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Diffstat (limited to 'external/rapidjson/internal/dtoa.h')
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-rw-r--r-- | external/rapidjson/internal/dtoa.h | 245 |
2 files changed, 0 insertions, 245 deletions
diff --git a/external/rapidjson b/external/rapidjson new file mode 160000 +Subproject af223d44f4e8d3772cb1ac0ce8bc2a132b51717 diff --git a/external/rapidjson/internal/dtoa.h b/external/rapidjson/internal/dtoa.h deleted file mode 100644 index 8d6350e62..000000000 --- a/external/rapidjson/internal/dtoa.h +++ /dev/null @@ -1,245 +0,0 @@ -// Tencent is pleased to support the open source community by making RapidJSON available. -// -// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved. -// -// Licensed under the MIT License (the "License"); you may not use this file except -// in compliance with the License. You may obtain a copy of the License at -// -// http://opensource.org/licenses/MIT -// -// Unless required by applicable law or agreed to in writing, software distributed -// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR -// CONDITIONS OF ANY KIND, either express or implied. See the License for the -// specific language governing permissions and limitations under the License. - -// This is a C++ header-only implementation of Grisu2 algorithm from the publication: -// Loitsch, Florian. "Printing floating-point numbers quickly and accurately with -// integers." ACM Sigplan Notices 45.6 (2010): 233-243. - -#ifndef RAPIDJSON_DTOA_ -#define RAPIDJSON_DTOA_ - -#include "itoa.h" // GetDigitsLut() -#include "diyfp.h" -#include "ieee754.h" - -RAPIDJSON_NAMESPACE_BEGIN -namespace internal { - -#ifdef __GNUC__ -RAPIDJSON_DIAG_PUSH -RAPIDJSON_DIAG_OFF(effc++) -RAPIDJSON_DIAG_OFF(array-bounds) // some gcc versions generate wrong warnings https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59124 -#endif - -inline void GrisuRound(char* buffer, int len, uint64_t delta, uint64_t rest, uint64_t ten_kappa, uint64_t wp_w) { - while (rest < wp_w && delta - rest >= ten_kappa && - (rest + ten_kappa < wp_w || /// closer - wp_w - rest > rest + ten_kappa - wp_w)) { - buffer[len - 1]--; - rest += ten_kappa; - } -} - -inline unsigned CountDecimalDigit32(uint32_t n) { - // Simple pure C++ implementation was faster than __builtin_clz version in this situation. - if (n < 10) return 1; - if (n < 100) return 2; - if (n < 1000) return 3; - if (n < 10000) return 4; - if (n < 100000) return 5; - if (n < 1000000) return 6; - if (n < 10000000) return 7; - if (n < 100000000) return 8; - // Will not reach 10 digits in DigitGen() - //if (n < 1000000000) return 9; - //return 10; - return 9; -} - -inline void DigitGen(const DiyFp& W, const DiyFp& Mp, uint64_t delta, char* buffer, int* len, int* K) { - static const uint32_t kPow10[] = { 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000 }; - const DiyFp one(uint64_t(1) << -Mp.e, Mp.e); - const DiyFp wp_w = Mp - W; - uint32_t p1 = static_cast<uint32_t>(Mp.f >> -one.e); - uint64_t p2 = Mp.f & (one.f - 1); - unsigned kappa = CountDecimalDigit32(p1); // kappa in [0, 9] - *len = 0; - - while (kappa > 0) { - uint32_t d = 0; - switch (kappa) { - case 9: d = p1 / 100000000; p1 %= 100000000; break; - case 8: d = p1 / 10000000; p1 %= 10000000; break; - case 7: d = p1 / 1000000; p1 %= 1000000; break; - case 6: d = p1 / 100000; p1 %= 100000; break; - case 5: d = p1 / 10000; p1 %= 10000; break; - case 4: d = p1 / 1000; p1 %= 1000; break; - case 3: d = p1 / 100; p1 %= 100; break; - case 2: d = p1 / 10; p1 %= 10; break; - case 1: d = p1; p1 = 0; break; - default:; - } - if (d || *len) - buffer[(*len)++] = static_cast<char>('0' + static_cast<char>(d)); - kappa--; - uint64_t tmp = (static_cast<uint64_t>(p1) << -one.e) + p2; - if (tmp <= delta) { - *K += kappa; - GrisuRound(buffer, *len, delta, tmp, static_cast<uint64_t>(kPow10[kappa]) << -one.e, wp_w.f); - return; - } - } - - // kappa = 0 - for (;;) { - p2 *= 10; - delta *= 10; - char d = static_cast<char>(p2 >> -one.e); - if (d || *len) - buffer[(*len)++] = static_cast<char>('0' + d); - p2 &= one.f - 1; - kappa--; - if (p2 < delta) { - *K += kappa; - int index = -static_cast<int>(kappa); - GrisuRound(buffer, *len, delta, p2, one.f, wp_w.f * (index < 9 ? kPow10[-static_cast<int>(kappa)] : 0)); - return; - } - } -} - -inline void Grisu2(double value, char* buffer, int* length, int* K) { - const DiyFp v(value); - DiyFp w_m, w_p; - v.NormalizedBoundaries(&w_m, &w_p); - - const DiyFp c_mk = GetCachedPower(w_p.e, K); - const DiyFp W = v.Normalize() * c_mk; - DiyFp Wp = w_p * c_mk; - DiyFp Wm = w_m * c_mk; - Wm.f++; - Wp.f--; - DigitGen(W, Wp, Wp.f - Wm.f, buffer, length, K); -} - -inline char* WriteExponent(int K, char* buffer) { - if (K < 0) { - *buffer++ = '-'; - K = -K; - } - - if (K >= 100) { - *buffer++ = static_cast<char>('0' + static_cast<char>(K / 100)); - K %= 100; - const char* d = GetDigitsLut() + K * 2; - *buffer++ = d[0]; - *buffer++ = d[1]; - } - else if (K >= 10) { - const char* d = GetDigitsLut() + K * 2; - *buffer++ = d[0]; - *buffer++ = d[1]; - } - else - *buffer++ = static_cast<char>('0' + static_cast<char>(K)); - - return buffer; -} - -inline char* Prettify(char* buffer, int length, int k, int maxDecimalPlaces) { - const int kk = length + k; // 10^(kk-1) <= v < 10^kk - - if (0 <= k && kk <= 21) { - // 1234e7 -> 12340000000 - for (int i = length; i < kk; i++) - buffer[i] = '0'; - buffer[kk] = '.'; - buffer[kk + 1] = '0'; - return &buffer[kk + 2]; - } - else if (0 < kk && kk <= 21) { - // 1234e-2 -> 12.34 - std::memmove(&buffer[kk + 1], &buffer[kk], static_cast<size_t>(length - kk)); - buffer[kk] = '.'; - if (0 > k + maxDecimalPlaces) { - // When maxDecimalPlaces = 2, 1.2345 -> 1.23, 1.102 -> 1.1 - // Remove extra trailing zeros (at least one) after truncation. - for (int i = kk + maxDecimalPlaces; i > kk + 1; i--) - if (buffer[i] != '0') - return &buffer[i + 1]; - return &buffer[kk + 2]; // Reserve one zero - } - else - return &buffer[length + 1]; - } - else if (-6 < kk && kk <= 0) { - // 1234e-6 -> 0.001234 - const int offset = 2 - kk; - std::memmove(&buffer[offset], &buffer[0], static_cast<size_t>(length)); - buffer[0] = '0'; - buffer[1] = '.'; - for (int i = 2; i < offset; i++) - buffer[i] = '0'; - if (length - kk > maxDecimalPlaces) { - // When maxDecimalPlaces = 2, 0.123 -> 0.12, 0.102 -> 0.1 - // Remove extra trailing zeros (at least one) after truncation. - for (int i = maxDecimalPlaces + 1; i > 2; i--) - if (buffer[i] != '0') - return &buffer[i + 1]; - return &buffer[3]; // Reserve one zero - } - else - return &buffer[length + offset]; - } - else if (kk < -maxDecimalPlaces) { - // Truncate to zero - buffer[0] = '0'; - buffer[1] = '.'; - buffer[2] = '0'; - return &buffer[3]; - } - else if (length == 1) { - // 1e30 - buffer[1] = 'e'; - return WriteExponent(kk - 1, &buffer[2]); - } - else { - // 1234e30 -> 1.234e33 - std::memmove(&buffer[2], &buffer[1], static_cast<size_t>(length - 1)); - buffer[1] = '.'; - buffer[length + 1] = 'e'; - return WriteExponent(kk - 1, &buffer[0 + length + 2]); - } -} - -inline char* dtoa(double value, char* buffer, int maxDecimalPlaces = 324) { - RAPIDJSON_ASSERT(maxDecimalPlaces >= 1); - Double d(value); - if (d.IsZero()) { - if (d.Sign()) - *buffer++ = '-'; // -0.0, Issue #289 - buffer[0] = '0'; - buffer[1] = '.'; - buffer[2] = '0'; - return &buffer[3]; - } - else { - if (value < 0) { - *buffer++ = '-'; - value = -value; - } - int length, K; - Grisu2(value, buffer, &length, &K); - return Prettify(buffer, length, K, maxDecimalPlaces); - } -} - -#ifdef __GNUC__ -RAPIDJSON_DIAG_POP -#endif - -} // namespace internal -RAPIDJSON_NAMESPACE_END - -#endif // RAPIDJSON_DTOA_ |