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/* i80386 __mpn_rshift --
Copyright (C) 1992, 1994 Free Software Foundation, Inc.
This file is part of the GNU MP Library.
The GNU MP 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 MP 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 MP 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. */
/*
INPUT PARAMETERS
res_ptr (sp + 4)
s_ptr (sp + 8)
size (sp + 12)
cnt (sp + 16)
*/
#include "sysdep.h"
#include "asm-syntax.h"
.text
ALIGN (3)
.globl C_SYMBOL_NAME(__mpn_rshift)
C_SYMBOL_NAME(__mpn_rshift:)
pushl %edi
pushl %esi
pushl %ebx
movl 16(%esp),%edi /* res_ptr */
movl 20(%esp),%esi /* s_ptr */
movl 24(%esp),%edx /* size */
movl 28(%esp),%ecx /* cnt */
leal -4(%edi,%edx,4),%edi
leal (%esi,%edx,4),%esi
negl %edx
movl (%esi,%edx,4),%ebx /* read least significant limb */
xorl %eax,%eax
shrdl %cl,%ebx,%eax /* compute carry limb */
incl %edx
jz Lend
pushl %eax /* push carry limb onto stack */
testb $1,%edx
jnz L1 /* enter loop in the middle */
movl %ebx,%eax
ALIGN (3)
Loop: movl (%esi,%edx,4),%ebx /* load next higher limb */
shrdl %cl,%ebx,%eax /* compute result limb */
movl %eax,(%edi,%edx,4) /* store it */
incl %edx
L1: movl (%esi,%edx,4),%eax
shrdl %cl,%eax,%ebx
movl %ebx,(%edi,%edx,4)
incl %edx
jnz Loop
shrl %cl,%eax /* compute most significant limb */
movl %eax,(%edi) /* store it */
popl %eax /* pop carry limb */
popl %ebx
popl %esi
popl %edi
ret
Lend: shrl %cl,%ebx /* compute most significant limb */
movl %ebx,(%edi) /* store it */
popl %ebx
popl %esi
popl %edi
ret
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