmp_var(arg, &const_zero);
+ if (stat == 0)
+ {
+ zero_var(result);
+ result->dscale = rscale;
+ return;
+ }
+
+ /*
+ * SQL2003 defines sqrt() in terms of power, so we need to emit the right
+ * SQLSTATE error code if the operand is negative.
+ */
+ if (stat < 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_POWER_FUNCTION),
+ errmsg("cannot take square root of a negative number")));
+
+ init_var(&s_var);
+ init_var(&r_var);
+ init_var(&a0_var);
+ init_var(&a1_var);
+ init_var(&q_var);
+ init_var(&u_var);
+
+ /*
+ * The result weight is half the input weight, rounded towards minus
+ * infinity --- res_weight = floor(arg->weight / 2).
+ */
+ if (arg->weight >= 0)
+ res_weight = arg->weight / 2;
+ else
+ res_weight = -((-arg->weight - 1) / 2 + 1);
+
+ /*
+ * Number of NBASE digits to compute. To ensure correct rounding, compute
+ * at least 1 extra decimal digit. We explicitly allow rscale to be
+ * negative here, but must always compute at least 1 NBASE digit. Thus
+ * res_ndigits = res_weight + 1 + ceil((rscale + 1) / DEC_DIGITS) or 1.
+ */
+ if (rscale + 1 >= 0)
+ res_ndigits = res_weight + 1 + (rscale + DEC_DIGITS) / DEC_DIGITS;
+ else
+ res_ndigits = res_weight + 1 - (-rscale - 1) / DEC_DIGITS;
+ res_ndigits = Max(res_ndigits, 1);
+
+ /*
+ * Number of source NBASE digits logically required to produce a result
+ * with this precision --- every digit before the decimal point, plus 2
+ * for each result digit after the decimal point (or minus 2 for each
+ * result digit we round before the decimal point).
+ */
+ src_ndigits = arg->weight + 1 + (res_ndigits - res_weight - 1) * 2;
+ src_ndigits = Max(src_ndigits, 1);
+
+ /* ----------
+ * From this point on, we treat the input and the result as integers and
+ * compute the integer square root and remainder using the Karatsuba
+ * Square Root algorithm, which may be written recursively as follows:
+ *
+ * SqrtRem(n = a3*b^3 + a2*b^2 + a1*b + a0):
+ * [ for some base b, and coefficients a0,a1,a2,a3 chosen so that
+ * 0 <= a0,a1,a2 < b and a3 >= b/4 ]
+ * Let (s,r) = SqrtRem(a3*b + a2)
+ * Let (q,u) = DivRem(r*b + a1, 2*s)
+ * Let s = s*b + q
+ * Let r = u*b + a0 - q^2
+ * If r < 0 Then
+ * Let r = r + s
+ * Let s = s - 1
+ * Let r = r + s
+ * Return (s,r)
+ *
+ * See "Karatsuba Square Root", Paul Zimmermann, INRIA Research Report
+ * RR-3805, November 1999. At the time of writing this was available
+ * on the net at <https://hal.inria.fr/inria-00072854>.
+ *
+ * The way to read the assumption "n = a3*b^3 + a2*b^2 + a1*b + a0" is
+ * "choose a base b such that n requires at least four base-b digits to
+ * express; then those digits are a3,a2,a1,a0, with a3 possibly larger
+ * than b". For optimal performance, b should have approximately a
+ * quarter the number of digits in the input, so that the outer square
+ * root computes roughly twice as many digits as the inner one. For
+ * simplicity, we choose b = NBASE^blen, an integer power of NBASE.
+ *
+ * We implement the algorithm iteratively rather than recursively, to
+ * allow the working variables to be reused. With this approach, each
+ * digit of the input is read precisely once --- src_idx tracks the number
+ * of input digits used so far.
+ *
+ * The array ndigits[] holds the number of NBASE digits of the input that
+ * will have been used at the end of each iteration, which roughly doubles
+ * each time. Note that the array elements are stored in reverse order,
+ * so if the final iteration requires src_ndigits = 37 input digits, the
+ * array will contain [37,19,11,7,5,3], and we would start by computing
+ * the square root of the 3 most significant NBASE digits.
+ *
+ * In each iteration, we choose blen to be the largest integer for which
+ * the input number has a3 >= b/4, when written in the form above. In
+ * general, this means blen = src_ndigits / 4 (truncated), but if
+ * src_ndigits is a multiple of 4, that might lead to the coefficient a3
+ * being less than b/4 (if the first input digit is less than NBASE/4), in
+ * which case we choose blen = src_ndigits / 4 - 1. The number of digits
+ * in the inner square root is then src_ndigits - 2*blen. So, for
+ * example, if we have src_ndigits = 26 initially, the array ndigits[]
+ * will be either [26,14,8,4] or [26,14,8,6,4], depending on the size of
+ * the first input digit.
+ *
+ * Additionally, we can put an upper bound on the number of steps required
+ * as follows --- suppose that the number of source digits is an n-bit
+ * number in the range [2^(n-1), 2^n-1], then blen will be in the range
+ * [2^(n-3)-1, 2^(n-2)-1] and the number of digits in the inner square
+ * root will be in the range [2^(n-2), 2^(n-1)+1]. In the next step, blen
+ * will be in the range [2^(n-4)-1, 2^(n-3)] and the number of digits in
+ * the next inner square root will be in the range [2^(n-3), 2^(n-2)+1].
+ * This pattern repeats, and in the worst case the array ndigits[] will
+ * contain [2^n-1, 2^(n-1)+1, 2^(n-2)+1, ... 9, 5, 3], and the computation
+ * will require n steps. Therefore, since all digit array sizes are
+ * signed 32-bit integers, the number of steps required is guaranteed to
+ * be less than 32.
+ * ----------
+ */
+ step = 0;
+ while ((ndigits[step] = src_ndigits) > 4)
+ {
+ /* Choose b so that a3 >= b/4, as described above */
+ blen = src_ndigits / 4;
+ if (blen * 4 == src_ndigits && arg->digits[0] < NBASE / 4)
+ blen--;
+
+ /* Number of digits in the next step (inner square root) */
+ src_ndigits -= 2 * blen;
+ step++;
+ }
+
+ /*
+ * First iteration (innermost square root and remainder):
+ *
+ * Here src_ndigits <= 4, and the input fits in an int64. Its square root
+ * has at most 9 decimal digits, so estimate it using double precision
+ * arithmetic, which will in fact almost certainly return the correct
+ * result with no further correction required.
+ */
+ arg_int64 = arg->digits[0];
+ for (src_idx = 1; src_idx < src_ndigits; src_idx++)
+ {
+ arg_int64 *= NBASE;
+ if (src_idx < arg->ndigits)
+ arg_int64 += arg->digits[src_idx];
+ }
+
+ s_int64 = (int64) sqrt((double) arg_int64);
+ r_int64 = arg_int64 - s_int64 * s_int64;
+
+ /*
+ * Use Newton's method to correct the result, if necessary.
+ *
+ * This uses integer division with truncation to compute the truncated
+ * integer square root by iterating using the formula x -> (x + n/x) / 2.
+ * This is known to converge to isqrt(n), unless n+1 is a perfect square.
+ * If n+1 is a perfect square, the sequence will oscillate between the two
+ * values isqrt(n) and isqrt(n)+1, so we can be assured of convergence by
+ * checking the remainder.
+ */
+ while (r_int64 < 0 || r_int64 > 2 * s_int64)
+ {
+ s_int64 = (s_int64 + arg_int64 / s_int64) / 2;
+ r_int64 = arg_int64 - s_int64 * s_int64;
+ }
+
+ /*
+ * Iterations with src_ndigits <= 8:
+ *
+ * The next 1 or 2 iterations compute larger (outer) square roots with
+ * src_ndigits <= 8, so the result still fits in an int64 (even though the
+ * input no longer does) and we can continue to compute using int64
+ * variables to avoid more expensive numeric computations.
+ *
+ * It is fairly easy to see that there is no risk of the intermediate
+ * values below overflowing 64-bit integers. In the worst case, the
+ * previous iteration will have computed a 3-digit square root (of a
+ * 6-digit input less than NBASE^6 / 4), so at the start of this
+ * iteration, s will be less than NBASE^3 / 2 = 10^12 / 2, and r will be
+ * less than 10^12. In this case, blen will be 1, so numer will be less
+ * than 10^17, and denom will be less than 10^12 (and hence u will also be
+ * less than 10^12). Finally, since q^2 = u*b + a0 - r, we can also be
+ * sure that q^2 < 10^17. Therefore all these quantities fit comfortably
+ * in 64-bit integers.
+ */
+ step--;
+ while (step >= 0 && (src_ndigits = ndigits[step]) <= 8)
+ {
+ int b;
+ int a0;
+ int a1;
+ int i;
+ int64 numer;
+ int64 denom;
+ int64 q;
+ int64 u;
+
+ blen = (src_ndigits - src_idx) / 2;
+
+ /* Extract a1 and a0, and compute b */
+ a0 = 0;
+ a1 = 0;
+ b = 1;
+
+ for (i = 0; i < blen; i++, src_idx++)
+ {
+ b *= NBASE;
+ a1 *= NBASE;
+ if (src_idx < arg->ndigits)
+ a1 += arg->digits[src_idx];
+ }
+
+ for (i = 0; i < blen; i++, src_idx++)
+ {
+ a0 *= NBASE;
+ if (src_idx < arg->ndigits)
+ a0 += arg->digits[src_idx];
+ }
+
+ /* Compute (q,u) = DivRem(r*b + a1, 2*s) */
+ numer = r_int64 * b + a1;
+ denom = 2 * s_int64;
+ q = numer / denom;
+ u = numer - q * denom;
+
+ /* Compute s = s*b + q and r = u*b + a0 - q^2 */
+ s_int64 = s_int64 * b + q;
+ r_int64 = u * b + a0 - q * q;
+
+ if (r_int64 < 0)
+ {
+ /* s is too large by 1; set r += s, s--, r += s */
+ r_int64 += s_int64;
+ s_int64--;
+ r_int64 += s_int64;
+ }
+
+ Assert(src_idx == src_ndigits); /* All input digits consumed */
+ step--;
+ }
+
+ /*
+ * On platforms with 128-bit integer support, we can further delay the
+ * need to use numeric variables.
+ */
+#ifdef HAVE_INT128
+ if (step >= 0)
+ {
+ int128 s_int128;
+ int128 r_int128;
+
+ s_int128 = s_int64;
+ r_int128 = r_int64;
+
+ /*
+ * Iterations with src_ndigits <= 16:
+ *
+ * The result fits in an int128 (even though the input doesn't) so we
+ * use int128 variables to avoid more expensive numeric computations.
+ */
+ while (step >= 0 && (src_ndigits = ndigits[step]) <= 16)
+ {
+ int64 b;
+ int64 a0;
+ int64 a1;
+ int64 i;
+ int128 numer;
+ int128 denom;
+ int128 q;
+ int128 u;
+
+ blen = (src_ndigits - src_idx) / 2;
+
+ /* Extract a1 and a0, and compute b */
+ a0 = 0;
+ a1 = 0;
+ b = 1;
+
+ for (i = 0; i < blen; i++, src_idx++)
+ {
+ b *= NBASE;
+ a1 *= NBASE;
+ if (src_idx < arg->ndigits)
+ a1 += arg->digits[src_idx];
+ }
+
+ for (i = 0; i < blen; i++, src_idx++)
+ {
+ a0 *= NBASE;
+ if (src_idx < arg->ndigits)
+ a0 += arg->digits[src_idx];
+ }
+
+ /* Compute (q,u) = DivRem(r*b + a1, 2*s) */
+ numer = r_int128 * b + a1;
+ denom = 2 * s_int128;
+ q = numer / denom;
+ u = numer - q * denom;
+
+ /* Compute s = s*b + q and r = u*b + a0 - q^2 */
+ s_int128 = s_int128 * b + q;
+ r_int128 = u * b + a0 - q * q;
+
+ if (r_int128 < 0)
+ {
+ /* s is too large by 1; set r += s, s--, r += s */
+ r_int128 += s_int128;
+ s_int128--;
+ r_int128 += s_int128;
+ }
+
+ Assert(src_idx == src_ndigits); /* All input digits consumed */
+ step--;
+ }
+
+ /*
+ * All remaining iterations require numeric variables. Convert the
+ * integer values to NumericVar and continue. Note that in the final
+ * iteration we don't need the remainder, so we can save a few cycles
+ * there by not fully computing it.
+ */
+ int128_to_numericvar(s_int128, &s_var);
+ if (step >= 0)
+ int128_to_numericvar(r_int128, &r_var);
+ }
+ else
+ {
+ int64_to_numericvar(s_int64, &s_var);
+ /* step < 0, so we certainly don't need r */
+ }
+#else /* !HAVE_INT128 */
+ int64_to_numericvar(s_int64, &s_var);
+ if (step >= 0)
+ int64_to_numericvar(r_int64, &r_var);
+#endif /* HAVE_INT128 */
+
+ /*
+ * The remaining iterations with src_ndigits > 8 (or 16, if have int128)
+ * use numeric variables.
+ */
+ while (step >= 0)
+ {
+ int tmp_len;
+
+ src_ndigits = ndigits[step];
+ blen = (src_ndigits - src_idx) / 2;
+
+ /* Extract a1 and a0 */
+ if (src_idx < arg->ndigits)
+ {
+ tmp_len = Min(blen, arg->ndigits - src_idx);
+ alloc_var(&a1_var, tmp_len);
+ memcpy(a1_var.digits, arg->digits + src_idx,
+ tmp_len * sizeof(NumericDigit));
+ a1_var.weight = blen - 1;
+ a1_var.sign = NUMERIC_POS;
+ a1_var.dscale = 0;
+ strip_var(&a1_var);
+ }
+ else
+ {
+ zero_var(&a1_var);
+ a1_var.dscale = 0;
+ }
+ src_idx += blen;
+
+ if (src_idx < arg->ndigits)
+ {
+ tmp_len = Min(blen, arg->ndigits - src_idx);
+ alloc_var(&a0_var, tmp_len);
+ memcpy(a0_var.digits, arg->digits + src_idx,
+ tmp_len * sizeof(NumericDigit));
+ a0_var.weight = blen - 1;
+ a0_var.sign = NUMERIC_POS;
+ a0_var.dscale = 0;
+ strip_var(&a0_var);
+ }
+ else
+ {
+ zero_var(&a0_var);
+ a0_var.dscale = 0;
+ }
+ src_idx += blen;
+
+ /* Compute (q,u) = DivRem(r*b + a1, 2*s) */
+ set_var_from_var(&r_var, &q_var);
+ q_var.weight += blen;
+ add_var(&q_var, &a1_var, &q_var);
+ add_var(&s_var, &s_var, &u_var);
+ div_mod_var(&q_var, &u_var, &q_var, &u_var);
+
+ /* Compute s = s*b + q */
+ s_var.weight += blen;
+ add_var(&s_var, &q_var, &s_var);
+
+ /*
+ * Compute r = u*b + a0 - q^2.
+ *
+ * In the final iteration, we don't actually need r; we just need to
+ * know whether it is negative, so that we know whether to adjust s.
+ * So instead of the final subtraction we can just compare.
+ */
+ u_var.weight += blen;
+ add_var(&u_var, &a0_var, &u_var);
+ mul_var(&q_var, &q_var, &q_var, 0);
+
+ if (step > 0)
+ {
+ /* Need r for later iterations */
+ sub_var(&u_var, &q_var, &r_var);
+ if (r_var.sign == NUMERIC_NEG)
+ {
+ /* s is too large by 1; set r += s, s--, r += s */
+ add_var(&r_var, &s_var, &r_var);
+ sub_var(&s_var, &const_one, &s_var);
+ add_var(&r_var, &s_var, &r_var);
+ }
+ }
+ else
+ {
+ /* Don't need r anymore, except to test if s is too large by 1 */
+ if (cmp_var(&u_var, &q_var) < 0)
+ sub_var(&s_var, &const_one, &s_var);
+ }
+
+ Assert(src_idx == src_ndigits); /* All input digits consumed */
+ step--;
+ }
+
+ /*
+ * Construct the final result, rounding it to the requested precision.
+ */
+ set_var_from_var(&s_var, result);
+ result->weight = res_weight;
+ result->sign = NUMERIC_POS;
+
+ /* Round to target rscale (and set result->dscale) */
+ round_var(result, rscale);
+
+ /* Strip leading and trailing zeroes */
+ strip_var(result);
+
+ free_var(&s_var);
+ free_var(&r_var);
+ free_var(&a0_var);
+ free_var(&a1_var);
+ free_var(&q_var);
+ free_var(&u_var);
+}
+
+
+/*
+ * exp_var() -
+ *
+ * Raise e to the power of x, computed to rscale fractional digits
+ */
+static void
+exp_var(const NumericVar *arg, NumericVar *result, int rscale)
+{
+ NumericVar x;
+ NumericVar elem;
+ NumericVar ni;
+ double val;
+ int dweight;
+ int ndiv2;
+ int sig_digits;
+ int local_rscale;
+
+ init_var(&x);
+ init_var(&elem);
+ init_var(&ni);
+
+ set_var_from_var(arg, &x);
+
+ /*
+ * Estimate the dweight of the result using floating point arithmetic, so
+ * that we can choose an appropriate local rscale for the calculation.
+ */
+ val = numericvar_to_double_no_overflow(&x);
+
+ /* Guard against overflow/underflow */
+ /* If you change this limit, see also power_var()'s limit */
+ if (Abs(val) >= NUMERIC_MAX_RESULT_SCALE * 3)
+ {
+ if (val > 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("value overflows numeric format")));
+ zero_var(result);
+ result->dscale = rscale;
+ return;
+ }
+
+ /* decimal weight = log10(e^x) = x * log10(e) */
+ dweight = (int) (val * 0.434294481903252);
+
+ /*
+ * Reduce x to the range -0.01 <= x <= 0.01 (approximately) by dividing by
+ * 2^n, to improve the convergence rate of the Taylor series.
+ */
+ if (Abs(val) > 0.01)
+ {
+ NumericVar tmp;
+
+ init_var(&tmp);
+ set_var_from_var(&const_two, &tmp);
+
+ ndiv2 = 1;
+ val /= 2;
+
+ while (Abs(val) > 0.01)
+ {
+ ndiv2++;
+ val /= 2;
+ add_var(&tmp, &tmp, &tmp);
+ }
+
+ local_rscale = x.dscale + ndiv2;
+ div_var_fast(&x, &tmp, &x, local_rscale, true);
+
+ free_var(&tmp);
+ }
+ else
+ ndiv2 = 0;
+
+ /*
+ * Set the scale for the Taylor series expansion. The final result has
+ * (dweight + rscale + 1) significant digits. In addition, we have to
+ * raise the Taylor series result to the power 2^ndiv2, which introduces
+ * an error of up to around log10(2^ndiv2) digits, so work with this many
+ * extra digits of precision (plus a few more for good measure).
+ */
+ sig_digits = 1 + dweight + rscale + (int) (ndiv2 * 0.301029995663981);
+ sig_digits = Max(sig_digits, 0) + 8;
+
+ local_rscale = sig_digits - 1;
+
+ /*
+ * Use the Taylor series
+ *
+ * exp(x) = 1 + x + x^2/2! + x^3/3! + ...
+ *
+ * Given the limited range of x, this should converge reasonably quickly.
+ * We run the series until the terms fall below the local_rscale limit.
+ */
+ add_var(&const_one, &x, result);
+
+ mul_var(&x, &x, &elem, local_rscale);
+ set_var_from_var(&const_two, &ni);
+ div_var_fast(&elem, &ni, &elem, local_rscale, true);
+
+ while (elem.ndigits != 0)
+ {
+ add_var(result, &elem, result);
+
+ mul_var(&elem, &x, &elem, local_rscale);
+ add_var(&ni, &const_one, &ni);
+ div_var_fast(&elem, &ni, &elem, local_rscale, true);
+ }
+
+ /*
+ * Compensate for the argument range reduction. Since the weight of the
+ * result doubles with each multiplication, we can reduce the local rscale
+ * as we proceed.
+ */
+ while (ndiv2-- > 0)
+ {
+ local_rscale = sig_digits - result->weight * 2 * DEC_DIGITS;
+ local_rscale = Max(local_rscale, NUMERIC_MIN_DISPLAY_SCALE);
+ mul_var(result, result, result, local_rscale);
+ }
+
+ /* Round to requested rscale */
+ round_var(result, rscale);
+
+ free_var(&x);
+ free_var(&elem);
+ free_var(&ni);
+}
+
+
+/*
+ * Estimate the dweight of the most significant decimal digit of the natural
+ * logarithm of a number.
+ *
+ * Essentially, we're approximating log10(abs(ln(var))). This is used to
+ * determine the appropriate rscale when computing natural logarithms.
+ *
+ * Note: many callers call this before range-checking the input. Therefore,
+ * we must be robust against values that are invalid to apply ln() to.
+ * We don't wish to throw an error here, so just return zero in such cases.
+ */
+static int
+estimate_ln_dweight(const NumericVar *var)
+{
+ int ln_dweight;
+
+ /* Caller should fail on ln(negative), but for the moment return zero */
+ if (var->sign != NUMERIC_POS)
+ return 0;
+
+ if (cmp_var(var, &const_zero_point_nine) >= 0 &&
+ cmp_var(var, &const_one_point_one) <= 0)
+ {
+ /*
+ * 0.9 <= var <= 1.1
+ *
+ * ln(var) has a negative weight (possibly very large). To get a
+ * reasonably accurate result, estimate it using ln(1+x) ~= x.
+ */
+ NumericVar x;
+
+ init_var(&x);
+ sub_var(var, &const_one, &x);
+
+ if (x.ndigits > 0)
+ {
+ /* Use weight of most significant decimal digit of x */
+ ln_dweight = x.weight * DEC_DIGITS + (int) log10(x.digits[0]);
+ }
+ else
+ {
+ /* x = 0. Since ln(1) = 0 exactly, we don't need extra digits */
+ ln_dweight = 0;
+ }
+
+ free_var(&x);
+ }
+ else
+ {
+ /*
+ * Estimate the logarithm using the first couple of digits from the
+ * input number. This will give an accurate result whenever the input
+ * is not too close to 1.
+ */
+ if (var->ndigits > 0)
+ {
+ int digits;
+ int dweight;
+ double ln_var;
+
+ digits = var->digits[0];
+ dweight = var->weight * DEC_DIGITS;
+
+ if (var->ndigits > 1)
+ {
+ digits = digits * NBASE + var->digits[1];
+ dweight -= DEC_DIGITS;
+ }
+
+ /*----------
+ * We have var ~= digits * 10^dweight
+ * so ln(var) ~= ln(digits) + dweight * ln(10)
+ *----------
+ */
+ ln_var = log((double) digits) + dweight * 2.302585092994046;
+ ln_dweight = (int) log10(Abs(ln_var));
+ }
+ else
+ {
+ /* Caller should fail on ln(0), but for the moment return zero */
+ ln_dweight = 0;
+ }
+ }
+
+ return ln_dweight;
+}
+
+
+/*
+ * ln_var() -
+ *
+ * Compute the natural log of x
+ */
+static void
+ln_var(const NumericVar *arg, NumericVar *result, int rscale)
+{
+ NumericVar x;
+ NumericVar xx;
+ NumericVar ni;
+ NumericVar elem;
+ NumericVar fact;
+ int nsqrt;
+ int local_rscale;
+ int cmp;
+
+ cmp = cmp_var(arg, &const_zero);
+ if (cmp == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_LOG),
+ errmsg("cannot take logarithm of zero")));
+ else if (cmp < 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_LOG),
+ errmsg("cannot take logarithm of a negative number")));
+
+ init_var(&x);
+ init_var(&xx);
+ init_var(&ni);
+ init_var(&elem);
+ init_var(&fact);
+
+ set_var_from_var(arg, &x);
+ set_var_from_var(&const_two, &fact);
+
+ /*
+ * Reduce input into range 0.9 < x < 1.1 with repeated sqrt() operations.
+ *
+ * The final logarithm will have up to around rscale+6 significant digits.
+ * Each sqrt() will roughly halve the weight of x, so adjust the local
+ * rscale as we work so that we keep this many significant digits at each
+ * step (plus a few more for good measure).
+ *
+ * Note that we allow local_rscale < 0 during this input reduction
+ * process, which implies rounding before the decimal point. sqrt_var()
+ * explicitly supports this, and it significantly reduces the work
+ * required to reduce very large inputs to the required range. Once the
+ * input reduction is complete, x.weight will be 0 and its display scale
+ * will be non-negative again.
+ */
+ nsqrt = 0;
+ while (cmp_var(&x, &const_zero_point_nine) <= 0)
+ {
+ local_rscale = rscale - x.weight * DEC_DIGITS / 2 + 8;
+ sqrt_var(&x, &x, local_rscale);
+ mul_var(&fact, &const_two, &fact, 0);
+ nsqrt++;
+ }
+ while (cmp_var(&x, &const_one_point_one) >= 0)
+ {
+ local_rscale = rscale - x.weight * DEC_DIGITS / 2 + 8;
+ sqrt_var(&x, &x, local_rscale);
+ mul_var(&fact, &const_two, &fact, 0);
+ nsqrt++;
+ }
+
+ /*
+ * We use the Taylor series for 0.5 * ln((1+z)/(1-z)),
+ *
+ * z + z^3/3 + z^5/5 + ...
+ *
+ * where z = (x-1)/(x+1) is in the range (approximately) -0.053 .. 0.048
+ * due to the above range-reduction of x.
+ *
+ * The convergence of this is not as fast as one would like, but is
+ * tolerable given that z is small.
+ *
+ * The Taylor series result will be multiplied by 2^(nsqrt+1), which has a
+ * decimal weight of (nsqrt+1) * log10(2), so work with this many extra
+ * digits of precision (plus a few more for good measure).
+ */
+ local_rscale = rscale + (int) ((nsqrt + 1) * 0.301029995663981) + 8;
+
+ sub_var(&x, &const_one, result);
+ add_var(&x, &const_one, &elem);
+ div_var_fast(result, &elem, result, local_rscale, true);
+ set_var_from_var(result, &xx);
+ mul_var(result, result, &x, local_rscale);
+
+ set_var_from_var(&const_one, &ni);
+
+ for (;;)
+ {
+ add_var(&ni, &const_two, &ni);
+ mul_var(&xx, &x, &xx, local_rscale);
+ div_var_fast(&xx, &ni, &elem, local_rscale, true);
+
+ if (elem.ndigits == 0)
+ break;
+
+ add_var(result, &elem, result);
+
+ if (elem.weight < (result->weight - local_rscale * 2 / DEC_DIGITS))
+ break;
+ }
+
+ /* Compensate for argument range reduction, round to requested rscale */
+ mul_var(result, &fact, result, rscale);
+
+ free_var(&x);
+ free_var(&xx);
+ free_var(&ni);
+ free_var(&elem);
+ free_var(&fact);
+}
+
+
+/*
+ * log_var() -
+ *
+ * Compute the logarithm of num in a given base.
+ *
+ * Note: this routine chooses dscale of the result.
+ */
+static void
+log_var(const NumericVar *base, const NumericVar *num, NumericVar *result)
+{
+ NumericVar ln_base;
+ NumericVar ln_num;
+ int ln_base_dweight;
+ int ln_num_dweight;
+ int result_dweight;
+ int rscale;
+ int ln_base_rscale;
+ int ln_num_rscale;
+
+ init_var(&ln_base);
+ init_var(&ln_num);
+
+ /* Estimated dweights of ln(base), ln(num) and the final result */
+ ln_base_dweight = estimate_ln_dweight(base);
+ ln_num_dweight = estimate_ln_dweight(num);
+ result_dweight = ln_num_dweight - ln_base_dweight;
+
+ /*
+ * Select the scale of the result so that it will have at least
+ * NUMERIC_MIN_SIG_DIGITS significant digits and is not less than either
+ * input's display scale.
+ */
+ rscale = NUMERIC_MIN_SIG_DIGITS - result_dweight;
+ rscale = Max(rscale, base->dscale);
+ rscale = Max(rscale, num->dscale);
+ rscale = Max(rscale, NUMERIC_MIN_DISPLAY_SCALE);
+ rscale = Min(rscale, NUMERIC_MAX_DISPLAY_SCALE);
+
+ /*
+ * Set the scales for ln(base) and ln(num) so that they each have more
+ * significant digits than the final result.
+ */
+ ln_base_rscale = rscale + result_dweight - ln_base_dweight + 8;
+ ln_base_rscale = Max(ln_base_rscale, NUMERIC_MIN_DISPLAY_SCALE);
+
+ ln_num_rscale = rscale + result_dweight - ln_num_dweight + 8;
+ ln_num_rscale = Max(ln_num_rscale, NUMERIC_MIN_DISPLAY_SCALE);
+
+ /* Form natural logarithms */
+ ln_var(base, &ln_base, ln_base_rscale);
+ ln_var(num, &ln_num, ln_num_rscale);
+
+ /* Divide and round to the required scale */
+ div_var_fast(&ln_num, &ln_base, result, rscale, true);
+
+ free_var(&ln_num);
+ free_var(&ln_base);
+}
+
+
+/*
+ * power_var() -
+ *
+ * Raise base to the power of exp
+ *
+ * Note: this routine chooses dscale of the result.
+ */
+static void
+power_var(const NumericVar *base, const NumericVar *exp, NumericVar *result)
+{
+ int res_sign;
+ NumericVar abs_base;
+ NumericVar ln_base;
+ NumericVar ln_num;
+ int ln_dweight;
+ int rscale;
+ int sig_digits;
+ int local_rscale;
+ double val;
+
+ /* If exp can be represented as an integer, use power_var_int */
+ if (exp->ndigits == 0 || exp->ndigits <= exp->weight + 1)
+ {
+ /* exact integer, but does it fit in int? */
+ int64 expval64;
+
+ if (numericvar_to_int64(exp, &expval64))
+ {
+ if (expval64 >= PG_INT32_MIN && expval64 <= PG_INT32_MAX)
+ {
+ /* Okay, select rscale */
+ rscale = NUMERIC_MIN_SIG_DIGITS;
+ rscale = Max(rscale, base->dscale);
+ rscale = Max(rscale, NUMERIC_MIN_DISPLAY_SCALE);
+ rscale = Min(rscale, NUMERIC_MAX_DISPLAY_SCALE);
+
+ power_var_int(base, (int) expval64, result, rscale);
+ return;
+ }
+ }
+ }
+
+ /*
+ * This avoids log(0) for cases of 0 raised to a non-integer. 0 ^ 0 is
+ * handled by power_var_int().
+ */
+ if (cmp_var(base, &const_zero) == 0)
+ {
+ set_var_from_var(&const_zero, result);
+ result->dscale = NUMERIC_MIN_SIG_DIGITS; /* no need to round */
+ return;
+ }
+
+ init_var(&abs_base);
+ init_var(&ln_base);
+ init_var(&ln_num);
+
+ /*
+ * If base is negative, insist that exp be an integer. The result is then
+ * positive if exp is even and negative if exp is odd.
+ */
+ if (base->sign == NUMERIC_NEG)
+ {
+ /*
+ * Check that exp is an integer. This error code is defined by the
+ * SQL standard, and matches other errors in numeric_power().
+ */
+ if (exp->ndigits > 0 && exp->ndigits > exp->weight + 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_ARGUMENT_FOR_POWER_FUNCTION),
+ errmsg("a negative number raised to a non-integer power yields a complex result")));
+
+ /* Test if exp is odd or even */
+ if (exp->ndigits > 0 && exp->ndigits == exp->weight + 1 &&
+ (exp->digits[exp->ndigits - 1] & 1))
+ res_sign = NUMERIC_NEG;
+ else
+ res_sign = NUMERIC_POS;
+
+ /* Then work with abs(base) below */
+ set_var_from_var(base, &abs_base);
+ abs_base.sign = NUMERIC_POS;
+ base = &abs_base;
+ }
+ else
+ res_sign = NUMERIC_POS;
+
+ /*----------
+ * Decide on the scale for the ln() calculation. For this we need an
+ * estimate of the weight of the result, which we obtain by doing an
+ * initial low-precision calculation of exp * ln(base).
+ *
+ * We want result = e ^ (exp * ln(base))
+ * so result dweight = log10(result) = exp * ln(base) * log10(e)
+ *
+ * We also perform a crude overflow test here so that we can exit early if
+ * the full-precision result is sure to overflow, and to guard against
+ * integer overflow when determining the scale for the real calculation.
+ * exp_var() supports inputs up to NUMERIC_MAX_RESULT_SCALE * 3, so the
+ * result will overflow if exp * ln(base) >= NUMERIC_MAX_RESULT_SCALE * 3.
+ * Since the values here are only approximations, we apply a small fuzz
+ * factor to this overflow test and let exp_var() determine the exact
+ * overflow threshold so that it is consistent for all inputs.
+ *----------
+ */
+ ln_dweight = estimate_ln_dweight(base);
+
+ /*
+ * Set the scale for the low-precision calculation, computing ln(base) to
+ * around 8 significant digits. Note that ln_dweight may be as small as
+ * -SHRT_MAX, so the scale may exceed NUMERIC_MAX_DISPLAY_SCALE here.
+ */
+ local_rscale = 8 - ln_dweight;
+ local_rscale = Max(local_rscale, NUMERIC_MIN_DISPLAY_SCALE);
+
+ ln_var(base, &ln_base, local_rscale);
+
+ mul_var(&ln_base, exp, &ln_num, local_rscale);
+
+ val = numericvar_to_double_no_overflow(&ln_num);
+
+ /* initial overflow/underflow test with fuzz factor */
+ if (Abs(val) > NUMERIC_MAX_RESULT_SCALE * 3.01)
+ {
+ if (val > 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("value overflows numeric format")));
+ zero_var(result);
+ result->dscale = NUMERIC_MAX_DISPLAY_SCALE;
+ return;
+ }
+
+ val *= 0.434294481903252; /* approximate decimal result weight */
+
+ /* choose the result scale */
+ rscale = NUMERIC_MIN_SIG_DIGITS - (int) val;
+ rscale = Max(rscale, base->dscale);
+ rscale = Max(rscale, exp->dscale);
+ rscale = Max(rscale, NUMERIC_MIN_DISPLAY_SCALE);
+ rscale = Min(rscale, NUMERIC_MAX_DISPLAY_SCALE);
+
+ /* significant digits required in the result */
+ sig_digits = rscale + (int) val;
+ sig_digits = Max(sig_digits, 0);
+
+ /* set the scale for the real exp * ln(base) calculation */
+ local_rscale = sig_digits - ln_dweight + 8;
+ local_rscale = Max(local_rscale, NUMERIC_MIN_DISPLAY_SCALE);
+
+ /* and do the real calculation */
+
+ ln_var(base, &ln_base, local_rscale);
+
+ mul_var(&ln_base, exp, &ln_num, local_rscale);
+
+ exp_var(&ln_num, result, rscale);
+
+ if (res_sign == NUMERIC_NEG && result->ndigits > 0)
+ result->sign = NUMERIC_NEG;
+
+ free_var(&ln_num);
+ free_var(&ln_base);
+ free_var(&abs_base);
+}
+
+/*
+ * power_var_int() -
+ *
+ * Raise base to the power of exp, where exp is an integer.
+ */
+static void
+power_var_int(const NumericVar *base, int exp, NumericVar *result, int rscale)
+{
+ double f;
+ int p;
+ int i;
+ int sig_digits;
+ unsigned int mask;
+ bool neg;
+ NumericVar base_prod;
+ int local_rscale;
+
+ /* Handle some common special cases, as well as corner cases */
+ switch (exp)
+ {
+ case 0:
+
+ /*
+ * While 0 ^ 0 can be either 1 or indeterminate (error), we treat
+ * it as 1 because most programming languages do this. SQL:2003
+ * also requires a return value of 1.
+ * https://en.wikipedia.org/wiki/Exponentiation#Zero_to_the_zero_power
+ */
+ set_var_from_var(&const_one, result);
+ result->dscale = rscale; /* no need to round */
+ return;
+ case 1:
+ set_var_from_var(base, result);
+ round_var(result, rscale);
+ return;
+ case -1:
+ div_var(&const_one, base, result, rscale, true);
+ return;
+ case 2:
+ mul_var(base, base, result, rscale);
+ return;
+ default:
+ break;
+ }
+
+ /* Handle the special case where the base is zero */
+ if (base->ndigits == 0)
+ {
+ if (exp < 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_DIVISION_BY_ZERO),
+ errmsg("division by zero")));
+ zero_var(result);
+ result->dscale = rscale;
+ return;
+ }
+
+ /*
+ * The general case repeatedly multiplies base according to the bit
+ * pattern of exp.
+ *
+ * First we need to estimate the weight of the result so that we know how
+ * many significant digits are needed.
+ */
+ f = base->digits[0];
+ p = base->weight * DEC_DIGITS;
+
+ for (i = 1; i < base->ndigits && i * DEC_DIGITS < 16; i++)
+ {
+ f = f * NBASE + base->digits[i];
+ p -= DEC_DIGITS;
+ }
+
+ /*----------
+ * We have base ~= f * 10^p
+ * so log10(result) = log10(base^exp) ~= exp * (log10(f) + p)
+ *----------
+ */
+ f = exp * (log10(f) + p);
+
+ /*
+ * Apply crude overflow/underflow tests so we can exit early if the result
+ * certainly will overflow/underflow.
+ */
+ if (f > 3 * SHRT_MAX * DEC_DIGITS)
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("value overflows numeric format")));
+ if (f + 1 < -rscale || f + 1 < -NUMERIC_MAX_DISPLAY_SCALE)
+ {
+ zero_var(result);
+ result->dscale = rscale;
+ return;
+ }
+
+ /*
+ * Approximate number of significant digits in the result. Note that the
+ * underflow test above means that this is necessarily >= 0.
+ */
+ sig_digits = 1 + rscale + (int) f;
+
+ /*
+ * The multiplications to produce the result may introduce an error of up
+ * to around log10(abs(exp)) digits, so work with this many extra digits
+ * of precision (plus a few more for good measure).
+ */
+ sig_digits += (int) log(fabs((double) exp)) + 8;
+
+ /*
+ * Now we can proceed with the multiplications.
+ */
+ neg = (exp < 0);
+ mask = Abs(exp);
+
+ init_var(&base_prod);
+ set_var_from_var(base, &base_prod);
+
+ if (mask & 1)
+ set_var_from_var(base, result);
+ else
+ set_var_from_var(&const_one, result);
+
+ while ((mask >>= 1) > 0)
+ {
+ /*
+ * Do the multiplications using rscales large enough to hold the
+ * results to the required number of significant digits, but don't
+ * waste time by exceeding the scales of the numbers themselves.
+ */
+ local_rscale = sig_digits - 2 * base_prod.weight * DEC_DIGITS;
+ local_rscale = Min(local_rscale, 2 * base_prod.dscale);
+ local_rscale = Max(local_rscale, NUMERIC_MIN_DISPLAY_SCALE);
+
+ mul_var(&base_prod, &base_prod, &base_prod, local_rscale);
+
+ if (mask & 1)
+ {
+ local_rscale = sig_digits -
+ (base_prod.weight + result->weight) * DEC_DIGITS;
+ local_rscale = Min(local_rscale,
+ base_prod.dscale + result->dscale);
+ local_rscale = Max(local_rscale, NUMERIC_MIN_DISPLAY_SCALE);
+
+ mul_var(&base_prod, result, result, local_rscale);
+ }
+
+ /*
+ * When abs(base) > 1, the number of digits to the left of the decimal
+ * point in base_prod doubles at each iteration, so if exp is large we
+ * could easily spend large amounts of time and memory space doing the
+ * multiplications. But once the weight exceeds what will fit in
+ * int16, the final result is guaranteed to overflow (or underflow, if
+ * exp < 0), so we can give up before wasting too many cycles.
+ */
+ if (base_prod.weight > SHRT_MAX || result->weight > SHRT_MAX)
+ {
+ /* overflow, unless neg, in which case result should be 0 */
+ if (!neg)
+ ereport(ERROR,
+ (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+ errmsg("value overflows numeric format")));
+ zero_var(result);
+ neg = false;
+ break;
+ }
+ }
+
+ free_var(&base_prod);
+
+ /* Compensate for input sign, and round to requested rscale */
+ if (neg)
+ div_var_fast(&const_one, result, result, rscale, true);
+ else
+ round_var(result, rscale);
+}
+
+/*
+ * power_ten_int() -
+ *
+ * Raise ten to the power of exp, where exp is an integer. Note that unlike
+ * power_var_int(), this does no overflow/underflow checking or rounding.
+ */
+static void
+power_ten_int(int exp, NumericVar *result)
+{
+ /* Construct the result directly, starting from 10^0 = 1 */
+ set_var_from_var(&const_one, result);
+
+ /* Scale needed to represent the result exactly */
+ result->dscale = exp < 0 ? -exp : 0;
+
+ /* Base-NBASE weight of result and remaining exponent */
+ if (exp >= 0)
+ result->weight = exp / DEC_DIGITS;
+ else
+ result->weight = (exp + 1) / DEC_DIGITS - 1;
+
+ exp -= result->weight * DEC_DIGITS;
+
+ /* Final adjustment of the result's single NBASE digit */
+ while (exp-- > 0)
+ result->digits[0] *= 10;
+}
+
+
+/* ----------------------------------------------------------------------
+ *
+ * Following are the lowest level functions that operate unsigned
+ * on the variable level
+ *
+ * ----------------------------------------------------------------------
+ */
+
+
+/* ----------
+ * cmp_abs() -
+ *
+ * Compare the absolute values of var1 and var2
+ * Returns: -1 for ABS(var1) < ABS(var2)
+ * 0 for ABS(var1) == ABS(var2)
+ * 1 for ABS(var1) > ABS(var2)
+ * ----------
+ */
+static int
+cmp_abs(const NumericVar *var1, const NumericVar *var2)
+{
+ return cmp_abs_common(var1->digits, var1->ndigits, var1->weight,
+ var2->digits, var2->ndigits, var2->weight);
+}
+
+/* ----------
+ * cmp_abs_common() -
+ *
+ * Main routine of cmp_abs(). This function can be used by both
+ * NumericVar and Numeric.
+ * ----------
+ */
+static int
+cmp_abs_common(const NumericDigit *var1digits, int var1ndigits, int var1weight,
+ const NumericDigit *var2digits, int var2ndigits, int var2weight)
+{
+ int i1 = 0;
+ int i2 = 0;
+
+ /* Check any digits before the first common digit */
+
+ while (var1weight > var2weight && i1 < var1ndigits)
+ {
+ if (var1digits[i1++] != 0)
+ return 1;
+ var1weight--;
+ }
+ while (var2weight > var1weight && i2 < var2ndigits)
+ {
+ if (var2digits[i2++] != 0)
+ return -1;
+ var2weight--;
+ }
+
+ /* At this point, either w1 == w2 or we've run out of digits */
+
+ if (var1weight == var2weight)
+ {
+ while (i1 < var1ndigits && i2 < var2ndigits)
+ {
+ int stat = var1digits[i1++] - var2digits[i2++];
+
+ if (stat)
+ {
+ if (stat > 0)
+ return 1;
+ return -1;
+ }
+ }
+ }
+
+ /*
+ * At this point, we've run out of digits on one side or the other; so any
+ * remaining nonzero digits imply that side is larger
+ */
+ while (i1 < var1ndigits)
+ {
+ if (var1digits[i1++] != 0)
+ return 1;
+ }
+ while (i2 < var2ndigits)
+ {
+ if (var2digits[i2++] != 0)
+ return -1;
+ }
+
+ return 0;
+}
+
+
+/*
+ * add_abs() -
+ *
+ * Add the absolute values of two variables into result.
+ * result might point to one of the operands without danger.
+ */
+static void
+add_abs(const NumericVar *var1, const NumericVar *var2, NumericVar *result)
+{
+ NumericDigit *res_buf;
+ NumericDigit *res_digits;
+ int res_ndigits;
+ int res_weight;
+ int res_rscale,
+ rscale1,
+ rscale2;
+ int res_dscale;
+ int i,
+ i1,
+ i2;
+ int carry = 0;
+
+ /* copy these values into local vars for speed in inner loop */
+ int var1ndigits = var1->ndigits;
+ int var2ndigits = var2->ndigits;
+ NumericDigit *var1digits = var1->digits;
+ NumericDigit *var2digits = var2->digits;
+
+ res_weight = Max(var1->weight, var2->weight) + 1;
+
+ res_dscale = Max(var1->dscale, var2->dscale);
+
+ /* Note: here we are figuring rscale in base-NBASE digits */
+ rscale1 = var1->ndigits - var1->weight - 1;
+ rscale2 = var2->ndigits - var2->weight - 1;
+ res_rscale = Max(rscale1, rscale2);
+
+ res_ndigits = res_rscale + res_weight + 1;
+ if (res_ndigits <= 0)
+ res_ndigits = 1;
+
+ res_buf = digitbuf_alloc(res_ndigits + 1);
+ res_buf[0] = 0; /* spare digit for later rounding */
+ res_digits = res_buf + 1;
+
+ i1 = res_rscale + var1->weight + 1;
+ i2 = res_rscale + var2->weight + 1;
+ for (i = res_ndigits - 1; i >= 0; i--)
+ {
+ i1--;
+ i2--;
+ if (i1 >= 0 && i1 < var1ndigits)
+ carry += var1digits[i1];
+ if (i2 >= 0 && i2 < var2ndigits)
+ carry += var2digits[i2];
+
+ if (carry >= NBASE)
+ {
+ res_digits[i] = carry - NBASE;
+ carry = 1;
+ }
+ else
+ {
+ res_digits[i] = carry;
+ carry = 0;
+ }
+ }
+
+ Assert(carry == 0); /* else we failed to allow for carry out */
+
+ digitbuf_free(result->buf);
+ result->ndigits = res_ndigits;
+ result->buf = res_buf;
+ result->digits = res_digits;
+ result->weight = res_weight;
+ result->dscale = res_dscale;
+
+ /* Remove leading/trailing zeroes */
+ strip_var(result);
+}
+
+
+/*
+ * sub_abs()
+ *
+ * Subtract the absolute value of var2 from the absolute value of var1
+ * and store in result. result might point to one of the operands
+ * without danger.
+ *
+ * ABS(var1) MUST BE GREATER OR EQUAL ABS(var2) !!!
+ */
+static void
+sub_abs(const NumericVar *var1, const NumericVar *var2, NumericVar *result)
+{
+ NumericDigit *res_buf;
+ NumericDigit *res_digits;
+ int res_ndigits;
+ int res_weight;
+ int res_rscale,
+ rscale1,
+ rscale2;
+ int res_dscale;
+ int i,
+ i1,
+ i2;
+ int borrow = 0;
+
+ /* copy these values into local vars for speed in inner loop */
+ int var1ndigits = var1->ndigits;
+ int var2ndigits = var2->ndigits;
+ NumericDigit *var1digits = var1->digits;
+ NumericDigit *var2digits = var2->digits;
+
+ res_weight = var1->weight;
+
+ res_dscale = Max(var1->dscale, var2->dscale);
+
+ /* Note: here we are figuring rscale in base-NBASE digits */
+ rscale1 = var1->ndigits - var1->weight - 1;
+ rscale2 = var2->ndigits - var2->weight - 1;
+ res_rscale = Max(rscale1, rscale2);
+
+ res_ndigits = res_rscale + res_weight + 1;
+ if (res_ndigits <= 0)
+ res_ndigits = 1;
+
+ res_buf = digitbuf_alloc(res_ndigits + 1);
+ res_buf[0] = 0; /* spare digit for later rounding */
+ res_digits = res_buf + 1;
+
+ i1 = res_rscale + var1->weight + 1;
+ i2 = res_rscale + var2->weight + 1;
+ for (i = res_ndigits - 1; i >= 0; i--)
+ {
+ i1--;
+ i2--;
+ if (i1 >= 0 && i1 < var1ndigits)
+ borrow += var1digits[i1];
+ if (i2 >= 0 && i2 < var2ndigits)
+ borrow -= var2digits[i2];
+
+ if (borrow < 0)
+ {
+ res_digits[i] = borrow + NBASE;
+ borrow = -1;
+ }
+ else
+ {
+ res_digits[i] = borrow;
+ borrow = 0;
+ }
+ }
+
+ Assert(borrow == 0); /* else caller gave us var1 < var2 */
+
+ digitbuf_free(result->buf);
+ result->ndigits = res_ndigits;
+ result->buf = res_buf;
+ result->digits = res_digits;
+ result->weight = res_weight;
+ result->dscale = res_dscale;
+
+ /* Remove leading/trailing zeroes */
+ strip_var(result);
+}
+
+/*
+ * round_var
+ *
+ * Round the value of a variable to no more than rscale decimal digits
+ * after the decimal point. NOTE: we allow rscale < 0 here, implying
+ * rounding before the decimal point.
+ */
+static void
+round_var(NumericVar *var, int rscale)
+{
+ NumericDigit *digits = var->digits;
+ int di;
+ int ndigits;
+ int carry;
+
+ var->dscale = rscale;
+
+ /* decimal digits wanted */
+ di = (var->weight + 1) * DEC_DIGITS + rscale;
+
+ /*
+ * If di = 0, the value loses all digits, but could round up to 1 if its
+ * first extra digit is >= 5. If di < 0 the result must be 0.
+ */
+ if (di < 0)
+ {
+ var->ndigits = 0;
+ var->weight = 0;
+ var->sign = NUMERIC_POS;
+ }
+ else
+ {
+ /* NBASE digits wanted */
+ ndigits = (di + DEC_DIGITS - 1) / DEC_DIGITS;
+
+ /* 0, or number of decimal digits to keep in last NBASE digit */
+ di %= DEC_DIGITS;
+
+ if (ndigits < var->ndigits ||
+ (ndigits == var->ndigits && di > 0))
+ {
+ var->ndigits = ndigits;
+
+#if DEC_DIGITS == 1
+ /* di must be zero */
+ carry = (digits[ndigits] >= HALF_NBASE) ? 1 : 0;
+#else
+ if (di == 0)
+ carry = (digits[ndigits] >= HALF_NBASE) ? 1 : 0;
+ else
+ {
+ /* Must round within last NBASE digit */
+ int extra,
+ pow10;
+
+#if DEC_DIGITS == 4
+ pow10 = round_powers[di];
+#elif DEC_DIGITS == 2
+ pow10 = 10;
+#else
+#error unsupported NBASE
+#endif
+ extra = digits[--ndigits] % pow10;
+ digits[ndigits] -= extra;
+ carry = 0;
+ if (extra >= pow10 / 2)
+ {
+ pow10 += digits[ndigits];
+ if (pow10 >= NBASE)
+ {
+ pow10 -= NBASE;
+ carry = 1;
+ }
+ digits[ndigits] = pow10;
+ }
+ }
+#endif
+
+ /* Propagate carry if needed */
+ while (carry)
+ {
+ carry += digits[--ndigits];
+ if (carry >= NBASE)
+ {
+ digits[ndigits] = carry - NBASE;
+ carry = 1;
+ }
+ else
+ {
+ digits[ndigits] = carry;
+ carry = 0;
+ }
+ }
+
+ if (ndigits < 0)
+ {
+ Assert(ndigits == -1); /* better not have added > 1 digit */
+ Assert(var->digits > var->buf);
+ var->digits--;
+ var->ndigits++;
+ var->weight++;
+ }
+ }
+ }
+}
+
+/*
+ * trunc_var
+ *
+ * Truncate (towards zero) the value of a variable at rscale decimal digits
+ * after the decimal point. NOTE: we allow rscale < 0 here, implying
+ * truncation before the decimal point.
+ */
+static void
+trunc_var(NumericVar *var, int rscale)
+{
+ int di;
+ int ndigits;
+
+ var->dscale = rscale;
+
+ /* decimal digits wanted */
+ di = (var->weight + 1) * DEC_DIGITS + rscale;
+
+ /*
+ * If di <= 0, the value loses all digits.
+ */
+ if (di <= 0)
+ {
+ var->ndigits = 0;
+ var->weight = 0;
+ var->sign = NUMERIC_POS;
+ }
+ else
+ {
+ /* NBASE digits wanted */
+ ndigits = (di + DEC_DIGITS - 1) / DEC_DIGITS;
+
+ if (ndigits <= var->ndigits)
+ {
+ var->ndigits = ndigits;
+
+#if DEC_DIGITS == 1
+ /* no within-digit stuff to worry about */
+#else
+ /* 0, or number of decimal digits to keep in last NBASE digit */
+ di %= DEC_DIGITS;
+
+ if (di > 0)
+ {
+ /* Must truncate within last NBASE digit */
+ NumericDigit *digits = var->digits;
+ int extra,
+ pow10;
+
+#if DEC_DIGITS == 4
+ pow10 = round_powers[di];
+#elif DEC_DIGITS == 2
+ pow10 = 10;
+#else
+#error unsupported NBASE
+#endif
+ extra = digits[--ndigits] % pow10;
+ digits[ndigits] -= extra;
+ }
+#endif
+ }
+ }
+}
+
+/*
+ * strip_var
+ *
+ * Strip any leading and trailing zeroes from a numeric variable
+ */
+static void
+strip_var(NumericVar *var)
+{
+ NumericDigit *digits = var->digits;
+ int ndigits = var->ndigits;
+
+ /* Strip leading zeroes */
+ while (ndigits > 0 && *digits == 0)
+ {
+ digits++;
+ var->weight--;
+ ndigits--;
+ }
+
+ /* Strip trailing zeroes */
+ while (ndigits > 0 && digits[ndigits - 1] == 0)
+ ndigits--;
+
+ /* If it's zero, normalize the sign and weight */
+ if (ndigits == 0)
+ {
+ var->sign = NUMERIC_POS;
+ var->weight = 0;
+ }
+
+ var->digits = digits;
+ var->ndigits = ndigits;
+}
+
+
+/* ----------------------------------------------------------------------
+ *
+ * Fast sum accumulator functions
+ *
+ * ----------------------------------------------------------------------
+ */
+
+/*
+ * Reset the accumulator's value to zero. The buffers to hold the digits
+ * are not free'd.
+ */
+static void
+accum_sum_reset(NumericSumAccum *accum)
+{
+ int i;
+
+ accum->dscale = 0;
+ for (i = 0; i < accum->ndigits; i++)
+ {
+ accum->pos_digits[i] = 0;
+ accum->neg_digits[i] = 0;
+ }
+}
+
+/*
+ * Accumulate a new value.
+ */
+static void
+accum_sum_add(NumericSumAccum *accum, const NumericVar *val)
+{
+ int32 *accum_digits;
+ int i,
+ val_i;
+ int val_ndigits;
+ NumericDigit *val_digits;
+
+ /*
+ * If we have accumulated too many values since the last carry
+ * propagation, do it now, to avoid overflowing. (We could allow more
+ * than NBASE - 1, if we reserved two extra digits, rather than one, for
+ * carry propagation. But even with NBASE - 1, this needs to be done so
+ * seldom, that the performance difference is negligible.)
+ */
+ if (accum->num_uncarried == NBASE - 1)
+ accum_sum_carry(accum);
+
+ /*
+ * Adjust the weight or scale of the old value, so that it can accommodate
+ * the new value.
+ */
+ accum_sum_rescale(accum, val);
+
+ /* */
+ if (val->sign == NUMERIC_POS)
+ accum_digits = accum->pos_digits;
+ else
+ accum_digits = accum->neg_digits;
+
+ /* copy these values into local vars for speed in loop */
+ val_ndigits = val->ndigits;
+ val_digits = val->digits;
+
+ i = accum->weight - val->weight;
+ for (val_i = 0; val_i < val_ndigits; val_i++)
+ {
+ accum_digits[i] += (int32) val_digits[val_i];
+ i++;
+ }
+
+ accum->num_uncarried++;
+}
+
+/*
+ * Propagate carries.
+ */
+static void
+accum_sum_carry(NumericSumAccum *accum)
+{
+ int i;
+ int ndigits;
+ int32 *dig;
+ int32 carry;
+ int32 newdig = 0;
+
+ /*
+ * If no new values have been added since last carry propagation, nothing
+ * to do.
+ */
+ if (accum->num_uncarried == 0)
+ return;
+
+ /*
+ * We maintain that the weight of the accumulator is always one larger
+ * than needed to hold the current value, before carrying, to make sure
+ * there is enough space for the possible extra digit when carry is
+ * propagated. We cannot expand the buffer here, unless we require
+ * callers of accum_sum_final() to switch to the right memory context.
+ */
+ Assert(accum->pos_digits[0] == 0 && accum->neg_digits[0] == 0);
+
+ ndigits = accum->ndigits;
+
+ /* Propagate carry in the positive sum */
+ dig = accum->pos_digits;
+ carry = 0;
+ for (i = ndigits - 1; i >= 0; i--)
+ {
+ newdig = dig[i] + carry;
+ if (newdig >= NBASE)
+ {
+ carry = newdig / NBASE;
+ newdig -= carry * NBASE;
+ }
+ else
+ carry = 0;
+ dig[i] = newdig;
+ }
+ /* Did we use up the digit reserved for carry propagation? */
+ if (newdig > 0)
+ accum->have_carry_space = false;
+
+ /* And the same for the negative sum */
+ dig = accum->neg_digits;
+ carry = 0;
+ for (i = ndigits - 1; i >= 0; i--)
+ {
+ newdig = dig[i] + carry;
+ if (newdig >= NBASE)
+ {
+ carry = newdig / NBASE;
+ newdig -= carry * NBASE;
+ }
+ else
+ carry = 0;
+ dig[i] = newdig;
+ }
+ if (newdig > 0)
+ accum->have_carry_space = false;
+
+ accum->num_uncarried = 0;
+}
+
+/*
+ * Re-scale accumulator to accommodate new value.
+ *
+ * If the new value has more digits than the current digit buffers in the
+ * accumulator, enlarge the buffers.
+ */
+static void
+accum_sum_rescale(NumericSumAccum *accum, const NumericVar *val)
+{
+ int old_weight = accum->weight;
+ int old_ndigits = accum->ndigits;
+ int accum_ndigits;
+ int accum_weight;
+ int accum_rscale;
+ int val_rscale;
+
+ accum_weight = old_weight;
+ accum_ndigits = old_ndigits;
+
+ /*
+ * Does the new value have a larger weight? If so, enlarge the buffers,
+ * and shift the existing value to the new weight, by adding leading
+ * zeros.
+ *
+ * We enforce that the accumulator always has a weight one larger than
+ * needed for the inputs, so that we have space for an extra digit at the
+ * final carry-propagation phase, if necessary.
+ */
+ if (val->weight >= accum_weight)
+ {
+ accum_weight = val->weight + 1;
+ accum_ndigits = accum_ndigits + (accum_weight - old_weight);
+ }
+
+ /*
+ * Even though the new value is small, we might've used up the space
+ * reserved for the carry digit in the last call to accum_sum_carry(). If
+ * so, enlarge to make room for another one.
+ */
+ else if (!accum->have_carry_space)
+ {
+ accum_weight++;
+ accum_ndigits++;
+ }
+
+ /* Is the new value wider on the right side? */
+ accum_rscale = accum_ndigits - accum_weight - 1;
+ val_rscale = val->ndigits - val->weight - 1;
+ if (val_rscale > accum_rscale)
+ accum_ndigits = accum_ndigits + (val_rscale - accum_rscale);
+
+ if (accum_ndigits != old_ndigits ||
+ accum_weight != old_weight)
+ {
+ int32 *new_pos_digits;
+ int32 *new_neg_digits;
+ int weightdiff;
+
+ weightdiff = accum_weight - old_weight;
+
+ new_pos_digits = palloc0(accum_ndigits * sizeof(int32));
+ new_neg_digits = palloc0(accum_ndigits * sizeof(int32));
+
+ if (accum->pos_digits)
+ {
+ memcpy(&new_pos_digits[weightdiff], accum->pos_digits,
+ old_ndigits * sizeof(int32));
+ pfree(accum->pos_digits);
+
+ memcpy(&new_neg_digits[weightdiff], accum->neg_digits,
+ old_ndigits * sizeof(int32));
+ pfree(accum->neg_digits);
+ }
+
+ accum->pos_digits = new_pos_digits;
+ accum->neg_digits = new_neg_digits;
+
+ accum->weight = accum_weight;
+ accum->ndigits = accum_ndigits;
+
+ Assert(accum->pos_digits[0] == 0 && accum->neg_digits[0] == 0);
+ accum->have_carry_space = true;
+ }
+
+ if (val->dscale > accum->dscale)
+ accum->dscale = val->dscale;
+}
+
+/*
+ * Return the current value of the accumulator. This perform final carry
+ * propagation, and adds together the positive and negative sums.
+ *
+ * Unlike all the other routines, the caller is not required to switch to
+ * the memory context that holds the accumulator.
+ */
+static void
+accum_sum_final(NumericSumAccum *accum, NumericVar *result)
+{
+ int i;
+ NumericVar pos_var;
+ NumericVar neg_var;
+
+ if (accum->ndigits == 0)
+ {
+ set_var_from_var(&const_zero, result);
+ return;
+ }
+
+ /* Perform final carry */
+ accum_sum_carry(accum);
+
+ /* Create NumericVars representing the positive and negative sums */
+ init_var(&pos_var);
+ init_var(&neg_var);
+
+ pos_var.ndigits = neg_var.ndigits = accum->ndigits;
+ pos_var.weight = neg_var.weight = accum->weight;
+ pos_var.dscale = neg_var.dscale = accum->dscale;
+ pos_var.sign = NUMERIC_POS;
+ neg_var.sign = NUMERIC_NEG;
+
+ pos_var.buf = pos_var.digits = digitbuf_alloc(accum->ndigits);
+ neg_var.buf = neg_var.digits = digitbuf_alloc(accum->ndigits);
+
+ for (i = 0; i < accum->ndigits; i++)
+ {
+ Assert(accum->pos_digits[i] < NBASE);
+ pos_var.digits[i] = (int16) accum->pos_digits[i];
+
+ Assert(accum->neg_digits[i] < NBASE);
+ neg_var.digits[i] = (int16) accum->neg_digits[i];
+ }
+
+ /* And add them together */
+ add_var(&pos_var, &neg_var, result);
+
+ /* Remove leading/trailing zeroes */
+ strip_var(result);
+}
+
+/*
+ * Copy an accumulator's state.
+ *
+ * 'dst' is assumed to be uninitialized beforehand. No attempt is made at
+ * freeing old values.
+ */
+static void
+accum_sum_copy(NumericSumAccum *dst, NumericSumAccum *src)
+{
+ dst->pos_digits = palloc(src->ndigits * sizeof(int32));
+ dst->neg_digits = palloc(src->ndigits * sizeof(int32));
+
+ memcpy(dst->pos_digits, src->pos_digits, src->ndigits * sizeof(int32));
+ memcpy(dst->neg_digits, src->neg_digits, src->ndigits * sizeof(int32));
+ dst->num_uncarried = src->num_uncarried;
+ dst->ndigits = src->ndigits;
+ dst->weight = src->weight;
+ dst->dscale = src->dscale;
+}
+
+/*
+ * Add the current value of 'accum2' into 'accum'.
+ */
+static void
+accum_sum_combine(NumericSumAccum *accum, NumericSumAccum *accum2)
+{
+ NumericVar tmp_var;
+
+ init_var(&tmp_var);
+
+ accum_sum_final(accum2, &tmp_var);
+ accum_sum_add(accum, &tmp_var);
+
+ free_var(&tmp_var);
+}