--- /dev/null
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis
+
+declare void %llvm.memmove(sbyte*, sbyte*, uint, uint)
+declare void %llvm.memcpy(sbyte*, sbyte*, uint, uint)
+declare void %llvm.memset(sbyte*, ubyte, uint, uint)
+
+%X = global sbyte 0
+%Y = global sbyte 12
+
+void %zero_byte_test() {
+ ; These process zero bytes, so they are a noop.
+ call void %llvm.memmove(sbyte* %X, sbyte* %Y, uint 0, uint 100)
+ call void %llvm.memcpy(sbyte* %X, sbyte* %Y, uint 0, uint 100)
+ call void %llvm.memset(sbyte* %X, ubyte 123, uint 0, uint 100)
+ ret void
+}
+