copyd.asm
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上传日期:2022-08-06
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- dnl AMD K7 mpn_copyd -- copy limb vector, decrementing.
- dnl Copyright 1999, 2000, 2002 Free Software 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 alignment dst/src, A=0mod8 N=4mod8
- C A/A A/N N/A N/N
- C K7 0.75 1.0 1.0 0.75
- C void mpn_copyd (mp_ptr dst, mp_srcptr src, mp_size_t size);
- C
- C The various comments in mpn/x86/k7/copyi.asm apply here too.
- defframe(PARAM_SIZE,12)
- defframe(PARAM_SRC, 8)
- defframe(PARAM_DST, 4)
- deflit(`FRAME',0)
- dnl parameter space reused
- define(SAVE_EBX,`PARAM_SIZE')
- define(SAVE_ESI,`PARAM_SRC')
- dnl minimum 5 since the unrolled code can't handle less than 5
- deflit(UNROLL_THRESHOLD, 5)
- TEXT
- ALIGN(32)
- PROLOGUE(mpn_copyd)
- movl PARAM_SIZE, %ecx
- movl %ebx, SAVE_EBX
- movl PARAM_SRC, %eax
- movl PARAM_DST, %edx
- cmpl $UNROLL_THRESHOLD, %ecx
- jae L(unroll)
- orl %ecx, %ecx
- jz L(simple_done)
- L(simple):
- C eax src
- C ebx scratch
- C ecx counter
- C edx dst
- C
- C this loop is 2 cycles/limb
- movl -4(%eax,%ecx,4), %ebx
- movl %ebx, -4(%edx,%ecx,4)
- decl %ecx
- jnz L(simple)
- L(simple_done):
- movl SAVE_EBX, %ebx
- ret
- L(unroll):
- movl %esi, SAVE_ESI
- leal (%eax,%ecx,4), %ebx
- leal (%edx,%ecx,4), %esi
- andl %esi, %ebx
- movl SAVE_ESI, %esi
- subl $4, %ecx C size-4
- testl $4, %ebx C testl to pad code closer to 16 bytes for L(top)
- jz L(aligned)
- C both src and dst unaligned, process one limb to align them
- movl 12(%eax,%ecx,4), %ebx
- movl %ebx, 12(%edx,%ecx,4)
- decl %ecx
- L(aligned):
- ALIGN(16)
- L(top):
- C eax src
- C ebx
- C ecx counter, limbs
- C edx dst
- movq 8(%eax,%ecx,4), %mm0
- movq (%eax,%ecx,4), %mm1
- subl $4, %ecx
- movq %mm0, 16+8(%edx,%ecx,4)
- movq %mm1, 16(%edx,%ecx,4)
- jns L(top)
- C now %ecx is -4 to -1 representing respectively 0 to 3 limbs remaining
- testb $2, %cl
- jz L(finish_not_two)
- movq 8(%eax,%ecx,4), %mm0
- movq %mm0, 8(%edx,%ecx,4)
- L(finish_not_two):
- testb $1, %cl
- jz L(done)
- movl (%eax), %ebx
- movl %ebx, (%edx)
- L(done):
- movl SAVE_EBX, %ebx
- emms
- ret
- EPILOGUE()