glibc/sysdeps/powerpc/rshift.S

57 lines
1.4 KiB
ArmAsm

/* Shift a limb right, low level routine.
Copyright (C) 1995, 1997 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. */
#include <sysdep.h>
/* INPUT PARAMETERS
res_ptr r3
s1_ptr r4
size r5
cnt r6 */
ENTRY(__mpn_rshift)
mtctr 5 # copy size into CTR
addi 7,3,-4 # move adjusted res_ptr to free return reg
subfic 8,6,32
lwz 11,0(4) # load first s1 limb
slw 3,11,8 # compute function return value
bdz 1f
0: lwzu 10,4(4)
srw 9,11,6
slw 12,10,8
or 9,9,12
stwu 9,4(7)
bdz 2f
lwzu 11,4(4)
srw 9,10,6
slw 12,11,8
or 9,9,12
stwu 9,4(7)
bdnz 0b
1: srw 0,11,6
stw 0,4(7)
blr
2: srw 0,10,6
stw 0,4(7)
blr
END(__mpn_rshift)