Fix field size

Fixes #32 (closed) and #31 (closed) and #3 (closed) and #7 (closed)

pystencils/cpu/cpujit.py

@@ -375,9 +375,11 @@ def create_function_boilerplate_code(parameter_info, name, ast_node, insert_chec
                 np_dtype = field.dtype.numpy_dtype
                 item_size = np_dtype.itemsize
 
-                aligned = any([a.lhs.args[2] for a in ast_node.assignments if
-                               hasattr(a, 'lhs') and isinstance(a.lhs, cast_func) and
-                               hasattr(a.lhs, 'dtype') and isinstance(a.lhs.dtype, VectorType)])
+                aligned = False
+                if ast_node.assignments:
+                    aligned = any([a.lhs.args[2] for a in ast_node.assignments
+                                   if hasattr(a, 'lhs') and isinstance(a.lhs, cast_func)
+                                   and hasattr(a.lhs, 'dtype') and isinstance(a.lhs.dtype, VectorType)])
 
                 if ast_node.instruction_set and aligned:
                     byte_width = ast_node.instruction_set['width'] * item_size
@@ -492,12 +494,13 @@ def run_compile_step(command):
 
 
 class ExtensionModuleCode:
-    def __init__(self, module_name='generated', custom_backend=None):
+    def __init__(self, module_name='generated', custom_backend=None, generated_code=None):
         self.module_name = module_name
 
         self._ast_nodes = []
         self._function_names = []
         self._custom_backend = custom_backend
+        self._generated_code = generated_code
 
     def add_function(self, ast, name=None):
         self._ast_nodes.append(ast)
@@ -521,7 +524,10 @@ class ExtensionModuleCode:
         for ast, name in zip(self._ast_nodes, self._function_names):
             old_name = ast.function_name
             ast.function_name = "kernel_" + name
-            print(generate_c(ast, custom_backend=self._custom_backend), file=file)
+            if self._generated_code:
+                print(self._generated_code, file=file)
+            else:
+                print(generate_c(ast, custom_backend=self._custom_backend), file=file)
             print(create_function_boilerplate_code(ast.get_parameters(), name, ast), file=file)
             ast.function_name = old_name
         print(create_module_boilerplate_code(self.module_name, self._function_names), file=file)
@@ -588,7 +594,7 @@ def compile_and_load(ast, custom_backend=None):
     # Also the information of the field size should be contained in the hash string. Due to padding the generated code
     # can look similar for different field sizes.
     code_hash_str = "mod_" + hashlib.sha256((generated_code + fields_accessed).encode()).hexdigest()
-    code = ExtensionModuleCode(module_name=code_hash_str, custom_backend=custom_backend)
+    code = ExtensionModuleCode(module_name=code_hash_str, custom_backend=custom_backend, generated_code=generated_code)
     code.add_function(ast, ast.function_name)
 
     if cache_config['object_cache'] is False: