/*
* String handling functions for PowerPC.
*
* Copyright (C) 1996 Paul Mackerras.
*
* 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.
*/
#define r0 0
#define r3 3
#define r4 4
#define r5 5
#define r6 6
#define r7 7
#define r8 8
.globl strlen
strlen:
addi r4,r3,-1
1: lbzu r0,1(r4)
cmpwi 0,r0,0
bne 1b
subf r3,r3,r4
blr
.globl memset
memset:
rlwimi r4,r4,8,16,23
rlwimi r4,r4,16,0,15
addi r6,r3,-4
cmplwi 0,r5,4
blt 7f
stwu r4,4(r6)
beqlr
andi. r0,r6,3
add r5,r0,r5
subf r6,r0,r6
rlwinm r0,r5,32-2,2,31
mtctr r0
bdz 6f
1: stwu r4,4(r6)
bdnz 1b
6: andi. r5,r5,3
7: cmpwi 0,r5,0
beqlr
mtctr r5
addi r6,r6,3
8: stbu r4,1(r6)
bdnz 8b
blr
.globl memmove
memmove:
cmplw 0,r3,r4
bgt backwards_memcpy
/* fall through */
.globl memcpy
memcpy:
rlwinm. r7,r5,32-3,3,31 /* r0 = r5 >> 3 */
addi r6,r3,-4
addi r4,r4,-4
beq 2f /* if less than 8 bytes to do */
andi. r0,r6,3 /* get dest word aligned */
mtctr r7
bne 5f
1: lwz r7,4(r4)
lwzu r8,8(r4)
stw r7,4(r6)
stwu r8,8(r6)
bdnz 1b
andi. r5,r5,7
2: cmplwi 0,r5,4
blt 3f
lwzu r0,4(r4)
addi r5,r5,-4
stwu r0,4(r6)
3: cmpwi 0,r5,0
beqlr
mtctr r5
addi r4,r4,3
addi r6,r6,3
4: lbzu r0,1(r4)
stbu r0,1(r6)
bdnz 4b
blr
5: subfic r0,r0,4
mtctr r0
6: lbz r7,4(r4)
addi r4,r4,1
stb r7,4(r6)
addi r6,r6,1
bdnz 6b
subf r5,r0,r5
rlwinm. r7,r5,32-3,3,31
beq 2b
mtctr r7
b 1b
.globl backwards_memcpy
backwards_memcpy:
rlwinm. r7,r5,32-3,3,31 /* r0 = r5 >> 3 */
add r6,r3,r5
add r4,r4,r5
beq 2f
andi. r0,r6,3
mtctr r7
bne 5f
1: lwz r7,-4(r4)
lwzu r8,-8(r4)
stw r7,-4(r6)
stwu r8,-8(r6)
bdnz 1b
andi. r5,r5,7
2: cmplwi 0,r5,4
blt 3f
lwzu r0,-4(r4)
subi r5,r5,4
stwu r0,-4(r6)
3: cmpwi 0,r5,0
beqlr
mtctr r5
4: lbzu r0,-1(r4)
stbu r0,-1(r6)
bdnz 4b
blr
5: mtctr r0
6: lbzu r7,-1(r4)
stbu r7,-1(r6)
bdnz 6b
subf r5,r0,r5
rlwinm. r7,r5,32-3,3,31
beq 2b
mtctr r7
b 1b
.globl memcmp
memcmp:
cmpwi 0,r5,0
blelr
mtctr r5
addi r6,r3,-1
addi r4,r4,-1
1: lbzu r3,1(r6)
lbzu r0,1(r4)
subf. r3,r0,r3
bdnzt 2,1b
blr
