summaryrefslogtreecommitdiffstats
path: root/kernel/arch/sh/lib/strlen.S
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/arch/sh/lib/strlen.S')
-rw-r--r--kernel/arch/sh/lib/strlen.S70
1 files changed, 70 insertions, 0 deletions
diff --git a/kernel/arch/sh/lib/strlen.S b/kernel/arch/sh/lib/strlen.S
new file mode 100644
index 000000000..1bcc13f05
--- /dev/null
+++ b/kernel/arch/sh/lib/strlen.S
@@ -0,0 +1,70 @@
+/* $Id: strlen.S,v 1.2 2001/06/29 14:07:15 gniibe Exp $
+ *
+ * "strlen" implementation of SuperH
+ *
+ * Copyright (C) 1999 Kaz Kojima
+ *
+ */
+
+/* size_t strlen (const char *s) */
+
+#include <linux/linkage.h>
+ENTRY(strlen)
+ mov r4,r0
+ and #3,r0
+ tst r0,r0
+ bt/s 1f
+ mov #0,r2
+
+ add #-1,r0
+ shll2 r0
+ shll r0
+ braf r0
+ nop
+
+ mov.b @r4+,r1
+ tst r1,r1
+ bt 8f
+ add #1,r2
+
+ mov.b @r4+,r1
+ tst r1,r1
+ bt 8f
+ add #1,r2
+
+ mov.b @r4+,r1
+ tst r1,r1
+ bt 8f
+ add #1,r2
+
+1:
+ mov #0,r3
+2:
+ mov.l @r4+,r1
+ cmp/str r3,r1
+ bf/s 2b
+ add #4,r2
+
+ add #-4,r2
+#ifndef __LITTLE_ENDIAN__
+ swap.b r1,r1
+ swap.w r1,r1
+ swap.b r1,r1
+#endif
+ extu.b r1,r0
+ tst r0,r0
+ bt/s 8f
+ shlr8 r1
+ add #1,r2
+ extu.b r1,r0
+ tst r0,r0
+ bt/s 8f
+ shlr8 r1
+ add #1,r2
+ extu.b r1,r0
+ tst r0,r0
+ bt 8f
+ add #1,r2
+8:
+ rts
+ mov r2,r0