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95 lines
3.4 KiB
C
95 lines
3.4 KiB
C
/* memcopy.h -- definitions for memory copy functions. Pentium version.
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Copyright (C) 1994-2023 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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/* Get the i386 definitions. We will override some of them below. */
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#include <sysdeps/i386/memcopy.h>
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/* Written like this, the Pentium pipeline can execute the loop at a
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sustained rate of 2 instructions/clock, or asymptotically 480
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Mbytes/second at 60Mhz. */
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#undef WORD_COPY_FWD
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#define WORD_COPY_FWD(dst_bp, src_bp, nbytes_left, nbytes) \
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do \
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{ \
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asm volatile ("subl $32,%2\n" \
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"js 2f\n" \
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"movl 0(%0),%%edx\n" /* alloc dest line */ \
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"1:\n" \
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"movl 28(%0),%%eax\n" /* alloc dest line */ \
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"subl $32,%2\n" /* decr loop count */ \
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"movl 0(%1),%%eax\n" /* U pipe */ \
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"movl 4(%1),%%edx\n" /* V pipe */ \
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"movl %%eax,0(%0)\n" /* U pipe */ \
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"movl %%edx,4(%0)\n" /* V pipe */ \
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"movl 8(%1),%%eax\n" \
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"movl 12(%1),%%edx\n" \
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"movl %%eax,8(%0)\n" \
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"movl %%edx,12(%0)\n" \
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"movl 16(%1),%%eax\n" \
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"movl 20(%1),%%edx\n" \
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"movl %%eax,16(%0)\n" \
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"movl %%edx,20(%0)\n" \
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"movl 24(%1),%%eax\n" \
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"movl 28(%1),%%edx\n" \
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"movl %%eax,24(%0)\n" \
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"movl %%edx,28(%0)\n" \
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"leal 32(%1),%1\n" /* update src ptr */ \
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"leal 32(%0),%0\n" /* update dst ptr */ \
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"jns 1b\n" \
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"2: addl $32,%2" : \
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"=r" (dst_bp), "=r" (src_bp), "=r" (nbytes_left) : \
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"0" (dst_bp), "1" (src_bp), "2" (nbytes) : \
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"ax", "dx"); \
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} while (0)
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#undef WORD_COPY_BWD
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#define WORD_COPY_BWD(dst_ep, src_ep, nbytes_left, nbytes) \
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do \
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{ \
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asm volatile ("subl $32,%2\n" \
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"js 2f\n" \
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"movl -4(%0),%%edx\n" \
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"1:\n" \
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"movl -32(%0),%%eax\n" \
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"subl $32,%2\n" \
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"movl -4(%1),%%eax\n" \
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"movl -8(%1),%%edx\n" \
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"movl %%eax,-4(%0)\n" \
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"movl %%edx,-8(%0)\n" \
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"movl -12(%1),%%eax\n" \
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"movl -16(%1),%%edx\n" \
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"movl %%eax,-12(%0)\n" \
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"movl %%edx,-16(%0)\n" \
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"movl -20(%1),%%eax\n" \
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"movl -24(%1),%%edx\n" \
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"movl %%eax,-20(%0)\n" \
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"movl %%edx,-24(%0)\n" \
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"movl -28(%1),%%eax\n" \
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"movl -32(%1),%%edx\n" \
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"movl %%eax,-28(%0)\n" \
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"movl %%edx,-32(%0)\n" \
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"leal -32(%1),%1\n" \
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"leal -32(%0),%0\n" \
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"jns 1b\n" \
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"2: addl $32,%2" : \
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"=r" (dst_ep), "=r" (src_ep), "=r" (nbytes_left) : \
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"0" (dst_ep), "1" (src_ep), "2" (nbytes) : \
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"ax", "dx"); \
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} while (0)
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