mirror of
git://git.gnupg.org/gnupg.git
synced 2024-12-23 10:29:58 +01:00
232 lines
4.8 KiB
ArmAsm
232 lines
4.8 KiB
ArmAsm
/* i80586 rshift
|
|
*
|
|
* Copyright (C) 1992, 1994, 1998,
|
|
* 2001 Free Software Foundation, Inc.
|
|
*
|
|
* This file is part of GnuPG.
|
|
*
|
|
* GnuPG is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* GnuPG 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 General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
|
|
* USA.
|
|
*
|
|
* Note: This code is heavily based on the GNU MP Library.
|
|
* Actually it's the same code with only minor changes in the
|
|
* way the data is stored; this is to support the abstraction
|
|
* of an optional secure memory allocation which may be used
|
|
* to avoid revealing of sensitive data due to paging etc.
|
|
* The GNU MP Library itself is published under the LGPL;
|
|
* however I decided to publish this code under the plain GPL.
|
|
*/
|
|
|
|
|
|
#include "sysdep.h"
|
|
#include "asm-syntax.h"
|
|
|
|
|
|
|
|
/*******************
|
|
* mpi_limb_t
|
|
* mpihelp_rshift( mpi_ptr_t wp, (sp + 4)
|
|
* mpi_ptr_t up, (sp + 8)
|
|
* mpi_size_t usize, (sp + 12)
|
|
* unsigned cnt) (sp + 16)
|
|
*/
|
|
|
|
.text
|
|
ALIGN (3)
|
|
.globl C_SYMBOL_NAME(mpihelp_rshift)
|
|
C_SYMBOL_NAME(mpihelp_rshift:)
|
|
pushl %edi
|
|
pushl %esi
|
|
pushl %ebx
|
|
pushl %ebp
|
|
|
|
movl 20(%esp),%edi /* res_ptr */
|
|
movl 24(%esp),%esi /* s_ptr */
|
|
movl 28(%esp),%ebp /* size */
|
|
movl 32(%esp),%ecx /* cnt */
|
|
|
|
/* We can use faster code for shift-by-1 under certain conditions. */
|
|
cmp $1,%ecx
|
|
jne Rnormal
|
|
leal 4(%edi),%eax
|
|
cmpl %esi,%eax
|
|
jnc Rspecial /* jump if res_ptr + 1 >= s_ptr */
|
|
leal (%edi,%ebp,4),%eax
|
|
cmpl %eax,%esi
|
|
jnc Rspecial /* jump if s_ptr >= res_ptr + size */
|
|
|
|
Rnormal:
|
|
movl (%esi),%edx
|
|
addl $4,%esi
|
|
xorl %eax,%eax
|
|
shrdl %cl,%edx,%eax /* compute carry limb */
|
|
pushl %eax /* push carry limb onto stack */
|
|
|
|
decl %ebp
|
|
pushl %ebp
|
|
shrl $3,%ebp
|
|
jz Rend
|
|
|
|
movl (%edi),%eax /* fetch destination cache line */
|
|
|
|
ALIGN (2)
|
|
Roop: movl 28(%edi),%eax /* fetch destination cache line */
|
|
movl %edx,%ebx
|
|
|
|
movl (%esi),%eax
|
|
movl 4(%esi),%edx
|
|
shrdl %cl,%eax,%ebx
|
|
shrdl %cl,%edx,%eax
|
|
movl %ebx,(%edi)
|
|
movl %eax,4(%edi)
|
|
|
|
movl 8(%esi),%ebx
|
|
movl 12(%esi),%eax
|
|
shrdl %cl,%ebx,%edx
|
|
shrdl %cl,%eax,%ebx
|
|
movl %edx,8(%edi)
|
|
movl %ebx,12(%edi)
|
|
|
|
movl 16(%esi),%edx
|
|
movl 20(%esi),%ebx
|
|
shrdl %cl,%edx,%eax
|
|
shrdl %cl,%ebx,%edx
|
|
movl %eax,16(%edi)
|
|
movl %edx,20(%edi)
|
|
|
|
movl 24(%esi),%eax
|
|
movl 28(%esi),%edx
|
|
shrdl %cl,%eax,%ebx
|
|
shrdl %cl,%edx,%eax
|
|
movl %ebx,24(%edi)
|
|
movl %eax,28(%edi)
|
|
|
|
addl $32,%esi
|
|
addl $32,%edi
|
|
decl %ebp
|
|
jnz Roop
|
|
|
|
Rend: popl %ebp
|
|
andl $7,%ebp
|
|
jz Rend2
|
|
Roop2: movl (%esi),%eax
|
|
shrdl %cl,%eax,%edx /* compute result limb */
|
|
movl %edx,(%edi)
|
|
movl %eax,%edx
|
|
addl $4,%esi
|
|
addl $4,%edi
|
|
decl %ebp
|
|
jnz Roop2
|
|
|
|
Rend2: shrl %cl,%edx /* compute most significant limb */
|
|
movl %edx,(%edi) /* store it */
|
|
|
|
popl %eax /* pop carry limb */
|
|
|
|
popl %ebp
|
|
popl %ebx
|
|
popl %esi
|
|
popl %edi
|
|
ret
|
|
|
|
/* We loop from least significant end of the arrays, which is only
|
|
permissable if the source and destination don't overlap, since the
|
|
function is documented to work for overlapping source and destination.
|
|
*/
|
|
|
|
Rspecial:
|
|
leal -4(%edi,%ebp,4),%edi
|
|
leal -4(%esi,%ebp,4),%esi
|
|
|
|
movl (%esi),%edx
|
|
subl $4,%esi
|
|
|
|
decl %ebp
|
|
pushl %ebp
|
|
shrl $3,%ebp
|
|
|
|
shrl $1,%edx
|
|
incl %ebp
|
|
decl %ebp
|
|
jz RLend
|
|
|
|
movl (%edi),%eax /* fetch destination cache line */
|
|
|
|
ALIGN (2)
|
|
RLoop: movl -28(%edi),%eax /* fetch destination cache line */
|
|
movl %edx,%ebx
|
|
|
|
movl (%esi),%eax
|
|
movl -4(%esi),%edx
|
|
rcrl $1,%eax
|
|
movl %ebx,(%edi)
|
|
rcrl $1,%edx
|
|
movl %eax,-4(%edi)
|
|
|
|
movl -8(%esi),%ebx
|
|
movl -12(%esi),%eax
|
|
rcrl $1,%ebx
|
|
movl %edx,-8(%edi)
|
|
rcrl $1,%eax
|
|
movl %ebx,-12(%edi)
|
|
|
|
movl -16(%esi),%edx
|
|
movl -20(%esi),%ebx
|
|
rcrl $1,%edx
|
|
movl %eax,-16(%edi)
|
|
rcrl $1,%ebx
|
|
movl %edx,-20(%edi)
|
|
|
|
movl -24(%esi),%eax
|
|
movl -28(%esi),%edx
|
|
rcrl $1,%eax
|
|
movl %ebx,-24(%edi)
|
|
rcrl $1,%edx
|
|
movl %eax,-28(%edi)
|
|
|
|
leal -32(%esi),%esi /* use leal not to clobber carry */
|
|
leal -32(%edi),%edi
|
|
decl %ebp
|
|
jnz RLoop
|
|
|
|
RLend: popl %ebp
|
|
sbbl %eax,%eax /* save carry in %eax */
|
|
andl $7,%ebp
|
|
jz RLend2
|
|
addl %eax,%eax /* restore carry from eax */
|
|
RLoop2: movl %edx,%ebx
|
|
movl (%esi),%edx
|
|
rcrl $1,%edx
|
|
movl %ebx,(%edi)
|
|
|
|
leal -4(%esi),%esi /* use leal not to clobber carry */
|
|
leal -4(%edi),%edi
|
|
decl %ebp
|
|
jnz RLoop2
|
|
|
|
jmp RL1
|
|
RLend2: addl %eax,%eax /* restore carry from eax */
|
|
RL1: movl %edx,(%edi) /* store last limb */
|
|
|
|
movl $0,%eax
|
|
rcrl $1,%eax
|
|
|
|
popl %ebp
|
|
popl %ebx
|
|
popl %esi
|
|
popl %edi
|
|
ret
|
|
|