dfc349402d
Optimised version of memset for the SH4 which uses movca.l. Signed-off-by: Stuart Menefy <stuart.menefy@st.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
107 lines
1.6 KiB
ArmAsm
107 lines
1.6 KiB
ArmAsm
/*
|
|
* "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
|