rshift.asm
上传用户:qaz666999
上传日期:2022-08-06
资源大小:2570k
文件大小:2k
- dnl x86 mpn_rshift -- mpn right shift.
- dnl Copyright 1992, 1994, 1996, 1999, 2000, 2001, 2002 Free Software
- dnl Foundation, Inc.
- dnl
- dnl This file is part of the GNU MP Library.
- dnl
- dnl The GNU MP Library is free software; you can redistribute it and/or
- dnl modify it under the terms of the GNU Lesser General Public License as
- dnl published by the Free Software Foundation; either version 3 of the
- dnl License, or (at your option) any later version.
- dnl
- dnl The GNU MP Library is distributed in the hope that it will be useful,
- dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
- dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- dnl Lesser General Public License for more details.
- dnl
- dnl You should have received a copy of the GNU Lesser General Public License
- dnl along with the GNU MP Library. If not, see http://www.gnu.org/licenses/.
- include(`../config.m4')
- C cycles/limb
- C P54: 7.5
- C P55: 7.0
- C P6: 2.5
- C K6: 4.5
- C K7: 5.0
- C P4: 16.5
- C mp_limb_t mpn_rshift (mp_ptr dst, mp_srcptr src, mp_size_t size,
- C unsigned shift);
- defframe(PARAM_SHIFT,16)
- defframe(PARAM_SIZE, 12)
- defframe(PARAM_SRC, 8)
- defframe(PARAM_DST, 4)
- TEXT
- ALIGN(8)
- PROLOGUE(mpn_rshift)
- pushl %edi
- pushl %esi
- pushl %ebx
- deflit(`FRAME',12)
- movl PARAM_DST,%edi
- movl PARAM_SRC,%esi
- movl PARAM_SIZE,%edx
- movl PARAM_SHIFT,%ecx
- leal -4(%edi,%edx,4),%edi
- leal (%esi,%edx,4),%esi
- negl %edx
- movl (%esi,%edx,4),%ebx C read least significant limb
- xorl %eax,%eax
- shrdl( %cl, %ebx, %eax) C compute carry limb
- incl %edx
- jz L(end)
- pushl %eax C push carry limb onto stack
- testb $1,%dl
- jnz L(1) C enter loop in the middle
- movl %ebx,%eax
- ALIGN(8)
- L(oop): movl (%esi,%edx,4),%ebx C load next higher limb
- shrdl( %cl, %ebx, %eax) C compute result limb
- movl %eax,(%edi,%edx,4) C 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 C compute most significant limb
- movl %eax,(%edi) C store it
- popl %eax C pop carry limb
- popl %ebx
- popl %esi
- popl %edi
- ret
- L(end): shrl %cl,%ebx C compute most significant limb
- movl %ebx,(%edi) C store it
- popl %ebx
- popl %esi
- popl %edi
- ret
- EPILOGUE()