glibc/sysdeps/powerpc/fpu/s_copysign.S

/* Copy a sign bit between floating-point values.
   Copyright (C) 1997, 1999 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 Library General Public License as
   published by the Free Software Foundation; either version 2 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

/* This has been coded in assembler because GCC makes such a mess of it
   when it's coded in C.  */

#include <sysdep.h>

ENTRY(__copysign)
/* double [f1] copysign (double [f1] x, double [f2] y);
   copysign(x,y) returns a value with the magnitude of x and
   with the sign bit of y.  */
	stwu	r1,-16(r1)
	stfd	fp2,8(r1)
	lwz	r3,8(r1)
	cmpwi   r3,0
	addi    r1,r1,16
	blt     0f
	fabs    fp1,fp1
	blr
0:	fnabs   fp1,fp1
	blr
	END (__copysign)

weak_alias(__copysign,copysign)

/* It turns out that it's safe to use this code even for single-precision.  */
weak_alias(__copysign,copysignf)
strong_alias(__copysign,__copysignf)

#ifdef NO_LONG_DOUBLE
weak_alias(__copysign,copysignl)
strong_alias(__copysign,__copysignl)
#endif