com.asm
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上传日期:2022-08-06
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- dnl AMD Athlon mpn_com -- mpn bitwise one's complement.
- dnl Copyright 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 K7: 1.0 cycles/limb
- C void mpn_com (mp_ptr dst, mp_srcptr src, mp_size_t size);
- C
- C The loop form below is necessary for the claimed speed. It needs to be
- C aligned to a 16 byte boundary and only 16 bytes long. Maybe that's so it
- C fits in a BTB entry. The adjustments to %eax and %edx avoid offsets on
- C the movq's and achieve the necessary size.
- C
- C If both src and dst are 4mod8, the loop runs at 1.5 c/l. So long as one
- C of the two is 0mod8, it runs at 1.0 c/l. On that basis dst is checked
- C (offset by the size, as per the loop addressing) and one high limb
- C processed separately to get alignment.
- C
- C The padding for the nails case is unattractive, but shouldn't cost any
- C cycles. Explicit .byte's guarantee the desired instructions, at a point
- C where we're probably stalled waiting for loads anyway.
- C
- C Enhancements:
- C
- C The combination load/pxor/store might be able to be unrolled to approach
- C 0.5 c/l if desired.
- defframe(PARAM_SIZE,12)
- defframe(PARAM_SRC, 8)
- defframe(PARAM_DST, 4)
- TEXT
- ALIGN(16)
- PROLOGUE(mpn_com)
- deflit(`FRAME',0)
- movl PARAM_DST, %edx
- movl PARAM_SIZE, %ecx
- pcmpeqd %mm7, %mm7
- leal (%edx,%ecx,4), %eax
- andl $4, %eax
- ifelse(GMP_NAIL_BITS,0,,
- ` psrld $GMP_NAIL_BITS, %mm7') C GMP_NUMB_MASK
- movl PARAM_SRC, %eax
- movd -4(%eax,%ecx,4), %mm0 C src high limb
- ifelse(GMP_NAIL_BITS,0,,
- ` C padding for alignment below
- .byte 0x8d, 0xb6, 0x00, 0x00, 0x00, 0x00 C lea 0(%esi),%esi
- .byte 0x8d, 0xbf, 0x00, 0x00, 0x00, 0x00 C lea 0(%edi),%edi
- ')
- jz L(aligned)
- pxor %mm7, %mm0
- movd %mm0, -4(%edx,%ecx,4) C dst high limb
- decl %ecx
- jz L(done)
- L(aligned):
- addl $4, %eax
- addl $4, %edx
- decl %ecx
- jz L(one)
- C offset 0x30 for no nails, or 0x40 for nails
- ALIGN(16)
- L(top):
- C eax src
- C ebx
- C ecx counter
- C edx dst
- subl $2, %ecx
- movq (%eax,%ecx,4), %mm0
- pxor %mm7, %mm0
- movq %mm0, (%edx,%ecx,4)
- jg L(top)
- jnz L(done) C if size even
- L(one):
- movd -4(%eax), %mm0 C src low limb
- pxor %mm7, %mm0
- movd %mm0, -4(%edx) C dst low limb
- L(done):
- emms
- ret
- EPILOGUE()