1/* strlen.S: Sparc optimized strlen code 2 * Hand optimized from GNU libc's strlen 3 * Copyright (C) 1991,1996 Free Software Foundation 4 * Copyright (C) 1996,2008 David S. Miller (davem@davemloft.net) 5 * Copyright (C) 1996, 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) 6 */ 7 8#include <linux/linkage.h> 9#include <asm/asm.h> 10 11#define LO_MAGIC 0x01010101 12#define HI_MAGIC 0x80808080 13 14 .text 15ENTRY(strlen) 16 mov %o0, %o1 17 andcc %o0, 3, %g0 18 BRANCH32(be, pt, 9f) 19 sethi %hi(HI_MAGIC), %o4 20 ldub [%o0], %o5 21 BRANCH_REG_ZERO(pn, %o5, 11f) 22 add %o0, 1, %o0 23 andcc %o0, 3, %g0 24 BRANCH32(be, pn, 4f) 25 or %o4, %lo(HI_MAGIC), %o3 26 ldub [%o0], %o5 27 BRANCH_REG_ZERO(pn, %o5, 12f) 28 add %o0, 1, %o0 29 andcc %o0, 3, %g0 30 BRANCH32(be, pt, 5f) 31 sethi %hi(LO_MAGIC), %o4 32 ldub [%o0], %o5 33 BRANCH_REG_ZERO(pn, %o5, 13f) 34 add %o0, 1, %o0 35 BRANCH32(ba, pt, 8f) 36 or %o4, %lo(LO_MAGIC), %o2 379: 38 or %o4, %lo(HI_MAGIC), %o3 394: 40 sethi %hi(LO_MAGIC), %o4 415: 42 or %o4, %lo(LO_MAGIC), %o2 438: 44 ld [%o0], %o5 452: 46 sub %o5, %o2, %o4 47 andcc %o4, %o3, %g0 48 BRANCH32(be, pt, 8b) 49 add %o0, 4, %o0 50 51 /* Check every byte. */ 52 srl %o5, 24, %g7 53 andcc %g7, 0xff, %g0 54 BRANCH32(be, pn, 1f) 55 add %o0, -4, %o4 56 srl %o5, 16, %g7 57 andcc %g7, 0xff, %g0 58 BRANCH32(be, pn, 1f) 59 add %o4, 1, %o4 60 srl %o5, 8, %g7 61 andcc %g7, 0xff, %g0 62 BRANCH32(be, pn, 1f) 63 add %o4, 1, %o4 64 andcc %o5, 0xff, %g0 65 BRANCH32_ANNUL(bne, pt, 2b) 66 ld [%o0], %o5 67 add %o4, 1, %o4 681: 69 retl 70 sub %o4, %o1, %o0 7111: 72 retl 73 mov 0, %o0 7412: 75 retl 76 mov 1, %o0 7713: 78 retl 79 mov 2, %o0 80ENDPROC(strlen) 81