/* Truncate argument to nearest integral value not larger than the argument.
Copyright (C) 1997, 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper , 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include
#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;
}
libm_hidden_def(trunc)