sysdeps/powerpc/powerpc32/fpu/s_copysign.S

   1 /* Copy a sign bit between floating-point values.
   2    Copyright (C) 1997, 1999, 2000 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 /* This has been coded in assembler because GCC makes such a mess of it
  21    when it's coded in C.  */
  22
  23 #include <sysdep.h>
  24
  25 ENTRY(__copysign)
  26 /* double [f1] copysign (double [f1] x, double [f2] y);
  27    copysign(x,y) returns a value with the magnitude of x and
  28    with the sign bit of y.  */
  29         stwu    r1,-16(r1)
  30         stfd    fp2,8(r1)
  31         lwz     r3,8(r1)
  32         cmpwi   r3,0
  33         addi    r1,r1,16
  34         blt     L(0)
  35         fabs    fp1,fp1
  36         blr
  37 L(0):   fnabs   fp1,fp1
  38         blr
  39         END (__copysign)
  40
  41 weak_alias(__copysign,copysign)
  42
  43 /* It turns out that it's safe to use this code even for single-precision.  */
  44 weak_alias(__copysign,copysignf)
  45 strong_alias(__copysign,__copysignf)
  46
  47 #ifdef NO_LONG_DOUBLE
  48 weak_alias(__copysign,copysignl)
  49 strong_alias(__copysign,__copysignl)
  50 #endif