glibc/sysdeps/powerpc/powerpc32/fpu/s_copysignl.S
Joseph Myers 05f3ed0a79 Stop powerpc copysignl raising "invalid" for sNaN argument (bug 20718).
The powerpc (hard-float) implementations of copysignl, both 32-bit and
64-bit, raise spurious "invalid" exceptions when the first argument is
a signaling NaN.  copysign functions should never raise exceptions
even for signaling NaNs.

The problem is the use of an fcmpu instruction to test the sign of the
high part of the long double argument.  This patch fixes the functions
to use fsel instead (as used for fabsl following my fixes for a
similar bug there), or to examine the integer representation for older
32-bit processors without fsel.

Tested for powerpc64 and powerpc32 (configurations with and without
fsel used).

	[BZ #20718]
	* sysdeps/powerpc/powerpc32/fpu/s_copysignl.S (__copysignl): Do
	not use floating-point comparisons to test sign.
	* sysdeps/powerpc/powerpc64/fpu/s_copysignl.S (__copysignl):
	Likewise.
2016-10-19 22:58:34 +00:00

67 lines
1.8 KiB
ArmAsm

/* Copy a sign bit between floating-point values.
IBM extended format long double version.
Copyright (C) 2006-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <math_ldbl_opt.h>
ENTRY(__copysignl)
/* long double [f1,f2] copysign (long double [f1,f2] x, long double [f3,f4] y);
copysign(x,y) returns a value with the magnitude of x and
with the sign bit of y. */
#ifdef _ARCH_PPCGR
/* fsel available. */
stwu r1,-16(r1)
cfi_adjust_cfa_offset (16)
stfd fp3,8(r1)
fmr fp0,fp1
fabs fp1,fp1
lwz r3,8+HIWORD(r1)
cmpwi cr6,r3,0
addi r1,r1,16
cfi_adjust_cfa_offset (-16)
fneg fp3,fp2
fsel fp2,fp0,fp2,fp3
bgelr cr6
fneg fp1,fp1
fneg fp2,fp2
blr
#else
stwu r1,-32(r1)
cfi_adjust_cfa_offset (32)
stfd fp3,8(r1)
stfd fp1,16(r1)
lwz r3,8+HIWORD(r1)
lwz r4,16+HIWORD(r1)
xor r3,r3,r4
cmpwi cr6,r3,0
addi r1,r1,32
cfi_adjust_cfa_offset (-32)
bgelr cr6
fneg fp1,fp1
fneg fp2,fp2
blr
#endif
END (__copysignl)
#if IS_IN (libm)
long_double_symbol (libm, __copysignl, copysignl)
#else
long_double_symbol (libc, __copysignl, copysignl)
#endif