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93 lines
3.4 KiB
C
93 lines
3.4 KiB
C
/* memcopy.h -- definitions for memory copy functions. i386 version.
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Copyright (C) 1991-2016 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Torbjorn Granlund (tege@sics.se).
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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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<http://www.gnu.org/licenses/>. */
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#include <sysdeps/generic/memcopy.h>
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#undef OP_T_THRES
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#define OP_T_THRES 8
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#undef BYTE_COPY_FWD
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#define BYTE_COPY_FWD(dst_bp, src_bp, nbytes) \
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do { \
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int __d0; \
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asm volatile(/* Clear the direction flag, so copying goes forward. */ \
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"cld\n" \
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/* Copy bytes. */ \
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"rep\n" \
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"movsb" : \
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"=D" (dst_bp), "=S" (src_bp), "=c" (__d0) : \
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"0" (dst_bp), "1" (src_bp), "2" (nbytes) : \
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"memory"); \
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} while (0)
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#undef BYTE_COPY_BWD
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#define BYTE_COPY_BWD(dst_ep, src_ep, nbytes) \
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do \
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{ \
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int __d0; \
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asm volatile(/* Set the direction flag, so copying goes backwards. */ \
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"std\n" \
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/* Copy bytes. */ \
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"rep\n" \
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"movsb\n" \
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/* Clear the dir flag. Convention says it should be 0. */ \
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"cld" : \
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"=D" (dst_ep), "=S" (src_ep), "=c" (__d0) : \
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"0" (dst_ep - 1), "1" (src_ep - 1), "2" (nbytes) : \
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"memory"); \
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dst_ep += 1; \
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src_ep += 1; \
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} while (0)
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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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int __d0; \
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asm volatile(/* Clear the direction flag, so copying goes forward. */ \
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"cld\n" \
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/* Copy longwords. */ \
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"rep\n" \
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"movsl" : \
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"=D" (dst_bp), "=S" (src_bp), "=c" (__d0) : \
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"0" (dst_bp), "1" (src_bp), "2" ((nbytes) / 4) : \
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"memory"); \
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(nbytes_left) = (nbytes) % 4; \
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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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int __d0; \
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asm volatile(/* Set the direction flag, so copying goes backwards. */ \
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"std\n" \
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/* Copy longwords. */ \
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"rep\n" \
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"movsl\n" \
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/* Clear the dir flag. Convention says it should be 0. */ \
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"cld" : \
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"=D" (dst_ep), "=S" (src_ep), "=c" (__d0) : \
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"0" (dst_ep - 4), "1" (src_ep - 4), "2" ((nbytes) / 4) : \
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"memory"); \
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dst_ep += 4; \
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src_ep += 4; \
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(nbytes_left) = (nbytes) % 4; \
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} while (0)
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