glibc/sysdeps/i386/lshift.S
1995-02-18 01:27:10 +00:00

85 lines
2.1 KiB
ArmAsm

/* i80386 __mpn_lshift --
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., 675 Mass Ave, Cambridge, MA 02139, 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_lshift)
C_SYMBOL_NAME(__mpn_lshift:)
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 */
subl $4,%esi /* adjust s_ptr */
movl (%esi,%edx,4),%ebx /* read most significant limb */
xorl %eax,%eax
shldl %cl,%ebx,%eax /* compute carry limb */
decl %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 lower limb */
shldl %cl,%ebx,%eax /* compute result limb */
movl %eax,(%edi,%edx,4) /* store it */
decl %edx
L1: movl (%esi,%edx,4),%eax
shldl %cl,%eax,%ebx
movl %ebx,(%edi,%edx,4)
decl %edx
jnz Loop
shll %cl,%eax /* compute least significant limb */
movl %eax,(%edi) /* store it */
popl %eax /* pop carry limb */
popl %ebx
popl %esi
popl %edi
ret
Lend: shll %cl,%ebx /* compute least significant limb */
movl %ebx,(%edi) /* store it */
popl %ebx
popl %esi
popl %edi
ret