added a unit test case for the adder circuit compilation

Signed-off-by: Thien Nguyen <nguyentm@ornl.gov>

mlir/parsers/qasm3/tests/test_subroutine.cpp

@@ -84,6 +84,70 @@ print("Avg <X0X1> = ", exp_val);
   EXPECT_FALSE(qcor::execute(sub1, "check_deuteron"));
 }
 
+TEST(qasm3VisitorTester, checkSubroutineAdder) {
+  const std::string sub1 = R"#(OPENQASM 3;
+gate ccx a,b,c
+{
+  h c;
+  cx b,c; tdg c;
+  cx a,c; t c;
+  cx b,c; tdg c;
+  cx a,c; t b; t c; h c;
+  cx a,b; t a; tdg b;
+  cx a,b;
+}
+
+gate majority a, b, c {
+  cx c, b;
+  cx c, a;
+  ccx a, b, c;
+}
+
+gate unmaj a, b, c {
+  ccx a, b, c;
+  cx c, a;
+  cx a, b;
+}
+
+qubit cin;
+qubit a[8];
+qubit b[8];
+qubit cout;
+bit ans[9];
+// Input values:
+uint[8] a_in = 5;  
+uint[8] b_in = 4; 
+
+for i in [0:8] {  
+  if (bool(a_in[i])) {
+    x a[i];
+  }
+  if (bool(b_in[i])) {
+    x b[i];
+  }
+}
+// add a to b, storing result in b
+majority cin, b[0], a[0];
+
+for i in [0: 7] { 
+  majority a[i], b[i + 1], a[i + 1]; 
+}
+
+cx a[7], cout;
+
+for i in [6: -1: -1] { 
+  unmaj a[i], b[i+1], a[i+1]; 
+}
+unmaj cin, b[0], a[0];
+
+measure b[0:7] -> ans[0:7];
+measure cout[0] -> ans[8];)#";
+  auto llvm_ir = qcor::mlir_compile(sub1, "check_deuteron",
+                                    qcor::OutputType::LLVMIR, false);
+
+  std::cout << llvm_ir << "\n";
+}
+
 int main(int argc, char **argv) {
   ::testing::InitGoogleTest(&argc, argv);
   auto ret = RUN_ALL_TESTS();