Add new test to make sure simplifycfg doesn't leave around trivially

dead instructions.

llvm-svn: 19211

llvm/test/Regression/Transforms/SimplifyCFG/DeadSetCC.ll

@@ -0,0 +1,26 @@
+; RUN: llvm-as < %s | opt -simplifycfg | llvm-dis | not grep seteq
+
+; Check that simplifycfg deletes a dead 'seteq' instruction when it
+; folds a conditional branch into a switch instruction.
+
+declare void %foo()
+declare void %bar()
+
+void %testcfg(uint %V) {
+	%C = seteq uint %V, 18
+	%D = seteq uint %V, 180
+	%E = or bool %C, %D
+	br bool %E, label %L1, label %Sw
+Sw:
+       switch uint %V, label %L1 [
+              uint 15, label %L2
+              uint 16, label %L2
+        ]
+L1:
+	call void %foo()
+	ret void
+L2:
+	call void %bar()
+	ret void
+}
+