+; RUN: llvm-as < %s | opt -simplify-libcalls -disable-output
+; PR4645
+
+define i32 @main() {
+entry:
+ br label %if.then
+
+lor.lhs.false: ; preds = %while.body
+ br i1 undef, label %if.then, label %for.cond
+
+if.then: ; preds = %lor.lhs.false, %while.body
+ call void @exit(i32 1)
+ br label %for.cond
+
+for.cond: ; preds = %for.end, %if.then, %lor.lhs.false
+ %j.0 = phi i32 [ %inc47, %for.end ], [ 0, %if.then ], [ 0, %lor.lhs.false ] ; <i32> [#uses=1]
+ unreachable
+
+for.end: ; preds = %for.cond20
+ %inc47 = add i32 %j.0, 1 ; <i32> [#uses=1]
+ br label %for.cond
+}
+
+declare void @exit(i32)