| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | /* strlen.S: Sparc optimized strlen code |
| 3 | * Hand optimized from GNU libc's strlen |
| 4 | * Copyright (C) 1991,1996 Free Software Foundation |
| 5 | * Copyright (C) 1996,2008 David S. Miller (davem@davemloft.net) |
| 6 | * Copyright (C) 1996, 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) |
| 7 | */ |
| 8 | |
| 9 | #include <linux/linkage.h> |
| 10 | #include <asm/asm.h> |
| 11 | #include <asm/export.h> |
| 12 | |
| 13 | #define LO_MAGIC 0x01010101 |
| 14 | #define HI_MAGIC 0x80808080 |
| 15 | |
| 16 | .text |
| 17 | ENTRY(strlen) |
| 18 | mov %o0, %o1 |
| 19 | andcc %o0, 3, %g0 |
| 20 | BRANCH32(be, pt, 9f) |
| 21 | sethi %hi(HI_MAGIC), %o4 |
| 22 | ldub [%o0], %o5 |
| 23 | BRANCH_REG_ZERO(pn, %o5, 11f) |
| 24 | add %o0, 1, %o0 |
| 25 | andcc %o0, 3, %g0 |
| 26 | BRANCH32(be, pn, 4f) |
| 27 | or %o4, %lo(HI_MAGIC), %o3 |
| 28 | ldub [%o0], %o5 |
| 29 | BRANCH_REG_ZERO(pn, %o5, 12f) |
| 30 | add %o0, 1, %o0 |
| 31 | andcc %o0, 3, %g0 |
| 32 | BRANCH32(be, pt, 5f) |
| 33 | sethi %hi(LO_MAGIC), %o4 |
| 34 | ldub [%o0], %o5 |
| 35 | BRANCH_REG_ZERO(pn, %o5, 13f) |
| 36 | add %o0, 1, %o0 |
| 37 | BRANCH32(ba, pt, 8f) |
| 38 | or %o4, %lo(LO_MAGIC), %o2 |
| 39 | 9: |
| 40 | or %o4, %lo(HI_MAGIC), %o3 |
| 41 | 4: |
| 42 | sethi %hi(LO_MAGIC), %o4 |
| 43 | 5: |
| 44 | or %o4, %lo(LO_MAGIC), %o2 |
| 45 | 8: |
| 46 | ld [%o0], %o5 |
| 47 | 2: |
| 48 | sub %o5, %o2, %o4 |
| 49 | andcc %o4, %o3, %g0 |
| 50 | BRANCH32(be, pt, 8b) |
| 51 | add %o0, 4, %o0 |
| 52 | |
| 53 | /* Check every byte. */ |
| 54 | srl %o5, 24, %g7 |
| 55 | andcc %g7, 0xff, %g0 |
| 56 | BRANCH32(be, pn, 1f) |
| 57 | add %o0, -4, %o4 |
| 58 | srl %o5, 16, %g7 |
| 59 | andcc %g7, 0xff, %g0 |
| 60 | BRANCH32(be, pn, 1f) |
| 61 | add %o4, 1, %o4 |
| 62 | srl %o5, 8, %g7 |
| 63 | andcc %g7, 0xff, %g0 |
| 64 | BRANCH32(be, pn, 1f) |
| 65 | add %o4, 1, %o4 |
| 66 | andcc %o5, 0xff, %g0 |
| 67 | BRANCH32_ANNUL(bne, pt, 2b) |
| 68 | ld [%o0], %o5 |
| 69 | add %o4, 1, %o4 |
| 70 | 1: |
| 71 | retl |
| 72 | sub %o4, %o1, %o0 |
| 73 | 11: |
| 74 | retl |
| 75 | mov 0, %o0 |
| 76 | 12: |
| 77 | retl |
| 78 | mov 1, %o0 |
| 79 | 13: |
| 80 | retl |
| 81 | mov 2, %o0 |
| 82 | ENDPROC(strlen) |
| 83 | EXPORT_SYMBOL(strlen) |