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authorUlrich Drepper <drepper@redhat.com>2009-08-24 10:20:58 -0700
committerUlrich Drepper <drepper@redhat.com>2009-08-24 10:20:58 -0700
commitef72d5f1b95fe91b032de0ad1ee777d7cf4fb49f (patch)
tree01e1c04b230edff01629be1e3a806b3b4323e6df /sysdeps/x86_64/fpu
parent4b6bf3f205cd4908019e03ac097f847e63677c32 (diff)
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Optimize x86-64 signbit{,f} a bit.
Diffstat (limited to 'sysdeps/x86_64/fpu')
-rw-r--r--sysdeps/x86_64/fpu/bits/mathinline.h12
1 files changed, 7 insertions, 5 deletions
diff --git a/sysdeps/x86_64/fpu/bits/mathinline.h b/sysdeps/x86_64/fpu/bits/mathinline.h
index e8a919fe92..8d4850dfc0 100644
--- a/sysdeps/x86_64/fpu/bits/mathinline.h
+++ b/sysdeps/x86_64/fpu/bits/mathinline.h
@@ -1,5 +1,5 @@
/* Inline math functions for x86-64.
- Copyright (C) 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2004, 2007, 2009 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Andreas Jaeger <aj@suse.de>, 2002.
@@ -35,14 +35,16 @@
__MATH_INLINE int
__NTH (__signbitf (float __x))
{
- __extension__ union { float __f; int __i; } __u = { __f: __x };
- return __u.__i < 0;
+ int __m;
+ asm ("pmovmskb %1, %0" : "=r" (__m) : "x" (__x));
+ return __m & 0x8;
}
__MATH_INLINE int
__NTH (__signbit (double __x))
{
- __extension__ union { double __d; int __i[2]; } __u = { __d: __x };
- return __u.__i[1] < 0;
+ int __m;
+ asm ("pmovmskb %1, %0" : "=r" (__m) : "x" (__x));
+ return __m & 0x80;
}
__MATH_INLINE int
__NTH (__signbitl (long double __x))