| /* $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 |
