New testcase, the optimizer can delete zero sized allocas

llvm-svn: 12506

llvm/test/Regression/Transforms/InstCombine/alloca.ll

@@ -0,0 +1,14 @@
+; Zero byte allocas should be deleted.
+
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep alloca
+
+declare void %use(...)
+void %test() {
+	%X = alloca [0 x int]
+	call void(...)* %use([0 x int] *%X)
+	%Y = alloca int, uint 0
+	call void(...)* %use(int* %Y)
+	%Z = alloca {}
+	call void(...)* %use({}* %Z)
+	ret void
+}