library/string_memmove.c
/*
* $Id: string_memmove.c,v 1.7 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 ___ovbcopy
___ovbcopy:
moveml sp@(4),a0-a1
movel sp@(12),d0
movel a2,sp@-
cmpal a0,a1
bcs forwards
| If A0 is less than A1 then we _may_ have to do the memory move
| backwards. However, since doing the memory move backwards is less
| efficient if we have to do any byte moves, I'll first check to see
| whether there is actually any overlap.
lea a0@(0,d0:l),a2
cmpal a2,a1 | If A2 is greater than A1 then there is overlap,
bcs backwards | and we'd better do the move backwards.
forwards:
movew a0,d1 | Make sure that A0 is long word aligned.
notw d1 | This may de-align A1, but that's life.
andiw #3,d1
align_loop1:
moveb a0@+,a1@+ | Move from one to four bytes to long
subql #1,d0 | word align A0.
dbeq d1,align_loop1
beq done
movew d0,d1
andiw #511,d1
movew d1,sp@-
moveq #9,d1
lsrl d1,d0
beq no_big_chunks_to_move1
moveml d2-d7/a3-a6,sp@-
swap d0
movew d0,sp@-
swap d0
bras move_big_chunk_end1
move_big_chunk1:
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_end1:
dbf d0,move_big_chunk1
subqw #1,sp@
bge move_big_chunk1
addqw #2,sp
moveml sp@+,d2-d7/a3-a6
no_big_chunks_to_move1:
movew sp@+,d0
movew d0,d1
lsrw #5,d1 | D1 now holds numbytes / 32 and
andiw #31,d0 | D0 holds numbytes % 32.
bras move_eight_longs_end1
move_eight_longs1:
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_end1:
dbf d1,move_eight_longs1
movew d0,d1
lsrw #2,d1 | D1 now holds numbytes / 4
bras move_long_end1
move_long1:
movel a0@+,a1@+
move_long_end1:
dbf d1,move_long1
andiw #3,d0 | D0 now holds numbytes % 4.
bra move_byte_end1
move_byte1:
moveb a0@+,a1@+
move_byte_end1:
dbf d0,move_byte1
done:
movel sp@+,a2
rts
backwards:
addal d0,a0
addal d0,a1
movew a0,d1 | Make sure that A0 is long word aligned.
subqw #1,d1 | This may de-align A1, but that's life.
andiw #3,d1
align_loop2:
moveb a0@-,a1@-
subql #1,d0
dbeq d1,align_loop2
beq done
movew d0,d1
andiw #511,d1
movew d1,sp@-
moveq #9,d1
lsrl d1,d0
beq no_big_chunks_to_move2
moveml d2-d7/a3-a6,sp@-
swap d0
movew d0,sp@-
swap d0
subaw #48,a0
bras move_big_chunk_end2
move_big_chunk2:
moveml a0@,d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@-
moveml a0@(-48),d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@-
moveml a0@(-96),d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@-
moveml a0@(-144),d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@-
moveml a0@(-192),d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@-
moveml a0@(-240),d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@-
moveml a0@(-288),d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@-
moveml a0@(-336),d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@-
moveml a0@(-384),d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@-
moveml a0@(-432),d1-d7/a2-a6
moveml d1-d7/a2-a6,a1@-
moveml a0@(-464),d1-d7/a2
moveml d1-d7/a2,a1@-
subaw #512,a0
move_big_chunk_end2:
dbf d0,move_big_chunk2
subqw #1,sp@
bge move_big_chunk2
addaw #48,a0
addqw #2,sp
moveml sp@+,d2-d7/a3-a6
no_big_chunks_to_move2:
movew sp@+,d0
movew d0,d1
lsrw #5,d1 | D1 now holds numbytes / 32 and
andiw #31,d0 | D0 holds numbytes % 32.
bras move_eight_longs_end2
move_eight_longs2:
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_end2:
dbf d1,move_eight_longs2
movew d0,d1
lsrw #2,d1 | D1 now holds numbytes / 4
bra move_long_end2
move_long2:
movel a0@-,a1@-
move_long_end2:
dbf d1,move_long2
andiw #3,d0 | D0 now holds numbytes % 4.
bra move_byte_end2
move_byte2:
moveb a0@-,a1@-
move_byte_end2:
dbf d0,move_byte2
movel sp@+,a2
rts
");
/****************************************************************************/
extern void __ovbcopy(const void * src,void * dest,size_t len);
/****************************************************************************/
void *
memmove(void *dest, const void * src, size_t len)
{
void * result = dest;
assert( (len == 0) || (dest != NULL && src != NULL && (int)len > 0) );
#if defined(CHECK_FOR_NULL_POINTERS)
{
if(dest == NULL || src == NULL)
{
__set_errno(EFAULT);
goto out;
}
}
#endif /* CHECK_FOR_NULL_POINTERS */
if(len > 0 && dest != src)
__ovbcopy(src,dest,len);
out:
return(result);
}
/****************************************************************************/
#else
/****************************************************************************/
INLINE STATIC VOID
__memmove(unsigned char * to,unsigned char * from,size_t len)
{
if(from < to && to < from + len)
{
to += len;
from += 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))
{
size_t distance;
/* 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);
}
/* Check the distance between source and destination. If it's shorter
* than a long word, don't dive into the copying routine below since
* the overlapping copying may clobber data.
*/
distance = (size_t)(to - from);
/* 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(distance >= sizeof(long) && 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 (-1..-8)
into the respective displacement values. This
should help the PowerPC by avoiding pipeline
stalls (removing the predecrement on the address
will do that) but has no noticeable impact on the
68k platform (I checked). */
_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 -= 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);
}
else
{
/* 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))
{
size_t distance;
/* 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);
}
/* Check the distance between source and destination. If it's shorter
* than a long word, don't dive into the copying routine below since
* the overlapping copying may clobber data.
*/
if(to >= from)
distance = (size_t)(to - from);
else
distance = (size_t)(from - to);
/* 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(distance >= sizeof(long) && 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++);
}
}
/****************************************************************************/
void *
memmove(void *dest, const void * src, size_t len)
{
void * result = dest;
assert( (len == 0) || (dest != NULL && src != NULL && (int)len > 0) );
#if defined(CHECK_FOR_NULL_POINTERS)
{
if(dest == NULL || src == NULL)
{
__set_errno(EFAULT);
goto out;
}
}
#endif /* CHECK_FOR_NULL_POINTERS */
if(len > 0 && dest != src)
{
char * to = dest;
const char * from = src;
#if 0
{
if(from < to && to < from + len)
{
to += len;
from += len;
while(len-- > 0)
(*--to) = (*--from);
}
else
{
while(len-- > 0)
(*to++) = (*from++);
}
}
#else
{
__memmove((unsigned char *)to,(unsigned char *)from,len);
}
#endif
}
out:
return(result);
}
/****************************************************************************/
#endif /* __GNUC__ && __mc68020__ */