Annotation of OpenXM_contrib/gmp/mpn/x86/k7/mmx/com_n.asm, Revision 1.1
1.1 ! ohara 1: dnl AMD Athlon mpn_com_n -- mpn bitwise one's complement.
! 2:
! 3: dnl Copyright 2002 Free Software Foundation, Inc.
! 4: dnl
! 5: dnl This file is part of the GNU MP Library.
! 6: dnl
! 7: dnl The GNU MP Library is free software; you can redistribute it and/or
! 8: dnl modify it under the terms of the GNU Lesser General Public License as
! 9: dnl published by the Free Software Foundation; either version 2.1 of the
! 10: dnl License, or (at your option) any later version.
! 11: dnl
! 12: dnl The GNU MP Library is distributed in the hope that it will be useful,
! 13: dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
! 14: dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
! 15: dnl Lesser General Public License for more details.
! 16: dnl
! 17: dnl You should have received a copy of the GNU Lesser General Public
! 18: dnl License along with the GNU MP Library; see the file COPYING.LIB. If
! 19: dnl not, write to the Free Software Foundation, Inc., 59 Temple Place -
! 20: dnl Suite 330, Boston, MA 02111-1307, USA.
! 21:
! 22: include(`../config.m4')
! 23:
! 24:
! 25: C K7: 1.0 cycles/limb
! 26:
! 27:
! 28: C void mpn_com_n (mp_ptr dst, mp_srcptr src, mp_size_t size);
! 29: C
! 30: C The loop form below is necessary for the claimed speed. It needs to be
! 31: C aligned to a 16 byte boundary and only 16 bytes long. Maybe that's so it
! 32: C fits in a BTB entry. The adjustments to %eax and %edx avoid offsets on
! 33: C the movq's and achieve the necessary size.
! 34: C
! 35: C If both src and dst are 4mod8, the loop runs at 1.5 c/l. So long as one
! 36: C of the two is 0mod8, it runs at 1.0 c/l. On that basis dst is checked
! 37: C (offset by the size, as per the loop addressing) and one high limb
! 38: C processed separately to get alignment.
! 39: C
! 40: C The padding for the nails case is unattractive, but shouldn't cost any
! 41: C cycles. Explicit .byte's guarantee the desired instructions, at a point
! 42: C where we're probably stalled waiting for loads anyway.
! 43: C
! 44: C Enhancements:
! 45: C
! 46: C The combination load/pxor/store might be able to be unrolled to approach
! 47: C 0.5 c/l if desired.
! 48:
! 49: defframe(PARAM_SIZE,12)
! 50: defframe(PARAM_SRC, 8)
! 51: defframe(PARAM_DST, 4)
! 52:
! 53: TEXT
! 54: ALIGN(16)
! 55:
! 56: PROLOGUE(mpn_com_n)
! 57: deflit(`FRAME',0)
! 58:
! 59: movl PARAM_DST, %edx
! 60: movl PARAM_SIZE, %ecx
! 61: pcmpeqd %mm7, %mm7
! 62:
! 63: leal (%edx,%ecx,4), %eax
! 64: andl $4, %eax
! 65: ifelse(GMP_NAIL_BITS,0,,
! 66: ` psrld $GMP_NAIL_BITS, %mm7') C GMP_NUMB_MASK
! 67:
! 68: movl PARAM_SRC, %eax
! 69: movd -4(%eax,%ecx,4), %mm0 C src high limb
! 70:
! 71: ifelse(GMP_NAIL_BITS,0,,
! 72: ` C padding for alignment below
! 73: .byte 0x8d, 0xb6, 0x00, 0x00, 0x00, 0x00 C lea 0(%esi),%esi
! 74: .byte 0x8d, 0xbf, 0x00, 0x00, 0x00, 0x00 C lea 0(%edi),%edi
! 75: ')
! 76:
! 77: jz L(aligned)
! 78:
! 79: pxor %mm7, %mm0
! 80: movd %mm0, -4(%edx,%ecx,4) C dst high limb
! 81: decl %ecx
! 82: jz L(done)
! 83: L(aligned):
! 84:
! 85: addl $4, %eax
! 86: addl $4, %edx
! 87: decl %ecx
! 88: jz L(one)
! 89:
! 90: C offset 0x30 for no nails, or 0x40 for nails
! 91: ALIGN(16)
! 92: L(top):
! 93: C eax src
! 94: C ebx
! 95: C ecx counter
! 96: C edx dst
! 97:
! 98: subl $2, %ecx
! 99: movq (%eax,%ecx,4), %mm0
! 100: pxor %mm7, %mm0
! 101: movq %mm0, (%edx,%ecx,4)
! 102: jg L(top)
! 103:
! 104: jnz L(done) C if size even
! 105:
! 106: L(one):
! 107: movd -4(%eax), %mm0 C src low limb
! 108: pxor %mm7, %mm0
! 109: movd %mm0, -4(%edx) C dst low limb
! 110:
! 111: L(done):
! 112: emms
! 113:
! 114: ret
! 115:
! 116: EPILOGUE()
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