Annotation of OpenXM_contrib/gmp/mpn/x86/pentium4/sse2/sub_n.asm, Revision 1.1
1.1 ! ohara 1: dnl Intel Pentium-4 mpn_sub_n -- mpn subtraction.
! 2:
! 3: dnl Copyright 2001, 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 P4: 4.0 cycles/limb if dst!=src1 and dst!=src2
! 26: C 6.0 cycles/limb if dst==src1 or dst==src2
! 27:
! 28:
! 29: C mp_limb_t mpn_sub_n (mp_ptr dst, mp_srcptr src1, mp_srcptr src2,
! 30: C mp_size_t size);
! 31: C mp_limb_t mpn_sub_nc (mp_ptr dst, mp_srcptr src1, mp_srcptr src2,
! 32: C mp_size_t size, mp_limb_t carry);
! 33: C
! 34: C The main loop code is 2x unrolled so that the carry bit can alternate
! 35: C between mm0 and mm1.
! 36:
! 37: defframe(PARAM_CARRY,20)
! 38: defframe(PARAM_SIZE, 16)
! 39: defframe(PARAM_SRC2, 12)
! 40: defframe(PARAM_SRC1, 8)
! 41: defframe(PARAM_DST, 4)
! 42:
! 43: dnl re-use parameter space
! 44: define(SAVE_EBX,`PARAM_SRC1')
! 45:
! 46: TEXT
! 47: ALIGN(8)
! 48:
! 49: PROLOGUE(mpn_sub_nc)
! 50: deflit(`FRAME',0)
! 51:
! 52: movd PARAM_CARRY, %mm0
! 53: jmp L(start_nc)
! 54:
! 55: EPILOGUE()
! 56:
! 57: ALIGN(8)
! 58: PROLOGUE(mpn_sub_n)
! 59: deflit(`FRAME',0)
! 60: pxor %mm0, %mm0
! 61: L(start_nc):
! 62: movl PARAM_SRC1, %eax
! 63: movl %ebx, SAVE_EBX
! 64: movl PARAM_SRC2, %ebx
! 65: movl PARAM_DST, %edx
! 66: movl PARAM_SIZE, %ecx
! 67:
! 68: leal (%eax,%ecx,4), %eax C src1 end
! 69: leal (%ebx,%ecx,4), %ebx C src2 end
! 70: leal (%edx,%ecx,4), %edx C dst end
! 71: negl %ecx C -size
! 72:
! 73: L(top):
! 74: C eax src1 end
! 75: C ebx src2 end
! 76: C ecx counter, limbs, negative
! 77: C edx dst end
! 78: C mm0 carry bit
! 79:
! 80: movd (%eax,%ecx,4), %mm1
! 81: movd (%ebx,%ecx,4), %mm2
! 82: psubq %mm2, %mm1
! 83:
! 84: psubq %mm0, %mm1
! 85: movd %mm1, (%edx,%ecx,4)
! 86:
! 87: psrlq $63, %mm1
! 88:
! 89: addl $1, %ecx
! 90: jz L(done_mm1)
! 91:
! 92: movd (%eax,%ecx,4), %mm0
! 93: movd (%ebx,%ecx,4), %mm2
! 94: psubq %mm2, %mm0
! 95:
! 96: psubq %mm1, %mm0
! 97: movd %mm0, (%edx,%ecx,4)
! 98:
! 99: psrlq $63, %mm0
! 100:
! 101: addl $1, %ecx
! 102: jnz L(top)
! 103:
! 104:
! 105: movd %mm0, %eax
! 106: movl SAVE_EBX, %ebx
! 107: emms
! 108: ret
! 109:
! 110: L(done_mm1):
! 111: movd %mm1, %eax
! 112: movl SAVE_EBX, %ebx
! 113: emms
! 114: ret
! 115:
! 116: EPILOGUE()
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>