glibc/sysdeps/i386/rshift.S

106 lines
2.5 KiB
ArmAsm

/* i80386 __mpn_rshift --
Copyright (C) 1992-2023 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 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 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 Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the GNU MP Library; see the file COPYING.LIB. If not,
see <https://www.gnu.org/licenses/>. */
#include "sysdep.h"
#include "asm-syntax.h"
#define PARMS 4+12 /* space for 3 saved regs */
#define RES PARMS
#define S RES+4
#define SIZE S+4
#define CNT SIZE+4
.text
ENTRY (__mpn_rshift)
pushl %edi
cfi_adjust_cfa_offset (4)
pushl %esi
cfi_adjust_cfa_offset (4)
pushl %ebx
cfi_adjust_cfa_offset (4)
movl RES(%esp),%edi
cfi_rel_offset (edi, 8)
movl S(%esp),%esi
cfi_rel_offset (esi, 4)
movl SIZE(%esp),%edx
movl CNT(%esp),%ecx
leal -4(%edi,%edx,4),%edi
leal (%esi,%edx,4),%esi
negl %edx
movl (%esi,%edx,4),%ebx /* read least significant limb */
cfi_rel_offset (ebx, 0)
cfi_remember_state
xorl %eax,%eax
shrdl %cl,%ebx,%eax /* compute carry limb */
incl %edx
jz L(end)
pushl %eax /* push carry limb onto stack */
cfi_adjust_cfa_offset (4)
testb $1,%dl
jnz L(1) /* enter loop in the middle */
movl %ebx,%eax
ALIGN (3)
L(oop): 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
L(1): movl (%esi,%edx,4),%eax
shrdl %cl,%eax,%ebx
movl %ebx,(%edi,%edx,4)
incl %edx
jnz L(oop)
shrl %cl,%eax /* compute most significant limb */
movl %eax,(%edi) /* store it */
popl %eax /* pop carry limb */
cfi_adjust_cfa_offset (-4)
popl %ebx
cfi_adjust_cfa_offset (-4)
cfi_restore (ebx)
popl %esi
cfi_adjust_cfa_offset (-4)
cfi_restore (esi)
popl %edi
cfi_adjust_cfa_offset (-4)
cfi_restore (edi)
ret
cfi_restore_state
L(end): shrl %cl,%ebx /* compute most significant limb */
movl %ebx,(%edi) /* store it */
popl %ebx
cfi_adjust_cfa_offset (-4)
cfi_restore (ebx)
popl %esi
cfi_adjust_cfa_offset (-4)
cfi_restore (esi)
popl %edi
cfi_adjust_cfa_offset (-4)
cfi_restore (edi)
ret
END (__mpn_rshift)