diff --git a/osaca/parser/base_parser.py b/osaca/parser/base_parser.py
index edfe8d1..9624737 100755
--- a/osaca/parser/base_parser.py
+++ b/osaca/parser/base_parser.py
@@ -33,7 +33,7 @@ class BaseParser(object):
             asm_instructions.append(self.parse_line(line, i + 1 + start_line))
         return asm_instructions
 
-    def parse_line(self, line, line_number):
+    def parse_line(self, line, line_number=None):
         # Done in derived classes
         raise NotImplementedError
 
@@ -51,7 +51,8 @@ class BaseParser(object):
         raise NotImplementedError
 
     def construct_parser(self):
-        raise NotImplementedError
+        return
+        # raise NotImplementedError
 
     ##################
     # Helper functions
diff --git a/osaca/semantics/semanticsAppender.py b/osaca/semantics/semanticsAppender.py
index 5f518ff..2428dff 100755
--- a/osaca/semantics/semanticsAppender.py
+++ b/osaca/semantics/semanticsAppender.py
@@ -58,7 +58,7 @@ class SemanticsAppender(object):
         if len(stores) == 0 or len(loads) == 0:
             # nothing to do
             return
-        if len(loads) < len(stores):
+        if len(loads) <= len(stores):
             # Hide all loads
             for load in loads:
                 load['flags'] += [INSTR_FLAGS.HIDDEN_LD]
diff --git a/tests/test_base_parser.py b/tests/test_base_parser.py
new file mode 100755
index 0000000..1ef8cea
--- /dev/null
+++ b/tests/test_base_parser.py
@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+"""
+Unit tests for base assembly parser
+"""
+
+import os
+import unittest
+
+from osaca.parser import AttrDict, BaseParser
+
+
+class TestBaseParser(unittest.TestCase):
+    @classmethod
+    def setUpClass(self):
+        try:
+            self.parser = BaseParser()
+        except NotImplementedError:
+            pass
+        with open(self._find_file('triad-x86-iaca.s')) as f:
+            self.triad_code = f.read()
+
+    ##################
+    # Test
+    ##################
+
+    def test_parse_file(self):
+        with self.assertRaises(NotImplementedError):
+            self.parser.parse_file(self.triad_code)
+
+    def test_parse_line(self):
+        line_instruction = '\t\tlea       2(%rax,%rax), %ecx #12.9'
+        with self.assertRaises(NotImplementedError):
+            self.parser.parse_line(line_instruction)
+
+    def test_parse_instruction(self):
+        instr1 = '\t\tvcvtsi2ss %edx, %xmm2, %xmm2\t\t\t#12.27'
+        with self.assertRaises(NotImplementedError):
+            self.parser.parse_instruction(instr1)
+
+    def test_register_funcs(self):
+        reg_a1 = AttrDict({'name': 'rax'})
+        reg_a2 = AttrDict({'name': 'eax'})
+        register_string = 'v1.2d'
+        with self.assertRaises(NotImplementedError):
+            self.parser.is_reg_dependend_of(reg_a1, reg_a2)
+        with self.assertRaises(NotImplementedError):
+            self.parser.parse_register(register_string)
+        with self.assertRaises(NotImplementedError):
+            self.parser.is_gpr(reg_a1)
+        with self.assertRaises(NotImplementedError):
+            self.parser.is_vector_register(reg_a1)
+        with self.assertRaises(NotImplementedError):
+            self.parser.process_operand(reg_a1)
+        with self.assertRaises(NotImplementedError):
+            self.parser.get_full_reg_name(reg_a1)
+
+    def test_normalize_imd(self):
+        imd_hex_1 = {'value': '0x4f'}
+        with self.assertRaises(NotImplementedError):
+            self.parser.normalize_imd(imd_hex_1)
+
+    ##################
+    # Helper functions
+    ##################
+
+    @staticmethod
+    def _find_file(name):
+        testdir = os.path.dirname(__file__)
+        name = os.path.join(testdir, 'test_files', name)
+        assert os.path.exists(name)
+        return name
+
+
+if __name__ == '__main__':
+    suite = unittest.TestLoader().loadTestsFromTestCase(TestBaseParser)
+    unittest.TextTestRunner(verbosity=2).run(suite)
diff --git a/tests/test_semantics.py b/tests/test_semantics.py
index df57214..441c0f0 100755
--- a/tests/test_semantics.py
+++ b/tests/test_semantics.py
@@ -157,14 +157,19 @@ class TestSemanticTools(unittest.TestCase):
         machine_model_zen = MachineModel(arch='ZEN1')
         semantics_zen = SemanticsAppender(machine_model_zen)
         kernel_zen = self.parser_x86.parse_file(self.code_x86)
+        kernel_zen_2 = self.parser_x86.parse_file(self.code_x86)
         kernel_zen_2 = self.parser_x86.parse_file(self.code_x86)[-3:]
+        kernel_zen_3 = self.parser_x86.parse_file(self.code_x86)[5:8]
         semantics_zen.add_semantics(kernel_zen)
         semantics_zen.add_semantics(kernel_zen_2)
+        semantics_zen.add_semantics(kernel_zen_3)
 
         num_hidden_loads = len([x for x in kernel_zen if INSTR_FLAGS.HIDDEN_LD in x['flags']])
         num_hidden_loads_2 = len([x for x in kernel_zen_2 if INSTR_FLAGS.HIDDEN_LD in x['flags']])
+        num_hidden_loads_3 = len([x for x in kernel_zen_3 if INSTR_FLAGS.HIDDEN_LD in x['flags']])
         self.assertEqual(num_hidden_loads, 1)
         self.assertEqual(num_hidden_loads_2, 0)
+        self.assertEqual(num_hidden_loads_3, 1)
 
     def test_cyclic_dag(self):
         dg = KernelDG(self.kernel_x86, self.parser_x86, self.machine_model_csx)