diff options
Diffstat (limited to 'carl9170fw/carlfw/src/memset.S')
-rw-r--r-- | carl9170fw/carlfw/src/memset.S | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/carl9170fw/carlfw/src/memset.S b/carl9170fw/carlfw/src/memset.S new file mode 100644 index 0000000..d39c8a6 --- /dev/null +++ b/carl9170fw/carlfw/src/memset.S @@ -0,0 +1,58 @@ +/* $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); + */ + + .globl _memset + .align 2 + _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 |