Add extra test for memcell and cpustate

Checks for flags and register dependencies in memcell and cpustate.

Author: boriel

tests/arch/zx48k/backend/test_memcell.py

@@ -151,3 +151,10 @@ def test_require_in(self):
         c = memcell.MemCell('in d, (c)', 1)
         self.assertSetEqual(c.requires, {'b', 'c'})
         self.assertSetEqual(c.destroys, {'d'})
+
+    def test_(self):
+        """ Test requires for out(c), a instruction
+        """
+        c = memcell.MemCell('ld (_push), a', 1)
+        self.assertSetEqual(c.requires, {'a'})
+        self.assertSetEqual(c.destroys, set())

tests/arch/zx48k/optimizer/test_cpustate.py

@@ -327,3 +327,13 @@ def test_in_a_c(self):
         self.assertEqual(self.cpu_state.C, 0)
         self.assertEqual(self.cpu_state.Z, 1)
 
+    def test_xor_a_ld_n_a(self):
+        code = """
+        xor a
+        ld (_push), a
+        """
+        self._eval(code)
+        self.assertEqual(self.regs['a'], '0')
+        self.assertFalse(helpers.is_unknown8(self.regs['a']))
+        self.assertEqual(self.cpu_state.C, 0)
+        self.assertEqual(self.cpu_state.Z, 1)