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-rw-r--r--arch/m32r/lib/strlen.S120
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
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+++ b/arch/m32r/lib/strlen.S
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+/*
+ * 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