glibc/sysdeps/powerpc/rshift.S

64 lines
1.7 KiB
ArmAsm

/* Shift a limb right, low level routine.
Copyright (C) 1995, 1997, 1999, 2000 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <sysdep.h>
#include <bp-sym.h>
#include <bp-asm.h>
/* INPUT PARAMETERS
res_ptr r3
s1_ptr r4
size r5
cnt r6 */
ENTRY (BP_SYM (__mpn_rshift))
#if __BOUNDED_POINTERS__
slwi r10,r5,2 /* convert limbs to bytes */
CHECK_BOUNDS_BOTH_WIDE (r3, r8, r9, r10)
CHECK_BOUNDS_BOTH_WIDE (r4, r8, r9, r10)
#endif
mtctr r5 # copy size into CTR
addi r7,r3,-4 # move adjusted res_ptr to free return reg
subfic r8,r6,32
lwz r11,0(r4) # load first s1 limb
slw r3,r11,r8 # compute function return value
bdz L(1)
L(0): lwzu r10,4(r4)
srw r9,r11,r6
slw r12,r10,r8
or r9,r9,r12
stwu r9,4(r7)
bdz L(2)
lwzu r11,4(r4)
srw r9,r10,r6
slw r12,r11,r8
or r9,r9,r12
stwu r9,4(r7)
bdnz L(0)
L(1): srw r0,r11,r6
stw r0,4(r7)
blr
L(2): srw r0,r10,r6
stw r0,4(r7)
blr
END (BP_SYM (__mpn_rshift))