mirror of
https://sourceware.org/git/glibc.git
synced 2024-09-22 17:34:05 +00:00
Add 64-bit optimized s_round.
This commit is contained in:
parent
65b14bcee2
commit
8405789520
@ -1,3 +1,7 @@
|
||||
2009-08-25 Ulrich Drepper <drepper@redhat.com>
|
||||
|
||||
* sysdeps/ieee754/dbl-64/wordsize-64/s_round.c: New file.
|
||||
|
||||
2009-08-25 Joseph Myers <joseph@codesourcery.com>
|
||||
|
||||
* math/s_fdiml.c (__fdiml): Use fpclassify instead of fpclassifyl.
|
||||
|
77
sysdeps/ieee754/dbl-64/wordsize-64/s_round.c
Normal file
77
sysdeps/ieee754/dbl-64/wordsize-64/s_round.c
Normal file
@ -0,0 +1,77 @@
|
||||
/* Round double to integer away from zero.
|
||||
Copyright (C) 1997, 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"
|
||||
|
||||
|
||||
static const double huge = 1.0e300;
|
||||
|
||||
|
||||
double
|
||||
__round (double x)
|
||||
{
|
||||
int64_t i0, j0;
|
||||
|
||||
EXTRACT_WORDS64 (i0, x);
|
||||
j0 = ((i0 >> 52) & 0x7ff) - 0x3ff;
|
||||
if (__builtin_expect (j0 < 52, 1))
|
||||
{
|
||||
if (j0 < 0)
|
||||
{
|
||||
if (huge + x > 0.0)
|
||||
{
|
||||
i0 &= UINT64_C(0x8000000000000000);
|
||||
if (j0 == -1)
|
||||
i0 |= UINT64_C(0x3ff0000000000000);
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
uint64_t i = UINT64_C(0x000fffffffffffff) >> j0;
|
||||
if ((i0 & i) == 0)
|
||||
/* X is integral. */
|
||||
return x;
|
||||
if (huge + x > 0.0)
|
||||
{
|
||||
/* Raise inexact if x != 0. */
|
||||
i0 += UINT64_C(0x0008000000000000) >> j0;
|
||||
i0 &= ~i;
|
||||
}
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
if (j0 == 0x400)
|
||||
/* Inf or NaN. */
|
||||
return x + x;
|
||||
else
|
||||
return x;
|
||||
}
|
||||
|
||||
INSERT_WORDS64 (x, i0);
|
||||
return x;
|
||||
}
|
||||
weak_alias (__round, round)
|
||||
#ifdef NO_LONG_DOUBLE
|
||||
strong_alias (__round, __roundl)
|
||||
weak_alias (__round, roundl)
|
||||
#endif
|
Loading…
Reference in New Issue
Block a user