/* | |
* "memset" implementation for SH4 | |
* | |
* Copyright (C) 1999 Niibe Yutaka | |
* Copyright (c) 2009 STMicroelectronics Limited | |
* Author: Stuart Menefy <stuart.menefy:st.com> | |
*/ | |
/* | |
* void *memset(void *s, int c, size_t n); | |
*/ | |
#include <linux/linkage.h> | |
ENTRY(memset) | |
mov #12,r0 | |
add r6,r4 | |
cmp/gt r6,r0 | |
bt/s 40f ! if it's too small, set a byte at once | |
mov r4,r0 | |
and #3,r0 | |
cmp/eq #0,r0 | |
bt/s 2f ! It's aligned | |
sub r0,r6 | |
1: | |
dt r0 | |
bf/s 1b | |
mov.b r5,@-r4 | |
2: ! make VVVV | |
extu.b r5,r5 | |
swap.b r5,r0 ! V0 | |
or r0,r5 ! VV | |
swap.w r5,r0 ! VV00 | |
or r0,r5 ! VVVV | |
! Check if enough bytes need to be copied to be worth the big loop | |
mov #0x40, r0 ! (MT) | |
cmp/gt r6,r0 ! (MT) 64 > len => slow loop | |
bt/s 22f | |
mov r6,r0 | |
! align the dst to the cache block size if necessary | |
mov r4, r3 | |
mov #~(0x1f), r1 | |
and r3, r1 | |
cmp/eq r3, r1 | |
bt/s 11f ! dst is already aligned | |
sub r1, r3 ! r3-r1 -> r3 | |
shlr2 r3 ! number of loops | |
10: mov.l r5,@-r4 | |
dt r3 | |
bf/s 10b | |
add #-4, r6 | |
11: ! dst is 32byte aligned | |
mov r6,r2 | |
mov #-5,r0 | |
shld r0,r2 ! number of loops | |
add #-32, r4 | |
mov r5, r0 | |
12: | |
movca.l r0,@r4 | |
mov.l r5,@(4, r4) | |
mov.l r5,@(8, r4) | |
mov.l r5,@(12,r4) | |
mov.l r5,@(16,r4) | |
mov.l r5,@(20,r4) | |
add #-0x20, r6 | |
mov.l r5,@(24,r4) | |
dt r2 | |
mov.l r5,@(28,r4) | |
bf/s 12b | |
add #-32, r4 | |
add #32, r4 | |
mov #8, r0 | |
cmp/ge r0, r6 | |
bf 40f | |
mov r6,r0 | |
22: | |
shlr2 r0 | |
shlr r0 ! r0 = r6 >> 3 | |
3: | |
dt r0 | |
mov.l r5,@-r4 ! set 8-byte at once | |
bf/s 3b | |
mov.l r5,@-r4 | |
! | |
mov #7,r0 | |
and r0,r6 | |
! fill bytes (length may be zero) | |
40: tst r6,r6 | |
bt 5f | |
4: | |
dt r6 | |
bf/s 4b | |
mov.b r5,@-r4 | |
5: | |
rts | |
mov r4,r0 |