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Diffstat (limited to 'src/common/f2s.c')
| -rw-r--r-- | src/common/f2s.c | 803 |
1 files changed, 803 insertions, 0 deletions
diff --git a/src/common/f2s.c b/src/common/f2s.c new file mode 100644 index 0000000..39366b6 --- /dev/null +++ b/src/common/f2s.c @@ -0,0 +1,803 @@ +/*--------------------------------------------------------------------------- + * + * Ryu floating-point output for single precision. + * + * Portions Copyright (c) 2018-2022, PostgreSQL Global Development Group + * + * IDENTIFICATION + * src/common/f2s.c + * + * This is a modification of code taken from github.com/ulfjack/ryu under the + * terms of the Boost license (not the Apache license). The original copyright + * notice follows: + * + * Copyright 2018 Ulf Adams + * + * The contents of this file may be used under the terms of the Apache + * License, Version 2.0. + * + * (See accompanying file LICENSE-Apache or copy at + * http://www.apache.org/licenses/LICENSE-2.0) + * + * Alternatively, the contents of this file may be used under the terms of the + * Boost Software License, Version 1.0. + * + * (See accompanying file LICENSE-Boost or copy at + * https://www.boost.org/LICENSE_1_0.txt) + * + * Unless required by applicable law or agreed to in writing, this software is + * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. + * + *--------------------------------------------------------------------------- + */ + +#ifndef FRONTEND +#include "postgres.h" +#else +#include "postgres_fe.h" +#endif + +#include "common/shortest_dec.h" +#include "digit_table.h" +#include "ryu_common.h" + +#define FLOAT_MANTISSA_BITS 23 +#define FLOAT_EXPONENT_BITS 8 +#define FLOAT_BIAS 127 + +/* + * This table is generated (by the upstream) by PrintFloatLookupTable, + * and modified (by us) to add UINT64CONST. + */ +#define FLOAT_POW5_INV_BITCOUNT 59 +static const uint64 FLOAT_POW5_INV_SPLIT[31] = { + UINT64CONST(576460752303423489), UINT64CONST(461168601842738791), UINT64CONST(368934881474191033), UINT64CONST(295147905179352826), + UINT64CONST(472236648286964522), UINT64CONST(377789318629571618), UINT64CONST(302231454903657294), UINT64CONST(483570327845851670), + UINT64CONST(386856262276681336), UINT64CONST(309485009821345069), UINT64CONST(495176015714152110), UINT64CONST(396140812571321688), + UINT64CONST(316912650057057351), UINT64CONST(507060240091291761), UINT64CONST(405648192073033409), UINT64CONST(324518553658426727), + UINT64CONST(519229685853482763), UINT64CONST(415383748682786211), UINT64CONST(332306998946228969), UINT64CONST(531691198313966350), + UINT64CONST(425352958651173080), UINT64CONST(340282366920938464), UINT64CONST(544451787073501542), UINT64CONST(435561429658801234), + UINT64CONST(348449143727040987), UINT64CONST(557518629963265579), UINT64CONST(446014903970612463), UINT64CONST(356811923176489971), + UINT64CONST(570899077082383953), UINT64CONST(456719261665907162), UINT64CONST(365375409332725730) +}; +#define FLOAT_POW5_BITCOUNT 61 +static const uint64 FLOAT_POW5_SPLIT[47] = { + UINT64CONST(1152921504606846976), UINT64CONST(1441151880758558720), UINT64CONST(1801439850948198400), UINT64CONST(2251799813685248000), + UINT64CONST(1407374883553280000), UINT64CONST(1759218604441600000), UINT64CONST(2199023255552000000), UINT64CONST(1374389534720000000), + UINT64CONST(1717986918400000000), UINT64CONST(2147483648000000000), UINT64CONST(1342177280000000000), UINT64CONST(1677721600000000000), + UINT64CONST(2097152000000000000), UINT64CONST(1310720000000000000), UINT64CONST(1638400000000000000), UINT64CONST(2048000000000000000), + UINT64CONST(1280000000000000000), UINT64CONST(1600000000000000000), UINT64CONST(2000000000000000000), UINT64CONST(1250000000000000000), + UINT64CONST(1562500000000000000), UINT64CONST(1953125000000000000), UINT64CONST(1220703125000000000), UINT64CONST(1525878906250000000), + UINT64CONST(1907348632812500000), UINT64CONST(1192092895507812500), UINT64CONST(1490116119384765625), UINT64CONST(1862645149230957031), + UINT64CONST(1164153218269348144), UINT64CONST(1455191522836685180), UINT64CONST(1818989403545856475), UINT64CONST(2273736754432320594), + UINT64CONST(1421085471520200371), UINT64CONST(1776356839400250464), UINT64CONST(2220446049250313080), UINT64CONST(1387778780781445675), + UINT64CONST(1734723475976807094), UINT64CONST(2168404344971008868), UINT64CONST(1355252715606880542), UINT64CONST(1694065894508600678), + UINT64CONST(2117582368135750847), UINT64CONST(1323488980084844279), UINT64CONST(1654361225106055349), UINT64CONST(2067951531382569187), + UINT64CONST(1292469707114105741), UINT64CONST(1615587133892632177), UINT64CONST(2019483917365790221) +}; + +static inline uint32 +pow5Factor(uint32 value) +{ + uint32 count = 0; + + for (;;) + { + Assert(value != 0); + const uint32 q = value / 5; + const uint32 r = value % 5; + + if (r != 0) + break; + + value = q; + ++count; + } + return count; +} + +/* Returns true if value is divisible by 5^p. */ +static inline bool +multipleOfPowerOf5(const uint32 value, const uint32 p) +{ + return pow5Factor(value) >= p; +} + +/* Returns true if value is divisible by 2^p. */ +static inline bool +multipleOfPowerOf2(const uint32 value, const uint32 p) +{ + /* return __builtin_ctz(value) >= p; */ + return (value & ((1u << p) - 1)) == 0; +} + +/* + * It seems to be slightly faster to avoid uint128_t here, although the + * generated code for uint128_t looks slightly nicer. + */ +static inline uint32 +mulShift(const uint32 m, const uint64 factor, const int32 shift) +{ + /* + * The casts here help MSVC to avoid calls to the __allmul library + * function. + */ + const uint32 factorLo = (uint32) (factor); + const uint32 factorHi = (uint32) (factor >> 32); + const uint64 bits0 = (uint64) m * factorLo; + const uint64 bits1 = (uint64) m * factorHi; + + Assert(shift > 32); + +#ifdef RYU_32_BIT_PLATFORM + + /* + * On 32-bit platforms we can avoid a 64-bit shift-right since we only + * need the upper 32 bits of the result and the shift value is > 32. + */ + const uint32 bits0Hi = (uint32) (bits0 >> 32); + uint32 bits1Lo = (uint32) (bits1); + uint32 bits1Hi = (uint32) (bits1 >> 32); + + bits1Lo += bits0Hi; + bits1Hi += (bits1Lo < bits0Hi); + + const int32 s = shift - 32; + + return (bits1Hi << (32 - s)) | (bits1Lo >> s); + +#else /* RYU_32_BIT_PLATFORM */ + + const uint64 sum = (bits0 >> 32) + bits1; + const uint64 shiftedSum = sum >> (shift - 32); + + Assert(shiftedSum <= PG_UINT32_MAX); + return (uint32) shiftedSum; + +#endif /* RYU_32_BIT_PLATFORM */ +} + +static inline uint32 +mulPow5InvDivPow2(const uint32 m, const uint32 q, const int32 j) +{ + return mulShift(m, FLOAT_POW5_INV_SPLIT[q], j); +} + +static inline uint32 +mulPow5divPow2(const uint32 m, const uint32 i, const int32 j) +{ + return mulShift(m, FLOAT_POW5_SPLIT[i], j); +} + +static inline uint32 +decimalLength(const uint32 v) +{ + /* Function precondition: v is not a 10-digit number. */ + /* (9 digits are sufficient for round-tripping.) */ + Assert(v < 1000000000); + if (v >= 100000000) + { + return 9; + } + if (v >= 10000000) + { + return 8; + } + if (v >= 1000000) + { + return 7; + } + if (v >= 100000) + { + return 6; + } + if (v >= 10000) + { + return 5; + } + if (v >= 1000) + { + return 4; + } + if (v >= 100) + { + return 3; + } + if (v >= 10) + { + return 2; + } + return 1; +} + +/* A floating decimal representing m * 10^e. */ +typedef struct floating_decimal_32 +{ + uint32 mantissa; + int32 exponent; +} floating_decimal_32; + +static inline floating_decimal_32 +f2d(const uint32 ieeeMantissa, const uint32 ieeeExponent) +{ + int32 e2; + uint32 m2; + + if (ieeeExponent == 0) + { + /* We subtract 2 so that the bounds computation has 2 additional bits. */ + e2 = 1 - FLOAT_BIAS - FLOAT_MANTISSA_BITS - 2; + m2 = ieeeMantissa; + } + else + { + e2 = ieeeExponent - FLOAT_BIAS - FLOAT_MANTISSA_BITS - 2; + m2 = (1u << FLOAT_MANTISSA_BITS) | ieeeMantissa; + } + +#if STRICTLY_SHORTEST + const bool even = (m2 & 1) == 0; + const bool acceptBounds = even; +#else + const bool acceptBounds = false; +#endif + + /* Step 2: Determine the interval of legal decimal representations. */ + const uint32 mv = 4 * m2; + const uint32 mp = 4 * m2 + 2; + + /* Implicit bool -> int conversion. True is 1, false is 0. */ + const uint32 mmShift = ieeeMantissa != 0 || ieeeExponent <= 1; + const uint32 mm = 4 * m2 - 1 - mmShift; + + /* Step 3: Convert to a decimal power base using 64-bit arithmetic. */ + uint32 vr, + vp, + vm; + int32 e10; + bool vmIsTrailingZeros = false; + bool vrIsTrailingZeros = false; + uint8 lastRemovedDigit = 0; + + if (e2 >= 0) + { + const uint32 q = log10Pow2(e2); + + e10 = q; + + const int32 k = FLOAT_POW5_INV_BITCOUNT + pow5bits(q) - 1; + const int32 i = -e2 + q + k; + + vr = mulPow5InvDivPow2(mv, q, i); + vp = mulPow5InvDivPow2(mp, q, i); + vm = mulPow5InvDivPow2(mm, q, i); + + if (q != 0 && (vp - 1) / 10 <= vm / 10) + { + /* + * We need to know one removed digit even if we are not going to + * loop below. We could use q = X - 1 above, except that would + * require 33 bits for the result, and we've found that 32-bit + * arithmetic is faster even on 64-bit machines. + */ + const int32 l = FLOAT_POW5_INV_BITCOUNT + pow5bits(q - 1) - 1; + + lastRemovedDigit = (uint8) (mulPow5InvDivPow2(mv, q - 1, -e2 + q - 1 + l) % 10); + } + if (q <= 9) + { + /* + * The largest power of 5 that fits in 24 bits is 5^10, but q <= 9 + * seems to be safe as well. + * + * Only one of mp, mv, and mm can be a multiple of 5, if any. + */ + if (mv % 5 == 0) + { + vrIsTrailingZeros = multipleOfPowerOf5(mv, q); + } + else if (acceptBounds) + { + vmIsTrailingZeros = multipleOfPowerOf5(mm, q); + } + else + { + vp -= multipleOfPowerOf5(mp, q); + } + } + } + else + { + const uint32 q = log10Pow5(-e2); + + e10 = q + e2; + + const int32 i = -e2 - q; + const int32 k = pow5bits(i) - FLOAT_POW5_BITCOUNT; + int32 j = q - k; + + vr = mulPow5divPow2(mv, i, j); + vp = mulPow5divPow2(mp, i, j); + vm = mulPow5divPow2(mm, i, j); + + if (q != 0 && (vp - 1) / 10 <= vm / 10) + { + j = q - 1 - (pow5bits(i + 1) - FLOAT_POW5_BITCOUNT); + lastRemovedDigit = (uint8) (mulPow5divPow2(mv, i + 1, j) % 10); + } + if (q <= 1) + { + /* + * {vr,vp,vm} is trailing zeros if {mv,mp,mm} has at least q + * trailing 0 bits. + */ + /* mv = 4 * m2, so it always has at least two trailing 0 bits. */ + vrIsTrailingZeros = true; + if (acceptBounds) + { + /* + * mm = mv - 1 - mmShift, so it has 1 trailing 0 bit iff + * mmShift == 1. + */ + vmIsTrailingZeros = mmShift == 1; + } + else + { + /* + * mp = mv + 2, so it always has at least one trailing 0 bit. + */ + --vp; + } + } + else if (q < 31) + { + /* TODO(ulfjack):Use a tighter bound here. */ + vrIsTrailingZeros = multipleOfPowerOf2(mv, q - 1); + } + } + + /* + * Step 4: Find the shortest decimal representation in the interval of + * legal representations. + */ + uint32 removed = 0; + uint32 output; + + if (vmIsTrailingZeros || vrIsTrailingZeros) + { + /* General case, which happens rarely (~4.0%). */ + while (vp / 10 > vm / 10) + { + vmIsTrailingZeros &= vm - (vm / 10) * 10 == 0; + vrIsTrailingZeros &= lastRemovedDigit == 0; + lastRemovedDigit = (uint8) (vr % 10); + vr /= 10; + vp /= 10; + vm /= 10; + ++removed; + } + if (vmIsTrailingZeros) + { + while (vm % 10 == 0) + { + vrIsTrailingZeros &= lastRemovedDigit == 0; + lastRemovedDigit = (uint8) (vr % 10); + vr /= 10; + vp /= 10; + vm /= 10; + ++removed; + } + } + + if (vrIsTrailingZeros && lastRemovedDigit == 5 && vr % 2 == 0) + { + /* Round even if the exact number is .....50..0. */ + lastRemovedDigit = 4; + } + + /* + * We need to take vr + 1 if vr is outside bounds or we need to round + * up. + */ + output = vr + ((vr == vm && (!acceptBounds || !vmIsTrailingZeros)) || lastRemovedDigit >= 5); + } + else + { + /* + * Specialized for the common case (~96.0%). Percentages below are + * relative to this. + * + * Loop iterations below (approximately): 0: 13.6%, 1: 70.7%, 2: + * 14.1%, 3: 1.39%, 4: 0.14%, 5+: 0.01% + */ + while (vp / 10 > vm / 10) + { + lastRemovedDigit = (uint8) (vr % 10); + vr /= 10; + vp /= 10; + vm /= 10; + ++removed; + } + + /* + * We need to take vr + 1 if vr is outside bounds or we need to round + * up. + */ + output = vr + (vr == vm || lastRemovedDigit >= 5); + } + + const int32 exp = e10 + removed; + + floating_decimal_32 fd; + + fd.exponent = exp; + fd.mantissa = output; + return fd; +} + +static inline int +to_chars_f(const floating_decimal_32 v, const uint32 olength, char *const result) +{ + /* Step 5: Print the decimal representation. */ + int index = 0; + + uint32 output = v.mantissa; + int32 exp = v.exponent; + + /*---- + * On entry, mantissa * 10^exp is the result to be output. + * Caller has already done the - sign if needed. + * + * We want to insert the point somewhere depending on the output length + * and exponent, which might mean adding zeros: + * + * exp | format + * 1+ | ddddddddd000000 + * 0 | ddddddddd + * -1 .. -len+1 | dddddddd.d to d.ddddddddd + * -len ... | 0.ddddddddd to 0.000dddddd + */ + uint32 i = 0; + int32 nexp = exp + olength; + + if (nexp <= 0) + { + /* -nexp is number of 0s to add after '.' */ + Assert(nexp >= -3); + /* 0.000ddddd */ + index = 2 - nexp; + /* copy 8 bytes rather than 5 to let compiler optimize */ + memcpy(result, "0.000000", 8); + } + else if (exp < 0) + { + /* + * dddd.dddd; leave space at the start and move the '.' in after + */ + index = 1; + } + else + { + /* + * We can save some code later by pre-filling with zeros. We know that + * there can be no more than 6 output digits in this form, otherwise + * we would not choose fixed-point output. memset 8 rather than 6 + * bytes to let the compiler optimize it. + */ + Assert(exp < 6 && exp + olength <= 6); + memset(result, '0', 8); + } + + while (output >= 10000) + { + const uint32 c = output - 10000 * (output / 10000); + const uint32 c0 = (c % 100) << 1; + const uint32 c1 = (c / 100) << 1; + + output /= 10000; + + memcpy(result + index + olength - i - 2, DIGIT_TABLE + c0, 2); + memcpy(result + index + olength - i - 4, DIGIT_TABLE + c1, 2); + i += 4; + } + if (output >= 100) + { + const uint32 c = (output % 100) << 1; + + output /= 100; + memcpy(result + index + olength - i - 2, DIGIT_TABLE + c, 2); + i += 2; + } + if (output >= 10) + { + const uint32 c = output << 1; + + memcpy(result + index + olength - i - 2, DIGIT_TABLE + c, 2); + } + else + { + result[index] = (char) ('0' + output); + } + + if (index == 1) + { + /* + * nexp is 1..6 here, representing the number of digits before the + * point. A value of 7+ is not possible because we switch to + * scientific notation when the display exponent reaches 6. + */ + Assert(nexp < 7); + /* gcc only seems to want to optimize memmove for small 2^n */ + if (nexp & 4) + { + memmove(result + index - 1, result + index, 4); + index += 4; + } + if (nexp & 2) + { + memmove(result + index - 1, result + index, 2); + index += 2; + } + if (nexp & 1) + { + result[index - 1] = result[index]; + } + result[nexp] = '.'; + index = olength + 1; + } + else if (exp >= 0) + { + /* we supplied the trailing zeros earlier, now just set the length. */ + index = olength + exp; + } + else + { + index = olength + (2 - nexp); + } + + return index; +} + +static inline int +to_chars(const floating_decimal_32 v, const bool sign, char *const result) +{ + /* Step 5: Print the decimal representation. */ + int index = 0; + + uint32 output = v.mantissa; + uint32 olength = decimalLength(output); + int32 exp = v.exponent + olength - 1; + + if (sign) + result[index++] = '-'; + + /* + * The thresholds for fixed-point output are chosen to match printf + * defaults. Beware that both the code of to_chars_f and the value of + * FLOAT_SHORTEST_DECIMAL_LEN are sensitive to these thresholds. + */ + if (exp >= -4 && exp < 6) + return to_chars_f(v, olength, result + index) + sign; + + /* + * If v.exponent is exactly 0, we might have reached here via the small + * integer fast path, in which case v.mantissa might contain trailing + * (decimal) zeros. For scientific notation we need to move these zeros + * into the exponent. (For fixed point this doesn't matter, which is why + * we do this here rather than above.) + * + * Since we already calculated the display exponent (exp) above based on + * the old decimal length, that value does not change here. Instead, we + * just reduce the display length for each digit removed. + * + * If we didn't get here via the fast path, the raw exponent will not + * usually be 0, and there will be no trailing zeros, so we pay no more + * than one div10/multiply extra cost. We claw back half of that by + * checking for divisibility by 2 before dividing by 10. + */ + if (v.exponent == 0) + { + while ((output & 1) == 0) + { + const uint32 q = output / 10; + const uint32 r = output - 10 * q; + + if (r != 0) + break; + output = q; + --olength; + } + } + + /*---- + * Print the decimal digits. + * The following code is equivalent to: + * + * for (uint32 i = 0; i < olength - 1; ++i) { + * const uint32 c = output % 10; output /= 10; + * result[index + olength - i] = (char) ('0' + c); + * } + * result[index] = '0' + output % 10; + */ + uint32 i = 0; + + while (output >= 10000) + { + const uint32 c = output - 10000 * (output / 10000); + const uint32 c0 = (c % 100) << 1; + const uint32 c1 = (c / 100) << 1; + + output /= 10000; + + memcpy(result + index + olength - i - 1, DIGIT_TABLE + c0, 2); + memcpy(result + index + olength - i - 3, DIGIT_TABLE + c1, 2); + i += 4; + } + if (output >= 100) + { + const uint32 c = (output % 100) << 1; + + output /= 100; + memcpy(result + index + olength - i - 1, DIGIT_TABLE + c, 2); + i += 2; + } + if (output >= 10) + { + const uint32 c = output << 1; + + /* + * We can't use memcpy here: the decimal dot goes between these two + * digits. + */ + result[index + olength - i] = DIGIT_TABLE[c + 1]; + result[index] = DIGIT_TABLE[c]; + } + else + { + result[index] = (char) ('0' + output); + } + + /* Print decimal point if needed. */ + if (olength > 1) + { + result[index + 1] = '.'; + index += olength + 1; + } + else + { + ++index; + } + + /* Print the exponent. */ + result[index++] = 'e'; + if (exp < 0) + { + result[index++] = '-'; + exp = -exp; + } + else + result[index++] = '+'; + + memcpy(result + index, DIGIT_TABLE + 2 * exp, 2); + index += 2; + + return index; +} + +static inline bool +f2d_small_int(const uint32 ieeeMantissa, + const uint32 ieeeExponent, + floating_decimal_32 *v) +{ + const int32 e2 = (int32) ieeeExponent - FLOAT_BIAS - FLOAT_MANTISSA_BITS; + + /* + * Avoid using multiple "return false;" here since it tends to provoke the + * compiler into inlining multiple copies of f2d, which is undesirable. + */ + + if (e2 >= -FLOAT_MANTISSA_BITS && e2 <= 0) + { + /*---- + * Since 2^23 <= m2 < 2^24 and 0 <= -e2 <= 23: + * 1 <= f = m2 / 2^-e2 < 2^24. + * + * Test if the lower -e2 bits of the significand are 0, i.e. whether + * the fraction is 0. We can use ieeeMantissa here, since the implied + * 1 bit can never be tested by this; the implied 1 can only be part + * of a fraction if e2 < -FLOAT_MANTISSA_BITS which we already + * checked. (e.g. 0.5 gives ieeeMantissa == 0 and e2 == -24) + */ + const uint32 mask = (1U << -e2) - 1; + const uint32 fraction = ieeeMantissa & mask; + + if (fraction == 0) + { + /*---- + * f is an integer in the range [1, 2^24). + * Note: mantissa might contain trailing (decimal) 0's. + * Note: since 2^24 < 10^9, there is no need to adjust + * decimalLength(). + */ + const uint32 m2 = (1U << FLOAT_MANTISSA_BITS) | ieeeMantissa; + + v->mantissa = m2 >> -e2; + v->exponent = 0; + return true; + } + } + + return false; +} + +/* + * Store the shortest decimal representation of the given float as an + * UNTERMINATED string in the caller's supplied buffer (which must be at least + * FLOAT_SHORTEST_DECIMAL_LEN-1 bytes long). + * + * Returns the number of bytes stored. + */ +int +float_to_shortest_decimal_bufn(float f, char *result) +{ + /* + * Step 1: Decode the floating-point number, and unify normalized and + * subnormal cases. + */ + const uint32 bits = float_to_bits(f); + + /* Decode bits into sign, mantissa, and exponent. */ + const bool ieeeSign = ((bits >> (FLOAT_MANTISSA_BITS + FLOAT_EXPONENT_BITS)) & 1) != 0; + const uint32 ieeeMantissa = bits & ((1u << FLOAT_MANTISSA_BITS) - 1); + const uint32 ieeeExponent = (bits >> FLOAT_MANTISSA_BITS) & ((1u << FLOAT_EXPONENT_BITS) - 1); + + /* Case distinction; exit early for the easy cases. */ + if (ieeeExponent == ((1u << FLOAT_EXPONENT_BITS) - 1u) || (ieeeExponent == 0 && ieeeMantissa == 0)) + { + return copy_special_str(result, ieeeSign, (ieeeExponent != 0), (ieeeMantissa != 0)); + } + + floating_decimal_32 v; + const bool isSmallInt = f2d_small_int(ieeeMantissa, ieeeExponent, &v); + + if (!isSmallInt) + { + v = f2d(ieeeMantissa, ieeeExponent); + } + + return to_chars(v, ieeeSign, result); +} + +/* + * Store the shortest decimal representation of the given float as a + * null-terminated string in the caller's supplied buffer (which must be at + * least FLOAT_SHORTEST_DECIMAL_LEN bytes long). + * + * Returns the string length. + */ +int +float_to_shortest_decimal_buf(float f, char *result) +{ + const int index = float_to_shortest_decimal_bufn(f, result); + + /* Terminate the string. */ + Assert(index < FLOAT_SHORTEST_DECIMAL_LEN); + result[index] = '\0'; + return index; +} + +/* + * Return the shortest decimal representation as a null-terminated palloc'd + * string (outside the backend, uses malloc() instead). + * + * Caller is responsible for freeing the result. + */ +char * +float_to_shortest_decimal(float f) +{ + char *const result = (char *) palloc(FLOAT_SHORTEST_DECIMAL_LEN); + + float_to_shortest_decimal_buf(f, result); + return result; +} |