| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* $Id: strlen.S,v 1.2 2001/06/29 14:07:15 gniibe Exp $ |
| 2 | * |
| 3 | * "strlen" implementation of SuperH |
| 4 | * |
| 5 | * Copyright (C) 1999 Kaz Kojima |
| 6 | * |
| 7 | */ |
| 8 | |
| 9 | /* size_t strlen (const char *s) */ |
| 10 | |
| 11 | #include <linux/linkage.h> |
| 12 | ENTRY(strlen) |
| 13 | mov r4,r0 |
| 14 | and #3,r0 |
| 15 | tst r0,r0 |
| 16 | bt/s 1f |
| 17 | mov #0,r2 |
| 18 | |
| 19 | add #-1,r0 |
| 20 | shll2 r0 |
| 21 | shll r0 |
| 22 | braf r0 |
| 23 | nop |
| 24 | |
| 25 | mov.b @r4+,r1 |
| 26 | tst r1,r1 |
| 27 | bt 8f |
| 28 | add #1,r2 |
| 29 | |
| 30 | mov.b @r4+,r1 |
| 31 | tst r1,r1 |
| 32 | bt 8f |
| 33 | add #1,r2 |
| 34 | |
| 35 | mov.b @r4+,r1 |
| 36 | tst r1,r1 |
| 37 | bt 8f |
| 38 | add #1,r2 |
| 39 | |
| 40 | 1: |
| 41 | mov #0,r3 |
| 42 | 2: |
| 43 | mov.l @r4+,r1 |
| 44 | cmp/str r3,r1 |
| 45 | bf/s 2b |
| 46 | add #4,r2 |
| 47 | |
| 48 | add #-4,r2 |
| 49 | #ifndef __LITTLE_ENDIAN__ |
| 50 | swap.b r1,r1 |
| 51 | swap.w r1,r1 |
| 52 | swap.b r1,r1 |
| 53 | #endif |
| 54 | extu.b r1,r0 |
| 55 | tst r0,r0 |
| 56 | bt/s 8f |
| 57 | shlr8 r1 |
| 58 | add #1,r2 |
| 59 | extu.b r1,r0 |
| 60 | tst r0,r0 |
| 61 | bt/s 8f |
| 62 | shlr8 r1 |
| 63 | add #1,r2 |
| 64 | extu.b r1,r0 |
| 65 | tst r0,r0 |
| 66 | bt 8f |
| 67 | add #1,r2 |
| 68 | 8: |
| 69 | rts |
| 70 | mov r2,r0 |