diff options
Diffstat (limited to 'arch/m32r/lib/strlen.S')
-rw-r--r-- | arch/m32r/lib/strlen.S | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/arch/m32r/lib/strlen.S b/arch/m32r/lib/strlen.S new file mode 100644 index 0000000..8d23cfb --- /dev/null +++ b/arch/m32r/lib/strlen.S @@ -0,0 +1,120 @@ +/* + * linux/arch/m32r/strlen.S -- strlen code. + * + * Copyright (C) 2001 Hirokazu Takata + * + * size_t strlen(const char *s); + * + */ +/* $Id$ */ + + +#include <linux/config.h> +#include <linux/linkage.h> +#include <asm/assembler.h> + +#ifdef CONFIG_ISA_DUAL_ISSUE + + .text +ENTRY(strlen) + mv r6, r0 || ldi r2, #0 + and3 r0, r0, #3 + bnez r0, strlen_byte +; +strlen_word: + ld r0, @r6+ +; + seth r5, #high(0x01010101) + or3 r5, r5, #low(0x01010101) + sll3 r7, r5, #7 +strlen_word_loop: + ld r1, @r6+ || not r4, r0 + sub r0, r5 || and r4, r7 + and r4, r0 + bnez r4, strlen_last_bytes + ld r0, @r6+ || not r4, r1 + sub r1, r5 || and r4, r7 + and r4, r1 || addi r2, #4 + bnez r4, strlen_last_bytes + addi r2, #4 || bra.s strlen_word_loop + + ; NOTE: If a null char. exists, return 0. + ; if ((x - 0x01010101) & ~x & 0x80808080) + ; return 0; +; +strlen_byte: + ldb r1, @r6 || addi r6, #1 + beqz r1, strlen_exit + addi r2, #1 || bra.s strlen_byte +; +strlen_last_bytes: + ldi r0, #4 || addi r6, #-8 +; +strlen_byte_loop: + ldb r1, @r6 || addi r6, #1 + addi r0, #-1 || cmpz r1 + bc.s strlen_exit || cmpz r0 + addi r2, #1 || bnc.s strlen_byte_loop +; +strlen_exit: + mv r0, r2 || jmp r14 + +#else /* not CONFIG_ISA_DUAL_ISSUE */ + + .text +ENTRY(strlen) + mv r6, r0 + ldi r2, #0 + and3 r0, r0, #3 + bnez r0, strlen_byte +; +strlen_word: + ld r0, @r6+ +; + seth r5, #high(0x01010101) + or3 r5, r5, #low(0x01010101) + sll3 r7, r5, #7 +strlen_word_loop: + ld r1, @r6+ + not r4, r0 ; NOTE: If a null char. exists, return 0. + sub r0, r5 ; if ((x - 0x01010101) & ~x & 0x80808080) + and r4, r7 ; return 0; + and r4, r0 + bnez r4, strlen_last_bytes + addi r2, #4 +; + ld r0, @r6+ + not r4, r1 ; NOTE: If a null char. exists, return 0. + sub r1, r5 ; if ((x - 0x01010101) & ~x & 0x80808080) + and r4, r7 ; return 0; + and r4, r1 + bnez r4, strlen_last_bytes + addi r2, #4 + bra strlen_word_loop +; +strlen_byte: + ldb r1, @r6 + addi r6, #1 + beqz r1, strlen_exit + addi r2, #1 + bra strlen_byte +; +strlen_last_bytes: + ldi r0, #4 + addi r6, #-8 +; +strlen_byte_loop: + ldb r1, @r6 + addi r6, #1 + addi r0, #-1 + beqz r1, strlen_exit + addi r2, #1 + bnez r0, strlen_byte_loop +; +strlen_exit: + mv r0, r2 + jmp r14 + +#endif /* not CONFIG_ISA_DUAL_ISSUE */ + + .end |