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Annotation of OpenXM_contrib/gmp/mpn/x86/copyi.asm, Revision 1.1

1.1     ! maekawa     1: dnl  x86 mpn_copyi -- copy limb vector, incrementing.
        !             2:
        !             3:
        !             4: dnl  Copyright (C) 1999, 2000 Free Software Foundation, Inc.
        !             5: dnl
        !             6: dnl  This file is part of the GNU MP Library.
        !             7: dnl
        !             8: dnl  The GNU MP Library is free software; you can redistribute it and/or
        !             9: dnl  modify it under the terms of the GNU Lesser General Public License as
        !            10: dnl  published by the Free Software Foundation; either version 2.1 of the
        !            11: dnl  License, or (at your option) any later version.
        !            12: dnl
        !            13: dnl  The GNU MP Library is distributed in the hope that it will be useful,
        !            14: dnl  but WITHOUT ANY WARRANTY; without even the implied warranty of
        !            15: dnl  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
        !            16: dnl  Lesser General Public License for more details.
        !            17: dnl
        !            18: dnl  You should have received a copy of the GNU Lesser General Public
        !            19: dnl  License along with the GNU MP Library; see the file COPYING.LIB.  If
        !            20: dnl  not, write to the Free Software Foundation, Inc., 59 Temple Place -
        !            21: dnl  Suite 330, Boston, MA 02111-1307, USA.
        !            22:
        !            23:
        !            24: include(`../config.m4')
        !            25:
        !            26:
        !            27: C void mpn_copyi (mp_ptr dst, mp_srcptr src, mp_size_t size);
        !            28: C
        !            29: C Copy src,size to dst,size, working from low to high addresses.
        !            30: C
        !            31: C The code here is very generic and can be expected to be reasonable on all
        !            32: C the x86 family.
        !            33: C
        !            34: C P5 - 1.0 cycles/limb.
        !            35: C
        !            36: C P6 - 0.75 cycles/limb.  An MMX based copy was tried, but was found to be
        !            37: C      slower than a rep movs in all cases.  The fastest MMX found was 0.8
        !            38: C      cycles/limb (when fully aligned).  A rep movs seems to have a startup
        !            39: C      time of about 15 cycles, but doing something special for small sizes
        !            40: C      could lead to a branch misprediction that would destroy any saving.
        !            41: C      For now a plain rep movs seems ok for P6.
        !            42:
        !            43: defframe(PARAM_SIZE,12)
        !            44: defframe(PARAM_SRC, 8)
        !            45: defframe(PARAM_DST, 4)
        !            46: deflit(`FRAME',0)
        !            47:
        !            48:        .text
        !            49:        ALIGN(32)
        !            50:
        !            51:        C eax   saved esi
        !            52:        C ebx
        !            53:        C ecx   counter
        !            54:        C edx   saved edi
        !            55:        C esi   src
        !            56:        C edi   dst
        !            57:        C ebp
        !            58:
        !            59: PROLOGUE(mpn_copyi)
        !            60:
        !            61:        movl    PARAM_SIZE, %ecx
        !            62:        movl    %esi, %eax
        !            63:
        !            64:        movl    PARAM_SRC, %esi
        !            65:        movl    %edi, %edx
        !            66:
        !            67:        movl    PARAM_DST, %edi
        !            68:
        !            69:        cld     C better safe than sorry, see mpn/x86/README.family
        !            70:
        !            71:        rep
        !            72:        movsl
        !            73:
        !            74:        movl    %eax, %esi
        !            75:        movl    %edx, %edi
        !            76:
        !            77:        ret
        !            78:
        !            79: EPILOGUE()