diff options
| author | Stuart Menefy <stuart.menefy@st.com> | 2009-10-27 15:14:06 +0000 |
|---|---|---|
| committer | Paul Mundt <lethal@linux-sh.org> | 2009-11-24 16:28:43 +0900 |
| commit | dfc349402de8e95f6a42e8341e9ea193b718eee3 (patch) | |
| tree | 7dfccd32dc3b5e0239f159dd3e94403f9b34501e /arch/sh/lib/memset-sh4.S | |
| parent | a0458b07c17a10ea316e6ae65ab15b78bf5f44ee (diff) | |
sh: Optimised memset for SH4
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>
Diffstat (limited to 'arch/sh/lib/memset-sh4.S')
| -rw-r--r-- | arch/sh/lib/memset-sh4.S | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/arch/sh/lib/memset-sh4.S b/arch/sh/lib/memset-sh4.S new file mode 100644 index 00000000000..1a6e32cc4e4 --- /dev/null +++ b/arch/sh/lib/memset-sh4.S @@ -0,0 +1,107 @@ +/* + * "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 |