library/string_memcpy.c
/*
* $Id: string_memcpy.c,v 1.8 2006-09-22 09:02:51 obarthel Exp $
*
* :ts=4
*
* Portable ISO 'C' (1994) runtime library for the Amiga computer
* Copyright (c) 2002-2015 by Olaf Barthel <obarthel (at) gmx.net>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Neither the name of Olaf Barthel nor the names of contributors
* may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _STDLIB_NULL_POINTER_CHECK_H
#include "stdlib_null_pointer_check.h"
#endif /* _STDLIB_NULL_POINTER_CHECK_H */
/****************************************************************************/
#ifndef _STRING_HEADERS_H
#include "string_headers.h"
#endif /* _STRING_HEADERS_H */
/****************************************************************************/
#if (defined(__GNUC__) && defined(__mc68020__) && defined(NDEBUG) && defined(undefined))
/****************************************************************************/
asm("
.text
.even
.globl ___bcopy
___bcopy:
moveml sp@(4),a0-a1
movel sp@(12),d0
movew a0,d1 | Make sure that A0 is long word aligned.
andiw #3,d1
beq already_aligned
notw d1 | This may de-align A1, but that's life.
andiw #3,d1
align_loop:
moveb a0@+,a1@+ | Move from one to four bytes to long
subql #1,d0 | word align A0.
dbeq d1,align_loop
beq done
already_aligned:
movew d0,d1
andiw #511,d1
movew d1,sp@-
moveq #9,d1
lsrl d1,d0
beq no_big_chunks_to_move
moveml d2-d7/a2-a6,sp@-
swap d0
movew d0,sp@-
swap d0
bra move_big_chunk_end
move_big_chunk:
moveml a0@+,d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@
moveml a0@+,d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@(48)
moveml a0@+,d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@(96)
moveml a0@+,d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@(144)
moveml a0@+,d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@(192)
moveml a0@+,d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@(240)
moveml a0@+,d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@(288)
moveml a0@+,d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@(336)
moveml a0@+,d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@(384)
moveml a0@+,d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@(432)
moveml a0@+,d1-d7/a2
moveml d1-d7/a2,a1@(480)
addaw #512,a1
move_big_chunk_end:
dbf d0,move_big_chunk
subqw #1,sp@
bge move_big_chunk
addqw #2,sp
moveml sp@+,d2-d7/a2-a6
no_big_chunks_to_move:
movew sp@+,d0
movew d0,d1
lsrw #5,d1 | D1 now holds numbytes / 32 and
andiw #31,d0 | D0 holds numbytes % 32.
bra move_eight_longs_end
move_eight_longs:
movel a0@+,a1@+
movel a0@+,a1@+
movel a0@+,a1@+
movel a0@+,a1@+
movel a0@+,a1@+
movel a0@+,a1@+
movel a0@+,a1@+
movel a0@+,a1@+
move_eight_longs_end:
dbf d1,move_eight_longs
movew d0,d1
lsrw #2,d1 | D1 now holds numbytes / 4 and
bra move_long_end
move_long:
movel a0@+,a1@+
move_long_end:
dbf d1,move_long
andiw #3,d0 | D0 holds numbytes % 4.
bra move_byte_end
move_byte:
moveb a0@+,a1@+
move_byte_end:
dbf d0,move_byte
done:
rts
");
/****************************************************************************/
extern void __bcopy(const void *src,void *dst,size_t len);
/****************************************************************************/
/* This is ugly: GCC 2.95.x assumes that 'unsigned long' is used in the built-in
memcmp/memcpy/memset functions instead of 'size_t'. This can produce warnings
where none are necessary. */
#if defined(__GNUC__) && (__GNUC__ < 3)
void *
memcpy(void *dst, const void *src, unsigned long len)
#else
void *
memcpy(void *dst, const void *src, size_t len)
#endif /* __GNUC__ && __GNUC__ < 3 */
{
void * result = dst;
assert( (len == 0) || (dst != NULL && src != NULL && (int)len > 0) );
#if defined(CHECK_FOR_NULL_POINTERS)
{
if(dst == NULL || src == NULL)
{
__set_errno(EFAULT);
goto out;
}
}
#endif /* CHECK_FOR_NULL_POINTERS */
if(len > 0 && dst != src)
{
/* The two memory regions may not overlap. */
assert((dst) >= (src)+len ||
(src) >= (dst)+len);
__bcopy(src,dst,len);
}
out:
return(result);
}
/****************************************************************************/
#else
/****************************************************************************/
INLINE STATIC VOID
__memcpy(unsigned char * to,unsigned char * from,size_t len)
{
/* The setup below is intended to speed up copying larger
* memory blocks. This can be very elaborate and should not be
* done unless a payoff can be expected.
*/
if(len > 4 * sizeof(long))
{
/* Try to align both source and destination to an even address. */
if(IS_UNALIGNED(to) && IS_UNALIGNED(from))
{
(*to++) = (*from++);
len--;
}
/* Try to align both source and destination to addresses which are
* multiples of four.
*/
if(len >= sizeof(short) && IS_SHORT_ALIGNED(to) && IS_SHORT_ALIGNED(from))
{
(*to++) = (*from++);
(*to++) = (*from++);
len -= sizeof(short);
}
/* If both source and destination are aligned to addresses which are
* multiples of four and there is still enough data left to be copied,
* try to move it in larger chunks.
*/
if(len >= sizeof(long) && IS_LONG_ALIGNED(to) && IS_LONG_ALIGNED(from))
{
unsigned long * _to = (unsigned long *)to;
unsigned long * _from = (unsigned long *)from;
/* An unrolled transfer loop, which shifts 32 bytes per iteration. */
while(len >= 8 * sizeof(long))
{
/* The following should translate into load/store
opcodes which encode the access offsets (0..7)
into the respective displacement values. This
should help the PowerPC by avoiding pipeline
stalls (removing the postincrement on the address
will do that) but has no noticeable impact on the
68k platform (I checked). */
_to[0] = _from[0];
_to[1] = _from[1];
_to[2] = _from[2];
_to[3] = _from[3];
_to[4] = _from[4];
_to[5] = _from[5];
_to[6] = _from[6];
_to[7] = _from[7];
_to += 8;
_from += 8;
/*
(*_to++) = (*_from++);
(*_to++) = (*_from++);
(*_to++) = (*_from++);
(*_to++) = (*_from++);
(*_to++) = (*_from++);
(*_to++) = (*_from++);
(*_to++) = (*_from++);
(*_to++) = (*_from++);
*/
len -= 8 * sizeof(long);
}
/* Try to mop up any small amounts of data still in need of
* copying...
*/
while(len >= sizeof(long))
{
(*_to++) = (*_from++);
len -= sizeof(long);
}
to = (unsigned char *)_to;
from = (unsigned char *)_from;
}
}
/* If there's anything left, copy the rest. */
while(len-- > 0)
(*to++) = (*from++);
}
/****************************************************************************/
/* This is ugly: GCC 2.95.x assumes that 'unsigned long' is used in the built-in
memcmp/memcpy/memset functions instead of 'size_t'. This can produce warnings
where none are necessary. */
#if defined(__GNUC__) && (__GNUC__ < 3)
void *
memcpy(void *dst, const void *src, unsigned long len)
#else
void *
memcpy(void *dst, const void *src, size_t len)
#endif /* __GNUC__ && __GNUC__ < 3 */
{
void * result = dst;
assert( (len == 0) || (dst != NULL && src != NULL && (int)len > 0) );
#if defined(CHECK_FOR_NULL_POINTERS)
{
if(dst == NULL || src == NULL)
{
__set_errno(EFAULT);
goto out;
}
}
#endif /* CHECK_FOR_NULL_POINTERS */
if(len > 0 && dst != src)
{
char * to = dst;
const char * from = src;
/* The two memory regions may not overlap. */
assert((to) >= (from)+len ||
(from) >= (to )+len);
#if 0
{
while(len-- > 0)
(*to++) = (*from++);
}
#else
{
__memcpy((unsigned char *)to,(unsigned char *)from,len);
}
#endif
}
out:
return(result);
}
/****************************************************************************/
#endif /* __GNUC__ && __mc68020__ */