diff options
Diffstat (limited to 'arch/sparc/lib/strlen.S')
| -rw-r--r-- | arch/sparc/lib/strlen.S | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/sparc/lib/strlen.S b/arch/sparc/lib/strlen.S new file mode 100644 index 000000000..27478b3f1 --- /dev/null +++ b/arch/sparc/lib/strlen.S @@ -0,0 +1,83 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* strlen.S: Sparc optimized strlen code + * Hand optimized from GNU libc's strlen + * Copyright (C) 1991,1996 Free Software Foundation + * Copyright (C) 1996,2008 David S. Miller (davem@davemloft.net) + * Copyright (C) 1996, 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) + */ + +#include <linux/export.h> +#include <linux/linkage.h> +#include <asm/asm.h> + +#define LO_MAGIC 0x01010101 +#define HI_MAGIC 0x80808080 + + .text +ENTRY(strlen) + mov %o0, %o1 + andcc %o0, 3, %g0 + BRANCH32(be, pt, 9f) + sethi %hi(HI_MAGIC), %o4 + ldub [%o0], %o5 + BRANCH_REG_ZERO(pn, %o5, 11f) + add %o0, 1, %o0 + andcc %o0, 3, %g0 + BRANCH32(be, pn, 4f) + or %o4, %lo(HI_MAGIC), %o3 + ldub [%o0], %o5 + BRANCH_REG_ZERO(pn, %o5, 12f) + add %o0, 1, %o0 + andcc %o0, 3, %g0 + BRANCH32(be, pt, 5f) + sethi %hi(LO_MAGIC), %o4 + ldub [%o0], %o5 + BRANCH_REG_ZERO(pn, %o5, 13f) + add %o0, 1, %o0 + BRANCH32(ba, pt, 8f) + or %o4, %lo(LO_MAGIC), %o2 +9: + or %o4, %lo(HI_MAGIC), %o3 +4: + sethi %hi(LO_MAGIC), %o4 +5: + or %o4, %lo(LO_MAGIC), %o2 +8: + ld [%o0], %o5 +2: + sub %o5, %o2, %o4 + andcc %o4, %o3, %g0 + BRANCH32(be, pt, 8b) + add %o0, 4, %o0 + + /* Check every byte. */ + srl %o5, 24, %g7 + andcc %g7, 0xff, %g0 + BRANCH32(be, pn, 1f) + add %o0, -4, %o4 + srl %o5, 16, %g7 + andcc %g7, 0xff, %g0 + BRANCH32(be, pn, 1f) + add %o4, 1, %o4 + srl %o5, 8, %g7 + andcc %g7, 0xff, %g0 + BRANCH32(be, pn, 1f) + add %o4, 1, %o4 + andcc %o5, 0xff, %g0 + BRANCH32_ANNUL(bne, pt, 2b) + ld [%o0], %o5 + add %o4, 1, %o4 +1: + retl + sub %o4, %o1, %o0 +11: + retl + mov 0, %o0 +12: + retl + mov 1, %o0 +13: + retl + mov 2, %o0 +ENDPROC(strlen) +EXPORT_SYMBOL(strlen) |