mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-29 22:11:18 +00:00
62 lines
1.7 KiB
C
62 lines
1.7 KiB
C
|
/* Truncate argument to nearest integral value not larger than the argument.
|
||
|
|
Copyright (C) 1997 Free Software Foundation, Inc.
|
||
|
|
This file is part of the GNU C Library.
|
||
|
|
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
|
||
|
|
|
||
|
|
The GNU C Library is free software; you can redistribute it and/or
|
||
|
|
modify it under the terms of the GNU Library General Public License as
|
||
|
|
published by the Free Software Foundation; either version 2 of the
|
||
|
|
License, or (at your option) any later version.
|
||
|
|
|
||
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
||
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||
|
|
Library General Public License for more details.
|
||
|
|
|
||
|
|
You should have received a copy of the GNU Library General Public
|
||
|
|
License along with the GNU C Library; see the file COPYING.LIB. If not,
|
||
|
|
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
||
|
|
Boston, MA 02111-1307, USA. */
|
||
|
|
|
||
|
|
#include <math.h>
|
||
|
|
|
||
|
|
#include "math_private.h"
|
||
|
|
|
||
|
|
|
||
|
|
double
|
||
|
|
__trunc (double x)
|
||
|
|
{
|
||
|
|
int32_t i0, j0;
|
||
|
|
u_int32_t i1;
|
||
|
|
int sx;
|
||
|
|
|
||
|
|
EXTRACT_WORDS (i0, i1, x);
|
||
|
|
sx = i0 & 0x80000000;
|
||
|
|
j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
|
||
|
|
if (j0 < 20)
|
||
|
|
{
|
||
|
|
if (j0 < 0)
|
||
|
|
/* The magnitude of the number is < 1 so the result is +-0. */
|
||
|
|
INSERT_WORDS (x, sx, 0);
|
||
|
|
else
|
||
|
|
INSERT_WORDS (x, sx | i0 & ~(0x000fffff >> j0), 0);
|
||
|
|
}
|
||
|
|
else if (j0 > 51)
|
||
|
|
{
|
||
|
|
if (j0 == 0x400)
|
||
|
|
/* x is inf or NaN. */
|
||
|
|
return x + x;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
INSERT_WORDS (x, i0, i1 & ~(0xffffffffu >> (j0 - 20)));
|
||
|
|
}
|
||
|
|
|
||
|
|
return x;
|
||
|
|
}
|
||
|
|
weak_alias (__trunc, trunc)
|
||
|
|
#ifdef NO_LONG_DOUBLE
|
||
|
|
strong_alias (__trunc, __truncl)
|
||
|
|
weak_alias (__trunc, truncl)
|
||
|
|
#endif
|