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| /*
| * linux/arch/m32r/strlen.S -- strlen code.
| *
| * Copyright (C) 2001 Hirokazu Takata
| *
| * size_t strlen(const char *s);
| *
| */
|
| #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
|
|
