glibc/sysdeps/ieee754/flt-32/s_truncf.c

52 lines
1.4 KiB
C

/* Truncate argument to nearest integral value not larger than the argument.
Copyright (C) 1997-2013 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <math.h>
#include <math_private.h>
float
__truncf (float x)
{
int32_t i0, j0;
int sx;
GET_FLOAT_WORD (i0, x);
sx = i0 & 0x80000000;
j0 = ((i0 >> 23) & 0xff) - 0x7f;
if (j0 < 23)
{
if (j0 < 0)
/* The magnitude of the number is < 1 so the result is +-0. */
SET_FLOAT_WORD (x, sx);
else
SET_FLOAT_WORD (x, sx | (i0 & ~(0x007fffff >> j0)));
}
else
{
if (j0 == 0x80)
/* x is inf or NaN. */
return x + x;
}
return x;
}
weak_alias (__truncf, truncf)