mirrors/cosmopolitan
1
0
Fork 0
mirror of https://github.com/jart/cosmopolitan.git synced 2025-05-22 21:32:31 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Add modf(), modff(), and modfl()

Browse source 
See #104
This commit is contained in:
Justine Tunney 2021-03-05 10:44:53 -08:00
parent f064183646
commit 3364fc5b03
3 changed files with 213 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

67
libc/tinymath/modff.c Normal file
View file

@ -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;
}