rockbox/firmware/target/coldfire/memmove-coldfire.S
Daniel Stenberg 2acc0ac542 Updated our source code header to explicitly mention that we are GPL v2 or
later. We still need to hunt down snippets used that are not. 1324 modified
files...
http://www.rockbox.org/mail/archive/rockbox-dev-archive-2008-06/0060.shtml


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17847 a1c6a512-1295-4272-9138-f99709370657
2008-06-28 18:10:04 +00:00

670 lines
27 KiB
ArmAsm

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2006 by Jens Arnold
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
.section .icode,"ax",@progbits
#define FULLSPEED /* use burst writing for word aligned destinations */
.align 2
.global memmove
.type memmove,@function
/* Moves <length> bytes of data in memory from <source> to <dest>
* Regions may overlap.
* This version is optimized for speed, and needs the corresponding memcpy
* implementation for the forward copy branch.
*
* arguments:
* (4,%sp) - destination address
* (8,%sp) - source address
* (12,%sp) - length
*
* return value:
* %d0 - destination address (like ANSI version)
*
* register usage:
* %a0 - current source address
* %a1 - current dest address
* %a2 - source start address (in line-copy loops)
* %d0 - source start address (byte and longword copy) / data / scratch
* %d1 - data / scratch
* %d2 - data / scratch
* %d3..%d7 - data
*
* For maximum speed this routine reads and writes whole lines using burst
* move (movem.l) where possible. For byte aligned destinations (long-1 and
* long-3) it writes longwords only. Same goes for word aligned destinations
* if FULLSPEED is undefined.
*/
memmove:
move.l (4,%sp),%a1 /* Destination */
move.l (8,%sp),%a0 /* Source */
move.l (12,%sp),%d1 /* Length */
cmp.l %a0,%a1
bhi.b .backward /* dest > src -> backward copy */
jmp __memcpy_fwd_entry
.backward:
move.l %a0,%d0 /* %d0 = source start */
add.l %d1,%a0 /* %a0 = source end */
add.l %d1,%a1 /* %a1 = destination end */
move.l %a0,%d1
and.l #0xFFFFFFFC,%d1 /* %d1 = last source long bound */
subq.l #4,%d1
cmp.l %d0,%d1 /* at least one aligned longword to copy? */
blo.w .bytes2r_start
addq.l #4,%d1 /* %d1 = last source long bound */
cmp.l %d1,%a0 /* any bytes to copy */
jls .bytes1r_end /* no: skip byte loop */
/* leading byte loop: copies 0..3 bytes */
.bytes1r_loop:
move.b -(%a0),-(%a1) /* copy byte */
cmp.l %d1,%a0 /* runs %a0 down to last long bound */
jhi .bytes1r_loop
.bytes1r_end:
moveq.l #-16,%d1
add.l %a0,%d1
and.l #0xFFFFFFF0,%d1 /* %d1 = last source line bound - 16 */
cmp.l %d0,%d1 /* at least one aligned line to copy? */
blo.w .longr_start /* no: jump to longword copy loop */
lea.l (-28,%sp),%sp /* free up some registers */
movem.l %d2-%d7/%a2,(%sp)
moveq.l #16,%d2
add.l %d2,%d1 /* %d1 = last source line bound */
move.l %d0,%a2 /* %a2 = start address */
lea.l (15,%a2),%a2 /* adjust start address for loops doing 16 bytes/pass */
move.l %a1,%d0
moveq.l #3,%d2 /* mask */
and.l %d2,%d0
jmp.l (2,%pc,%d0.l*4) /* switch (dest_addr & 3) */
bra.w .lines_do0r_start
bra.w .lines_do1r_start
bra.w .lines_do2r_start
/* bra.w .lines_do3r_start implicit */
/* byte aligned destination (long - 1): use line burst reads in main loop */
.lines_do3r_start:
moveq.l #24,%d0 /* shift count for shifting by 3 bytes */
cmp.l %d1,%a0 /* any leading longwords? */
jhi .lines_do3r_head_start /* yes: leading longword copy */
lea.l (-16,%a0),%a0
movem.l (%a0),%d3-%d6 /* load initial line */
move.l %d6,%d2 /* last longword, bytes 3210 */
move.b %d2,-(%a1) /* store byte */
lsr.l #8,%d2 /* last longword, bytes .321 */
move.w %d2,-(%a1) /* store word */
jra .lines_do3r_entry
.lines_do3r_head_start:
move.l -(%a0),%d3 /* load initial longword */
move.l %d3,%d2 /* bytes 3210 */
move.b %d2,-(%a1) /* store byte */
lsr.l #8,%d2 /* bytes .321 */
move.w %d2,-(%a1) /* store word */
jra .lines_do3r_head_entry
.lines_do3r_head_loop:
move.l %d3,%d4 /* move old longword away */
move.l -(%a0),%d3 /* load new longword */
move.l %d3,%d2
lsl.l #8,%d2 /* get bytes 210. */
or.l %d2,%d4 /* combine with old high byte */
move.l %d4,-(%a1) /* store longword */
.lines_do3r_head_entry:
lsr.l %d0,%d3 /* shift down high byte */
cmp.l %d1,%a0 /* run %a0 down to last line bound */
jhi .lines_do3r_head_loop
.lines_do3r_loop:
move.l %d3,%d7 /* move first longword of last line away */
lea.l (-16,%a0),%a0
movem.l (%a0),%d3-%d6 /* load new line */
move.l %d6,%d2
lsl.l #8,%d2 /* get bytes 210. of 4th longword */
or.l %d2,%d7 /* combine with high byte of old longword */
move.l %d7,-(%a1) /* store longword */
.lines_do3r_entry:
lsr.l %d0,%d6 /* shift down high byte */
move.l %d5,%d2
lsl.l #8,%d2 /* get bytes 210. of 3rd longword */
or.l %d2,%d6 /* combine with high byte of 4th longword */
move.l %d6,-(%a1) /* store longword */
lsr.l %d0,%d5 /* shift down high byte */
move.l %d4,%d2
lsl.l #8,%d2 /* get bytes 210. of 2nd longword */
or.l %d2,%d5 /* combine with high byte or 3rd longword */
move.l %d5,-(%a1) /* store longword */
lsr.l %d0,%d4 /* shift down high byte */
move.l %d3,%d2
lsl.l #8,%d2 /* get bytes 210. of 1st longword */
or.l %d2,%d4 /* combine with high byte of 2nd longword */
move.l %d4,-(%a1) /* store longword */
lsr.l %d0,%d3 /* shift down high byte */
cmp.l %a2,%a0 /* run %a0 down to first line bound */
jhi .lines_do3r_loop
lea.l (-12,%a2),%a2 /* readjust start address for doing longwords */
cmp.l %a2,%a0 /* any trailing longwords? */
jls .lines_do3r_tail_end /* no: just store last high byte */
.lines_do3r_tail_loop:
move.l %d3,%d4 /* move old longword away */
move.l -(%a0),%d3 /* load new longword */
move.l %d3,%d2
lsl.l #8,%d2 /* get bytes 210. */
or.l %d2,%d4 /* combine with old high byte */
move.l %d4,-(%a1) /* store longword */
lsr.l %d0,%d3 /* shift down high byte */
cmp.l %a2,%a0 /* run %a0 down to first long bound */
jhi .lines_do3r_tail_loop
.lines_do3r_tail_end:
move.b %d3,-(%a1) /* store shifted-down high byte */
jra .linesr_end
/* byte aligned destination (long - 3): use line burst reads in main loop */
.lines_do1r_start:
moveq.l #24,%d0 /* shift count for shifting by 3 bytes */
cmp.l %d1,%a0 /* any leading longwords? */
jhi .lines_do1r_head_start /* yes: leading longword copy */
lea.l (-16,%a0),%a0
movem.l (%a0),%d3-%d6 /* load initial line */
move.b %d6,-(%a1) /* store low byte of last longword */
jra .lines_do1r_entry
.lines_do1r_head_start:
move.l -(%a0),%d3 /* load initial longword */
move.b %d3,-(%a1) /* store low byte */
jra .lines_do1r_head_entry
.lines_do1r_head_loop:
move.l %d3,%d4 /* move old longword away */
move.l -(%a0),%d3 /* load new longword */
move.l %d3,%d2
lsl.l %d0,%d2 /* get low byte */
or.l %d2,%d4 /* combine with old bytes .321 */
move.l %d4,-(%a1) /* store longword */
.lines_do1r_head_entry:
lsr.l #8,%d3 /* get bytes .321 */
cmp.l %d1,%a0 /* run %a0 down to last line bound */
jhi .lines_do1r_head_loop
.lines_do1r_loop:
move.l %d3,%d7 /* move first longword of old line away */
lea.l (-16,%a0),%a0
movem.l (%a0),%d3-%d6 /* load new line */
move.l %d6,%d2
lsl.l %d0,%d2 /* get low byte of 4th longword */
or.l %d2,%d7 /* combine with bytes .321 of old longword */
move.l %d7,-(%a1) /* store longword */
.lines_do1r_entry:
lsr.l #8,%d6 /* get bytes .321 */
move.l %d5,%d2
lsl.l %d0,%d2 /* get low byte of 3rd longword */
or.l %d2,%d6 /* combine with bytes .321 of 4th longword */
move.l %d6,-(%a1) /* store longword */
lsr.l #8,%d5 /* get bytes .321 */
move.l %d4,%d2
lsl.l %d0,%d2 /* get low byte of 2nd longword */
or.l %d2,%d5 /* combine with bytes .321 of 3rd longword */
move.l %d5,-(%a1) /* store longword */
lsr.l #8,%d4 /* get bytes .321 */
move.l %d3,%d2
lsl.l %d0,%d2 /* get low byte of 1st longword */
or.l %d2,%d4 /* combine with bytes .321 of 2nd longword */
move.l %d4,-(%a1) /* store longword */
lsr.l #8,%d3 /* get bytes .321 */
cmp.l %a2,%a0 /* run %a0 down to first line bound */
jhi .lines_do1r_loop
lea.l (-12,%a2),%a2 /* readjust start address for doing longwords */
cmp.l %a2,%a0 /* any trailing longwords? */
jls .lines_do1r_tail_end /* no: just store last high byte */
.lines_do1r_tail_loop:
move.l %d3,%d4 /* move old longword away */
move.l -(%a0),%d3 /* load new longword */
move.l %d3,%d2
lsl.l %d0,%d2 /* get low byte */
or.l %d2,%d4 /* combine with old bytes .321 */
move.l %d4,-(%a1) /* store longword */
lsr.l #8,%d3 /* get bytes .321 */
cmp.l %a2,%a0 /* run %a0 down to first long bound */
jhi .lines_do1r_tail_loop
.lines_do1r_tail_end:
move.w %d3,-(%a1) /* store word 21 */
swap %d3
move.b %d3,-(%a1) /* store byte 3 */
jra .linesr_end
/* long aligned destination (line - 0/4/8/12): head */
.lines_do0r_head_loop:
move.l -(%a0),-(%a1) /* copy longword */
.lines_do0r_start:
cmp.l %d1,%a0 /* run %a0 down to last line bound */
jhi .lines_do0r_head_loop
.lines_do0r_head_end:
move.l %a1,%d1
lsr.l #2,%d1
moveq.l #3,%d0 /* mask */
and.l %d0,%d1
moveq.l #16,%d0 /* address decrement for one main loop pass */
jmp.l (2,%pc,%d1.l*2) /* switch ((dest_addr >> 2) & 3) */
bra.b .lines_lo0r_start
bra.b .lines_lo4r_start
bra.b .lines_lo8r_start
/* bra.b .lines_lo12r_start implicit */
/* long aligned destination (line - 4): use line bursts in the loop */
.lines_lo12r_start:
sub.l %d0,%a0
movem.l (%a0),%d1-%d4 /* load initial line */
move.l %d4,-(%a1) /* store 4th longword */
move.l %d3,-(%a1) /* store 3rd longword */
move.l %d2,-(%a1) /* store 2nd longword */
cmp.l %a2,%a0 /* any full lines? */
jls .lines_lo12r_end /* no: skip main loop */
.lines_lo12r_loop:
move.l %d1,%d5 /* move first longword of old line away */
sub.l %d0,%a0
movem.l (%a0),%d1-%d4 /* load new line */
sub.l %d0,%a1
movem.l %d2-%d5,(%a1) /* store line (1 old + 3 new longwords */
cmp.l %a2,%a0 /* run %a0 down to first line bound */
jhi .lines_lo12r_loop
jra .lines_lo12r_end /* handle trailing longwords */
/* line aligned destination: use line bursts in the loop */
.lines_lo0r_start:
.lines_lo0r_loop:
sub.l %d0,%a0
movem.l (%a0),%d1-%d4 /* load line */
sub.l %d0,%a1
movem.l %d1-%d4,(%a1) /* store line */
cmp.l %a2,%a0 /* run %a0 down to first line bound */
jhi .lines_lo0r_loop
jra .lines_lo0r_end /* handle trailing longwords */
/* long aligned destination (line - 8): use line bursts in the loop */
.lines_lo8r_start:
sub.l %d0,%a0
movem.l (%a0),%d1-%d4 /* load initial line */
move.l %d4,-(%a1) /* store 4th longword */
move.l %d3,-(%a1) /* store 3rd longword */
cmp.l %a2,%a0 /* any full lines? */
jls .lines_lo8r_end /* no: skip main loop */
.lines_lo8r_loop:
move.l %d2,%d6 /* move first 2 longwords of old line away */
move.l %d1,%d5
sub.l %d0,%a0
movem.l (%a0),%d1-%d4 /* load new line */
sub.l %d0,%a1
movem.l %d3-%d6,(%a1) /* store line (2 old + 2 new longwords */
cmp.l %a2,%a0 /* run %a0 down to first line bound */
jhi .lines_lo8r_loop
jra .lines_lo8r_end /* handle trailing longwords */
/* long aligned destination (line - 12): use line bursts in the loop */
.lines_lo4r_start:
sub.l %d0,%a0
movem.l (%a0),%d1-%d4 /* load initial line */
move.l %d4,-(%a1) /* store 4th longword */
cmp.l %a2,%a0 /* any full lines? */
jls .lines_lo4r_end /* no: skip main loop */
.lines_lo4r_loop:
move.l %d3,%d7 /* move first 3 longwords of old line away */
move.l %d2,%d6
move.l %d1,%d5
sub.l %d0,%a0
movem.l (%a0),%d1-%d4 /* load new line */
sub.l %d0,%a1
movem.l %d4-%d7,(%a1) /* store line (3 old + 1 new longwords */
cmp.l %a2,%a0 /* run %a0 down to first line bound */
jhi .lines_lo4r_loop
/* long aligned destination (line - 0/4/8/12): tail */
.lines_lo4r_end:
move.l %d3,-(%a1) /* store 3rd last longword */
.lines_lo8r_end:
move.l %d2,-(%a1) /* store 2nd last longword */
.lines_lo12r_end:
move.l %d1,-(%a1) /* store last longword */
.lines_lo0r_end:
lea.l (-12,%a2),%a2 /* readjust end address for doing longwords */
cmp.l %a2,%a0 /* any trailing longwords? */
jls .linesr_end /* no: get outta here */
.lines_do0r_tail_loop:
move.l -(%a0),-(%a1) /* copy longword */
cmp.l %a2,%a0 /* run %a0 down to first long bound */
jhi .lines_do0r_tail_loop
jra .linesr_end
#ifdef FULLSPEED
/* word aligned destination (line - 2/6/10/14): head */
.lines_do2r_start:
cmp.l %d1,%a0 /* any leading longwords? */
jls .lines_do2r_selector /* no: jump to mainloop selector */
move.l -(%a0),%d3 /* load initial longword */
move.w %d3,-(%a1) /* store low word */
cmp.l %d1,%a0 /* any more longwords? */
jls .lines_do2r_head_end /* no: skip head loop */
.lines_do2r_head_loop:
move.l %d3,%d4 /* move old longword away */
move.l -(%a0),%d3 /* load new longword */
move.w %d3,%d4 /* combine low word with old high word */
swap %d4 /* swap words */
move.l %d4,-(%a1) /* store longword */
cmp.l %d1,%a0 /* run %a0 down to last line bound */
jhi .lines_do2r_head_loop
.lines_do2r_head_end:
swap %d3 /* get high word */
move.w %d3,-(%a1) /* and store it */
.lines_do2r_selector:
move.l %a1,%d1
lsr.l #2,%d1
moveq.l #3,%d0 /* mask */
and.l %d0,%d1
moveq.l #16,%d7 /* address decrement for one main loop pass */
jmp.l (2,%pc,%d1.l*4) /* switch ((dest_addr >> 2) & 3) */
bra.w .lines_lo2r_start
bra.w .lines_lo6r_start
bra.w .lines_lo10r_start
/* bra.w .lines_lo14r_start implicit */
/* word aligned destination (line - 2): use line bursts in the loop */
.lines_lo14r_start:
sub.l %d7,%a0
movem.l (%a0),%d0-%d3 /* load initial line */
move.w %d3,-(%a1) /* store last low word */
move.w %d2,%d3 /* combine 3rd low word with 4th high word */
swap %d3 /* swap words of 3rd long */
move.w %d1,%d2 /* combine 2nd low word with 3rd high word */
swap %d2 /* swap words of 2nd long */
move.w %d0,%d1 /* combine 1st low word with 2nd high word */
swap %d1 /* swap words of 1st long */
move.l %d3,-(%a1) /* store 3rd longword */
move.l %d2,-(%a1) /* store 2nd longword */
move.l %d1,-(%a1) /* store 1st longword */
cmp.l %a2,%a0 /* any full lines? */
jls .lines_lo14r_end /* no: skip main loop */
.lines_lo14r_loop:
move.l %d0,%d4 /* move first longword of old line away */
sub.l %d7,%a0
movem.l (%a0),%d0-%d3 /* load line */
move.w %d3,%d4 /* combine 4th low word with old high word */
swap %d4 /* swap words of 4th long */
move.w %d2,%d3 /* combine 3rd low word with 4th high word */
swap %d3 /* swap words of 3rd long */
move.w %d1,%d2 /* combine 2nd low word with 3rd high word */
swap %d2 /* swap words of 2nd long */
move.w %d0,%d1 /* combine 1st low word with 2nd high word */
swap %d1 /* swap words of 1st long */
sub.l %d7,%a1
movem.l %d1-%d4,(%a1) /* store line */
cmp.l %a2,%a0 /* run %a0 down to first line bound */
jhi .lines_lo14r_loop
jra .lines_lo14r_end /* handle trailing longwords */
/* word aligned destination (line - 6): use line bursts in the loop */
.lines_lo10r_start:
sub.l %d7,%a0
movem.l (%a0),%d0-%d3 /* load initial line */
move.w %d3,-(%a1) /* store last low word */
move.w %d2,%d3 /* combine 3rd low word with 4th high word */
swap %d3 /* swap words of 3rd long */
move.w %d1,%d2 /* combine 2nd low word with 3rd high word */
swap %d2 /* swap words of 2nd long */
move.l %d3,-(%a1) /* store 3rd longword */
move.l %d2,-(%a1) /* store 2nd longword */
jra .lines_lo10r_entry /* jump into main loop */
.lines_lo10r_loop:
move.l %d0,%d4 /* move first 2 longwords of old line away */
move.l %d1,%d5
sub.l %d7,%a0
movem.l (%a0),%d0-%d3 /* load line */
move.w %d3,%d4 /* combine 4th low word with old high word */
swap %d4 /* swap words of 4th long */
move.w %d2,%d3 /* combine 3rd low word with 4th high word */
swap %d3 /* swap words of 3rd long */
move.w %d1,%d2 /* combine 2nd low word with 3rd high word */
swap %d2 /* swap words of 2nd long */
sub.l %d7,%a1
movem.l %d2-%d5,(%a1) /* store line */
.lines_lo10r_entry:
move.w %d0,%d1 /* combine 1st low word with 2nd high word */
swap %d1 /* swap words of 1st long */
cmp.l %a2,%a0 /* run %a0 down to first line bound */
jhi .lines_lo10r_loop
jra .lines_lo10r_end /* handle trailing longwords */
/* word aligned destination (line - 10): use line bursts in the loop */
.lines_lo6r_start:
sub.l %d7,%a0
movem.l (%a0),%d0-%d3 /* load initial line */
move.w %d3,-(%a1) /* store last low word */
move.w %d2,%d3 /* combine 3rd low word with 4th high word */
swap %d3 /* swap words of 3rd long */
move.l %d3,-(%a1) /* store 3rd longword */
jra .lines_lo6r_entry /* jump into main loop */
.lines_lo6r_loop:
move.l %d0,%d4 /* move first 3 longwords of old line away */
move.l %d1,%d5
move.l %d2,%d6
sub.l %d7,%a0
movem.l (%a0),%d0-%d3 /* load line */
move.w %d3,%d4 /* combine 4th low word with old high word */
swap %d4 /* swap words of 4th long */
move.w %d2,%d3 /* combine 3rd low word with 4th high word */
swap %d3 /* swap words of 3rd long */
sub.l %d7,%a1
movem.l %d3-%d6,(%a1) /* store line */
.lines_lo6r_entry:
move.w %d1,%d2 /* combine 2nd low word with 3rd high word */
swap %d2 /* swap words of 2nd long */
move.w %d0,%d1 /* combine 1st low word with 2nd high word */
swap %d1 /* swap words of 1st long */
cmp.l %a2,%a0 /* run %a0 down to first line bound */
jhi .lines_lo6r_loop
jra .lines_lo6r_end /* handle trailing longwords */
/* word aligned destination (line - 14): use line bursts in the loop */
.lines_lo2r_start:
sub.l %d7,%a0
movem.l (%a0),%d0-%d3 /* load initial line */
move.w %d3,-(%a1) /* store last low word */
jra .lines_lo2r_entry /* jump into main loop */
.lines_lo2r_loop:
move.l %d0,%d4 /* move old line away */
move.l %d1,%d5
move.l %d2,%d6
move.l %d3,%d7
lea.l (-16,%a0),%a0
movem.l (%a0),%d0-%d3 /* load line */
move.w %d3,%d4 /* combine 4th low word with old high word */
swap %d4 /* swap words of 4th long */
lea.l (-16,%a1),%a1
movem.l %d4-%d7,(%a1) /* store line */
.lines_lo2r_entry:
move.w %d2,%d3 /* combine 3rd low word with 4th high word */
swap %d3 /* swap words of 3rd long */
move.w %d1,%d2 /* combine 2nd low word with 3rd high word */
swap %d2 /* swap words of 2nd long */
move.w %d0,%d1 /* combine 1st low word with 2nd high word */
swap %d1 /* swap words of 1st long */
cmp.l %a2,%a0 /* run %a0 down to first line bound */
jhi .lines_lo2r_loop
/* word aligned destination (line - 2/6/10/14): tail */
.lines_lo2r_end:
move.l %d3,-(%a1) /* store third last longword */
.lines_lo6r_end:
move.l %d2,-(%a1) /* store second last longword */
.lines_lo10r_end:
move.l %d1,-(%a1) /* store last longword */
.lines_lo14r_end:
lea.l (-12,%a2),%a2 /* readjust start address for doing longwords */
cmp.l %a2,%a0 /* any trailing longwords? */
jls .lines_do2r_tail_end /* no: skip tail loop */
.lines_do2r_tail_loop:
move.l %d0,%d1 /* move old longword away */
move.l -(%a0),%d0 /* load new longword */
move.w %d0,%d1 /* combine low word with old high word */
swap %d1 /* swap words */
move.l %d1,-(%a1) /* store longword */
cmp.l %a2,%a0 /* run %a0 down to first long bound */
jhi .lines_do2r_tail_loop
.lines_do2r_tail_end:
swap %d0 /* get final high word */
move.w %d0,-(%a1) /* store it */
/* jra .linesr_end implicit */
#else /* !FULLSPEED */
/* word aligned destination (long - 2): use line burst reads in the loop */
.lines_do2r_start:
cmp.l %d1,%a0 /* any leading longwords? */
jhi .lines_do2r_head_start /* yes: leading longword copy */
lea.l (-16,%a0),%a0
movem.l (%a0),%d3-%d6 /* load initial line */
move.w %d6,-(%a1) /* store last low word */
jra .lines_do2r_entry /* jump into main loop */
.lines_do2r_head_start:
move.l -(%a0),%d3 /* load initial longword */
move.w %d3,-(%a1) /* store low word */
cmp.l %d1,%a0 /* any full longword? */
jls .lines_do2r_loop /* no: skip head loop */
.lines_do2r_head_loop:
move.l %d3,%d4 /* move old longword away */
move.l -(%a0),%d3 /* load new longword */
move.w %d3,%d4 /* combine low word with old high word */
swap %d4 /* swap words */
move.l %d4,-(%a1) /* store longword */
cmp.l %d1,%a0 /* run %a0 down to last line bound */
jhi .lines_do2r_head_loop
.lines_do2r_loop:
move.l %d3,%d7 /* move first longword of old line away */
lea.l (-16,%a0),%a0
movem.l (%a0),%d3-%d6 /* load line */
move.w %d6,%d7 /* combine 4th low word with old high word */
swap %d7 /* swap words of 4th long */
move.l %d7,-(%a1) /* store 4th longword */
.lines_do2r_entry:
move.w %d5,%d6 /* combine 3rd low word with 4th high word */
swap %d6 /* swap words of 3rd long */
move.l %d6,-(%a1) /* store 3rd longword */
move.w %d4,%d5 /* combine 2nd low word with 3rd high word */
swap %d5 /* swap words of 2nd long */
move.l %d5,-(%a1) /* store 2nd longword */
move.w %d3,%d4 /* combine 1st low word with 2nd high word */
swap %d4 /* swap words of 1st long */
move.l %d4,-(%a1) /* store 1st longword */
cmp.l %a2,%a0 /* run %a0 down to first line bound */
jhi .lines_do2r_loop
.lines_do2r_end:
lea.l (-12,%a2),%a2 /* readjust start address for doing longwords */
cmp.l %a2,%a0 /* any trailing longwords? */
jls .lines_do2r_tail_end /* no: skip tail loop */
.lines_do2r_tail_loop:
move.l %d3,%d4 /* move old longword away */
move.l -(%a0),%d3 /* load new longword */
move.w %d3,%d4 /* combine low word with old high word */
swap %d4 /* swap words */
move.l %d4,-(%a1) /* store longword */
cmp.l %a2,%a0 /* run %a0 down to first long bound */
jhi .lines_do2r_tail_loop
.lines_do2r_tail_end:
swap %d3 /* get final high word */
move.w %d3,-(%a1) /* store it */
/* jra .linesr_end implicit */
#endif /* !FULLSPEED */
.linesr_end:
subq.l #3,%a2 /* readjust end address */
move.l %a2,%d0 /* start address in %d0 again */
movem.l (%sp),%d2-%d7/%a2 /* restore registers */
lea.l (28,%sp),%sp
jra .bytes2r_start /* jump to trailing byte loop */
.longr_start:
addq.l #3,%d0 /* adjust start address for doing 4 bytes/ pass */
/* longword copy loop - no lines */
.longr_loop:
move.l -(%a0),-(%a1) /* copy longword (write can be unaligned) */
cmp.l %d0,%a0 /* runs %a0 down to first long bound */
jhi .longr_loop
subq.l #3,%d0 /* readjust start address */
cmp.l %d0,%a0 /* any bytes left? */
jls .bytes2r_end /* no: skip trailing byte loop */
/* trailing byte loop */
.bytes2r_loop:
move.b -(%a0),-(%a1) /* copy byte */
.bytes2r_start:
cmp.l %d0,%a0 /* runs %a0 down to start address */
jhi .bytes2r_loop
.bytes2r_end:
rts /* returns start address */
.end:
.size memmove,.end-memmove