| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* $Id: memset.S,v 1.1 2000/04/14 16:49:01 mjd Exp $ |
| 2 | * |
| 3 | * "memset" implementation of SuperH |
| 4 | * |
| 5 | * Copyright (C) 1999 Niibe Yutaka |
| 6 | * |
| 7 | */ |
| 8 | |
| 9 | /* |
| 10 | * void *memset(void *s, int c, size_t n); |
| 11 | */ |
| 12 | |
| 13 | #include <linux/linkage.h> |
| 14 | |
| 15 | ENTRY(memset) |
| 16 | tst r6,r6 |
| 17 | bt/s 5f ! if n=0, do nothing |
| 18 | add r6,r4 |
| 19 | mov #12,r0 |
| 20 | cmp/gt r6,r0 |
| 21 | bt/s 4f ! if it's too small, set a byte at once |
| 22 | mov r4,r0 |
| 23 | and #3,r0 |
| 24 | cmp/eq #0,r0 |
| 25 | bt/s 2f ! It's aligned |
| 26 | sub r0,r6 |
| 27 | 1: |
| 28 | dt r0 |
| 29 | bf/s 1b |
| 30 | mov.b r5,@-r4 |
| 31 | 2: ! make VVVV |
| 32 | swap.b r5,r0 ! V0 |
| 33 | or r0,r5 ! VV |
| 34 | swap.w r5,r0 ! VV00 |
| 35 | or r0,r5 ! VVVV |
| 36 | ! |
| 37 | mov r6,r0 |
| 38 | shlr2 r0 |
| 39 | shlr r0 ! r0 = r6 >> 3 |
| 40 | 3: |
| 41 | dt r0 |
| 42 | mov.l r5,@-r4 ! set 8-byte at once |
| 43 | bf/s 3b |
| 44 | mov.l r5,@-r4 |
| 45 | ! |
| 46 | mov #7,r0 |
| 47 | and r0,r6 |
| 48 | tst r6,r6 |
| 49 | bt 5f |
| 50 | ! fill bytes |
| 51 | 4: |
| 52 | dt r6 |
| 53 | bf/s 4b |
| 54 | mov.b r5,@-r4 |
| 55 | 5: |
| 56 | rts |
| 57 | mov r4,r0 |