1/*
  2 *  linux/arch/m32r/strlen.S --  strlen code.
  3 *
  4 *  Copyright (C) 2001  Hirokazu Takata
  5 *
  6 *  size_t strlen(const char *s);
  7 *
  8 */
  9
 10#include <linux/linkage.h>
 11#include <asm/assembler.h>
 12
 13#ifdef CONFIG_ISA_DUAL_ISSUE
 14
 15	.text
 16ENTRY(strlen)
 17	mv	r6, r0		    ||	ldi	r2, #0
 18	and3	r0, r0, #3
 19	bnez	r0, strlen_byte
 20;
 21strlen_word:
 22	ld	r0, @r6+
 23;
 24	seth	r5, #high(0x01010101)
 25	or3	r5, r5, #low(0x01010101)
 26	sll3	r7, r5, #7
 27strlen_word_loop:
 28	ld	r1, @r6+	    ||	not	r4, r0
 29	sub	r0, r5		    ||	and	r4, r7
 30	and	r4, r0
 31	bnez	r4, strlen_last_bytes
 32	ld	r0, @r6+	    ||	not	r4, r1
 33	sub	r1, r5		    ||	and	r4, r7
 34	and	r4, r1		    ||	addi	r2, #4
 35	bnez	r4, strlen_last_bytes
 36	addi	r2, #4		    ||	bra.s	strlen_word_loop
 37
 38	; NOTE: If a null char. exists, return 0.
 39	; if ((x - 0x01010101) & ~x & 0x80808080)
 40	;     return 0;
 41;
 42strlen_byte:
 43	ldb	r1, @r6		    ||	addi	r6, #1
 44	beqz	r1, strlen_exit
 45	addi	r2, #1		    ||	bra.s	strlen_byte
 46;
 47strlen_last_bytes:
 48	ldi	r0, #4		    ||	addi	r6, #-8
 49;
 50strlen_byte_loop:
 51	ldb	r1, @r6		    ||	addi	r6, #1
 52	addi	r0, #-1		    ||  cmpz	r1
 53	bc.s	strlen_exit	    ||  cmpz	r0
 54	addi	r2, #1		    ||	bnc.s	strlen_byte_loop
 55;
 56strlen_exit:
 57	mv	r0, r2		    ||	jmp	r14
 58
 59#else /* not CONFIG_ISA_DUAL_ISSUE */
 60
 61	.text
 62ENTRY(strlen)
 63	mv	r6, r0
 64	ldi	r2, #0
 65	and3	r0, r0, #3
 66	bnez	r0, strlen_byte
 67;
 68strlen_word:
 69	ld	r0, @r6+
 70;
 71	seth	r5, #high(0x01010101)
 72	or3	r5, r5, #low(0x01010101)
 73	sll3	r7, r5, #7
 74strlen_word_loop:
 75	ld	r1, @r6+
 76	not	r4, r0		; NOTE: If a null char. exists, return 0.
 77	sub	r0, r5		; if ((x - 0x01010101) & ~x & 0x80808080)
 78	and	r4, r7		;     return 0;
 79	and	r4, r0
 80	bnez	r4, strlen_last_bytes
 81	addi	r2, #4
 82;
 83	ld	r0, @r6+
 84	not	r4, r1		; NOTE: If a null char. exists, return 0.
 85	sub	r1, r5		; if ((x - 0x01010101) & ~x & 0x80808080)
 86	and	r4, r7		;     return 0;
 87	and	r4, r1
 88	bnez	r4, strlen_last_bytes
 89	addi	r2, #4
 90	bra	strlen_word_loop
 91;
 92strlen_byte:
 93	ldb	r1, @r6
 94	addi	r6, #1
 95	beqz	r1, strlen_exit
 96	addi	r2, #1
 97	bra	strlen_byte
 98;
 99strlen_last_bytes:
100	ldi	r0, #4
101	addi	r6, #-8
102;
103strlen_byte_loop:
104	ldb	r1, @r6
105	addi	r6, #1
106	addi	r0, #-1
107	beqz	r1, strlen_exit
108	addi	r2, #1
109	bnez	r0, strlen_byte_loop
110;
111strlen_exit:
112	mv	r0, r2
113	jmp	r14
114
115#endif /* not CONFIG_ISA_DUAL_ISSUE */
116
117	.end