Add an asm version of strlen() for arm (how useful).

2 files changed, 78 insertions, 1 deletions

diff --git a/lib/libc/arm/string/Makefile.inc b/lib/libc/arm/string/Makefile.inc
index 7b73e58..6658ce7 100644
--- a/lib/libc/arm/string/Makefile.inc
+++ b/lib/libc/arm/string/Makefile.inc
@@ -3,5 +3,5 @@
 
 MDSRCS+=bcmp.c bcopy.S bzero.S ffs.S index.c memchr.c memcmp.S memcpy.S \
 	memmove.S memset.S rindex.c strcat.c strchr.c strcmp.S strcpy.c \
-	strlen.c strncmp.S strrchr.c swab.c wcschr.c wcscmp.c wcslen.c \
+	strlen.S strncmp.S strrchr.c swab.c wcschr.c wcscmp.c wcslen.c \
 	wmemchr.c
diff --git a/lib/libc/arm/string/strlen.S b/lib/libc/arm/string/strlen.S
new file mode 100644
index 0000000..fa503e9
--- /dev/null
+++ b/lib/libc/arm/string/strlen.S
@@ -0,0 +1,77 @@
+/*-
+ * Copyright (c) 2005 Olivier Houchard
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright             *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <machine/asm.h>
+__FBSDID("$FreeBSD$");
+
+ENTRY(strlen)
+	mov	r1, #0
+	/* Check that the pointer is aligned on 32 bits. */
+	ands	r3, r0, #3
+	beq	.Loop
+	sub	r0, r0, r3
+	ldr	r2, [r0]
+	add	r0, r0, #4
+	cmp	r3, #2
+	blt	.Ldo_3
+	bgt	.Ldo_1
+	/* So that the N bit is set. */
+	cmp	r3, #0
+	b	.Ldo_2
+
+.Loop:
+	ldr	r2, [r0]
+	add	r0, r0, #4
+#ifndef __ARMEB__
+	ands	r3, r2, #0x000000ff
+#else
+	ands	r3, r2, #0xff000000
+#endif
+	addne	r1, r1, #1
+.Ldo_3:
+#ifndef __ARMEB__
+	andnes    r3, r2, #0x0000ff00
+#else
+  	andnes    r3, r2, #0x00ff0000
+#endif  
+	addne     r1, r1, #1
+.Ldo_2:
+#ifndef __ARMEB__
+	andnes    r3, r2, #0x00ff0000
+#else
+	andnes    r3, r2, #0x0000ff00
+#endif  
+	addne	r1, r1, #1
+.Ldo_1:
+#ifndef __ARMEB__
+	andnes	r3, r2, #0xff000000
+#else
+	andnes	r3, r2, #0x000000ff
+#endif  
+	addne	r1, r1, #1
+	bne	.Loop				
+.Lexit:
+	mov	r0, r1
+	RET