| /*************************************************************************** |
| * __________ __ ___. |
| * Open \______ \ ____ ____ | | _\_ |__ _______ ___ |
| * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / |
| * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < |
| * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ |
| * \/ \/ \/ \/ \/ |
| * $Id$ |
| * |
| * Copyright (C) 2004-2005 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 |
| |
| .align 2 |
| .global _memcpy |
| .global ___memcpy_fwd_entry |
| .type _memcpy,@function |
| |
| /* Copies <length> bytes of data in memory from <source> to <dest> |
| * This version is optimized for speed |
| * |
| * arguments: |
| * r4 - destination address |
| * r5 - source address |
| * r6 - length |
| * |
| * return value: |
| * r0 - destination address (like ANSI version) |
| * |
| * register usage: |
| * r0 - data / scratch |
| * r1 - 2nd data / scratch |
| * r2 - scratch |
| * r3 - first long bound / adjusted end address (only if >= 11 bytes) |
| * r4 - current dest address |
| * r5 - current source address |
| * r6 - source end address |
| * r7 - stored dest start address |
| * |
| * The instruction order is devised in a way to utilize the pipelining |
| * of the SH1 to the max. The routine also tries to utilize fast page mode. |
| */ |
| |
| _memcpy: |
| mov r4,r7 /* store dest for returning */ |
| ___memcpy_fwd_entry: |
| add #-8,r4 /* offset for early increment (max. 2 longs) */ |
| mov #11,r0 |
| cmp/hs r0,r6 /* at least 11 bytes to copy? (ensures 2 aligned longs) */ |
| add r5,r6 /* r6 = source_end */ |
| bf .start_b2 /* no: jump directly to byte loop */ |
| |
| mov #3,r0 |
| neg r5,r3 |
| and r0,r3 /* r3 = (4 - align_offset) % 4 */ |
| tst r3,r3 /* already aligned? */ |
| bt .end_b1 /* yes: skip leading byte loop */ |
| |
| add r5,r3 /* r3 = first source long bound */ |
| |
| /* leading byte loop: copies 0..3 bytes */ |
| .loop_b1: |
| mov.b @r5+,r0 /* load byte & increment source addr */ |
| add #1,r4 /* increment dest addr */ |
| mov.b r0,@(7,r4) /* store byte */ |
| cmp/hi r5,r3 /* runs r5 up to first long bound */ |
| bt .loop_b1 |
| /* now r5 is always at a long boundary */ |
| /* -> memory reading is done in longs for all dest alignments */ |
| |
| /* selector for main copy loop */ |
| .end_b1: |
| mov #3,r1 |
| and r4,r1 /* r1 = dest alignment offset */ |
| mova .jmptab,r0 |
| mov.b @(r0,r1),r1 /* select appropriate main loop */ |
| add r0,r1 |
| mov r6,r3 /* move end address to r3 */ |
| jmp @r1 /* and jump to it */ |
| add #-7,r3 /* adjust end addr for main loops doing 2 longs/pass */ |
| |
| /** main loops, copying 2 longs per pass to profit from fast page mode **/ |
| |
| /* long aligned destination (fastest) */ |
| .align 2 |
| .loop_do0: |
| mov.l @r5+,r1 /* load first long & increment source addr */ |
| add #16,r4 /* increment dest addr & account for decrementing stores */ |
| mov.l @r5+,r0 /* load second long & increment source addr */ |
| cmp/hi r5,r3 /* runs r5 up to last or second last long bound */ |
| mov.l r0,@-r4 /* store second long */ |
| mov.l r1,@-r4 /* store first long; NOT ALIGNED - no speed loss here! */ |
| bt .loop_do0 |
| |
| add #4,r3 /* readjust end address */ |
| cmp/hi r5,r3 /* one long left? */ |
| bf .start_b2 /* no, jump to trailing byte loop */ |
| |
| mov.l @r5+,r0 /* load last long & increment source addr */ |
| add #4,r4 /* increment dest addr */ |
| bra .start_b2 /* jump to trailing byte loop */ |
| mov.l r0,@(4,r4) /* store last long */ |
| |
| /* word aligned destination (long + 2) */ |
| .align 2 |
| .loop_do2: |
| mov.l @r5+,r1 /* load first long & increment source addr */ |
| add #16,r4 /* increment dest addr */ |
| mov.l @r5+,r0 /* load second long & increment source addr */ |
| cmp/hi r5,r3 /* runs r5 up to last or second last long bound */ |
| mov.w r0,@-r4 /* store low word of second long */ |
| xtrct r1,r0 /* extract low word of first long & high word of second long */ |
| mov.l r0,@-r4 /* and store as long */ |
| swap.w r1,r0 /* get high word of first long */ |
| mov.w r0,@-r4 /* and store it */ |
| bt .loop_do2 |
| |
| add #4,r3 /* readjust end address */ |
| cmp/hi r5,r3 /* one long left? */ |
| bf .start_b2 /* no, jump to trailing byte loop */ |
| |
| mov.l @r5+,r0 /* load last long & increment source addr */ |
| add #4,r4 /* increment dest addr */ |
| mov.w r0,@(6,r4) /* store low word */ |
| shlr16 r0 /* get high word */ |
| bra .start_b2 /* jump to trailing byte loop */ |
| mov.w r0,@(4,r4) /* and store it */ |
| |
| /* jumptable for loop selector */ |
| .align 2 |
| .jmptab: |
| .byte .loop_do0 - .jmptab /* placed in the middle because the SH1 */ |
| .byte .loop_do1 - .jmptab /* loads bytes sign-extended. Otherwise */ |
| .byte .loop_do2 - .jmptab /* the last loop would be out of reach */ |
| .byte .loop_do3 - .jmptab /* of the offset range. */ |
| |
| /* byte aligned destination (long + 1) */ |
| .align 2 |
| .loop_do1: |
| mov.l @r5+,r1 /* load first long & increment source addr */ |
| add #16,r4 /* increment dest addr */ |
| mov.l @r5+,r0 /* load second long & increment source addr */ |
| cmp/hi r5,r3 /* runs r5 up to last or second last long bound */ |
| mov.b r0,@-r4 /* store low byte of second long */ |
| shlr8 r0 /* get upper 3 bytes */ |
| mov r1,r2 /* copy first long */ |
| shll16 r2 /* move low byte of first long all the way up, .. */ |
| shll8 r2 |
| or r2,r0 /* ..combine with the 3 bytes of second long.. */ |
| mov.l r0,@-r4 /* ..and store as long */ |
| shlr8 r1 /* get middle 2 bytes */ |
| mov.w r1,@-r4 /* store as word */ |
| shlr16 r1 /* get upper byte */ |
| mov.b r1,@-r4 /* and store */ |
| bt .loop_do1 |
| |
| add #4,r3 /* readjust end address */ |
| .last_do13: |
| cmp/hi r5,r3 /* one long left? */ |
| bf .start_b2 /* no, jump to trailing byte loop */ |
| |
| mov.l @r5+,r0 /* load last long & increment source addr */ |
| add #12,r4 /* increment dest addr */ |
| mov.b r0,@-r4 /* store low byte */ |
| shlr8 r0 /* get middle 2 bytes */ |
| mov.w r0,@-r4 /* store as word */ |
| shlr16 r0 /* get upper byte */ |
| mov.b r0,@-r4 /* and store */ |
| bra .start_b2 /* jump to trailing byte loop */ |
| add #-4,r4 /* readjust destination */ |
| |
| /* byte aligned destination (long + 3) */ |
| .align 2 |
| .loop_do3: |
| mov.l @r5+,r1 /* load first long & increment source addr */ |
| add #16,r4 /* increment dest addr */ |
| mov.l @r5+,r0 /* load second long & increment source addr */ |
| mov r1,r2 /* copy first long */ |
| mov.b r0,@-r4 /* store low byte of second long */ |
| shlr8 r0 /* get middle 2 bytes */ |
| mov.w r0,@-r4 /* store as word */ |
| shlr16 r0 /* get upper byte */ |
| shll8 r2 /* move lower 3 bytes of first long one up.. */ |
| or r2,r0 /* ..combine with the 1 byte of second long.. */ |
| mov.l r0,@-r4 /* ..and store as long */ |
| shlr16 r1 /* get upper byte of first long.. */ |
| shlr8 r1 |
| cmp/hi r5,r3 /* runs r5 up to last or second last long bound */ |
| mov.b r1,@-r4 /* ..and store */ |
| bt .loop_do3 |
| |
| bra .last_do13 /* handle last longword: reuse routine for (long + 1) */ |
| add #4,r3 /* readjust end address */ |
| |
| /* trailing byte loop: copies 0..3 bytes (or all for < 11 in total) */ |
| .align 2 |
| .loop_b2: |
| mov.b @r5+,r0 /* load byte & increment source addr */ |
| add #1,r4 /* increment dest addr */ |
| mov.b r0,@(7,r4) /* store byte */ |
| .start_b2: |
| cmp/hi r5,r6 /* runs r5 up to end address */ |
| bt .loop_b2 |
| |
| rts |
| mov r7,r0 /* return dest start address */ |
| .end: |
| .size _memcpy,.end-_memcpy |