diff --git a/lib/ir/module.cc b/lib/ir/module.cc
index 1665bffb7..626065224 100644
--- a/lib/ir/module.cc
+++ b/lib/ir/module.cc
@@ -107,9 +107,12 @@ ir::value *module::get_value_recursive(const std::string& name, ir::basic_block
     ir::phi_node* phi = make_phi(ty, 1, block);
     set_value(name, block, phi);
     result = add_phi_operands(name, phi);
+    if(auto *phi = dynamic_cast<ir::phi_node*>(result))
+      result = try_remove_trivial_phis(phi);
   }
-  if(auto *phi = dynamic_cast<ir::phi_node*>(result))
+  if(auto *phi = dynamic_cast<ir::phi_node*>(result)){
     result = try_remove_trivial_phis(phi);
+  }
   set_value(name, block, result);
   return result;
 }
diff --git a/python/src/triton.cc b/python/src/triton.cc
index 97fd20a40..c102f4a35 100644
--- a/python/src/triton.cc
+++ b/python/src/triton.cc
@@ -181,6 +181,9 @@ void init_triton_ir(py::module &&m) {
   py::class_<ir::constant_fp, ir::constant>(m, "constant_float")
       .def_property_readonly("value", &ir::constant_fp::get_value);
 
+  py::class_<ir::instruction, ir::user>(m, "instruction");
+  py::class_<ir::phi_node, ir::user>(m, "phi_node");
+
   py::class_<ir::type>(m, "type")
       .def("is_ptr", &ir::type::is_pointer_ty)
       .def("is_int", static_cast<bool (ir::type::*)() const>(&ir::type::is_integer_ty))
diff --git a/python/triton/code_gen.py b/python/triton/code_gen.py
index c2f6fdfd8..3a43acd16 100644
--- a/python/triton/code_gen.py
+++ b/python/triton/code_gen.py
@@ -51,7 +51,7 @@ class CodeGenerator(ast.NodeVisitor):
                 break
         if add_scope:
             self.module.pop_scope()
-        return self.last_ret
+        return stmts and isinstance(stmt, ast.Return)
 
     def __init__(self, context, prototype, gscope, attributes, constants, kwargs):
         self.builder = _triton.ir.builder(context)
@@ -85,7 +85,10 @@ class CodeGenerator(ast.NodeVisitor):
 
     # By design, only non-kernel functions can return
     def visit_Return(self, node):
-        return self.visit(node.value)
+        ret = self.visit(node.value)
+        if ret is None:
+            return self.builder.ret_void()
+        return ret
 
     def visit_FunctionDef(self, node, inline=False, arg_values=None):
         arg_names, kwarg_names = self.visit(node.args)
@@ -112,7 +115,8 @@ class CodeGenerator(ast.NodeVisitor):
         for arg_name, arg_value in zip(arg_names, arg_values):
             self.set_value(arg_name, arg_value)
         if inline:
-            return self.visit_compound_statement(node.body, add_scope=True)
+            self.visit_compound_statement(node.body, add_scope=True)
+            return self.last_ret
         else:
             entry = _triton.ir.basic_block.create(self.builder.context, "entry", fn)
             self.module.seal_block(entry)
@@ -140,6 +144,8 @@ class CodeGenerator(ast.NodeVisitor):
         assert len(names) == 1
         name = names[0]
         value = self.visit(node.value)
+        if not isinstance(value, triton.language.block):
+            value = triton.language._to_ir(value, self.builder)
         self.set_value(names[0], value)
 
     def visit_AugAssign(self, node):
@@ -208,14 +214,16 @@ class CodeGenerator(ast.NodeVisitor):
             else:
                 self.builder.cond_br(cond.handle, then_bb, endif_bb)
             self.builder.set_insert_block(then_bb)
-            self.visit_compound_statement(node.body, add_scope=True)
+            is_terminator = self.visit_compound_statement(node.body, add_scope=True)
             # TODO: last statement is a terminator?
-            self.builder.br(endif_bb)
+            if not is_terminator:
+                self.builder.br(endif_bb)
             if else_bb:
                 self.builder.set_insert_block(else_bb)
-                self.visit_compound_statement(node.orelse, add_scope=True)
+                is_terminator = self.visit_compound_statement(node.orelse, add_scope=True)
                 #TODO: last statement is a terminator?
-                self.builder.br(endif_bb)
+                if not is_terminator:
+                    self.builder.br(endif_bb)
             self.module.seal_block(endif_bb)
             self.builder.set_insert_block(endif_bb)
         else:
diff --git a/python/triton/language.py b/python/triton/language.py
index 0ee34151f..ccfda885a 100644
--- a/python/triton/language.py
+++ b/python/triton/language.py
@@ -4,22 +4,22 @@ from triton._C.libtriton.triton import frontend
 from functools import wraps
 
 
+# convert block/dtype to ir values
+def _to_ir(x, builder):
+    if isinstance(x, bool):
+        return builder.get_int1(x)
+    elif isinstance(x, int):
+        return builder.get_int32(x)
+    elif isinstance(x, float):
+        return builder.get_float32(x)
+    if isinstance(x, block):
+        return x.handle
+    if isinstance(x, dtype):
+        return x.handle(builder)
+    return x
+
+
 def _patch(fn):
-
-    # convert block/dtype to ir values
-    def _to_ir(x, builder):
-        if isinstance(x, bool):
-            return builder.get_int1(x)
-        elif isinstance(x, int):
-            return builder.get_int32(x)
-        elif isinstance(x, float):
-            return builder.get_float32(x)
-        if isinstance(x, block):
-            return x.handle
-        if isinstance(x, dtype):
-            return x.handle(builder)
-        return x
-
     def _from_ir(x):
         if isinstance(x, ir.value):
             if x.type.is_void():
@@ -306,6 +306,7 @@ def zeros(shape, dtype, builder=None):
     :param dtype: Data-type of the new array, e.g., :code:`triton.float16`
     :type dtype: DType
     """
+    shape = [int(x.handle) if isinstance(x, block) else x for x in shape]
     return frontend.zeros(shape, dtype, builder)