From 4f9f85c6d1b7ca4bfab4599cb76e885c71ad07f6 Mon Sep 17 00:00:00 2001 From: Vsevolod Stakhov Date: Sat, 6 Apr 2019 12:24:22 +0100 Subject: [PATCH] [Feature] Import fpconv library Source: https://github.com/night-shift/fpconv --- contrib/fpconv/CMakeLists.txt | 12 ++ contrib/fpconv/LICENSE | 23 +++ contrib/fpconv/fpconv.c | 332 ++++++++++++++++++++++++++++++++++ contrib/fpconv/fpconv.h | 33 ++++ contrib/fpconv/powers.h | 87 +++++++++ 5 files changed, 487 insertions(+) create mode 100644 contrib/fpconv/CMakeLists.txt create mode 100644 contrib/fpconv/LICENSE create mode 100644 contrib/fpconv/fpconv.c create mode 100644 contrib/fpconv/fpconv.h create mode 100644 contrib/fpconv/powers.h diff --git a/contrib/fpconv/CMakeLists.txt b/contrib/fpconv/CMakeLists.txt new file mode 100644 index 000000000..0d27dbb7f --- /dev/null +++ b/contrib/fpconv/CMakeLists.txt @@ -0,0 +1,12 @@ +SET(FPCONVSRC fpconv.c) + +SET(FTPCONV_COMPILE_FLAGS "-DRSPAMD_LIB") +IF(ENABLE_FULL_DEBUG MATCHES "OFF") + if ("${CMAKE_C_COMPILER_ID}" STREQUAL "Clang" OR "${CMAKE_C_COMPILER_ID}" STREQUAL "GNU") + set(FTPCONV_COMPILE_FLAGS "${FTPCONV_COMPILE_FLAGS} -O3") + endif () +ENDIF() + +ADD_LIBRARY(rspamd-fpconv STATIC ${FPCONVSRC}) +SET_TARGET_PROPERTIES(rspamd-fpconv PROPERTIES VERSION ${RSPAMD_VERSION}) +SET_TARGET_PROPERTIES(rspamd-fpconv PROPERTIES COMPILE_FLAGS "${FTPCONV_COMPILE_FLAGS}") \ No newline at end of file diff --git a/contrib/fpconv/LICENSE b/contrib/fpconv/LICENSE new file mode 100644 index 000000000..36b7cd93c --- /dev/null +++ b/contrib/fpconv/LICENSE @@ -0,0 +1,23 @@ +Boost Software License - Version 1.0 - August 17th, 2003 + +Permission is hereby granted, free of charge, to any person or organization +obtaining a copy of the software and accompanying documentation covered by +this license (the "Software") to use, reproduce, display, distribute, +execute, and transmit the Software, and to prepare derivative works of the +Software, and to permit third-parties to whom the Software is furnished to +do so, all subject to the following: + +The copyright notices in the Software and this entire statement, including +the above license grant, this restriction and the following disclaimer, +must be included in all copies of the Software, in whole or in part, and +all derivative works of the Software, unless such copies or derivative +works are solely in the form of machine-executable object code generated by +a source language processor. + +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, TITLE AND NON-INFRINGEMENT. IN NO EVENT +SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE +FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE, +ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER +DEALINGS IN THE SOFTWARE. diff --git a/contrib/fpconv/fpconv.c b/contrib/fpconv/fpconv.c new file mode 100644 index 000000000..3fbd55af0 --- /dev/null +++ b/contrib/fpconv/fpconv.c @@ -0,0 +1,332 @@ +#include +#include + +#include "fpconv.h" +#include "powers.h" + +#define fracmask 0x000FFFFFFFFFFFFFU +#define expmask 0x7FF0000000000000U +#define hiddenbit 0x0010000000000000U +#define signmask 0x8000000000000000U +#define expbias (1023 + 52) + +#define absv(n) ((n) < 0 ? -(n) : (n)) +#define minv(a, b) ((a) < (b) ? (a) : (b)) + +static uint64_t tens[] = { + 10000000000000000000U, 1000000000000000000U, 100000000000000000U, + 10000000000000000U, 1000000000000000U, 100000000000000U, + 10000000000000U, 1000000000000U, 100000000000U, + 10000000000U, 1000000000U, 100000000U, + 10000000U, 1000000U, 100000U, + 10000U, 1000U, 100U, + 10U, 1U +}; + +static inline uint64_t get_dbits(double d) +{ + union { + double dbl; + uint64_t i; + } dbl_bits = { d }; + + return dbl_bits.i; +} + +static Fp build_fp(double d) +{ + uint64_t bits = get_dbits(d); + + Fp fp; + fp.frac = bits & fracmask; + fp.exp = (bits & expmask) >> 52; + + if(fp.exp) { + fp.frac += hiddenbit; + fp.exp -= expbias; + + } else { + fp.exp = -expbias + 1; + } + + return fp; +} + +static void normalize(Fp* fp) +{ + while ((fp->frac & hiddenbit) == 0) { + fp->frac <<= 1; + fp->exp--; + } + + int shift = 64 - 52 - 1; + fp->frac <<= shift; + fp->exp -= shift; +} + +static void get_normalized_boundaries(Fp* fp, Fp* lower, Fp* upper) +{ + upper->frac = (fp->frac << 1) + 1; + upper->exp = fp->exp - 1; + + while ((upper->frac & (hiddenbit << 1)) == 0) { + upper->frac <<= 1; + upper->exp--; + } + + int u_shift = 64 - 52 - 2; + + upper->frac <<= u_shift; + upper->exp = upper->exp - u_shift; + + + int l_shift = fp->frac == hiddenbit ? 2 : 1; + + lower->frac = (fp->frac << l_shift) - 1; + lower->exp = fp->exp - l_shift; + + + lower->frac <<= lower->exp - upper->exp; + lower->exp = upper->exp; +} + +static Fp multiply(Fp* a, Fp* b) +{ + const uint64_t lomask = 0x00000000FFFFFFFF; + + uint64_t ah_bl = (a->frac >> 32) * (b->frac & lomask); + uint64_t al_bh = (a->frac & lomask) * (b->frac >> 32); + uint64_t al_bl = (a->frac & lomask) * (b->frac & lomask); + uint64_t ah_bh = (a->frac >> 32) * (b->frac >> 32); + + uint64_t tmp = (ah_bl & lomask) + (al_bh & lomask) + (al_bl >> 32); + /* round up */ + tmp += 1U << 31; + + Fp fp = { + ah_bh + (ah_bl >> 32) + (al_bh >> 32) + (tmp >> 32), + a->exp + b->exp + 64 + }; + + return fp; +} + +static void round_digit(char* digits, int ndigits, uint64_t delta, uint64_t rem, uint64_t kappa, uint64_t frac) +{ + while (rem < frac && delta - rem >= kappa && + (rem + kappa < frac || frac - rem > rem + kappa - frac)) { + + digits[ndigits - 1]--; + rem += kappa; + } +} + +static int generate_digits(Fp* fp, Fp* upper, Fp* lower, char* digits, int* K) +{ + uint64_t wfrac = upper->frac - fp->frac; + uint64_t delta = upper->frac - lower->frac; + + Fp one; + one.frac = 1ULL << -upper->exp; + one.exp = upper->exp; + + uint64_t part1 = upper->frac >> -one.exp; + uint64_t part2 = upper->frac & (one.frac - 1); + + int idx = 0, kappa = 10; + uint64_t* divp; + /* 1000000000 */ + for(divp = tens + 10; kappa > 0; divp++) { + + uint64_t div = *divp; + unsigned digit = part1 / div; + + if (digit || idx) { + digits[idx++] = digit + '0'; + } + + part1 -= digit * div; + kappa--; + + uint64_t tmp = (part1 <<-one.exp) + part2; + if (tmp <= delta) { + *K += kappa; + round_digit(digits, idx, delta, tmp, div << -one.exp, wfrac); + + return idx; + } + } + + /* 10 */ + uint64_t* unit = tens + 18; + + while(true) { + part2 *= 10; + delta *= 10; + kappa--; + + unsigned digit = part2 >> -one.exp; + if (digit || idx) { + digits[idx++] = digit + '0'; + } + + part2 &= one.frac - 1; + if (part2 < delta) { + *K += kappa; + round_digit(digits, idx, delta, part2, one.frac, wfrac * *unit); + + return idx; + } + + unit--; + } +} + +static int grisu2(double d, char* digits, int* K) +{ + Fp w = build_fp(d); + + Fp lower, upper; + get_normalized_boundaries(&w, &lower, &upper); + + normalize(&w); + + int k; + Fp cp = find_cachedpow10(upper.exp, &k); + + w = multiply(&w, &cp); + upper = multiply(&upper, &cp); + lower = multiply(&lower, &cp); + + lower.frac++; + upper.frac--; + + *K = -k; + + return generate_digits(&w, &upper, &lower, digits, K); +} + +static int emit_digits(char* digits, int ndigits, char* dest, int K, bool neg) +{ + int exp = absv(K + ndigits - 1); + + /* write plain integer */ + if(K >= 0 && (exp < (ndigits + 7))) { + memcpy(dest, digits, ndigits); + memset(dest + ndigits, '0', K); + + return ndigits + K; + } + + /* write decimal w/o scientific notation */ + if(K < 0 && (K > -7 || exp < 4)) { + int offset = ndigits - absv(K); + /* fp < 1.0 -> write leading zero */ + if(offset <= 0) { + offset = -offset; + dest[0] = '0'; + dest[1] = '.'; + memset(dest + 2, '0', offset); + memcpy(dest + offset + 2, digits, ndigits); + + return ndigits + 2 + offset; + + /* fp > 1.0 */ + } else { + memcpy(dest, digits, offset); + dest[offset] = '.'; + memcpy(dest + offset + 1, digits + offset, ndigits - offset); + + return ndigits + 1; + } + } + + /* write decimal w/ scientific notation */ + ndigits = minv(ndigits, 18 - neg); + + int idx = 0; + dest[idx++] = digits[0]; + + if(ndigits > 1) { + dest[idx++] = '.'; + memcpy(dest + idx, digits + 1, ndigits - 1); + idx += ndigits - 1; + } + + dest[idx++] = 'e'; + + char sign = K + ndigits - 1 < 0 ? '-' : '+'; + dest[idx++] = sign; + + int cent = 0; + + if(exp > 99) { + cent = exp / 100; + dest[idx++] = cent + '0'; + exp -= cent * 100; + } + if(exp > 9) { + int dec = exp / 10; + dest[idx++] = dec + '0'; + exp -= dec * 10; + + } else if(cent) { + dest[idx++] = '0'; + } + + dest[idx++] = exp % 10 + '0'; + + return idx; +} + +static int filter_special(double fp, char* dest) +{ + if(fp == 0.0) { + dest[0] = '0'; + return 1; + } + + uint64_t bits = get_dbits(fp); + + bool nan = (bits & expmask) == expmask; + + if(!nan) { + return 0; + } + + if(bits & fracmask) { + dest[0] = 'n'; dest[1] = 'a'; dest[2] = 'n'; + + } else { + dest[0] = 'i'; dest[1] = 'n'; dest[2] = 'f'; + } + + return 3; +} + +int fpconv_dtoa(double d, char dest[24]) +{ + char digits[18]; + + int str_len = 0; + bool neg = false; + + if(get_dbits(d) & signmask) { + dest[0] = '-'; + str_len++; + neg = true; + } + + int spec = filter_special(d, dest + str_len); + + if(spec) { + return str_len + spec; + } + + int K = 0; + int ndigits = grisu2(d, digits, &K); + + str_len += emit_digits(digits, ndigits, dest + str_len, K, neg); + + return str_len; +} diff --git a/contrib/fpconv/fpconv.h b/contrib/fpconv/fpconv.h new file mode 100644 index 000000000..58bbcccbb --- /dev/null +++ b/contrib/fpconv/fpconv.h @@ -0,0 +1,33 @@ +#ifndef FPCONV_H +#define FPCONV_H + +/* Fast and accurate double to string conversion based on Florian Loitsch's + * Grisu-algorithm[1]. + * + * Input: + * fp -> the double to convert, dest -> destination buffer. + * The generated string will never be longer than 24 characters. + * Make sure to pass a pointer to at least 24 bytes of memory. + * The emitted string will not be null terminated. + * + * Output: + * The number of written characters. + * + * Exemplary usage: + * + * void print(double d) + * { + * char buf[24 + 1] // plus null terminator + * int str_len = fpconv_dtoa(d, buf); + * + * buf[str_len] = '\0'; + * printf("%s", buf); + * } + * + */ + +int fpconv_dtoa(double fp, char dest[24]); + +#endif + +/* [1] http://florian.loitsch.com/publications/dtoa-pldi2010.pdf */ diff --git a/contrib/fpconv/powers.h b/contrib/fpconv/powers.h new file mode 100644 index 000000000..c707eedb0 --- /dev/null +++ b/contrib/fpconv/powers.h @@ -0,0 +1,87 @@ +#include + +#define npowers 87 +#define steppowers 8 +#define firstpower -348 /* 10 ^ -348 */ + +#define expmax -32 +#define expmin -60 + + +typedef struct Fp { + uint64_t frac; + int exp; +} Fp; + +static Fp powers_ten[] = { + { 18054884314459144840U, -1220 }, { 13451937075301367670U, -1193 }, + { 10022474136428063862U, -1166 }, { 14934650266808366570U, -1140 }, + { 11127181549972568877U, -1113 }, { 16580792590934885855U, -1087 }, + { 12353653155963782858U, -1060 }, { 18408377700990114895U, -1034 }, + { 13715310171984221708U, -1007 }, { 10218702384817765436U, -980 }, + { 15227053142812498563U, -954 }, { 11345038669416679861U, -927 }, + { 16905424996341287883U, -901 }, { 12595523146049147757U, -874 }, + { 9384396036005875287U, -847 }, { 13983839803942852151U, -821 }, + { 10418772551374772303U, -794 }, { 15525180923007089351U, -768 }, + { 11567161174868858868U, -741 }, { 17236413322193710309U, -715 }, + { 12842128665889583758U, -688 }, { 9568131466127621947U, -661 }, + { 14257626930069360058U, -635 }, { 10622759856335341974U, -608 }, + { 15829145694278690180U, -582 }, { 11793632577567316726U, -555 }, + { 17573882009934360870U, -529 }, { 13093562431584567480U, -502 }, + { 9755464219737475723U, -475 }, { 14536774485912137811U, -449 }, + { 10830740992659433045U, -422 }, { 16139061738043178685U, -396 }, + { 12024538023802026127U, -369 }, { 17917957937422433684U, -343 }, + { 13349918974505688015U, -316 }, { 9946464728195732843U, -289 }, + { 14821387422376473014U, -263 }, { 11042794154864902060U, -236 }, + { 16455045573212060422U, -210 }, { 12259964326927110867U, -183 }, + { 18268770466636286478U, -157 }, { 13611294676837538539U, -130 }, + { 10141204801825835212U, -103 }, { 15111572745182864684U, -77 }, + { 11258999068426240000U, -50 }, { 16777216000000000000U, -24 }, + { 12500000000000000000U, 3 }, { 9313225746154785156U, 30 }, + { 13877787807814456755U, 56 }, { 10339757656912845936U, 83 }, + { 15407439555097886824U, 109 }, { 11479437019748901445U, 136 }, + { 17105694144590052135U, 162 }, { 12744735289059618216U, 189 }, + { 9495567745759798747U, 216 }, { 14149498560666738074U, 242 }, + { 10542197943230523224U, 269 }, { 15709099088952724970U, 295 }, + { 11704190886730495818U, 322 }, { 17440603504673385349U, 348 }, + { 12994262207056124023U, 375 }, { 9681479787123295682U, 402 }, + { 14426529090290212157U, 428 }, { 10748601772107342003U, 455 }, + { 16016664761464807395U, 481 }, { 11933345169920330789U, 508 }, + { 17782069995880619868U, 534 }, { 13248674568444952270U, 561 }, + { 9871031767461413346U, 588 }, { 14708983551653345445U, 614 }, + { 10959046745042015199U, 641 }, { 16330252207878254650U, 667 }, + { 12166986024289022870U, 694 }, { 18130221999122236476U, 720 }, + { 13508068024458167312U, 747 }, { 10064294952495520794U, 774 }, + { 14996968138956309548U, 800 }, { 11173611982879273257U, 827 }, + { 16649979327439178909U, 853 }, { 12405201291620119593U, 880 }, + { 9242595204427927429U, 907 }, { 13772540099066387757U, 933 }, + { 10261342003245940623U, 960 }, { 15290591125556738113U, 986 }, + { 11392378155556871081U, 1013 }, { 16975966327722178521U, 1039 }, + { 12648080533535911531U, 1066 } +}; + +static Fp find_cachedpow10(int exp, int* k) +{ + const double one_log_ten = 0.30102999566398114; + + int approx = -(exp + npowers) * one_log_ten; + int idx = (approx - firstpower) / steppowers; + + while(1) { + int current = exp + powers_ten[idx].exp + 64; + + if(current < expmin) { + idx++; + continue; + } + + if(current > expmax) { + idx--; + continue; + } + + *k = (firstpower + idx * steppowers); + + return powers_ten[idx]; + } +} -- 2.39.5