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Diffstat (limited to 'util/integer_to_string.cc')
-rw-r--r-- | util/integer_to_string.cc | 639 |
1 files changed, 639 insertions, 0 deletions
diff --git a/util/integer_to_string.cc b/util/integer_to_string.cc new file mode 100644 index 000000000..32047291d --- /dev/null +++ b/util/integer_to_string.cc @@ -0,0 +1,639 @@ +/* Fast integer to string conversion. +Source: https://github.com/miloyip/itoa-benchmark +Local modifications: +1. Return end of buffer instead of null terminating +2. Collapse to single file +3. Namespace +4. Remove test hook +5. Non-x86 support from the branch_lut code +6. Rename functions + +Copyright (C) 2014 Milo Yip + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +THE SOFTWARE. + +Which is based on: http://0x80.pl/snippets/asm/sse-utoa.c + + SSE: conversion integers to decimal representation + + Author: Wojciech Muła + e-mail: wojciech_mula@poczta.onet.pl + www: http://0x80.pl/ + + License: BSD + + initial release 2011-10-21 + $Id$ +*/ + +#include "util/integer_to_string.hh" +#include <cassert> +#include <stdint.h> + +namespace util { + +namespace { +const char gDigitsLut[200] = { + '0','0','0','1','0','2','0','3','0','4','0','5','0','6','0','7','0','8','0','9', + '1','0','1','1','1','2','1','3','1','4','1','5','1','6','1','7','1','8','1','9', + '2','0','2','1','2','2','2','3','2','4','2','5','2','6','2','7','2','8','2','9', + '3','0','3','1','3','2','3','3','3','4','3','5','3','6','3','7','3','8','3','9', + '4','0','4','1','4','2','4','3','4','4','4','5','4','6','4','7','4','8','4','9', + '5','0','5','1','5','2','5','3','5','4','5','5','5','6','5','7','5','8','5','9', + '6','0','6','1','6','2','6','3','6','4','6','5','6','6','6','7','6','8','6','9', + '7','0','7','1','7','2','7','3','7','4','7','5','7','6','7','7','7','8','7','9', + '8','0','8','1','8','2','8','3','8','4','8','5','8','6','8','7','8','8','8','9', + '9','0','9','1','9','2','9','3','9','4','9','5','9','6','9','7','9','8','9','9' +}; +} // namespace + +// SSE2 implementation according to http://0x80.pl/articles/sse-itoa.html +// Modifications: (1) fix incorrect digits (2) accept all ranges (3) write to user provided buffer. + +#if defined(i386) || defined(__amd64) || defined(_M_IX86) || defined(_M_X64) + +#include <emmintrin.h> + +#ifdef _MSC_VER +#include "intrin.h" +#endif + +#ifdef _MSC_VER +#define ALIGN_PRE __declspec(align(16)) +#define ALIGN_SUF +#else +#define ALIGN_PRE +#define ALIGN_SUF __attribute__ ((aligned(16))) +#endif + +namespace { + +static const uint32_t kDiv10000 = 0xd1b71759; +ALIGN_PRE static const uint32_t kDiv10000Vector[4] ALIGN_SUF = { kDiv10000, kDiv10000, kDiv10000, kDiv10000 }; +ALIGN_PRE static const uint32_t k10000Vector[4] ALIGN_SUF = { 10000, 10000, 10000, 10000 }; +ALIGN_PRE static const uint16_t kDivPowersVector[8] ALIGN_SUF = { 8389, 5243, 13108, 32768, 8389, 5243, 13108, 32768 }; // 10^3, 10^2, 10^1, 10^0 +ALIGN_PRE static const uint16_t kShiftPowersVector[8] ALIGN_SUF = { + 1 << (16 - (23 + 2 - 16)), + 1 << (16 - (19 + 2 - 16)), + 1 << (16 - 1 - 2), + 1 << (15), + 1 << (16 - (23 + 2 - 16)), + 1 << (16 - (19 + 2 - 16)), + 1 << (16 - 1 - 2), + 1 << (15) +}; +ALIGN_PRE static const uint16_t k10Vector[8] ALIGN_SUF = { 10, 10, 10, 10, 10, 10, 10, 10 }; +ALIGN_PRE static const char kAsciiZero[16] ALIGN_SUF = { '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0' }; + +inline __m128i Convert8DigitsSSE2(uint32_t value) { + assert(value <= 99999999); + + // abcd, efgh = abcdefgh divmod 10000 + const __m128i abcdefgh = _mm_cvtsi32_si128(value); + const __m128i abcd = _mm_srli_epi64(_mm_mul_epu32(abcdefgh, reinterpret_cast<const __m128i*>(kDiv10000Vector)[0]), 45); + const __m128i efgh = _mm_sub_epi32(abcdefgh, _mm_mul_epu32(abcd, reinterpret_cast<const __m128i*>(k10000Vector)[0])); + + // v1 = [ abcd, efgh, 0, 0, 0, 0, 0, 0 ] + const __m128i v1 = _mm_unpacklo_epi16(abcd, efgh); + + // v1a = v1 * 4 = [ abcd * 4, efgh * 4, 0, 0, 0, 0, 0, 0 ] + const __m128i v1a = _mm_slli_epi64(v1, 2); + + // v2 = [ abcd * 4, abcd * 4, abcd * 4, abcd * 4, efgh * 4, efgh * 4, efgh * 4, efgh * 4 ] + const __m128i v2a = _mm_unpacklo_epi16(v1a, v1a); + const __m128i v2 = _mm_unpacklo_epi32(v2a, v2a); + + // v4 = v2 div 10^3, 10^2, 10^1, 10^0 = [ a, ab, abc, abcd, e, ef, efg, efgh ] + const __m128i v3 = _mm_mulhi_epu16(v2, reinterpret_cast<const __m128i*>(kDivPowersVector)[0]); + const __m128i v4 = _mm_mulhi_epu16(v3, reinterpret_cast<const __m128i*>(kShiftPowersVector)[0]); + + // v5 = v4 * 10 = [ a0, ab0, abc0, abcd0, e0, ef0, efg0, efgh0 ] + const __m128i v5 = _mm_mullo_epi16(v4, reinterpret_cast<const __m128i*>(k10Vector)[0]); + + // v6 = v5 << 16 = [ 0, a0, ab0, abc0, 0, e0, ef0, efg0 ] + const __m128i v6 = _mm_slli_epi64(v5, 16); + + // v7 = v4 - v6 = { a, b, c, d, e, f, g, h } + const __m128i v7 = _mm_sub_epi16(v4, v6); + + return v7; +} + +inline __m128i ShiftDigits_SSE2(__m128i a, unsigned digit) { + assert(digit <= 8); + switch (digit) { + case 0: return a; + case 1: return _mm_srli_si128(a, 1); + case 2: return _mm_srli_si128(a, 2); + case 3: return _mm_srli_si128(a, 3); + case 4: return _mm_srli_si128(a, 4); + case 5: return _mm_srli_si128(a, 5); + case 6: return _mm_srli_si128(a, 6); + case 7: return _mm_srli_si128(a, 7); + case 8: return _mm_srli_si128(a, 8); + } + return a; // should not execute here. +} + +} // namespace + +// Original name: u32toa_sse2 +char *ToString(uint32_t value, char* buffer) { + if (value < 10000) { + const uint32_t d1 = (value / 100) << 1; + const uint32_t d2 = (value % 100) << 1; + + if (value >= 1000) + *buffer++ = gDigitsLut[d1]; + if (value >= 100) + *buffer++ = gDigitsLut[d1 + 1]; + if (value >= 10) + *buffer++ = gDigitsLut[d2]; + *buffer++ = gDigitsLut[d2 + 1]; + //*buffer++ = '\0'; + return buffer; + } + else if (value < 100000000) { + // Experiment shows that this case SSE2 is slower +#if 0 + const __m128i a = Convert8DigitsSSE2(value); + + // Convert to bytes, add '0' + const __m128i va = _mm_add_epi8(_mm_packus_epi16(a, _mm_setzero_si128()), reinterpret_cast<const __m128i*>(kAsciiZero)[0]); + + // Count number of digit + const unsigned mask = _mm_movemask_epi8(_mm_cmpeq_epi8(va, reinterpret_cast<const __m128i*>(kAsciiZero)[0])); + unsigned long digit; +#ifdef _MSC_VER + _BitScanForward(&digit, ~mask | 0x8000); +#else + digit = __builtin_ctz(~mask | 0x8000); +#endif + + // Shift digits to the beginning + __m128i result = ShiftDigits_SSE2(va, digit); + //__m128i result = _mm_srl_epi64(va, _mm_cvtsi32_si128(digit * 8)); + _mm_storel_epi64(reinterpret_cast<__m128i*>(buffer), result); + buffer[8 - digit] = '\0'; +#else + // value = bbbbcccc + const uint32_t b = value / 10000; + const uint32_t c = value % 10000; + + const uint32_t d1 = (b / 100) << 1; + const uint32_t d2 = (b % 100) << 1; + + const uint32_t d3 = (c / 100) << 1; + const uint32_t d4 = (c % 100) << 1; + + if (value >= 10000000) + *buffer++ = gDigitsLut[d1]; + if (value >= 1000000) + *buffer++ = gDigitsLut[d1 + 1]; + if (value >= 100000) + *buffer++ = gDigitsLut[d2]; + *buffer++ = gDigitsLut[d2 + 1]; + + *buffer++ = gDigitsLut[d3]; + *buffer++ = gDigitsLut[d3 + 1]; + *buffer++ = gDigitsLut[d4]; + *buffer++ = gDigitsLut[d4 + 1]; +// *buffer++ = '\0'; + return buffer; +#endif + } + else { + // value = aabbbbbbbb in decimal + + const uint32_t a = value / 100000000; // 1 to 42 + value %= 100000000; + + if (a >= 10) { + const unsigned i = a << 1; + *buffer++ = gDigitsLut[i]; + *buffer++ = gDigitsLut[i + 1]; + } + else + *buffer++ = '0' + static_cast<char>(a); + + const __m128i b = Convert8DigitsSSE2(value); + const __m128i ba = _mm_add_epi8(_mm_packus_epi16(_mm_setzero_si128(), b), reinterpret_cast<const __m128i*>(kAsciiZero)[0]); + const __m128i result = _mm_srli_si128(ba, 8); + _mm_storel_epi64(reinterpret_cast<__m128i*>(buffer), result); +// buffer[8] = '\0'; + return buffer + 8; + } +} + +// Original name: u64toa_sse2 +char *ToString(uint64_t value, char* buffer) { + if (value < 100000000) { + uint32_t v = static_cast<uint32_t>(value); + if (v < 10000) { + const uint32_t d1 = (v / 100) << 1; + const uint32_t d2 = (v % 100) << 1; + + if (v >= 1000) + *buffer++ = gDigitsLut[d1]; + if (v >= 100) + *buffer++ = gDigitsLut[d1 + 1]; + if (v >= 10) + *buffer++ = gDigitsLut[d2]; + *buffer++ = gDigitsLut[d2 + 1]; + //*buffer++ = '\0'; + return buffer; + } + else { + // Experiment shows that this case SSE2 is slower +#if 0 + const __m128i a = Convert8DigitsSSE2(v); + + // Convert to bytes, add '0' + const __m128i va = _mm_add_epi8(_mm_packus_epi16(a, _mm_setzero_si128()), reinterpret_cast<const __m128i*>(kAsciiZero)[0]); + + // Count number of digit + const unsigned mask = _mm_movemask_epi8(_mm_cmpeq_epi8(va, reinterpret_cast<const __m128i*>(kAsciiZero)[0])); + unsigned long digit; +#ifdef _MSC_VER + _BitScanForward(&digit, ~mask | 0x8000); +#else + digit = __builtin_ctz(~mask | 0x8000); +#endif + + // Shift digits to the beginning + __m128i result = ShiftDigits_SSE2(va, digit); + _mm_storel_epi64(reinterpret_cast<__m128i*>(buffer), result); + buffer[8 - digit] = '\0'; +#else + // value = bbbbcccc + const uint32_t b = v / 10000; + const uint32_t c = v % 10000; + + const uint32_t d1 = (b / 100) << 1; + const uint32_t d2 = (b % 100) << 1; + + const uint32_t d3 = (c / 100) << 1; + const uint32_t d4 = (c % 100) << 1; + + if (value >= 10000000) + *buffer++ = gDigitsLut[d1]; + if (value >= 1000000) + *buffer++ = gDigitsLut[d1 + 1]; + if (value >= 100000) + *buffer++ = gDigitsLut[d2]; + *buffer++ = gDigitsLut[d2 + 1]; + + *buffer++ = gDigitsLut[d3]; + *buffer++ = gDigitsLut[d3 + 1]; + *buffer++ = gDigitsLut[d4]; + *buffer++ = gDigitsLut[d4 + 1]; + //*buffer++ = '\0'; + return buffer; +#endif + } + } + else if (value < 10000000000000000) { + const uint32_t v0 = static_cast<uint32_t>(value / 100000000); + const uint32_t v1 = static_cast<uint32_t>(value % 100000000); + + const __m128i a0 = Convert8DigitsSSE2(v0); + const __m128i a1 = Convert8DigitsSSE2(v1); + + // Convert to bytes, add '0' + const __m128i va = _mm_add_epi8(_mm_packus_epi16(a0, a1), reinterpret_cast<const __m128i*>(kAsciiZero)[0]); + + // Count number of digit + const unsigned mask = _mm_movemask_epi8(_mm_cmpeq_epi8(va, reinterpret_cast<const __m128i*>(kAsciiZero)[0])); +#ifdef _MSC_VER + unsigned long digit; + _BitScanForward(&digit, ~mask | 0x8000); +#else + unsigned digit = __builtin_ctz(~mask | 0x8000); +#endif + + // Shift digits to the beginning + __m128i result = ShiftDigits_SSE2(va, digit); + _mm_storeu_si128(reinterpret_cast<__m128i*>(buffer), result); +// buffer[16 - digit] = '\0'; + return &buffer[16 - digit]; + } + else { + const uint32_t a = static_cast<uint32_t>(value / 10000000000000000); // 1 to 1844 + value %= 10000000000000000; + + if (a < 10) + *buffer++ = '0' + static_cast<char>(a); + else if (a < 100) { + const uint32_t i = a << 1; + *buffer++ = gDigitsLut[i]; + *buffer++ = gDigitsLut[i + 1]; + } + else if (a < 1000) { + *buffer++ = '0' + static_cast<char>(a / 100); + + const uint32_t i = (a % 100) << 1; + *buffer++ = gDigitsLut[i]; + *buffer++ = gDigitsLut[i + 1]; + } + else { + const uint32_t i = (a / 100) << 1; + const uint32_t j = (a % 100) << 1; + *buffer++ = gDigitsLut[i]; + *buffer++ = gDigitsLut[i + 1]; + *buffer++ = gDigitsLut[j]; + *buffer++ = gDigitsLut[j + 1]; + } + + const uint32_t v0 = static_cast<uint32_t>(value / 100000000); + const uint32_t v1 = static_cast<uint32_t>(value % 100000000); + + const __m128i a0 = Convert8DigitsSSE2(v0); + const __m128i a1 = Convert8DigitsSSE2(v1); + + // Convert to bytes, add '0' + const __m128i va = _mm_add_epi8(_mm_packus_epi16(a0, a1), reinterpret_cast<const __m128i*>(kAsciiZero)[0]); + _mm_storeu_si128(reinterpret_cast<__m128i*>(buffer), va); +// buffer[16] = '\0'; + return &buffer[16]; + } +} + +#else // Generic Non-x86 case + +// Orignal name: u32toa_branchlut +char *ToString(uint32_t value, char* buffer) { + if (value < 10000) { + const uint32_t d1 = (value / 100) << 1; + const uint32_t d2 = (value % 100) << 1; + + if (value >= 1000) + *buffer++ = gDigitsLut[d1]; + if (value >= 100) + *buffer++ = gDigitsLut[d1 + 1]; + if (value >= 10) + *buffer++ = gDigitsLut[d2]; + *buffer++ = gDigitsLut[d2 + 1]; + } + else if (value < 100000000) { + // value = bbbbcccc + const uint32_t b = value / 10000; + const uint32_t c = value % 10000; + + const uint32_t d1 = (b / 100) << 1; + const uint32_t d2 = (b % 100) << 1; + + const uint32_t d3 = (c / 100) << 1; + const uint32_t d4 = (c % 100) << 1; + + if (value >= 10000000) + *buffer++ = gDigitsLut[d1]; + if (value >= 1000000) + *buffer++ = gDigitsLut[d1 + 1]; + if (value >= 100000) + *buffer++ = gDigitsLut[d2]; + *buffer++ = gDigitsLut[d2 + 1]; + + *buffer++ = gDigitsLut[d3]; + *buffer++ = gDigitsLut[d3 + 1]; + *buffer++ = gDigitsLut[d4]; + *buffer++ = gDigitsLut[d4 + 1]; + } + else { + // value = aabbbbcccc in decimal + + const uint32_t a = value / 100000000; // 1 to 42 + value %= 100000000; + + if (a >= 10) { + const unsigned i = a << 1; + *buffer++ = gDigitsLut[i]; + *buffer++ = gDigitsLut[i + 1]; + } + else + *buffer++ = '0' + static_cast<char>(a); + + const uint32_t b = value / 10000; // 0 to 9999 + const uint32_t c = value % 10000; // 0 to 9999 + + const uint32_t d1 = (b / 100) << 1; + const uint32_t d2 = (b % 100) << 1; + + const uint32_t d3 = (c / 100) << 1; + const uint32_t d4 = (c % 100) << 1; + + *buffer++ = gDigitsLut[d1]; + *buffer++ = gDigitsLut[d1 + 1]; + *buffer++ = gDigitsLut[d2]; + *buffer++ = gDigitsLut[d2 + 1]; + *buffer++ = gDigitsLut[d3]; + *buffer++ = gDigitsLut[d3 + 1]; + *buffer++ = gDigitsLut[d4]; + *buffer++ = gDigitsLut[d4 + 1]; + } + return buffer; //*buffer++ = '\0'; +} + +// Original name: u64toa_branchlut +char *ToString(uint64_t value, char* buffer) { + if (value < 100000000) { + uint32_t v = static_cast<uint32_t>(value); + if (v < 10000) { + const uint32_t d1 = (v / 100) << 1; + const uint32_t d2 = (v % 100) << 1; + + if (v >= 1000) + *buffer++ = gDigitsLut[d1]; + if (v >= 100) + *buffer++ = gDigitsLut[d1 + 1]; + if (v >= 10) + *buffer++ = gDigitsLut[d2]; + *buffer++ = gDigitsLut[d2 + 1]; + } + else { + // value = bbbbcccc + const uint32_t b = v / 10000; + const uint32_t c = v % 10000; + + const uint32_t d1 = (b / 100) << 1; + const uint32_t d2 = (b % 100) << 1; + + const uint32_t d3 = (c / 100) << 1; + const uint32_t d4 = (c % 100) << 1; + + if (value >= 10000000) + *buffer++ = gDigitsLut[d1]; + if (value >= 1000000) + *buffer++ = gDigitsLut[d1 + 1]; + if (value >= 100000) + *buffer++ = gDigitsLut[d2]; + *buffer++ = gDigitsLut[d2 + 1]; + + *buffer++ = gDigitsLut[d3]; + *buffer++ = gDigitsLut[d3 + 1]; + *buffer++ = gDigitsLut[d4]; + *buffer++ = gDigitsLut[d4 + 1]; + } + } + else if (value < 10000000000000000) { + const uint32_t v0 = static_cast<uint32_t>(value / 100000000); + const uint32_t v1 = static_cast<uint32_t>(value % 100000000); + + const uint32_t b0 = v0 / 10000; + const uint32_t c0 = v0 % 10000; + + const uint32_t d1 = (b0 / 100) << 1; + const uint32_t d2 = (b0 % 100) << 1; + + const uint32_t d3 = (c0 / 100) << 1; + const uint32_t d4 = (c0 % 100) << 1; + + const uint32_t b1 = v1 / 10000; + const uint32_t c1 = v1 % 10000; + + const uint32_t d5 = (b1 / 100) << 1; + const uint32_t d6 = (b1 % 100) << 1; + + const uint32_t d7 = (c1 / 100) << 1; + const uint32_t d8 = (c1 % 100) << 1; + + if (value >= 1000000000000000) + *buffer++ = gDigitsLut[d1]; + if (value >= 100000000000000) + *buffer++ = gDigitsLut[d1 + 1]; + if (value >= 10000000000000) + *buffer++ = gDigitsLut[d2]; + if (value >= 1000000000000) + *buffer++ = gDigitsLut[d2 + 1]; + if (value >= 100000000000) + *buffer++ = gDigitsLut[d3]; + if (value >= 10000000000) + *buffer++ = gDigitsLut[d3 + 1]; + if (value >= 1000000000) + *buffer++ = gDigitsLut[d4]; + if (value >= 100000000) + *buffer++ = gDigitsLut[d4 + 1]; + + *buffer++ = gDigitsLut[d5]; + *buffer++ = gDigitsLut[d5 + 1]; + *buffer++ = gDigitsLut[d6]; + *buffer++ = gDigitsLut[d6 + 1]; + *buffer++ = gDigitsLut[d7]; + *buffer++ = gDigitsLut[d7 + 1]; + *buffer++ = gDigitsLut[d8]; + *buffer++ = gDigitsLut[d8 + 1]; + } + else { + const uint32_t a = static_cast<uint32_t>(value / 10000000000000000); // 1 to 1844 + value %= 10000000000000000; + + if (a < 10) + *buffer++ = '0' + static_cast<char>(a); + else if (a < 100) { + const uint32_t i = a << 1; + *buffer++ = gDigitsLut[i]; + *buffer++ = gDigitsLut[i + 1]; + } + else if (a < 1000) { + *buffer++ = '0' + static_cast<char>(a / 100); + + const uint32_t i = (a % 100) << 1; + *buffer++ = gDigitsLut[i]; + *buffer++ = gDigitsLut[i + 1]; + } + else { + const uint32_t i = (a / 100) << 1; + const uint32_t j = (a % 100) << 1; + *buffer++ = gDigitsLut[i]; + *buffer++ = gDigitsLut[i + 1]; + *buffer++ = gDigitsLut[j]; + *buffer++ = gDigitsLut[j + 1]; + } + + const uint32_t v0 = static_cast<uint32_t>(value / 100000000); + const uint32_t v1 = static_cast<uint32_t>(value % 100000000); + + const uint32_t b0 = v0 / 10000; + const uint32_t c0 = v0 % 10000; + + const uint32_t d1 = (b0 / 100) << 1; + const uint32_t d2 = (b0 % 100) << 1; + + const uint32_t d3 = (c0 / 100) << 1; + const uint32_t d4 = (c0 % 100) << 1; + + const uint32_t b1 = v1 / 10000; + const uint32_t c1 = v1 % 10000; + + const uint32_t d5 = (b1 / 100) << 1; + const uint32_t d6 = (b1 % 100) << 1; + + const uint32_t d7 = (c1 / 100) << 1; + const uint32_t d8 = (c1 % 100) << 1; + + *buffer++ = gDigitsLut[d1]; + *buffer++ = gDigitsLut[d1 + 1]; + *buffer++ = gDigitsLut[d2]; + *buffer++ = gDigitsLut[d2 + 1]; + *buffer++ = gDigitsLut[d3]; + *buffer++ = gDigitsLut[d3 + 1]; + *buffer++ = gDigitsLut[d4]; + *buffer++ = gDigitsLut[d4 + 1]; + *buffer++ = gDigitsLut[d5]; + *buffer++ = gDigitsLut[d5 + 1]; + *buffer++ = gDigitsLut[d6]; + *buffer++ = gDigitsLut[d6 + 1]; + *buffer++ = gDigitsLut[d7]; + *buffer++ = gDigitsLut[d7 + 1]; + *buffer++ = gDigitsLut[d8]; + *buffer++ = gDigitsLut[d8 + 1]; + } + return buffer; +} + +#endif // End of architecture if statement. + +// Signed wrappers. The negation is done on the unsigned version because +// doing so has defined behavior for INT_MIN. +char *ToString(int32_t value, char *to) { + uint32_t un = static_cast<uint32_t>(value); + if (value < 0) { + *to++ = '-'; + un = -un; + } + return ToString(un, to); +} + +char *ToString(int64_t value, char *to) { + uint64_t un = static_cast<uint64_t>(value); + if (value < 0) { + *to++ = '-'; + un = -un; + } + return ToString(un, to); +} + +// No optimization for this case yet. +char *ToString(int16_t value, char *to) { + return ToString((int32_t)value, to); +} +char *ToString(uint16_t value, char *to) { + return ToString((uint32_t)value, to); +} + +} // namespace util |