New testcase for adce

llvm-svn: 2546

llvm/test/Regression/Transforms/ADCE/adcetest.ll

@@ -0,0 +1,37 @@
+; This is the test case taken from Appel's book that illustrates a hard case
+; that SCCP gets right, and when followed by ADCE, is completely eliminated
+;
+; RUN: if as < %s | opt -sccp -adce | dis | grep br
+; RUN: then exit 1
+; RUN: else exit 0
+; RUN: fi
+
+int "test function"(int %i0, int %j0) {
+BB1:
+	br label %BB2
+BB2:
+	%j2 = phi int [%j4, %BB7], [1, %BB1]
+	%k2 = phi int [%k4, %BB7], [0, %BB1]
+	%kcond = setlt int %k2, 100
+	br bool %kcond, label %BB3, label %BB4
+
+BB3:
+	%jcond = setlt int %j2, 20
+	br bool %jcond, label %BB5, label %BB6
+
+BB4:
+	ret int %j2
+
+BB5:
+	%k3 = add int %k2, 1
+	br label %BB7
+
+BB6:
+	%k5 = add int %k2, 1
+	br label %BB7
+
+BB7:
+	%j4 = phi int [1, %BB5], [%k2, %BB6]
+	%k4 = phi int [%k3, %BB5], [%k5, %BB6]
+	br label %BB2
+}