diff --git a/qbraid_qir/qasm3/convert.py b/qbraid_qir/qasm3/convert.py
index d33bf5c..c05af29 100644
--- a/qbraid_qir/qasm3/convert.py
+++ b/qbraid_qir/qasm3/convert.py
@@ -50,13 +50,6 @@ def qasm3_to_qir(
         # Supported conversions qasm3 -> qiskit :
         # https://github.com/Qiskit/qiskit-qasm3-import/blob/main/src/qiskit_qasm3_import/converter.py
 
-        # PROPOSED SEMANTIC + DECOMPOSITION PASS
-        # qiskit_circuit = loads(program).decompose(reps=3)
-        # decomposed_qasm = Exporter().dumps(qiskit_circuit)
-        # PROPOSED SEMANTIC + DECOMPOSITION PASS
-
-        # program = openqasm3.parse(decomposed_qasm)
-
         program = openqasm3.parse(program)
 
     elif not isinstance(program, openqasm3.ast.Program):
diff --git a/qbraid_qir/qasm3/preprocess.py b/qbraid_qir/qasm3/preprocess.py
index 4adf30b..9bf5fdb 100644
--- a/qbraid_qir/qasm3/preprocess.py
+++ b/qbraid_qir/qasm3/preprocess.py
@@ -17,34 +17,3 @@
 
 
 # can use rigetti simulator for qir programs and qiskit for qasm3 programs
-
-
-# what are some problems which we face?
-
-# 1. let us just unfold the gates once.
-# assumption - we do not define any variables inside the gate
-# - gate parameters are directly passed on to other gate calls
-# - no if else conditions inside the gate
-# - no loops inside the gate
-# - no function calls inside the gate
-
-# eg. gate x2(a,b,c) p, q {
-#     h p;
-#     h q;
-#     rx(a) p;
-#     ry(b) q;
-#     rz(c) p;
-#     cx p, q;
-# }
-#    qubit[2] q;
-#    x2(1,2,3) q[0], q[1];
-
-# will be converted to
-
-# qubit[2] q;
-# h q[0];
-# h q[1];
-# rx(1) q[0];
-# ry(2) q[1];
-# rz(3) q[0];
-# cx q[0], q[1];
diff --git a/qbraid_qir/qasm3/visitor.py b/qbraid_qir/qasm3/visitor.py
index 4a8e3a5..2769f5d 100644
--- a/qbraid_qir/qasm3/visitor.py
+++ b/qbraid_qir/qasm3/visitor.py
@@ -277,7 +277,6 @@ def _visit_measurement(self, statement: QuantumMeasurementStatement) -> None:
         target = statement.target
         source_id, target_id = None, None
 
-        # handle measurement operation
         source_name = source.name
         if isinstance(source, IndexedIdentifier):
             source_name = source.name.name
@@ -318,7 +317,6 @@ def _build_qir_measurement(
             pyqir._native.mz(self._builder, source_qubit, result)
 
         if source_id is None and target_id is None:
-            # sizes should match
             if self._qreg_size_map[source_name] != self._creg_size_map[target_name]:
                 raise ValueError(
                     f"Register sizes of {source_name} and {target_name} do not match for measurement operation"
@@ -365,7 +363,6 @@ def _visit_reset(self, statement: QuantumReset) -> None:
             qreg_size = self._qreg_size_map[qreg_name]
             qubit_ids = [self._qubit_labels[f"{qreg_name}_{i}"] for i in range(qreg_size)]
 
-        # generate pyqir reset equivalent
         for qid in qubit_ids:
             pyqir._native.reset(self._builder, pyqir.qubit(self._module.context, qid))
 
@@ -402,11 +399,8 @@ def _get_op_parameters(self, operation: QuantumGate) -> List[float]:
         """
         param_list = []
         for param in operation.arguments:
-            if not isinstance(param, (FloatLiteral, IntegerLiteral)):
-                raise ValueError(
-                    f"Unsupported parameter type {type(param)} for operation {operation}"
-                )
-            param_list.append(float(param.value))
+            param_value = self._evaluate_expression(param)
+            param_list.append(param_value)
 
         if len(param_list) > 1:
             raise ValueError(f"Parameterized gate {operation} with > 1 params not supported")
@@ -414,6 +408,14 @@ def _get_op_parameters(self, operation: QuantumGate) -> List[float]:
         return param_list
 
     def _visit_gate_definition(self, definition: QuantumGateDefinition) -> None:
+        """Visit a gate definition element.
+
+        Args:
+            definition (QuantumGateDefinition): The gate definition to visit.
+
+        Returns:
+            None
+        """
         gate_name = definition.name.name
         if gate_name in self._custom_gates:
             raise ValueError(f"Duplicate gate definition for {gate_name}")
@@ -429,9 +431,8 @@ def _visit_basic_gate_operation(self, operation: QuantumGate) -> None:
             None
         """
 
-        # Currently handling the gates in the stdgates.inc file
         _log.debug("Visiting basic gate operation '%s'", str(operation))
-        op_name = operation.name.name
+        op_name : str = operation.name.name
         op_qubits = self._get_op_qubits(operation)
         qir_func, op_qubit_count = map_qasm_op_to_pyqir_callable(op_name)
         op_parameters = None
@@ -466,7 +467,6 @@ def _transform_gate_qubits(self, gate_op, qubit_map):
         for i, qubit in enumerate(gate_op.qubits):
             if isinstance(qubit, IndexedIdentifier):
                 raise ValueError(f"Indexing {qubit} not supported in gate definition")
-            # now we have an Identifier
             gate_op.qubits[i] = qubit_map[qubit.name]
 
     def _transform_gate_params(self, gate_op, param_map):
@@ -480,7 +480,6 @@ def _transform_gate_params(self, gate_op, param_map):
             None
         """
         for i, param in enumerate(gate_op.arguments):
-            # replace only if we have an Identifier
             if isinstance(param, Identifier):
                 gate_op.arguments[i] = param_map[param.name]
 
@@ -493,8 +492,8 @@ def _visit_custom_gate_operation(self, operation: QuantumGate) -> None:
         Returns:in computation
         """
         _log.debug("Visiting custom gate operation '%s'", str(operation))
-        gate_name = operation.name.name
-        gate_definition = self._custom_gates[gate_name]
+        gate_name : str = operation.name.name
+        gate_definition : QuantumGateDefinition = self._custom_gates[gate_name]
 
         if len(operation.arguments) != len(gate_definition.arguments):
             raise ValueError(
@@ -588,7 +587,7 @@ def _visit_classical_operation(self, statement: ClassicalDeclaration) -> None:
         else:
             raise ValueError(f"Unsupported classical type {decl_type} in {statement}")
 
-    def evaluate_expression(self, expression: Any) -> bool:
+    def _evaluate_expression(self, expression: Any) -> bool:
         """Evaluate an expression.
 
         Args:
@@ -598,26 +597,32 @@ def evaluate_expression(self, expression: Any) -> bool:
             bool: The result of the evaluation.
         """
         if isinstance(expression, (ImaginaryLiteral, DurationLiteral)):
-            raise ValueError(f"Unsupported expression type {type(expression)} in if condition")
+            raise ValueError(f"Unsupported expression type {type(expression)}")
+        elif isinstance(expression, Identifier):
+            # we need to check our scope and context to get the value of the identifier
+            # if it is a classical register, we can directly get the value
+            # how to get the value of the identifier in the QIR??
+            # TO DO : extend this
+            raise ValueError(f"Unsupported expression type {type(expression)}")
         elif isinstance(expression, BooleanLiteral):
             return expression.value
         elif isinstance(expression, (IntegerLiteral, FloatLiteral)):
-            return int(expression.value)
+            return expression.value
         elif isinstance(expression, UnaryExpression):
             op = expression.op.name  # can be '!', '~' or '-'
             if op == "!":
-                return not self.evaluate_expression(expression.expression)
+                return not self._evaluate_expression(expression.expression)
             elif op == "-":
-                return -1 * self.evaluate_expression(expression.expression)
+                return -1 * self._evaluate_expression(expression.expression)
             elif op == "~":
-                value = self.evaluate_expression(expression.expression)
+                value = self._evaluate_expression(expression.expression)
                 if not isinstance(value, int):
                     raise ValueError(f"Unsupported expression type {type(value)} in ~ operation")
         elif isinstance(expression, BinaryExpression):
-            lhs = self.evaluate_expression(expression.lhs)
+            lhs = self._evaluate_expression(expression.lhs)
             op = expression.op.name
-            rhs = self.evaluate_expression(expression.rhs)
-            return qasm3_expression_op_map[op](lhs, rhs)
+            rhs = self._evaluate_expression(expression.rhs)
+            return qasm3_expression_op_map(op, lhs, rhs)
 
     def _visit_branching_statement(self, statement: BranchingStatement) -> None:
         """Visit a branching statement element.
diff --git a/tests/qasm3_qir/converter/test_expressions.py b/tests/qasm3_qir/converter/test_expressions.py
new file mode 100644
index 0000000..20b1bb3
--- /dev/null
+++ b/tests/qasm3_qir/converter/test_expressions.py
@@ -0,0 +1,49 @@
+# Copyright (C) 2023 qBraid
+#
+# This file is part of the qBraid-SDK
+#
+# The qBraid-SDK is free software released under the GNU General Public License v3
+# or later. You can redistribute and/or modify it under the terms of the GPL v3.
+# See the LICENSE file in the project root or <https://www.gnu.org/licenses/gpl-3.0.html>.
+#
+# THERE IS NO WARRANTY for the qBraid-SDK, as per Section 15 of the GPL v3.
+
+"""
+Module containing unit tests for QASM3 to QIR conversion functions.
+
+"""
+import pytest
+
+from qbraid_qir.qasm3.convert import qasm3_to_qir
+from tests.qir_utils import check_attributes, check_expressions
+
+
+def test_correct_expressions():
+    qasm_str = """OPENQASM 3;
+    qubit q;
+
+    // supported
+    rx(1.57) q;
+    rz(3-2*3) q;
+    rz(3-2*3*(8/2)) q;
+    rx(-1.57) q;
+    rx(4%2) q;
+    """
+
+    result = qasm3_to_qir(qasm_str)
+    generated_qir = str(result).splitlines()
+
+    check_attributes(generated_qir, 1, 0)
+    gates = ["rx", "rz", "rz", "rx", "rx"]
+    expression_values = [1.57, 3 - 2 * 3, 3 - 2 * 3 * (8 / 2), -1.57, 4 % 2]
+    qubits = [0, 0, 0, 0, 0]
+    check_expressions(generated_qir, 5, gates, expression_values, qubits)
+
+
+def test_incorrect_expressions():
+    with pytest.raises(ValueError, match=r"Unsupported expression type .*"):
+        qasm3_to_qir("OPENQASM 3; qubit q; rz(1 - 2 + 32im) q;")
+    with pytest.raises(ValueError, match=r"Unsupported expression type .* in ~ operation"):
+        qasm3_to_qir("OPENQASM 3; qubit q; rx(~1.3) q;")
+    with pytest.raises(ValueError, match=r"Unsupported expression type .* in ~ operation"):
+        qasm3_to_qir("OPENQASM 3; qubit q; rx(~1.3+5im) q;")
diff --git a/tests/qasm3_qir/converter/test_gates.py b/tests/qasm3_qir/converter/test_gates.py
index afc710b..d34253f 100644
--- a/tests/qasm3_qir/converter/test_gates.py
+++ b/tests/qasm3_qir/converter/test_gates.py
@@ -149,7 +149,7 @@ def test_incorrect_single_qubit_gates():
 
     # Invalid use of variables in gate application
 
-    with pytest.raises(ValueError, match=r"Unsupported parameter type .* for operation .*"):
+    with pytest.raises(ValueError, match=r"Unsupported expression type .*"):
         _ = qasm3_to_qir(
             """
             OPENQASM 3;
diff --git a/tests/qasm3_qir/fixtures/resources/custom_gate_complex.qasm b/tests/qasm3_qir/fixtures/resources/custom_gate_complex.qasm
index dd74d70..5652971 100644
--- a/tests/qasm3_qir/fixtures/resources/custom_gate_complex.qasm
+++ b/tests/qasm3_qir/fixtures/resources/custom_gate_complex.qasm
@@ -20,5 +20,4 @@ gate custom3(p, q) c, d {
 
 qubit[2] q;
 
-custom3(0.1, 0.2) q[0], q[1];
-custom3(0.3, 0.4) q[0:];
\ No newline at end of file
+custom3(0.1, 0.2) q[0:];
\ No newline at end of file
diff --git a/tests/qasm3_qir/fixtures/resources/custom_gate_nested.qasm b/tests/qasm3_qir/fixtures/resources/custom_gate_nested.qasm
index eda0dab..918c5d9 100644
--- a/tests/qasm3_qir/fixtures/resources/custom_gate_nested.qasm
+++ b/tests/qasm3_qir/fixtures/resources/custom_gate_nested.qasm
@@ -10,8 +10,8 @@ gate custom(a,b,c) p, q{
     h p;
     cx p,q;
     rx(a) q;
-    ry(0.5) q;
+    ry(0.5/0.1) q;
 }
 
 qubit[2] q;
-custom(0.1, 0.2, 0.3) q[0], q[1];
+custom(2 + 3 - 1/5, 0.1, 0.3) q[0], q[1];
diff --git a/tests/qasm3_qir/fixtures/resources/custom_gate_simple.qasm b/tests/qasm3_qir/fixtures/resources/custom_gate_simple.qasm
index e84e3da..acd4a0c 100644
--- a/tests/qasm3_qir/fixtures/resources/custom_gate_simple.qasm
+++ b/tests/qasm3_qir/fixtures/resources/custom_gate_simple.qasm
@@ -9,4 +9,4 @@ gate custom(a) p, q {
 }
 
 qubit[2] q;
-custom(0.1) q[0], q[1];
\ No newline at end of file
+custom(0.1+1) q[0], q[1];
\ No newline at end of file
diff --git a/tests/qir_utils.py b/tests/qir_utils.py
index 050f1ae..d4d84a1 100644
--- a/tests/qir_utils.py
+++ b/tests/qir_utils.py
@@ -306,7 +306,7 @@ def _validate_simple_custom_op(entry_body: List[str]):
         initialize_call_string(),
         single_op_call_string("h", 0),
         single_op_call_string("z", 1),
-        rotation_call_string("rx", 0.1, 0),
+        rotation_call_string("rx", 1.1, 0),
         double_op_call_string("cnot", 0, 1),
         result_record_output_string(0),
         result_record_output_string(1),
@@ -322,11 +322,11 @@ def _validate_nested_custom_op(entry_body: List[str]):
     nested_op_lines = [
         initialize_call_string(),
         single_op_call_string("h", 1),
-        rotation_call_string("rz", 0.1, 1),
+        rotation_call_string("rz", 4.8, 1),
         single_op_call_string("h", 0),
         double_op_call_string("cnot", 0, 1),
-        rotation_call_string("rx", 0.1, 1),
-        rotation_call_string("ry", 0.5, 1),
+        rotation_call_string("rx", 4.8, 1),
+        rotation_call_string("ry", 5, 1),
         result_record_output_string(0),
         result_record_output_string(1),
         return_string(),
@@ -338,8 +338,22 @@ def _validate_nested_custom_op(entry_body: List[str]):
 
 
 def _validate_complex_custom_op(entry_body: List[str]):
-    pass
-    # todo...
+    complex_op_lines = [
+        initialize_call_string(),
+        single_op_call_string("h", 0),
+        single_op_call_string("x", 0),
+        rotation_call_string("rx", 0.5, 0),
+        rotation_call_string("ry", 0.1, 0),
+        rotation_call_string("rz", 0.2, 0),
+        double_op_call_string("cnot", 0, 1),
+        result_record_output_string(0),
+        result_record_output_string(1),
+        return_string(),
+    ]
+
+    assert len(entry_body) == len(complex_op_lines), "Incorrect number of lines in complex op"
+    for i in range(len(entry_body)):
+        assert entry_body[i].strip() == complex_op_lines[i].strip(), "Incorrect complex op line"
 
 
 def check_custom_qasm_gate_op(qir: List[str], test_type: str):
@@ -353,3 +367,25 @@ def check_custom_qasm_gate_op(qir: List[str], test_type: str):
         _validate_complex_custom_op(entry_body)
     else:
         assert False, f"Unknown test type {test_type} for custom ops"
+
+
+def check_expressions(
+    qir: List[str], expected_ops: int, gates: List[str], expression_values, qubits: List[int]
+):
+    entry_body = get_entry_point_body(qir)
+    op_count = 0
+    q_id = 0
+
+    for line in entry_body:
+        if line.strip().startswith("call") and "qis__" in line:
+            assert line.strip() == rotation_call_string(
+                gates[q_id], expression_values[q_id], qubits[q_id]
+            ), f"Incorrect rotation gate call in qir - {line}"
+            op_count += 1
+            q_id += 1
+
+        if op_count == expected_ops:
+            break
+
+    if op_count != expected_ops:
+        assert False, f"Incorrect rotation gate count: {expected_ops} expected, {op_count} actual"