monitor: add repeat loop test without a fork problem

Author: ekiwi

monitor/tests/adders/add_var_cyc.err

@@ -0,0 +1,27 @@
+// trace 0
+trace {
+    loop_add(1, 2, 3, 2);
+    loop_add(10, 20, 30, 0);
+}
+
+// trace 1
+trace {
+    loop_add(1, 2, 3, 0);
+    loop_add(1, 2, 3, 1);
+    loop_add(10, 20, 30, 0);
+}
+
+// trace 2
+trace {
+    loop_add(1, 2, 3, 1);
+    loop_add(1, 2, 3, 0);
+    loop_add(10, 20, 30, 0);
+}
+
+// trace 3
+trace {
+    loop_add(1, 2, 3, 0);
+    loop_add(1, 2, 3, 0);
+    loop_add(1, 2, 3, 0);
+    loop_add(10, 20, 30, 0);
+}

monitor/tests/adders/add_var_cyc.out

@@ -0,0 +1,26 @@
+// ARGS: --wave adders/loop_with_assigns.fst --instances add_d1:Adder
+struct Adder {
+  in a: u32,
+  in b: u32,
+  out s: u32,
+}
+
+prot loop_add<DUT: Adder>(a: u32, b: u32, s: u32, extra_cycles: uint) {
+  // first cycle
+  DUT.a := a;
+  DUT.b := b;
+  step();
+
+  // extra cycles (keeping inputs constant)
+  repeat extra_cycles iterations {
+    assert_eq(s, DUT.s);
+    step();
+  }
+
+  // final cycle
+  DUT.a := X;
+  DUT.b := X;
+  assert_eq(s, DUT.s);
+  fork();
+  step();
+}