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Diffstat (limited to 'flatcc/external/grisu3/grisu3_math.h')
| -rw-r--r-- | flatcc/external/grisu3/grisu3_math.h | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/flatcc/external/grisu3/grisu3_math.h b/flatcc/external/grisu3/grisu3_math.h new file mode 100644 index 0000000..cff6e8c --- /dev/null +++ b/flatcc/external/grisu3/grisu3_math.h @@ -0,0 +1,329 @@ +/* + * Copyright (c) 2016 Mikkel F. Jørgensen, dvide.com + * Copyright author of MathGeoLib (https://github.com/juj) + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * 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. http://www.apache.org/licenses/LICENSE-2.0 + */ + +/* 2016-02-02: Updated by mikkelfj + * + * Extracted from MatGeoLib grisu3.c, Apache 2.0 license, and extended. + * + * This file is usually include via grisu3_print.h or grisu3_parse.h. + * + * The original MatGeoLib dtoa_grisu3 implementation is largely + * unchanged except for the uint64 to double cast. The remaining changes + * are file structure, name changes, and new additions for parsing: + * + * - Split into header files only: + * grisu3_math.h, grisu3_print.h, (added grisu3_parse.h) + * + * - names prefixed with grisu3_, grisu3_diy_fp_, GRISU3_. + * - added static to all functions. + * - disabled clang unused function warnings. + * - guarded <stdint.h> to allow for alternative impl. + * - added extra numeric constants needed for parsing. + * - added dec_pow, cast_double_from_diy_fp. + * - changed some function names for consistency. + * - moved printing specific grisu3 functions to grisu3_print.h. + * - changed double to uint64 cast to avoid aliasing. + * - added new grisu3_parse.h for parsing doubles. + * - grisu3_print_double (dtoa_grisu3) format .1 as 0.1 needed for valid JSON output + * and grisu3_parse_double wouldn't consume it. + * - grsu3_print_double changed formatting to prefer 0.012 over 1.2e-2. + * + * These changes make it possible to include the files as headers only + * in other software libraries without risking name conflicts, and to + * extend the implementation with a port of Googles Double Conversion + * strtod functionality for parsing doubles. + * + * Extracted from: rev. 915501a / Dec 22, 2015 + * <https://github.com/juj/MathGeoLib/blob/master/src/Math/grisu3.c> + * MathGeoLib License: http://www.apache.org/licenses/LICENSE-2.0.html + */ + +#ifndef GRISU3_MATH_H +#define GRISU3_MATH_H + +#ifdef __cplusplus +extern "C" { +#endif + +/* Guarded to allow inclusion of pstdint.h first, if stdint.h is not supported. */ +#ifndef UINT8_MAX +#include <stdint.h> /* uint64_t etc. */ +#endif + +#ifdef GRISU3_NO_ASSERT +#undef GRISU3_ASSERT +#define GRISU3_ASSERT(x) ((void)0) +#endif + +#ifndef GRISU3_ASSERT +#include <assert.h> /* assert */ +#define GRISU3_ASSERT(x) assert(x) +#endif + +#ifdef _MSC_VER +#pragma warning(disable : 4204) /* nonstandard extension used : non-constant aggregate initializer */ +#endif + +#define GRISU3_D64_SIGN 0x8000000000000000ULL +#define GRISU3_D64_EXP_MASK 0x7FF0000000000000ULL +#define GRISU3_D64_FRACT_MASK 0x000FFFFFFFFFFFFFULL +#define GRISU3_D64_IMPLICIT_ONE 0x0010000000000000ULL +#define GRISU3_D64_EXP_POS 52 +#define GRISU3_D64_EXP_BIAS 1075 +#define GRISU3_D64_DENORM_EXP (-GRISU3_D64_EXP_BIAS + 1) +#define GRISU3_DIY_FP_FRACT_SIZE 64 +#define GRISU3_D_1_LOG2_10 0.30102999566398114 /* 1 / lg(10) */ +#define GRISU3_MIN_TARGET_EXP -60 +#define GRISU3_MASK32 0xFFFFFFFFULL +#define GRISU3_MIN_CACHED_EXP -348 +#define GRISU3_MAX_CACHED_EXP 340 +#define GRISU3_CACHED_EXP_STEP 8 +#define GRISU3_D64_MAX_DEC_EXP 309 +#define GRISU3_D64_MIN_DEC_EXP -324 +#define GRISU3_D64_INF GRISU3_D64_EXP_MASK + +#define GRISU3_MIN(x,y) ((x) <= (y) ? (x) : (y)) +#define GRISU3_MAX(x,y) ((x) >= (y) ? (x) : (y)) + + +typedef struct grisu3_diy_fp +{ + uint64_t f; + int e; +} grisu3_diy_fp_t; + +typedef struct grisu3_diy_fp_power +{ + uint64_t fract; + int16_t b_exp, d_exp; +} grisu3_diy_fp_power_t; + +typedef union { + uint64_t u64; + double d64; +} grisu3_cast_double_t; + +static uint64_t grisu3_cast_uint64_from_double(double d) +{ + grisu3_cast_double_t cd; + cd.d64 = d; + return cd.u64; +} + +static double grisu3_cast_double_from_uint64(uint64_t u) +{ + grisu3_cast_double_t cd; + cd.u64 = u; + return cd.d64; +} + +#define grisu3_double_infinity grisu3_cast_double_from_uint64(GRISU3_D64_INF) +#define grisu3_double_nan grisu3_cast_double_from_uint64(GRISU3_D64_INF + 1) + +static const grisu3_diy_fp_power_t grisu3_diy_fp_pow_cache[] = +{ + { 0xfa8fd5a0081c0288ULL, -1220, -348 }, + { 0xbaaee17fa23ebf76ULL, -1193, -340 }, + { 0x8b16fb203055ac76ULL, -1166, -332 }, + { 0xcf42894a5dce35eaULL, -1140, -324 }, + { 0x9a6bb0aa55653b2dULL, -1113, -316 }, + { 0xe61acf033d1a45dfULL, -1087, -308 }, + { 0xab70fe17c79ac6caULL, -1060, -300 }, + { 0xff77b1fcbebcdc4fULL, -1034, -292 }, + { 0xbe5691ef416bd60cULL, -1007, -284 }, + { 0x8dd01fad907ffc3cULL, -980, -276 }, + { 0xd3515c2831559a83ULL, -954, -268 }, + { 0x9d71ac8fada6c9b5ULL, -927, -260 }, + { 0xea9c227723ee8bcbULL, -901, -252 }, + { 0xaecc49914078536dULL, -874, -244 }, + { 0x823c12795db6ce57ULL, -847, -236 }, + { 0xc21094364dfb5637ULL, -821, -228 }, + { 0x9096ea6f3848984fULL, -794, -220 }, + { 0xd77485cb25823ac7ULL, -768, -212 }, + { 0xa086cfcd97bf97f4ULL, -741, -204 }, + { 0xef340a98172aace5ULL, -715, -196 }, + { 0xb23867fb2a35b28eULL, -688, -188 }, + { 0x84c8d4dfd2c63f3bULL, -661, -180 }, + { 0xc5dd44271ad3cdbaULL, -635, -172 }, + { 0x936b9fcebb25c996ULL, -608, -164 }, + { 0xdbac6c247d62a584ULL, -582, -156 }, + { 0xa3ab66580d5fdaf6ULL, -555, -148 }, + { 0xf3e2f893dec3f126ULL, -529, -140 }, + { 0xb5b5ada8aaff80b8ULL, -502, -132 }, + { 0x87625f056c7c4a8bULL, -475, -124 }, + { 0xc9bcff6034c13053ULL, -449, -116 }, + { 0x964e858c91ba2655ULL, -422, -108 }, + { 0xdff9772470297ebdULL, -396, -100 }, + { 0xa6dfbd9fb8e5b88fULL, -369, -92 }, + { 0xf8a95fcf88747d94ULL, -343, -84 }, + { 0xb94470938fa89bcfULL, -316, -76 }, + { 0x8a08f0f8bf0f156bULL, -289, -68 }, + { 0xcdb02555653131b6ULL, -263, -60 }, + { 0x993fe2c6d07b7facULL, -236, -52 }, + { 0xe45c10c42a2b3b06ULL, -210, -44 }, + { 0xaa242499697392d3ULL, -183, -36 }, + { 0xfd87b5f28300ca0eULL, -157, -28 }, + { 0xbce5086492111aebULL, -130, -20 }, + { 0x8cbccc096f5088ccULL, -103, -12 }, + { 0xd1b71758e219652cULL, -77, -4 }, + { 0x9c40000000000000ULL, -50, 4 }, + { 0xe8d4a51000000000ULL, -24, 12 }, + { 0xad78ebc5ac620000ULL, 3, 20 }, + { 0x813f3978f8940984ULL, 30, 28 }, + { 0xc097ce7bc90715b3ULL, 56, 36 }, + { 0x8f7e32ce7bea5c70ULL, 83, 44 }, + { 0xd5d238a4abe98068ULL, 109, 52 }, + { 0x9f4f2726179a2245ULL, 136, 60 }, + { 0xed63a231d4c4fb27ULL, 162, 68 }, + { 0xb0de65388cc8ada8ULL, 189, 76 }, + { 0x83c7088e1aab65dbULL, 216, 84 }, + { 0xc45d1df942711d9aULL, 242, 92 }, + { 0x924d692ca61be758ULL, 269, 100 }, + { 0xda01ee641a708deaULL, 295, 108 }, + { 0xa26da3999aef774aULL, 322, 116 }, + { 0xf209787bb47d6b85ULL, 348, 124 }, + { 0xb454e4a179dd1877ULL, 375, 132 }, + { 0x865b86925b9bc5c2ULL, 402, 140 }, + { 0xc83553c5c8965d3dULL, 428, 148 }, + { 0x952ab45cfa97a0b3ULL, 455, 156 }, + { 0xde469fbd99a05fe3ULL, 481, 164 }, + { 0xa59bc234db398c25ULL, 508, 172 }, + { 0xf6c69a72a3989f5cULL, 534, 180 }, + { 0xb7dcbf5354e9beceULL, 561, 188 }, + { 0x88fcf317f22241e2ULL, 588, 196 }, + { 0xcc20ce9bd35c78a5ULL, 614, 204 }, + { 0x98165af37b2153dfULL, 641, 212 }, + { 0xe2a0b5dc971f303aULL, 667, 220 }, + { 0xa8d9d1535ce3b396ULL, 694, 228 }, + { 0xfb9b7cd9a4a7443cULL, 720, 236 }, + { 0xbb764c4ca7a44410ULL, 747, 244 }, + { 0x8bab8eefb6409c1aULL, 774, 252 }, + { 0xd01fef10a657842cULL, 800, 260 }, + { 0x9b10a4e5e9913129ULL, 827, 268 }, + { 0xe7109bfba19c0c9dULL, 853, 276 }, + { 0xac2820d9623bf429ULL, 880, 284 }, + { 0x80444b5e7aa7cf85ULL, 907, 292 }, + { 0xbf21e44003acdd2dULL, 933, 300 }, + { 0x8e679c2f5e44ff8fULL, 960, 308 }, + { 0xd433179d9c8cb841ULL, 986, 316 }, + { 0x9e19db92b4e31ba9ULL, 1013, 324 }, + { 0xeb96bf6ebadf77d9ULL, 1039, 332 }, + { 0xaf87023b9bf0ee6bULL, 1066, 340 } +}; + +/* Avoid dependence on lib math to get (int)ceil(v) */ +static int grisu3_iceil(double v) +{ + int k = (int)v; + if (v < 0) return k; + return v - k == 0 ? k : k + 1; +} + +static int grisu3_diy_fp_cached_pow(int exp, grisu3_diy_fp_t *p) +{ + int k = grisu3_iceil((exp+GRISU3_DIY_FP_FRACT_SIZE-1) * GRISU3_D_1_LOG2_10); + int i = (k-GRISU3_MIN_CACHED_EXP-1) / GRISU3_CACHED_EXP_STEP + 1; + p->f = grisu3_diy_fp_pow_cache[i].fract; + p->e = grisu3_diy_fp_pow_cache[i].b_exp; + return grisu3_diy_fp_pow_cache[i].d_exp; +} + +static grisu3_diy_fp_t grisu3_diy_fp_minus(grisu3_diy_fp_t x, grisu3_diy_fp_t y) +{ + grisu3_diy_fp_t d; d.f = x.f - y.f; d.e = x.e; + GRISU3_ASSERT(x.e == y.e && x.f >= y.f); + return d; +} + +static grisu3_diy_fp_t grisu3_diy_fp_multiply(grisu3_diy_fp_t x, grisu3_diy_fp_t y) +{ + uint64_t a, b, c, d, ac, bc, ad, bd, tmp; + grisu3_diy_fp_t r; + a = x.f >> 32; b = x.f & GRISU3_MASK32; + c = y.f >> 32; d = y.f & GRISU3_MASK32; + ac = a*c; bc = b*c; + ad = a*d; bd = b*d; + tmp = (bd >> 32) + (ad & GRISU3_MASK32) + (bc & GRISU3_MASK32); + tmp += 1U << 31; /* round */ + r.f = ac + (ad >> 32) + (bc >> 32) + (tmp >> 32); + r.e = x.e + y.e + 64; + return r; +} + +static grisu3_diy_fp_t grisu3_diy_fp_normalize(grisu3_diy_fp_t n) +{ + GRISU3_ASSERT(n.f != 0); + while(!(n.f & 0xFFC0000000000000ULL)) { n.f <<= 10; n.e -= 10; } + while(!(n.f & GRISU3_D64_SIGN)) { n.f <<= 1; --n.e; } + return n; +} + +static grisu3_diy_fp_t grisu3_cast_diy_fp_from_double(double d) +{ + grisu3_diy_fp_t fp; + uint64_t u64 = grisu3_cast_uint64_from_double(d); + if (!(u64 & GRISU3_D64_EXP_MASK)) { fp.f = u64 & GRISU3_D64_FRACT_MASK; fp.e = 1 - GRISU3_D64_EXP_BIAS; } + else { fp.f = (u64 & GRISU3_D64_FRACT_MASK) + GRISU3_D64_IMPLICIT_ONE; fp.e = (int)((u64 & GRISU3_D64_EXP_MASK) >> GRISU3_D64_EXP_POS) - GRISU3_D64_EXP_BIAS; } + return fp; +} + +static double grisu3_cast_double_from_diy_fp(grisu3_diy_fp_t n) +{ + const uint64_t hidden_bit = GRISU3_D64_IMPLICIT_ONE; + const uint64_t frac_mask = GRISU3_D64_FRACT_MASK; + const int denorm_exp = GRISU3_D64_DENORM_EXP; + const int exp_bias = GRISU3_D64_EXP_BIAS; + const int exp_pos = GRISU3_D64_EXP_POS; + + grisu3_diy_fp_t v = n; + uint64_t e_biased; + + while (v.f > hidden_bit + frac_mask) { + v.f >>= 1; + ++v.e; + } + if (v.e < denorm_exp) { + return 0.0; + } + while (v.e > denorm_exp && (v.f & hidden_bit) == 0) { + v.f <<= 1; + --v.e; + } + if (v.e == denorm_exp && (v.f & hidden_bit) == 0) { + e_biased = 0; + } else { + e_biased = (uint64_t)(v.e + exp_bias); + } + return grisu3_cast_double_from_uint64((v.f & frac_mask) | (e_biased << exp_pos)); +} + +/* pow10_cache[i] = 10^(i-1) */ +static const unsigned int grisu3_pow10_cache[] = { 0, 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000 }; + +static int grisu3_largest_pow10(uint32_t n, int n_bits, uint32_t *power) +{ + int guess = ((n_bits + 1) * 1233 >> 12) + 1/*skip first entry*/; + if (n < grisu3_pow10_cache[guess]) --guess; /* We don't have any guarantees that 2^n_bits <= n. */ + *power = grisu3_pow10_cache[guess]; + return guess; +} + +#ifdef __cplusplus +} +#endif + +#endif /* GRISU3_MATH_H */ |