glibc/sysdeps/i386/memcopy.h
1995-02-18 01:27:10 +00:00

87 lines
3.2 KiB
C

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