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64-bit optimized implementation of trunc.

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Ulrich Drepper 2009-08-25 12:02:13 -07:00
parent 84088310ce
commit 8392ff2dc7
2 changed files with 58 additions and 0 deletions
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@ -1,5 +1,7 @@
2009-08-25 Ulrich Drepper <drepper@redhat.com>
* sysdeps/ieee754/dbl-64/wordsize-64/s_trunc.c: New file.
* sysdeps/x86_64/dl-trampoline.S (_dl_runtime_profile): Remove
leftover YMM_SIZE definition.

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sysdeps/ieee754/dbl-64/wordsize-64/s_trunc.c Normal file
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/* Truncate argument to nearest integral value not larger than the argument.
Copyright (C) 1997, 1998, 2009 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, 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)
{
int64_t i0, j0;
int64_t sx;
EXTRACT_WORDS64 (i0, x);
sx = i0 & UINT64_C(0x8000000000000000);
j0 = ((i0 >> 52) & 0x7ff) - 0x3ff;
if (j0 < 52)
{
if (j0 < 0)
/* The magnitude of the number is < 1 so the result is +-0. */
INSERT_WORDS64 (x, sx);
else
INSERT_WORDS64 (x, sx | (i0 & ~(UINT64_C(0x000fffffffffffff) >> j0)));
}
else
{
if (j0 == 0x400)
/* x is inf or NaN. */
return x + x;
}
return x;
}
weak_alias (__trunc, trunc)
#ifdef NO_LONG_DOUBLE
strong_alias (__trunc, __truncl)
weak_alias (__trunc, truncl)
#endif