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/* memcopy.h -- definitions for memory copy functions. Pentium version.
Copyright (C) 1994 Free Software Foundation, Inc.
Contributed by Torbjorn Granlund (tege@sics.se).
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
/* Get the i386 definitions. We will override some of them below. */
#include_next <memcopy.h>
/* Written like this, the Pentium pipeline can execute the loop at a
sustained rate of 2 instructions/clock, or asymptotically 480
Mbytes/second at 60Mhz. */
#undef WORD_COPY_FWD
#define WORD_COPY_FWD(dst_bp, src_bp, nbytes_left, nbytes) \
do \
{ \
asm volatile ("subl $32,%2\n" \
"js 2f\n" \
"1:\n" \
"movl 0(%1),%%eax\n" \
"movl 4(%1),%%edx\n" \
"movl %%eax,0(%0)\n" \
"movl %%edx,4(%0)\n" \
"movl 8(%1),%%eax\n" \
"movl 12(%1),%%edx\n" \
"movl %%eax,8(%0)\n" \
"movl %%edx,12(%0)\n" \
"movl 16(%1),%%eax\n" \
"movl 20(%1),%%edx\n" \
"movl %%eax,16(%0)\n" \
"movl %%edx,20(%0)\n" \
"movl 24(%1),%%eax\n" \
"movl 28(%1),%%edx\n" \
"movl %%eax,24(%0)\n" \
"movl %%edx,28(%0)\n" \
"addl $32,%1\n" \
"addl $32,%0\n" \
"subl $32,%2\n" \
"jns 1b\n" \
"2: addl $32,%2" : \
"=r" (dst_bp), "=r" (src_bp), "=r" (nbytes_left) : \
"0" (dst_bp), "1" (src_bp), "2" (nbytes) : \
"ax", "dx"); \
} while (0)
#undef WORD_COPY_BWD
#define WORD_COPY_BWD(dst_ep, src_ep, nbytes_left, nbytes) \
do \
{ \
asm volatile ("subl $32,%2\n" \
"js 2f\n" \
"1:\n" \
"movl -4(%1),%%eax\n" \
"movl -8(%1),%%edx\n" \
"movl %%eax,-4(%0)\n" \
"movl %%edx,-8(%0)\n" \
"movl -12(%1),%%eax\n" \
"movl -16(%1),%%edx\n" \
"movl %%eax,-12(%0)\n" \
"movl %%edx,-16(%0)\n" \
"movl -20(%1),%%eax\n" \
"movl -24(%1),%%edx\n" \
"movl %%eax,-20(%0)\n" \
"movl %%edx,-24(%0)\n" \
"movl -28(%1),%%eax\n" \
"movl -32(%1),%%edx\n" \
"movl %%eax,-28(%0)\n" \
"movl %%edx,-32(%0)\n" \
"subl $32,%1\n" \
"subl $32,%0\n" \
"subl $32,%2\n" \
"jns 1b\n" \
"2: addl $32,%2" : \
"=r" (dst_bp), "=r" (src_bp), "=r" (nbytes_left) : \
"0" (dst_bp), "1" (src_bp), "2" (nbytes) : \
"ax", "dx"); \
} while (0)
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