Adding upstream version 14.5.upstream/14.5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1628 insertions, 0 deletions

diff --git a/src/backend/utils/adt/int.c b/src/backend/utils/adt/int.c
new file mode 100644
index 0000000..e9f1084
--- /dev/null
+++ b/src/backend/utils/adt/int.c
@@ -0,0 +1,1628 @@
+/*-------------------------------------------------------------------------
+ *
+ * int.c
+ *	  Functions for the built-in integer types (except int8).
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/int.c
+ *
+ *-------------------------------------------------------------------------
+ */
+/*
+ * OLD COMMENTS
+ *		I/O routines:
+ *		 int2in, int2out, int2recv, int2send
+ *		 int4in, int4out, int4recv, int4send
+ *		 int2vectorin, int2vectorout, int2vectorrecv, int2vectorsend
+ *		Boolean operators:
+ *		 inteq, intne, intlt, intle, intgt, intge
+ *		Arithmetic operators:
+ *		 intpl, intmi, int4mul, intdiv
+ *
+ *		Arithmetic operators:
+ *		 intmod
+ */
+#include "postgres.h"
+
+#include <ctype.h>
+#include <limits.h>
+#include <math.h>
+
+#include "catalog/pg_type.h"
+#include "common/int.h"
+#include "funcapi.h"
+#include "libpq/pqformat.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/supportnodes.h"
+#include "optimizer/optimizer.h"
+#include "utils/array.h"
+#include "utils/builtins.h"
+
+#define Int2VectorSize(n)	(offsetof(int2vector, values) + (n) * sizeof(int16))
+
+typedef struct
+{
+	int32		current;
+	int32		finish;
+	int32		step;
+} generate_series_fctx;
+
+
+/*****************************************************************************
+ *	 USER I/O ROUTINES														 *
+ *****************************************************************************/
+
+/*
+ *		int2in			- converts "num" to short
+ */
+Datum
+int2in(PG_FUNCTION_ARGS)
+{
+	char	   *num = PG_GETARG_CSTRING(0);
+
+	PG_RETURN_INT16(pg_strtoint16(num));
+}
+
+/*
+ *		int2out			- converts short to "num"
+ */
+Datum
+int2out(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	char	   *result = (char *) palloc(7);	/* sign, 5 digits, '\0' */
+
+	pg_itoa(arg1, result);
+	PG_RETURN_CSTRING(result);
+}
+
+/*
+ *		int2recv			- converts external binary format to int2
+ */
+Datum
+int2recv(PG_FUNCTION_ARGS)
+{
+	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+
+	PG_RETURN_INT16((int16) pq_getmsgint(buf, sizeof(int16)));
+}
+
+/*
+ *		int2send			- converts int2 to binary format
+ */
+Datum
+int2send(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	StringInfoData buf;
+
+	pq_begintypsend(&buf);
+	pq_sendint16(&buf, arg1);
+	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+}
+
+/*
+ * construct int2vector given a raw array of int2s
+ *
+ * If int2s is NULL then caller must fill values[] afterward
+ */
+int2vector *
+buildint2vector(const int16 *int2s, int n)
+{
+	int2vector *result;
+
+	result = (int2vector *) palloc0(Int2VectorSize(n));
+
+	if (n > 0 && int2s)
+		memcpy(result->values, int2s, n * sizeof(int16));
+
+	/*
+	 * Attach standard array header.  For historical reasons, we set the index
+	 * lower bound to 0 not 1.
+	 */
+	SET_VARSIZE(result, Int2VectorSize(n));
+	result->ndim = 1;
+	result->dataoffset = 0;		/* never any nulls */
+	result->elemtype = INT2OID;
+	result->dim1 = n;
+	result->lbound1 = 0;
+
+	return result;
+}
+
+/*
+ *		int2vectorin			- converts "num num ..." to internal form
+ */
+Datum
+int2vectorin(PG_FUNCTION_ARGS)
+{
+	char	   *intString = PG_GETARG_CSTRING(0);
+	int2vector *result;
+	int			n;
+
+	result = (int2vector *) palloc0(Int2VectorSize(FUNC_MAX_ARGS));
+
+	for (n = 0; *intString && n < FUNC_MAX_ARGS; n++)
+	{
+		while (*intString && isspace((unsigned char) *intString))
+			intString++;
+		if (*intString == '\0')
+			break;
+		result->values[n] = pg_atoi(intString, sizeof(int16), ' ');
+		while (*intString && !isspace((unsigned char) *intString))
+			intString++;
+	}
+	while (*intString && isspace((unsigned char) *intString))
+		intString++;
+	if (*intString)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("int2vector has too many elements")));
+
+	SET_VARSIZE(result, Int2VectorSize(n));
+	result->ndim = 1;
+	result->dataoffset = 0;		/* never any nulls */
+	result->elemtype = INT2OID;
+	result->dim1 = n;
+	result->lbound1 = 0;
+
+	PG_RETURN_POINTER(result);
+}
+
+/*
+ *		int2vectorout		- converts internal form to "num num ..."
+ */
+Datum
+int2vectorout(PG_FUNCTION_ARGS)
+{
+	int2vector *int2Array = (int2vector *) PG_GETARG_POINTER(0);
+	int			num,
+				nnums = int2Array->dim1;
+	char	   *rp;
+	char	   *result;
+
+	/* assumes sign, 5 digits, ' ' */
+	rp = result = (char *) palloc(nnums * 7 + 1);
+	for (num = 0; num < nnums; num++)
+	{
+		if (num != 0)
+			*rp++ = ' ';
+		rp += pg_itoa(int2Array->values[num], rp);
+	}
+	*rp = '\0';
+	PG_RETURN_CSTRING(result);
+}
+
+/*
+ *		int2vectorrecv			- converts external binary format to int2vector
+ */
+Datum
+int2vectorrecv(PG_FUNCTION_ARGS)
+{
+	LOCAL_FCINFO(locfcinfo, 3);
+	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+	int2vector *result;
+
+	/*
+	 * Normally one would call array_recv() using DirectFunctionCall3, but
+	 * that does not work since array_recv wants to cache some data using
+	 * fcinfo->flinfo->fn_extra.  So we need to pass it our own flinfo
+	 * parameter.
+	 */
+	InitFunctionCallInfoData(*locfcinfo, fcinfo->flinfo, 3,
+							 InvalidOid, NULL, NULL);
+
+	locfcinfo->args[0].value = PointerGetDatum(buf);
+	locfcinfo->args[0].isnull = false;
+	locfcinfo->args[1].value = ObjectIdGetDatum(INT2OID);
+	locfcinfo->args[1].isnull = false;
+	locfcinfo->args[2].value = Int32GetDatum(-1);
+	locfcinfo->args[2].isnull = false;
+
+	result = (int2vector *) DatumGetPointer(array_recv(locfcinfo));
+
+	Assert(!locfcinfo->isnull);
+
+	/* sanity checks: int2vector must be 1-D, 0-based, no nulls */
+	if (ARR_NDIM(result) != 1 ||
+		ARR_HASNULL(result) ||
+		ARR_ELEMTYPE(result) != INT2OID ||
+		ARR_LBOUND(result)[0] != 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
+				 errmsg("invalid int2vector data")));
+
+	/* check length for consistency with int2vectorin() */
+	if (ARR_DIMS(result)[0] > FUNC_MAX_ARGS)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("oidvector has too many elements")));
+
+	PG_RETURN_POINTER(result);
+}
+
+/*
+ *		int2vectorsend			- converts int2vector to binary format
+ */
+Datum
+int2vectorsend(PG_FUNCTION_ARGS)
+{
+	return array_send(fcinfo);
+}
+
+
+/*****************************************************************************
+ *	 PUBLIC ROUTINES														 *
+ *****************************************************************************/
+
+/*
+ *		int4in			- converts "num" to int4
+ */
+Datum
+int4in(PG_FUNCTION_ARGS)
+{
+	char	   *num = PG_GETARG_CSTRING(0);
+
+	PG_RETURN_INT32(pg_strtoint32(num));
+}
+
+/*
+ *		int4out			- converts int4 to "num"
+ */
+Datum
+int4out(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	char	   *result = (char *) palloc(12);	/* sign, 10 digits, '\0' */
+
+	pg_ltoa(arg1, result);
+	PG_RETURN_CSTRING(result);
+}
+
+/*
+ *		int4recv			- converts external binary format to int4
+ */
+Datum
+int4recv(PG_FUNCTION_ARGS)
+{
+	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+
+	PG_RETURN_INT32((int32) pq_getmsgint(buf, sizeof(int32)));
+}
+
+/*
+ *		int4send			- converts int4 to binary format
+ */
+Datum
+int4send(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	StringInfoData buf;
+
+	pq_begintypsend(&buf);
+	pq_sendint32(&buf, arg1);
+	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+}
+
+
+/*
+ *		===================
+ *		CONVERSION ROUTINES
+ *		===================
+ */
+
+Datum
+i2toi4(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+
+	PG_RETURN_INT32((int32) arg1);
+}
+
+Datum
+i4toi2(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+
+	if (unlikely(arg1 < SHRT_MIN) || unlikely(arg1 > SHRT_MAX))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("smallint out of range")));
+
+	PG_RETURN_INT16((int16) arg1);
+}
+
+/* Cast int4 -> bool */
+Datum
+int4_bool(PG_FUNCTION_ARGS)
+{
+	if (PG_GETARG_INT32(0) == 0)
+		PG_RETURN_BOOL(false);
+	else
+		PG_RETURN_BOOL(true);
+}
+
+/* Cast bool -> int4 */
+Datum
+bool_int4(PG_FUNCTION_ARGS)
+{
+	if (PG_GETARG_BOOL(0) == false)
+		PG_RETURN_INT32(0);
+	else
+		PG_RETURN_INT32(1);
+}
+
+/*
+ *		============================
+ *		COMPARISON OPERATOR ROUTINES
+ *		============================
+ */
+
+/*
+ *		inteq			- returns 1 iff arg1 == arg2
+ *		intne			- returns 1 iff arg1 != arg2
+ *		intlt			- returns 1 iff arg1 < arg2
+ *		intle			- returns 1 iff arg1 <= arg2
+ *		intgt			- returns 1 iff arg1 > arg2
+ *		intge			- returns 1 iff arg1 >= arg2
+ */
+
+Datum
+int4eq(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_BOOL(arg1 == arg2);
+}
+
+Datum
+int4ne(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_BOOL(arg1 != arg2);
+}
+
+Datum
+int4lt(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_BOOL(arg1 < arg2);
+}
+
+Datum
+int4le(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_BOOL(arg1 <= arg2);
+}
+
+Datum
+int4gt(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_BOOL(arg1 > arg2);
+}
+
+Datum
+int4ge(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_BOOL(arg1 >= arg2);
+}
+
+Datum
+int2eq(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_BOOL(arg1 == arg2);
+}
+
+Datum
+int2ne(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_BOOL(arg1 != arg2);
+}
+
+Datum
+int2lt(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_BOOL(arg1 < arg2);
+}
+
+Datum
+int2le(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_BOOL(arg1 <= arg2);
+}
+
+Datum
+int2gt(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_BOOL(arg1 > arg2);
+}
+
+Datum
+int2ge(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_BOOL(arg1 >= arg2);
+}
+
+Datum
+int24eq(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_BOOL(arg1 == arg2);
+}
+
+Datum
+int24ne(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_BOOL(arg1 != arg2);
+}
+
+Datum
+int24lt(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_BOOL(arg1 < arg2);
+}
+
+Datum
+int24le(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_BOOL(arg1 <= arg2);
+}
+
+Datum
+int24gt(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_BOOL(arg1 > arg2);
+}
+
+Datum
+int24ge(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_BOOL(arg1 >= arg2);
+}
+
+Datum
+int42eq(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_BOOL(arg1 == arg2);
+}
+
+Datum
+int42ne(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_BOOL(arg1 != arg2);
+}
+
+Datum
+int42lt(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_BOOL(arg1 < arg2);
+}
+
+Datum
+int42le(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_BOOL(arg1 <= arg2);
+}
+
+Datum
+int42gt(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_BOOL(arg1 > arg2);
+}
+
+Datum
+int42ge(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_BOOL(arg1 >= arg2);
+}
+
+
+/*----------------------------------------------------------
+ *	in_range functions for int4 and int2,
+ *	including cross-data-type comparisons.
+ *
+ *	Note: we provide separate intN_int8 functions for performance
+ *	reasons.  This forces also providing intN_int2, else cases with a
+ *	smallint offset value would fail to resolve which function to use.
+ *	But that's an unlikely situation, so don't duplicate code for it.
+ *---------------------------------------------------------*/
+
+Datum
+in_range_int4_int4(PG_FUNCTION_ARGS)
+{
+	int32		val = PG_GETARG_INT32(0);
+	int32		base = PG_GETARG_INT32(1);
+	int32		offset = PG_GETARG_INT32(2);
+	bool		sub = PG_GETARG_BOOL(3);
+	bool		less = PG_GETARG_BOOL(4);
+	int32		sum;
+
+	if (offset < 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
+				 errmsg("invalid preceding or following size in window function")));
+
+	if (sub)
+		offset = -offset;		/* cannot overflow */
+
+	if (unlikely(pg_add_s32_overflow(base, offset, &sum)))
+	{
+		/*
+		 * If sub is false, the true sum is surely more than val, so correct
+		 * answer is the same as "less".  If sub is true, the true sum is
+		 * surely less than val, so the answer is "!less".
+		 */
+		PG_RETURN_BOOL(sub ? !less : less);
+	}
+
+	if (less)
+		PG_RETURN_BOOL(val <= sum);
+	else
+		PG_RETURN_BOOL(val >= sum);
+}
+
+Datum
+in_range_int4_int2(PG_FUNCTION_ARGS)
+{
+	/* Doesn't seem worth duplicating code for, so just invoke int4_int4 */
+	return DirectFunctionCall5(in_range_int4_int4,
+							   PG_GETARG_DATUM(0),
+							   PG_GETARG_DATUM(1),
+							   Int32GetDatum((int32) PG_GETARG_INT16(2)),
+							   PG_GETARG_DATUM(3),
+							   PG_GETARG_DATUM(4));
+}
+
+Datum
+in_range_int4_int8(PG_FUNCTION_ARGS)
+{
+	/* We must do all the math in int64 */
+	int64		val = (int64) PG_GETARG_INT32(0);
+	int64		base = (int64) PG_GETARG_INT32(1);
+	int64		offset = PG_GETARG_INT64(2);
+	bool		sub = PG_GETARG_BOOL(3);
+	bool		less = PG_GETARG_BOOL(4);
+	int64		sum;
+
+	if (offset < 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
+				 errmsg("invalid preceding or following size in window function")));
+
+	if (sub)
+		offset = -offset;		/* cannot overflow */
+
+	if (unlikely(pg_add_s64_overflow(base, offset, &sum)))
+	{
+		/*
+		 * If sub is false, the true sum is surely more than val, so correct
+		 * answer is the same as "less".  If sub is true, the true sum is
+		 * surely less than val, so the answer is "!less".
+		 */
+		PG_RETURN_BOOL(sub ? !less : less);
+	}
+
+	if (less)
+		PG_RETURN_BOOL(val <= sum);
+	else
+		PG_RETURN_BOOL(val >= sum);
+}
+
+Datum
+in_range_int2_int4(PG_FUNCTION_ARGS)
+{
+	/* We must do all the math in int32 */
+	int32		val = (int32) PG_GETARG_INT16(0);
+	int32		base = (int32) PG_GETARG_INT16(1);
+	int32		offset = PG_GETARG_INT32(2);
+	bool		sub = PG_GETARG_BOOL(3);
+	bool		less = PG_GETARG_BOOL(4);
+	int32		sum;
+
+	if (offset < 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
+				 errmsg("invalid preceding or following size in window function")));
+
+	if (sub)
+		offset = -offset;		/* cannot overflow */
+
+	if (unlikely(pg_add_s32_overflow(base, offset, &sum)))
+	{
+		/*
+		 * If sub is false, the true sum is surely more than val, so correct
+		 * answer is the same as "less".  If sub is true, the true sum is
+		 * surely less than val, so the answer is "!less".
+		 */
+		PG_RETURN_BOOL(sub ? !less : less);
+	}
+
+	if (less)
+		PG_RETURN_BOOL(val <= sum);
+	else
+		PG_RETURN_BOOL(val >= sum);
+}
+
+Datum
+in_range_int2_int2(PG_FUNCTION_ARGS)
+{
+	/* Doesn't seem worth duplicating code for, so just invoke int2_int4 */
+	return DirectFunctionCall5(in_range_int2_int4,
+							   PG_GETARG_DATUM(0),
+							   PG_GETARG_DATUM(1),
+							   Int32GetDatum((int32) PG_GETARG_INT16(2)),
+							   PG_GETARG_DATUM(3),
+							   PG_GETARG_DATUM(4));
+}
+
+Datum
+in_range_int2_int8(PG_FUNCTION_ARGS)
+{
+	/* Doesn't seem worth duplicating code for, so just invoke int4_int8 */
+	return DirectFunctionCall5(in_range_int4_int8,
+							   Int32GetDatum((int32) PG_GETARG_INT16(0)),
+							   Int32GetDatum((int32) PG_GETARG_INT16(1)),
+							   PG_GETARG_DATUM(2),
+							   PG_GETARG_DATUM(3),
+							   PG_GETARG_DATUM(4));
+}
+
+
+/*
+ *		int[24]pl		- returns arg1 + arg2
+ *		int[24]mi		- returns arg1 - arg2
+ *		int[24]mul		- returns arg1 * arg2
+ *		int[24]div		- returns arg1 / arg2
+ */
+
+Datum
+int4um(PG_FUNCTION_ARGS)
+{
+	int32		arg = PG_GETARG_INT32(0);
+
+	if (unlikely(arg == PG_INT32_MIN))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("integer out of range")));
+	PG_RETURN_INT32(-arg);
+}
+
+Datum
+int4up(PG_FUNCTION_ARGS)
+{
+	int32		arg = PG_GETARG_INT32(0);
+
+	PG_RETURN_INT32(arg);
+}
+
+Datum
+int4pl(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+	int32		result;
+
+	if (unlikely(pg_add_s32_overflow(arg1, arg2, &result)))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("integer out of range")));
+	PG_RETURN_INT32(result);
+}
+
+Datum
+int4mi(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+	int32		result;
+
+	if (unlikely(pg_sub_s32_overflow(arg1, arg2, &result)))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("integer out of range")));
+	PG_RETURN_INT32(result);
+}
+
+Datum
+int4mul(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+	int32		result;
+
+	if (unlikely(pg_mul_s32_overflow(arg1, arg2, &result)))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("integer out of range")));
+	PG_RETURN_INT32(result);
+}
+
+Datum
+int4div(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+	int32		result;
+
+	if (arg2 == 0)
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DIVISION_BY_ZERO),
+				 errmsg("division by zero")));
+		/* ensure compiler realizes we mustn't reach the division (gcc bug) */
+		PG_RETURN_NULL();
+	}
+
+	/*
+	 * INT_MIN / -1 is problematic, since the result can't be represented on a
+	 * two's-complement machine.  Some machines produce INT_MIN, some produce
+	 * zero, some throw an exception.  We can dodge the problem by recognizing
+	 * that division by -1 is the same as negation.
+	 */
+	if (arg2 == -1)
+	{
+		if (unlikely(arg1 == PG_INT32_MIN))
+			ereport(ERROR,
+					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+					 errmsg("integer out of range")));
+		result = -arg1;
+		PG_RETURN_INT32(result);
+	}
+
+	/* No overflow is possible */
+
+	result = arg1 / arg2;
+
+	PG_RETURN_INT32(result);
+}
+
+Datum
+int4inc(PG_FUNCTION_ARGS)
+{
+	int32		arg = PG_GETARG_INT32(0);
+	int32		result;
+
+	if (unlikely(pg_add_s32_overflow(arg, 1, &result)))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("integer out of range")));
+
+	PG_RETURN_INT32(result);
+}
+
+Datum
+int2um(PG_FUNCTION_ARGS)
+{
+	int16		arg = PG_GETARG_INT16(0);
+
+	if (unlikely(arg == PG_INT16_MIN))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("smallint out of range")));
+	PG_RETURN_INT16(-arg);
+}
+
+Datum
+int2up(PG_FUNCTION_ARGS)
+{
+	int16		arg = PG_GETARG_INT16(0);
+
+	PG_RETURN_INT16(arg);
+}
+
+Datum
+int2pl(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+	int16		result;
+
+	if (unlikely(pg_add_s16_overflow(arg1, arg2, &result)))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("smallint out of range")));
+	PG_RETURN_INT16(result);
+}
+
+Datum
+int2mi(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+	int16		result;
+
+	if (unlikely(pg_sub_s16_overflow(arg1, arg2, &result)))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("smallint out of range")));
+	PG_RETURN_INT16(result);
+}
+
+Datum
+int2mul(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+	int16		result;
+
+	if (unlikely(pg_mul_s16_overflow(arg1, arg2, &result)))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("smallint out of range")));
+
+	PG_RETURN_INT16(result);
+}
+
+Datum
+int2div(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+	int16		result;
+
+	if (arg2 == 0)
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DIVISION_BY_ZERO),
+				 errmsg("division by zero")));
+		/* ensure compiler realizes we mustn't reach the division (gcc bug) */
+		PG_RETURN_NULL();
+	}
+
+	/*
+	 * SHRT_MIN / -1 is problematic, since the result can't be represented on
+	 * a two's-complement machine.  Some machines produce SHRT_MIN, some
+	 * produce zero, some throw an exception.  We can dodge the problem by
+	 * recognizing that division by -1 is the same as negation.
+	 */
+	if (arg2 == -1)
+	{
+		if (unlikely(arg1 == PG_INT16_MIN))
+			ereport(ERROR,
+					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+					 errmsg("smallint out of range")));
+		result = -arg1;
+		PG_RETURN_INT16(result);
+	}
+
+	/* No overflow is possible */
+
+	result = arg1 / arg2;
+
+	PG_RETURN_INT16(result);
+}
+
+Datum
+int24pl(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+	int32		result;
+
+	if (unlikely(pg_add_s32_overflow((int32) arg1, arg2, &result)))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("integer out of range")));
+	PG_RETURN_INT32(result);
+}
+
+Datum
+int24mi(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+	int32		result;
+
+	if (unlikely(pg_sub_s32_overflow((int32) arg1, arg2, &result)))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("integer out of range")));
+	PG_RETURN_INT32(result);
+}
+
+Datum
+int24mul(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+	int32		result;
+
+	if (unlikely(pg_mul_s32_overflow((int32) arg1, arg2, &result)))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("integer out of range")));
+	PG_RETURN_INT32(result);
+}
+
+Datum
+int24div(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	if (unlikely(arg2 == 0))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DIVISION_BY_ZERO),
+				 errmsg("division by zero")));
+		/* ensure compiler realizes we mustn't reach the division (gcc bug) */
+		PG_RETURN_NULL();
+	}
+
+	/* No overflow is possible */
+	PG_RETURN_INT32((int32) arg1 / arg2);
+}
+
+Datum
+int42pl(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+	int32		result;
+
+	if (unlikely(pg_add_s32_overflow(arg1, (int32) arg2, &result)))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("integer out of range")));
+	PG_RETURN_INT32(result);
+}
+
+Datum
+int42mi(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+	int32		result;
+
+	if (unlikely(pg_sub_s32_overflow(arg1, (int32) arg2, &result)))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("integer out of range")));
+	PG_RETURN_INT32(result);
+}
+
+Datum
+int42mul(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+	int32		result;
+
+	if (unlikely(pg_mul_s32_overflow(arg1, (int32) arg2, &result)))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("integer out of range")));
+	PG_RETURN_INT32(result);
+}
+
+Datum
+int42div(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+	int32		result;
+
+	if (unlikely(arg2 == 0))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DIVISION_BY_ZERO),
+				 errmsg("division by zero")));
+		/* ensure compiler realizes we mustn't reach the division (gcc bug) */
+		PG_RETURN_NULL();
+	}
+
+	/*
+	 * INT_MIN / -1 is problematic, since the result can't be represented on a
+	 * two's-complement machine.  Some machines produce INT_MIN, some produce
+	 * zero, some throw an exception.  We can dodge the problem by recognizing
+	 * that division by -1 is the same as negation.
+	 */
+	if (arg2 == -1)
+	{
+		if (unlikely(arg1 == PG_INT32_MIN))
+			ereport(ERROR,
+					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+					 errmsg("integer out of range")));
+		result = -arg1;
+		PG_RETURN_INT32(result);
+	}
+
+	/* No overflow is possible */
+
+	result = arg1 / arg2;
+
+	PG_RETURN_INT32(result);
+}
+
+Datum
+int4mod(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	if (unlikely(arg2 == 0))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DIVISION_BY_ZERO),
+				 errmsg("division by zero")));
+		/* ensure compiler realizes we mustn't reach the division (gcc bug) */
+		PG_RETURN_NULL();
+	}
+
+	/*
+	 * Some machines throw a floating-point exception for INT_MIN % -1, which
+	 * is a bit silly since the correct answer is perfectly well-defined,
+	 * namely zero.
+	 */
+	if (arg2 == -1)
+		PG_RETURN_INT32(0);
+
+	/* No overflow is possible */
+
+	PG_RETURN_INT32(arg1 % arg2);
+}
+
+Datum
+int2mod(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	if (unlikely(arg2 == 0))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DIVISION_BY_ZERO),
+				 errmsg("division by zero")));
+		/* ensure compiler realizes we mustn't reach the division (gcc bug) */
+		PG_RETURN_NULL();
+	}
+
+	/*
+	 * Some machines throw a floating-point exception for INT_MIN % -1, which
+	 * is a bit silly since the correct answer is perfectly well-defined,
+	 * namely zero.  (It's not clear this ever happens when dealing with
+	 * int16, but we might as well have the test for safety.)
+	 */
+	if (arg2 == -1)
+		PG_RETURN_INT16(0);
+
+	/* No overflow is possible */
+
+	PG_RETURN_INT16(arg1 % arg2);
+}
+
+
+/* int[24]abs()
+ * Absolute value
+ */
+Datum
+int4abs(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		result;
+
+	if (unlikely(arg1 == PG_INT32_MIN))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("integer out of range")));
+	result = (arg1 < 0) ? -arg1 : arg1;
+	PG_RETURN_INT32(result);
+}
+
+Datum
+int2abs(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		result;
+
+	if (unlikely(arg1 == PG_INT16_MIN))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("smallint out of range")));
+	result = (arg1 < 0) ? -arg1 : arg1;
+	PG_RETURN_INT16(result);
+}
+
+/*
+ * Greatest Common Divisor
+ *
+ * Returns the largest positive integer that exactly divides both inputs.
+ * Special cases:
+ *   - gcd(x, 0) = gcd(0, x) = abs(x)
+ *   		because 0 is divisible by anything
+ *   - gcd(0, 0) = 0
+ *   		complies with the previous definition and is a common convention
+ *
+ * Special care must be taken if either input is INT_MIN --- gcd(0, INT_MIN),
+ * gcd(INT_MIN, 0) and gcd(INT_MIN, INT_MIN) are all equal to abs(INT_MIN),
+ * which cannot be represented as a 32-bit signed integer.
+ */
+static int32
+int4gcd_internal(int32 arg1, int32 arg2)
+{
+	int32		swap;
+	int32		a1,
+				a2;
+
+	/*
+	 * Put the greater absolute value in arg1.
+	 *
+	 * This would happen automatically in the loop below, but avoids an
+	 * expensive modulo operation, and simplifies the special-case handling
+	 * for INT_MIN below.
+	 *
+	 * We do this in negative space in order to handle INT_MIN.
+	 */
+	a1 = (arg1 < 0) ? arg1 : -arg1;
+	a2 = (arg2 < 0) ? arg2 : -arg2;
+	if (a1 > a2)
+	{
+		swap = arg1;
+		arg1 = arg2;
+		arg2 = swap;
+	}
+
+	/* Special care needs to be taken with INT_MIN.  See comments above. */
+	if (arg1 == PG_INT32_MIN)
+	{
+		if (arg2 == 0 || arg2 == PG_INT32_MIN)
+			ereport(ERROR,
+					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+					 errmsg("integer out of range")));
+
+		/*
+		 * Some machines throw a floating-point exception for INT_MIN % -1,
+		 * which is a bit silly since the correct answer is perfectly
+		 * well-defined, namely zero.  Guard against this and just return the
+		 * result, gcd(INT_MIN, -1) = 1.
+		 */
+		if (arg2 == -1)
+			return 1;
+	}
+
+	/* Use the Euclidean algorithm to find the GCD */
+	while (arg2 != 0)
+	{
+		swap = arg2;
+		arg2 = arg1 % arg2;
+		arg1 = swap;
+	}
+
+	/*
+	 * Make sure the result is positive. (We know we don't have INT_MIN
+	 * anymore).
+	 */
+	if (arg1 < 0)
+		arg1 = -arg1;
+
+	return arg1;
+}
+
+Datum
+int4gcd(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+	int32		result;
+
+	result = int4gcd_internal(arg1, arg2);
+
+	PG_RETURN_INT32(result);
+}
+
+/*
+ * Least Common Multiple
+ */
+Datum
+int4lcm(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+	int32		gcd;
+	int32		result;
+
+	/*
+	 * Handle lcm(x, 0) = lcm(0, x) = 0 as a special case.  This prevents a
+	 * division-by-zero error below when x is zero, and an overflow error from
+	 * the GCD computation when x = INT_MIN.
+	 */
+	if (arg1 == 0 || arg2 == 0)
+		PG_RETURN_INT32(0);
+
+	/* lcm(x, y) = abs(x / gcd(x, y) * y) */
+	gcd = int4gcd_internal(arg1, arg2);
+	arg1 = arg1 / gcd;
+
+	if (unlikely(pg_mul_s32_overflow(arg1, arg2, &result)))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("integer out of range")));
+
+	/* If the result is INT_MIN, it cannot be represented. */
+	if (unlikely(result == PG_INT32_MIN))
+		ereport(ERROR,
+				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
+				 errmsg("integer out of range")));
+
+	if (result < 0)
+		result = -result;
+
+	PG_RETURN_INT32(result);
+}
+
+Datum
+int2larger(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_INT16((arg1 > arg2) ? arg1 : arg2);
+}
+
+Datum
+int2smaller(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_INT16((arg1 < arg2) ? arg1 : arg2);
+}
+
+Datum
+int4larger(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_INT32((arg1 > arg2) ? arg1 : arg2);
+}
+
+Datum
+int4smaller(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_INT32((arg1 < arg2) ? arg1 : arg2);
+}
+
+/*
+ * Bit-pushing operators
+ *
+ *		int[24]and		- returns arg1 & arg2
+ *		int[24]or		- returns arg1 | arg2
+ *		int[24]xor		- returns arg1 # arg2
+ *		int[24]not		- returns ~arg1
+ *		int[24]shl		- returns arg1 << arg2
+ *		int[24]shr		- returns arg1 >> arg2
+ */
+
+Datum
+int4and(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_INT32(arg1 & arg2);
+}
+
+Datum
+int4or(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_INT32(arg1 | arg2);
+}
+
+Datum
+int4xor(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_INT32(arg1 ^ arg2);
+}
+
+Datum
+int4shl(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_INT32(arg1 << arg2);
+}
+
+Datum
+int4shr(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_INT32(arg1 >> arg2);
+}
+
+Datum
+int4not(PG_FUNCTION_ARGS)
+{
+	int32		arg1 = PG_GETARG_INT32(0);
+
+	PG_RETURN_INT32(~arg1);
+}
+
+Datum
+int2and(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_INT16(arg1 & arg2);
+}
+
+Datum
+int2or(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_INT16(arg1 | arg2);
+}
+
+Datum
+int2xor(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int16		arg2 = PG_GETARG_INT16(1);
+
+	PG_RETURN_INT16(arg1 ^ arg2);
+}
+
+Datum
+int2not(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+
+	PG_RETURN_INT16(~arg1);
+}
+
+
+Datum
+int2shl(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_INT16(arg1 << arg2);
+}
+
+Datum
+int2shr(PG_FUNCTION_ARGS)
+{
+	int16		arg1 = PG_GETARG_INT16(0);
+	int32		arg2 = PG_GETARG_INT32(1);
+
+	PG_RETURN_INT16(arg1 >> arg2);
+}
+
+/*
+ * non-persistent numeric series generator
+ */
+Datum
+generate_series_int4(PG_FUNCTION_ARGS)
+{
+	return generate_series_step_int4(fcinfo);
+}
+
+Datum
+generate_series_step_int4(PG_FUNCTION_ARGS)
+{
+	FuncCallContext *funcctx;
+	generate_series_fctx *fctx;
+	int32		result;
+	MemoryContext oldcontext;
+
+	/* stuff done only on the first call of the function */
+	if (SRF_IS_FIRSTCALL())
+	{
+		int32		start = PG_GETARG_INT32(0);
+		int32		finish = PG_GETARG_INT32(1);
+		int32		step = 1;
+
+		/* see if we were given an explicit step size */
+		if (PG_NARGS() == 3)
+			step = PG_GETARG_INT32(2);
+		if (step == 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_fctx *) palloc(sizeof(generate_series_fctx));
+
+		/*
+		 * Use fctx to keep state from call to call. Seed current with the
+		 * original start value
+		 */
+		fctx->current = start;
+		fctx->finish = finish;
+		fctx->step = 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 as the result for this iteration
+	 */
+	fctx = funcctx->user_fctx;
+	result = fctx->current;
+
+	if ((fctx->step > 0 && fctx->current <= fctx->finish) ||
+		(fctx->step < 0 && fctx->current >= fctx->finish))
+	{
+		/*
+		 * Increment current in preparation for next iteration. If next-value
+		 * computation overflows, this is the final result.
+		 */
+		if (pg_add_s32_overflow(fctx->current, fctx->step, &fctx->current))
+			fctx->step = 0;
+
+		/* do when there is more left to send */
+		SRF_RETURN_NEXT(funcctx, Int32GetDatum(result));
+	}
+	else
+		/* do when there is no more left */
+		SRF_RETURN_DONE(funcctx);
+}
+
+/*
+ * Planner support function for generate_series(int4, int4 [, int4])
+ */
+Datum
+generate_series_int4_support(PG_FUNCTION_ARGS)
+{
+	Node	   *rawreq = (Node *) PG_GETARG_POINTER(0);
+	Node	   *ret = NULL;
+
+	if (IsA(rawreq, SupportRequestRows))
+	{
+		/* Try to estimate the number of rows returned */
+		SupportRequestRows *req = (SupportRequestRows *) rawreq;
+
+		if (is_funcclause(req->node))	/* be paranoid */
+		{
+			List	   *args = ((FuncExpr *) req->node)->args;
+			Node	   *arg1,
+					   *arg2,
+					   *arg3;
+
+			/* We can use estimated argument values here */
+			arg1 = estimate_expression_value(req->root, linitial(args));
+			arg2 = estimate_expression_value(req->root, lsecond(args));
+			if (list_length(args) >= 3)
+				arg3 = estimate_expression_value(req->root, lthird(args));
+			else
+				arg3 = NULL;
+
+			/*
+			 * If any argument is constant NULL, we can safely assume that
+			 * zero rows are returned.  Otherwise, if they're all non-NULL
+			 * constants, we can calculate the number of rows that will be
+			 * returned.  Use double arithmetic to avoid overflow hazards.
+			 */
+			if ((IsA(arg1, Const) &&
+				 ((Const *) arg1)->constisnull) ||
+				(IsA(arg2, Const) &&
+				 ((Const *) arg2)->constisnull) ||
+				(arg3 != NULL && IsA(arg3, Const) &&
+				 ((Const *) arg3)->constisnull))
+			{
+				req->rows = 0;
+				ret = (Node *) req;
+			}
+			else if (IsA(arg1, Const) &&
+					 IsA(arg2, Const) &&
+					 (arg3 == NULL || IsA(arg3, Const)))
+			{
+				double		start,
+							finish,
+							step;
+
+				start = DatumGetInt32(((Const *) arg1)->constvalue);
+				finish = DatumGetInt32(((Const *) arg2)->constvalue);
+				step = arg3 ? DatumGetInt32(((Const *) arg3)->constvalue) : 1;
+
+				/* This equation works for either sign of step */
+				if (step != 0)
+				{
+					req->rows = floor((finish - start + step) / step);
+					ret = (Node *) req;
+				}
+			}
+		}
+	}
+
+	PG_RETURN_POINTER(ret);
+}