Index: memchr.S
===================================================================
RCS file: /cvs/src/src/newlib/libc/machine/aarch64/memchr.S,v
retrieving revision 1.1
diff -u -p -r1.1 memchr.S
--- memchr.S	11 Jul 2014 09:10:50 -0000	1.1
+++ memchr.S	19 Aug 2014 09:30:23 -0000
@@ -79,6 +79,8 @@
 	.endm
 
 def_fn memchr
+	/* Do not dereference srcin if no bytes to compare.  */
+	cbz	cntin, .Lzero_length
 	/*
 	 * Magic constant 0x40100401 allows us to identify which lane matches
 	 * the requested byte.
@@ -166,5 +168,9 @@ def_fn memchr
 	csel	result, xzr, result, eq
 	ret
 
+.Lzero_length:
+	mov	result, #0
+	ret
+
 	.size	memchr, . - memchr
 #endif