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- /* $Id: memset.S,v 1.1 2000/04/14 16:49:01 mjd Exp $
- *
- * "memset" implementation of SuperH
- *
- * Copyright (C) 1999 Niibe Yutaka
- *
- */
- /*
- * void *memset(void *s, int c, size_t n);
- */
- #include <linux/linkage.h>
- ENTRY(memset)
- tst r6,r6
- bt/s 5f ! if n=0, do nothing
- add r6,r4
- mov #12,r0
- cmp/gt r6,r0
- bt/s 4f ! 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
- !
- mov r6,r0
- 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
- tst r6,r6
- bt 5f
- ! fill bytes
- 4:
- dt r6
- bf/s 4b
- mov.b r5,@-r4
- 5:
- rts
- mov r4,r0
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