mirror of
git://sourceware.org/git/glibc.git
synced 2024-12-27 04:41:02 +08:00
116ff9ad18
Partial revert of bebc49030c. Even with the revert, ceil and floor are
still faster than libcpml's equivalent.
Fixes bug 5350.
Signed-off-by: Matt Turner <mattst88@gmail.com>
59 lines
1.8 KiB
C
59 lines
1.8 KiB
C
/* Copyright (C) 1998, 2000, 2006, 2007 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Richard Henderson.
|
|
|
|
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_ldbl_opt.h>
|
|
|
|
/* Use the -inf rounding mode conversion instructions to implement
|
|
ceil, via something akin to -floor(-x). This is much faster than
|
|
playing with the fpcr to achieve +inf rounding mode. */
|
|
|
|
double
|
|
__ceil (double x)
|
|
{
|
|
if (isless (fabs (x), 9007199254740992.0)) /* 1 << DBL_MANT_DIG */
|
|
{
|
|
double tmp1, new_x;
|
|
|
|
new_x = -x;
|
|
__asm (
|
|
#ifdef _IEEE_FP_INEXACT
|
|
"cvttq/svim %2,%1\n\t"
|
|
#else
|
|
"cvttq/svm %2,%1\n\t"
|
|
#endif
|
|
"cvtqt/m %1,%0\n\t"
|
|
: "=f"(new_x), "=&f"(tmp1)
|
|
: "f"(new_x));
|
|
|
|
/* Fix up the negation we did above, as well as handling -0 properly. */
|
|
x = copysign(new_x, x);
|
|
}
|
|
return x;
|
|
}
|
|
|
|
weak_alias (__ceil, ceil)
|
|
#ifdef NO_LONG_DOUBLE
|
|
strong_alias (__ceil, __ceill)
|
|
weak_alias (__ceil, ceill)
|
|
#endif
|
|
#if LONG_DOUBLE_COMPAT(libm, GLIBC_2_0)
|
|
compat_symbol (libm, __ceil, ceill, GLIBC_2_0);
|
|
#endif
|