From 3364fc5b03af165f88303ed78b19acdeabc18e2d Mon Sep 17 00:00:00 2001 From: Justine Tunney Date: Fri, 5 Mar 2021 10:44:53 -0800 Subject: [PATCH] Add modf(), modff(), and modfl() See #104 --- libc/tinymath/modf.c | 67 ++++++++++++++++++++++++++++++++++++ libc/tinymath/modff.c | 67 ++++++++++++++++++++++++++++++++++++ libc/tinymath/modfl.c | 79 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 213 insertions(+) create mode 100644 libc/tinymath/modf.c create mode 100644 libc/tinymath/modff.c create mode 100644 libc/tinymath/modfl.c diff --git a/libc/tinymath/modf.c b/libc/tinymath/modf.c new file mode 100644 index 00000000000..7c988d07c66 --- /dev/null +++ b/libc/tinymath/modf.c @@ -0,0 +1,67 @@ +/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│ +│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│ +╚──────────────────────────────────────────────────────────────────────────────╝ +│ │ +│ Musl Libc │ +│ Copyright © 2005-2014 Rich Felker, et al. │ +│ │ +│ 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. │ +│ │ +╚─────────────────────────────────────────────────────────────────────────────*/ +#include "libc/math.h" + +asm(".ident\t\"\\n\\n\ +Musl libc (MIT License)\\n\ +Copyright 2005-2014 Rich Felker, et. al.\""); +asm(".include \"libc/disclaimer.inc\""); +/* clang-format off */ + +double modf(double x, double *iptr) +{ + union {double f; uint64_t i;} u = {x}; + uint64_t mask; + int e = (int)(u.i>>52 & 0x7ff) - 0x3ff; + + /* no fractional part */ + if (e >= 52) { + *iptr = x; + if (e == 0x400 && u.i<<12 != 0) /* nan */ + return x; + u.i &= 1ULL<<63; + return u.f; + } + + /* no integral part*/ + if (e < 0) { + u.i &= 1ULL<<63; + *iptr = u.f; + return x; + } + + mask = -1ULL>>12>>e; + if ((u.i & mask) == 0) { + *iptr = x; + u.i &= 1ULL<<63; + return u.f; + } + u.i &= ~mask; + *iptr = u.f; + return x - u.f; +} diff --git a/libc/tinymath/modff.c b/libc/tinymath/modff.c new file mode 100644 index 00000000000..6c753df1c5a --- /dev/null +++ b/libc/tinymath/modff.c @@ -0,0 +1,67 @@ +/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│ +│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│ +╚──────────────────────────────────────────────────────────────────────────────╝ +│ │ +│ Musl Libc │ +│ Copyright © 2005-2014 Rich Felker, et al. │ +│ │ +│ 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. │ +│ │ +╚─────────────────────────────────────────────────────────────────────────────*/ +#include "libc/math.h" + +asm(".ident\t\"\\n\\n\ +Musl libc (MIT License)\\n\ +Copyright 2005-2014 Rich Felker, et. al.\""); +asm(".include \"libc/disclaimer.inc\""); +/* clang-format off */ + +float modff(float x, float *iptr) +{ + union {float f; uint32_t i;} u = {x}; + uint32_t mask; + int e = (int)(u.i>>23 & 0xff) - 0x7f; + + /* no fractional part */ + if (e >= 23) { + *iptr = x; + if (e == 0x80 && u.i<<9 != 0) { /* nan */ + return x; + } + u.i &= 0x80000000; + return u.f; + } + /* no integral part */ + if (e < 0) { + u.i &= 0x80000000; + *iptr = u.f; + return x; + } + + mask = 0x007fffff>>e; + if ((u.i & mask) == 0) { + *iptr = x; + u.i &= 0x80000000; + return u.f; + } + u.i &= ~mask; + *iptr = u.f; + return x - u.f; +} diff --git a/libc/tinymath/modfl.c b/libc/tinymath/modfl.c new file mode 100644 index 00000000000..08b40a42a86 --- /dev/null +++ b/libc/tinymath/modfl.c @@ -0,0 +1,79 @@ +/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│ +│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│ +╚──────────────────────────────────────────────────────────────────────────────╝ +│ │ +│ Musl Libc │ +│ Copyright © 2005-2014 Rich Felker, et al. │ +│ │ +│ 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. │ +│ │ +╚─────────────────────────────────────────────────────────────────────────────*/ +#include "libc/math.h" + +asm(".ident\t\"\\n\\n\ +Musl libc (MIT License)\\n\ +Copyright 2005-2014 Rich Felker, et. al.\""); +asm(".include \"libc/disclaimer.inc\""); +/* clang-format off */ + +static const long double toint = 1/LDBL_EPSILON; + +long double modfl(long double x, long double *iptr) +{ + union { + long double f; + struct { + uint64_t m; + uint16_t se; + } i; + } u = {x}; + int e = (u.i.se & 0x7fff) - 0x3fff; + int s = u.i.se >> 15; + long double absx; + long double y; + + /* no fractional part */ + if (e >= LDBL_MANT_DIG-1) { + *iptr = x; + if (isnan(x)) + return x; + return s ? -0.0 : 0.0; + } + + /* no integral part*/ + if (e < 0) { + *iptr = s ? -0.0 : 0.0; + return x; + } + + /* raises spurious inexact */ + absx = s ? -x : x; + y = absx + toint - toint - absx; + if (y == 0) { + *iptr = x; + return s ? -0.0 : 0.0; + } + if (y > 0) + y -= 1; + if (s) + y = -y; + *iptr = x + y; + return -y; +}