diff --git a/py/compile.c b/py/compile.c
index 2d2f800d42..f0d3934fd7 100644
--- a/py/compile.c
+++ b/py/compile.c
@@ -27,6 +27,10 @@ typedef enum {
 
 #define EMIT(fun, arg...) (comp->emit_method_table->fun(comp->emit, ##arg))
 
+#define EMIT_OPT_NONE           (0)
+#define EMIT_OPT_BYTE_CODE      (1)
+#define EMIT_OPT_NATIVE_PYTHON  (2)
+
 typedef struct _compiler_t {
     qstr qstr___class__;
     qstr qstr___locals__;
@@ -35,6 +39,8 @@ typedef struct _compiler_t {
     qstr qstr___qualname__;
     qstr qstr___doc__;
     qstr qstr_assertion_error;
+    qstr qstr_micropython;
+    qstr qstr_native;
 
     pass_kind_t pass;
 
@@ -56,8 +62,8 @@ typedef struct _compiler_t {
     scope_t *scope_head;
     scope_t *scope_cur;
 
-    emit_t *emit;
-    const emit_method_table_t *emit_method_table;
+    emit_t *emit;                                   // current emitter
+    const emit_method_table_t *emit_method_table;   // current emit method table
 } compiler_t;
 
 py_parse_node_t fold_constants(py_parse_node_t pn) {
@@ -165,8 +171,8 @@ static int comp_next_label(compiler_t *comp) {
     return comp->next_label++;
 }
 
-static scope_t *scope_new_and_link(compiler_t *comp, scope_kind_t kind, py_parse_node_t pn) {
-    scope_t *scope = scope_new(kind, pn, rt_get_new_unique_code_id());
+static scope_t *scope_new_and_link(compiler_t *comp, scope_kind_t kind, py_parse_node_t pn, uint emit_options) {
+    scope_t *scope = scope_new(kind, pn, rt_get_new_unique_code_id(), emit_options);
     scope->parent = comp->scope_cur;
     scope->next = NULL;
     if (comp->scope_head == NULL) {
@@ -661,10 +667,10 @@ void compile_funcdef_param(compiler_t *comp, py_parse_node_t pn) {
 
 // leaves function object on stack
 // returns function name
-qstr compile_funcdef_helper(compiler_t *comp, py_parse_node_struct_t *pns) {
+qstr compile_funcdef_helper(compiler_t *comp, py_parse_node_struct_t *pns, uint emit_options) {
     if (comp->pass == PASS_1) {
         // create a new scope for this function
-        scope_t *s = scope_new_and_link(comp, SCOPE_FUNCTION, (py_parse_node_t)pns);
+        scope_t *s = scope_new_and_link(comp, SCOPE_FUNCTION, (py_parse_node_t)pns, emit_options);
         // store the function scope so the compiling function can use it at each pass
         pns->nodes[4] = (py_parse_node_t)s;
     }
@@ -705,10 +711,10 @@ qstr compile_funcdef_helper(compiler_t *comp, py_parse_node_struct_t *pns) {
 
 // leaves class object on stack
 // returns class name
-qstr compile_classdef_helper(compiler_t *comp, py_parse_node_struct_t *pns) {
+qstr compile_classdef_helper(compiler_t *comp, py_parse_node_struct_t *pns, uint emit_options) {
     if (comp->pass == PASS_1) {
         // create a new scope for this class
-        scope_t *s = scope_new_and_link(comp, SCOPE_CLASS, (py_parse_node_t)pns);
+        scope_t *s = scope_new_and_link(comp, SCOPE_CLASS, (py_parse_node_t)pns, emit_options);
         // store the class scope so the compiling function can use it at each pass
         pns->nodes[3] = (py_parse_node_t)s;
     }
@@ -739,24 +745,65 @@ qstr compile_classdef_helper(compiler_t *comp, py_parse_node_struct_t *pns) {
     return cscope->simple_name;
 }
 
+// returns true if it was a built-in decorator (even if the built-in had an error)
+static bool compile_built_in_decorator(compiler_t *comp, int name_len, py_parse_node_t *name_nodes, uint *emit_options) {
+    if (PY_PARSE_NODE_LEAF_ARG(name_nodes[0]) != comp->qstr_micropython) {
+        return false;
+    }
+
+    if (name_len != 2) {
+        printf("SyntaxError: invalid micropython decorator\n");
+        return true;
+    }
+
+    qstr attr = PY_PARSE_NODE_LEAF_ARG(name_nodes[1]);
+    if (attr == comp->qstr_native) {
+        *emit_options = EMIT_OPT_NATIVE_PYTHON;
+    } else {
+        printf("SyntaxError: invalid micropython decorator\n");
+    }
+
+    return true;
+}
+
 void compile_decorated(compiler_t *comp, py_parse_node_struct_t *pns) {
     // get the list of decorators
     py_parse_node_t *nodes;
     int n = list_get(&pns->nodes[0], PN_decorators, &nodes);
 
-    // load each decorator
+    // inherit emit options for this function/class definition
+    uint emit_options = comp->scope_cur->emit_options;
+
+    // compile each decorator
+    int num_built_in_decorators = 0;
     for (int i = 0; i < n; i++) {
         assert(PY_PARSE_NODE_IS_STRUCT_KIND(nodes[i], PN_decorator)); // should be
         py_parse_node_struct_t *pns_decorator = (py_parse_node_struct_t*)nodes[i];
-        py_parse_node_t *nodes2;
-        int n2 = list_get(&pns_decorator->nodes[0], PN_dotted_name, &nodes2);
-        compile_node(comp, nodes2[0]);
-        for (int i = 1; i < n2; i++) {
-            EMIT(load_attr, PY_PARSE_NODE_LEAF_ARG(nodes2[i]));
-        }
-        if (!PY_PARSE_NODE_IS_NULL(pns_decorator->nodes[1])) {
-            // first call the function with these arguments
-            compile_node(comp, pns_decorator->nodes[1]);
+
+        // nodes[0] contains the decorator function, which is a dotted name
+        py_parse_node_t *name_nodes;
+        int name_len = list_get(&pns_decorator->nodes[0], PN_dotted_name, &name_nodes);
+
+        // check for built-in decorators
+        if (compile_built_in_decorator(comp, name_len, name_nodes, &emit_options)) {
+            // this was a built-in
+            num_built_in_decorators += 1;
+
+        } else {
+            // not a built-in, compile normally
+
+            // compile the decorator function
+            compile_node(comp, name_nodes[0]);
+            for (int i = 1; i < name_len; i++) {
+                assert(PY_PARSE_NODE_IS_ID(name_nodes[i])); // should be
+                EMIT(load_attr, PY_PARSE_NODE_LEAF_ARG(name_nodes[i]));
+            }
+
+            // nodes[1] contains arguments to the decorator function, if any
+            if (!PY_PARSE_NODE_IS_NULL(pns_decorator->nodes[1])) {
+                // call the decorator function with the arguments in nodes[1]
+                compile_node(comp, pns_decorator->nodes[1]);
+            }
         }
     }
 
@@ -764,16 +811,16 @@ void compile_decorated(compiler_t *comp, py_parse_node_struct_t *pns) {
     py_parse_node_struct_t *pns_body = (py_parse_node_struct_t*)pns->nodes[1];
     qstr body_name = 0;
     if (PY_PARSE_NODE_STRUCT_KIND(pns_body) == PN_funcdef) {
-        body_name = compile_funcdef_helper(comp, pns_body);
+        body_name = compile_funcdef_helper(comp, pns_body, emit_options);
     } else if (PY_PARSE_NODE_STRUCT_KIND(pns_body) == PN_classdef) {
-        body_name = compile_classdef_helper(comp, pns_body);
+        body_name = compile_classdef_helper(comp, pns_body, emit_options);
     } else {
         // shouldn't happen
         assert(0);
     }
 
     // call each decorator
-    for (int i = 0; i < n; i++) {
+    for (int i = 0; i < n - num_built_in_decorators; i++) {
         EMIT(call_function, 1, 0, false, false);
     }
 
@@ -782,7 +829,7 @@ void compile_decorated(compiler_t *comp, py_parse_node_struct_t *pns) {
 }
 
 void compile_funcdef(compiler_t *comp, py_parse_node_struct_t *pns) {
-    qstr fname = compile_funcdef_helper(comp, pns);
+    qstr fname = compile_funcdef_helper(comp, pns, comp->scope_cur->emit_options);
     // store function object into function name
     EMIT(store_id, fname);
 }
@@ -1514,7 +1561,7 @@ void compile_lambdef(compiler_t *comp, py_parse_node_struct_t *pns) {
 
     if (comp->pass == PASS_1) {
         // create a new scope for this lambda
-        scope_t *s = scope_new_and_link(comp, SCOPE_LAMBDA, (py_parse_node_t)pns);
+        scope_t *s = scope_new_and_link(comp, SCOPE_LAMBDA, (py_parse_node_t)pns, comp->scope_cur->emit_options);
         // store the lambda scope so the compiling function (this one) can use it at each pass
         pns->nodes[2] = (py_parse_node_t)s;
     }
@@ -1780,7 +1827,7 @@ void compile_comprehension(compiler_t *comp, py_parse_node_struct_t *pns, scope_
 
     if (comp->pass == PASS_1) {
         // create a new scope for this comprehension
-        scope_t *s = scope_new_and_link(comp, kind, (py_parse_node_t)pns);
+        scope_t *s = scope_new_and_link(comp, kind, (py_parse_node_t)pns, comp->scope_cur->emit_options);
         // store the comprehension scope so the compiling function (this one) can use it at each pass
         pns_comp_for->nodes[3] = (py_parse_node_t)s;
     }
@@ -2048,7 +2095,7 @@ void compile_dictorsetmaker_item(compiler_t *comp, py_parse_node_struct_t *pns)
 }
 
 void compile_classdef(compiler_t *comp, py_parse_node_struct_t *pns) {
-    qstr cname = compile_classdef_helper(comp, pns);
+    qstr cname = compile_classdef_helper(comp, pns, comp->scope_cur->emit_options);
     // store class object into class name
     EMIT(store_id, cname);
 }
@@ -2332,6 +2379,7 @@ void compile_scope(compiler_t *comp, scope_t *scope, pass_kind_t pass) {
         assert(PY_PARSE_NODE_STRUCT_KIND(pns) == PN_funcdef);
 
         // work out number of parameters, keywords and default parameters, and add them to the id_info array
+        // must be done before compiling the body so that arguments are numbered first (for LOAD_FAST etc)
         if (comp->pass == PASS_1) {
             comp->have_bare_star = false;
             apply_to_single_or_list(comp, pns->nodes[1], PN_typedargslist, compile_scope_func_param);
@@ -2351,6 +2399,7 @@ void compile_scope(compiler_t *comp, scope_t *scope, pass_kind_t pass) {
         assert(PY_PARSE_NODE_STRUCT_NUM_NODES(pns) == 3);
 
         // work out number of parameters, keywords and default parameters, and add them to the id_info array
+        // must be done before compiling the body so that arguments are numbered first (for LOAD_FAST etc)
         if (comp->pass == PASS_1) {
             comp->have_bare_star = false;
             apply_to_single_or_list(comp, pns->nodes[0], PN_varargslist, compile_scope_lambda_param);
@@ -2367,7 +2416,7 @@ void compile_scope(compiler_t *comp, scope_t *scope, pass_kind_t pass) {
         assert(PY_PARSE_NODE_IS_STRUCT_KIND(pns->nodes[1], PN_comp_for));
         py_parse_node_struct_t *pns_comp_for = (py_parse_node_struct_t*)pns->nodes[1];
 
-        qstr qstr_arg = qstr_from_strn_copy(".0", 2);
+        qstr qstr_arg = qstr_from_str_static(".0");
         if (comp->pass == PASS_1) {
             bool added;
             id_info_t *id_info = scope_find_or_add_id(comp->scope_cur, qstr_arg, &added);
@@ -2493,13 +2542,15 @@ void compile_scope_compute_things(compiler_t *comp, scope_t *scope) {
 void py_compile(py_parse_node_t pn) {
     compiler_t *comp = m_new(compiler_t, 1);
 
-    comp->qstr___class__ = qstr_from_strn_copy("__class__", 9);
-    comp->qstr___locals__ = qstr_from_strn_copy("__locals__", 10);
-    comp->qstr___name__ = qstr_from_strn_copy("__name__", 8);
-    comp->qstr___module__ = qstr_from_strn_copy("__module__", 10);
-    comp->qstr___qualname__ = qstr_from_strn_copy("__qualname__", 12);
-    comp->qstr___doc__ = qstr_from_strn_copy("__doc__", 7);
-    comp->qstr_assertion_error = qstr_from_strn_copy("AssertionError", 14);
+    comp->qstr___class__ = qstr_from_str_static("__class__");
+    comp->qstr___locals__ = qstr_from_str_static("__locals__");
+    comp->qstr___name__ = qstr_from_str_static("__name__");
+    comp->qstr___module__ = qstr_from_str_static("__module__");
+    comp->qstr___qualname__ = qstr_from_str_static("__qualname__");
+    comp->qstr___doc__ = qstr_from_str_static("__doc__");
+    comp->qstr_assertion_error = qstr_from_str_static("AssertionError");
+    comp->qstr_micropython = qstr_from_str_static("micropython");
+    comp->qstr_native = qstr_from_str_static("native");
 
     comp->max_num_labels = 0;
     comp->break_label = 0;
@@ -2508,10 +2559,11 @@ void py_compile(py_parse_node_t pn) {
     comp->scope_head = NULL;
     comp->scope_cur = NULL;
 
-    emit_pass1_new(&comp->emit, &comp->emit_method_table, comp->qstr___class__);
+    comp->emit = emit_pass1_new(comp->qstr___class__);
+    comp->emit_method_table = &emit_pass1_method_table;
 
     pn = fold_constants(pn);
-    scope_new_and_link(comp, SCOPE_MODULE, pn);
+    scope_new_and_link(comp, SCOPE_MODULE, pn, EMIT_OPT_NONE);
 
     for (scope_t *s = comp->scope_head; s != NULL; s = s->next) {
         compile_scope(comp, s, PASS_1);
@@ -2521,11 +2573,29 @@ void py_compile(py_parse_node_t pn) {
         compile_scope_compute_things(comp, s);
     }
 
-    emit_cpython_new(&comp->emit, &comp->emit_method_table, comp->max_num_labels);
-    //emit_bc_new(&comp->emit, &comp->emit_method_table, comp->max_num_labels);
-    //emit_x64_new(&comp->emit, &comp->emit_method_table, comp->max_num_labels);
+    emit_pass1_free(comp->emit);
+
+    emit_t *emit_bc = NULL;
+    emit_t *emit_x64 = NULL;
 
     for (scope_t *s = comp->scope_head; s != NULL; s = s->next) {
+        switch (s->emit_options) {
+            case EMIT_OPT_NATIVE_PYTHON:
+                if (emit_x64 == NULL) {
+                    emit_x64 = emit_x64_new(comp->max_num_labels);
+                }
+                comp->emit = emit_x64;
+                comp->emit_method_table = &emit_x64_method_table;
+                break;
+
+            default:
+                if (emit_bc == NULL) {
+                    emit_bc = emit_bc_new(comp->max_num_labels);
+                }
+                comp->emit = emit_bc;
+                comp->emit_method_table = &emit_bc_method_table;
+                break;
+        }
         compile_scope(comp, s, PASS_2);
         compile_scope(comp, s, PASS_3);
     }
diff --git a/py/emit.h b/py/emit.h
index c27b231db5..288141303b 100644
--- a/py/emit.h
+++ b/py/emit.h
@@ -116,8 +116,15 @@ void emit_common_load_id(emit_t *emit, const emit_method_table_t *emit_method_ta
 void emit_common_store_id(emit_t *emit, const emit_method_table_t *emit_method_table, scope_t *scope, qstr qstr);
 void emit_common_delete_id(emit_t *emit, const emit_method_table_t *emit_method_table, scope_t *scope, qstr qstr);
 
-void emit_pass1_new(emit_t **emit, const emit_method_table_t **emit_method_table, qstr qstr___class__);
-void emit_cpython_new(emit_t **emit_out, const emit_method_table_t **emit_method_table_out, uint max_num_labels);
-void emit_bc_new(emit_t **emit, const emit_method_table_t **emit_method_table, uint max_num_labels);
-void emit_x64_new(emit_t **emit, const emit_method_table_t **emit_method_table, uint max_num_labels);
-void emit_thumb_new(emit_t **emit, const emit_method_table_t **emit_method_table, uint max_num_labels);
+extern const emit_method_table_t emit_pass1_method_table;
+extern const emit_method_table_t emit_cpython_method_table;
+extern const emit_method_table_t emit_bc_method_table;
+extern const emit_method_table_t emit_x64_method_table;
+extern const emit_method_table_t emit_thumb_method_table;
+
+emit_t *emit_pass1_new(qstr qstr___class__);
+void emit_pass1_free(emit_t *emit);
+emit_t *emit_cpython_new(uint max_num_labels);
+emit_t *emit_bc_new(uint max_num_labels);
+emit_t *emit_x64_new(uint max_num_labels);
+emit_t *emit_thumb_new(uint max_num_labels);
diff --git a/py/emitbc.c b/py/emitbc.c
index 4cfd88ed4f..5c566ccb8c 100644
--- a/py/emitbc.c
+++ b/py/emitbc.c
@@ -32,8 +32,15 @@ struct _emit_t {
     byte dummy_data[8];
 };
 
-// forward declaration
-static const emit_method_table_t emit_bc_method_table;
+emit_t *emit_bc_new(uint max_num_labels) {
+    emit_t *emit = m_new(emit_t, 1);
+    emit->max_num_labels = max_num_labels;
+    emit->label_offsets = m_new(uint, emit->max_num_labels);
+    emit->code_offset = 0;
+    emit->code_size = 0;
+    emit->code_base = NULL;
+    return emit;
+}
 
 uint emit_bc_get_code_size(emit_t* emit) {
     return emit->code_size;
@@ -672,7 +679,7 @@ static void emit_bc_yield_from(emit_t *emit) {
     emit_write_byte_1(emit, PYBC_YIELD_FROM);
 }
 
-static const emit_method_table_t emit_bc_method_table = {
+const emit_method_table_t emit_bc_method_table = {
     emit_bc_set_native_types,
     emit_bc_start_pass,
     emit_bc_end_pass,
@@ -767,15 +774,3 @@ static const emit_method_table_t emit_bc_method_table = {
     emit_bc_yield_value,
     emit_bc_yield_from,
 };
-
-void emit_bc_new(emit_t **emit_out, const emit_method_table_t **emit_method_table_out, uint max_num_labels) {
-    emit_t *emit = m_new(emit_t, 1);
-    emit->max_num_labels = max_num_labels;
-    emit->label_offsets = m_new(uint, emit->max_num_labels);
-    emit->code_offset = 0;
-    emit->code_size = 0;
-    emit->code_base = NULL;
-
-    *emit_out = emit;
-    *emit_method_table_out = &emit_bc_method_table;
-}
diff --git a/py/emitcpy.c b/py/emitcpy.c
index 0a3149fcd5..db5c118673 100644
--- a/py/emitcpy.c
+++ b/py/emitcpy.c
@@ -29,10 +29,16 @@ struct _emit_t {
     int *label_offsets;
 };
 
-// forward declarations
-static const emit_method_table_t emit_cpy_method_table;
+// forward declaration
 static void emit_cpy_load_const_verbatim_quoted_str(emit_t *emit, qstr qstr, bool bytes);
 
+emit_t *emit_cpython_new(uint max_num_labels) {
+    emit_t *emit = m_new(emit_t, 1);
+    emit->max_num_labels = max_num_labels;
+    emit->label_offsets = m_new(int, max_num_labels);
+    return emit;
+}
+
 static void emit_cpy_set_native_types(emit_t *emit, bool do_native_types) {
 }
 
@@ -68,15 +74,15 @@ static void emit_cpy_set_stack_size(emit_t *emit, int size) {
 }
 
 static void emit_cpy_load_id(emit_t *emit, qstr qstr) {
-    emit_common_load_id(emit, &emit_cpy_method_table, emit->scope, qstr);
+    emit_common_load_id(emit, &emit_cpython_method_table, emit->scope, qstr);
 }
 
 static void emit_cpy_store_id(emit_t *emit, qstr qstr) {
-    emit_common_store_id(emit, &emit_cpy_method_table, emit->scope, qstr);
+    emit_common_store_id(emit, &emit_cpython_method_table, emit->scope, qstr);
 }
 
 static void emit_cpy_delete_id(emit_t *emit, qstr qstr) {
-    emit_common_delete_id(emit, &emit_cpy_method_table, emit->scope, qstr);
+    emit_common_delete_id(emit, &emit_cpython_method_table, emit->scope, qstr);
 }
 
 static void emit_pre(emit_t *emit, int stack_size_delta, int byte_code_size) {
@@ -260,6 +266,13 @@ static void emit_cpy_load_const_verbatim_end(emit_t *emit) {
     }
 }
 
+static void emit_cpy_load_fast(emit_t *emit, qstr qstr, int local_num) {
+    emit_pre(emit, 1, 3);
+    if (emit->pass == PASS_3) {
+        printf("LOAD_FAST %d %s\n", local_num, qstr_str(qstr));
+    }
+}
+
 static void emit_cpy_load_name(emit_t *emit, qstr qstr) {
     emit_pre(emit, 1, 3);
     if (emit->pass == PASS_3) {
@@ -274,13 +287,6 @@ static void emit_cpy_load_global(emit_t *emit, qstr qstr) {
     }
 }
 
-static void emit_cpy_load_fast(emit_t *emit, qstr qstr, int local_num) {
-    emit_pre(emit, 1, 3);
-    if (emit->pass == PASS_3) {
-        printf("LOAD_FAST %s\n", qstr_str(qstr));
-    }
-}
-
 static void emit_cpy_load_deref(emit_t *emit, qstr qstr) {
     emit_pre(emit, 1, 3);
     if (emit->pass == PASS_3) {
@@ -313,6 +319,13 @@ static void emit_cpy_load_build_class(emit_t *emit) {
     }
 }
 
+static void emit_cpy_store_fast(emit_t *emit, qstr qstr, int local_num) {
+    emit_pre(emit, -1, 3);
+    if (emit->pass == PASS_3) {
+        printf("STORE_FAST %d %s\n", local_num, qstr_str(qstr));
+    }
+}
+
 static void emit_cpy_store_name(emit_t *emit, qstr qstr) {
     emit_pre(emit, -1, 3);
     if (emit->pass == PASS_3) {
@@ -327,13 +340,6 @@ static void emit_cpy_store_global(emit_t *emit, qstr qstr) {
     }
 }
 
-static void emit_cpy_store_fast(emit_t *emit, qstr qstr, int local_num) {
-    emit_pre(emit, -1, 3);
-    if (emit->pass == PASS_3) {
-        printf("STORE_FAST %s\n", qstr_str(qstr));
-    }
-}
-
 static void emit_cpy_store_deref(emit_t *emit, qstr qstr) {
     emit_pre(emit, -1, 3);
     if (emit->pass == PASS_3) {
@@ -362,6 +368,13 @@ static void emit_cpy_store_subscr(emit_t *emit) {
     }
 }
 
+static void emit_cpy_delete_fast(emit_t *emit, qstr qstr, int local_num) {
+    emit_pre(emit, 0, 3);
+    if (emit->pass == PASS_3) {
+        printf("DELETE_FAST %d %s\n", local_num, qstr_str(qstr));
+    }
+}
+
 static void emit_cpy_delete_name(emit_t *emit, qstr qstr) {
     emit_pre(emit, 0, 3);
     if (emit->pass == PASS_3) {
@@ -376,13 +389,6 @@ static void emit_cpy_delete_global(emit_t *emit, qstr qstr) {
     }
 }
 
-static void emit_cpy_delete_fast(emit_t *emit, qstr qstr, int local_num) {
-    emit_pre(emit, 0, 3);
-    if (emit->pass == PASS_3) {
-        printf("DELETE_FAST %s\n", qstr_str(qstr));
-    }
-}
-
 static void emit_cpy_delete_deref(emit_t *emit, qstr qstr) {
     emit_pre(emit, 0, 3);
     if (emit->pass == PASS_3) {
@@ -825,7 +831,7 @@ static void emit_cpy_yield_from(emit_t *emit) {
     }
 }
 
-static const emit_method_table_t emit_cpy_method_table = {
+const emit_method_table_t emit_cpython_method_table = {
     emit_cpy_set_native_types,
     emit_cpy_start_pass,
     emit_cpy_end_pass,
@@ -921,13 +927,4 @@ static const emit_method_table_t emit_cpy_method_table = {
     emit_cpy_yield_from,
 };
 
-void emit_cpython_new(emit_t **emit_out, const emit_method_table_t **emit_method_table_out, uint max_num_labels) {
-    emit_t *emit = m_new(emit_t, 1);
-    emit->max_num_labels = max_num_labels;
-    emit->label_offsets = m_new(int, max_num_labels);
-
-    *emit_out = emit;
-    *emit_method_table_out = &emit_cpy_method_table;
-}
-
 #endif // EMIT_ENABLE_CPY
diff --git a/py/emitx64.c b/py/emitx64.c
index cde98fe457..8ed617f2b0 100644
--- a/py/emitx64.c
+++ b/py/emitx64.c
@@ -53,8 +53,12 @@ struct _emit_t {
     bool do_native_types;
 };
 
-// forward declaration
-static const emit_method_table_t emit_x64_method_table;
+emit_t *emit_x64_new(uint max_num_labels) {
+    emit_t *emit = m_new(emit_t, 1);
+    emit->as = asm_x64_new(max_num_labels);
+    emit->do_native_types = false;
+    return emit;
+}
 
 static void emit_x64_set_native_types(emit_t *emit, bool do_native_types) {
     emit->do_native_types = do_native_types;
@@ -678,7 +682,7 @@ static void emit_x64_yield_from(emit_t *emit) {
     assert(0);
 }
 
-static const emit_method_table_t emit_x64_method_table = {
+const emit_method_table_t emit_x64_method_table = {
     emit_x64_set_native_types,
     emit_x64_start_pass,
     emit_x64_end_pass,
@@ -774,13 +778,4 @@ static const emit_method_table_t emit_x64_method_table = {
     emit_x64_yield_from,
 };
 
-void emit_x64_new(emit_t **emit_out, const emit_method_table_t **emit_method_table_out, uint max_num_labels) {
-    emit_t *emit = m_new(emit_t, 1);
-    emit->as = asm_x64_new(max_num_labels);
-    emit->do_native_types = false;
-
-    *emit_out = emit;
-    *emit_method_table_out = &emit_x64_method_table;
-}
-
 #endif // EMIT_ENABLE_X64
diff --git a/py/main.c b/py/main.c
index d765bc24f1..7b17c38a85 100644
--- a/py/main.c
+++ b/py/main.c
@@ -40,7 +40,7 @@ int main(int argc, char **argv) {
 
     py_lexer_free(lex);
 
-    if (0) {
+    if (1) {
         // execute it
         py_obj_t module_fun = rt_make_function_from_id(1);
         if (module_fun != py_const_none) {
diff --git a/py/runtime.c b/py/runtime.c
index 21f3c8c50a..26ecdc14fe 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -9,8 +9,8 @@
 #include "runtime.h"
 #include "vm.h"
 
-#define DEBUG_printf(args...) (void)0
-//#define DEBUG_printf(args...) printf(args)
+//#define DEBUG_printf(args...) (void)0
+#define DEBUG_printf(args...) printf(args)
 
 #define DEBUG_OP_printf(args...) (void)0
 //#define DEBUG_OP_printf(args...) printf(args)
@@ -423,6 +423,12 @@ const char *py_obj_get_type_str(py_obj_t o_in) {
             case O_FLOAT:
                 return "float";
 #endif
+            case O_FUN_0:
+            case O_FUN_1:
+            case O_FUN_2:
+            case O_FUN_N:
+            case O_FUN_BC:
+                return "function";
             case O_LIST:
                 return "list";
             case O_SET:
@@ -714,12 +720,12 @@ py_obj_t rt_call_function_0(py_obj_t fun) {
 py_obj_t rt_call_function_1(py_obj_t fun, py_obj_t arg) {
     if (IS_O(fun, O_FUN_1)) {
         py_obj_base_t *o = fun;
-        DEBUG_OP_printf("calling native %p...\n", o->u_fun.fun);
+        DEBUG_OP_printf("calling native %p with 1 arg\n", o->u_fun.fun);
         return ((py_fun_1_t)o->u_fun.fun)(arg);
     } else if (IS_O(fun, O_FUN_BC)) {
         py_obj_base_t *o = fun;
         assert(o->u_fun_bc.n_args == 1);
-        DEBUG_OP_printf("calling byte code %p...\n", o->u_fun_bc.code);
+        DEBUG_OP_printf("calling byte code %p with 1 arg\n", o->u_fun_bc.code);
         return py_execute_byte_code(o->u_fun_bc.code, o->u_fun_bc.len, &arg, 1);
     } else if (IS_O(fun, O_BOUND_METH)) {
         py_obj_base_t *o = fun;
diff --git a/py/scope.c b/py/scope.c
index 57a7e6875d..640d4f742b 100644
--- a/py/scope.c
+++ b/py/scope.c
@@ -8,7 +8,7 @@
 #include "parse.h"
 #include "scope.h"
 
-scope_t *scope_new(scope_kind_t kind, py_parse_node_t pn, uint unique_code_id) {
+scope_t *scope_new(scope_kind_t kind, py_parse_node_t pn, uint unique_code_id, uint emit_options) {
     scope_t *scope = m_new(scope_t, 1);
     scope->kind = kind;
     scope->parent = NULL;
@@ -53,6 +53,7 @@ scope_t *scope_new(scope_kind_t kind, py_parse_node_t pn, uint unique_code_id) {
     */
     scope->num_locals = 0;
     scope->unique_code_id = unique_code_id;
+    scope->emit_options = emit_options;
 
     return scope;
 }
@@ -80,17 +81,23 @@ id_info_t *scope_find_or_add_id(scope_t *scope, qstr qstr, bool *added) {
     */
     }
 
-    {
-    // sort insert into id_info array, so we are equivalent to CPython (no other reason to do it)
-    scope->id_info_len += 1;
-    for (int i = scope->id_info_len - 1;; i--) {
-        if (i == 0 || strcmp(qstr_str(scope->id_info[i - 1].qstr), qstr_str(qstr)) < 0) {
-            id_info = &scope->id_info[i];
-            break;
-        } else {
-            scope->id_info[i] = scope->id_info[i - 1];
+    if (0) {
+        // sort insert into id_info array, so we are equivalent to CPython (no other reason to do it)
+        // actually, seems that this is not what CPython does...
+        scope->id_info_len += 1;
+        for (int i = scope->id_info_len - 1;; i--) {
+            if (i == 0 || strcmp(qstr_str(scope->id_info[i - 1].qstr), qstr_str(qstr)) < 0) {
+                id_info = &scope->id_info[i];
+                break;
+            } else {
+                scope->id_info[i] = scope->id_info[i - 1];
+            }
         }
-    }
+    } else {
+        // just add new id to end of array of all ids; this seems to match CPython
+        // important thing is that function arguments are first, but that is
+        // handled by the compiler because it adds arguments before compiling the body
+        id_info = &scope->id_info[scope->id_info_len++];
     }
 
     id_info->param = false;
diff --git a/py/scope.h b/py/scope.h
index f9ad748d97..1b626c8ec1 100644
--- a/py/scope.h
+++ b/py/scope.h
@@ -47,9 +47,10 @@ typedef struct _scope_t {
     int num_locals;
     int stack_size;
     uint unique_code_id;
+    uint emit_options;
 } scope_t;
 
-scope_t *scope_new(scope_kind_t kind, py_parse_node_t pn, uint unique_code_id);
+scope_t *scope_new(scope_kind_t kind, py_parse_node_t pn, uint unique_code_id, uint emit_options);
 id_info_t *scope_find_or_add_id(scope_t *scope, qstr qstr, bool *added);
 id_info_t *scope_find(scope_t *scope, qstr qstr);
 id_info_t *scope_find_global(scope_t *scope, qstr qstr);