Remove mp_obj_type_t.methods entry and use .locals_dict instead.

Originally, .methods was used for methods in a ROM class, and
locals_dict for methods in a user-created class.  That distinction is
unnecessary, and we can use locals_dict for ROM classes now that we have
ROMable maps.

This removes an entry in the bloated mp_obj_type_t struct, saving a word
for each ROM object and each RAM object.  ROM objects that have a
methods table (now a locals_dict) need an extra word in total (removed
the methods pointer (1 word), no longer need the sentinel (2 words), but
now need an mp_obj_dict_t wrapper (4 words)).  But RAM objects save a
word because they never used the methods entry.

Overall the ROM usage is down by a few hundred bytes, and RAM usage is
down 1 word per user-defined type/class.

There is less code (no need to check 2 tables), and now consistent with
the way ROM modules have their tables initialised.

Efficiency is very close to equivaluent.

1 files changed, 8 insertions, 6 deletions

diff --git a/py/objgenerator.c b/py/objgenerator.c
index f440923ee6..9f609ce509 100644
--- a/py/objgenerator.c
+++ b/py/objgenerator.c
@@ -6,6 +6,7 @@
 #include "mpconfig.h"
 #include "qstr.h"
 #include "obj.h"
+#include "map.h"
 #include "runtime.h"
 #include "bc.h"
 #include "objgenerator.h"
@@ -192,20 +193,21 @@ STATIC mp_obj_t gen_instance_close(mp_obj_t self_in) {
 
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(gen_instance_close_obj, gen_instance_close);
 
-STATIC const mp_method_t gen_type_methods[] = {
-    { MP_QSTR_close, &gen_instance_close_obj },
-    { MP_QSTR_send, &gen_instance_send_obj },
-    { MP_QSTR_throw, &gen_instance_throw_obj },
-    { MP_QSTR_NULL, NULL }, // end-of-list sentinel
+STATIC const mp_map_elem_t gen_instance_locals_dict_table[] = {
+    { MP_OBJ_NEW_QSTR(MP_QSTR_close), (mp_obj_t)&gen_instance_close_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_send), (mp_obj_t)&gen_instance_send_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_throw), (mp_obj_t)&gen_instance_throw_obj },
 };
 
+STATIC MP_DEFINE_CONST_DICT(gen_instance_locals_dict, gen_instance_locals_dict_table);
+
 const mp_obj_type_t gen_instance_type = {
     { &mp_type_type },
     .name = MP_QSTR_generator,
     .print = gen_instance_print,
     .getiter = gen_instance_getiter,
     .iternext = gen_instance_iternext,
-    .methods = gen_type_methods,
+    .locals_dict = (mp_obj_t)&gen_instance_locals_dict,
 };
 
 mp_obj_t mp_obj_new_gen_instance(const byte *bytecode, uint n_state, int n_args, const mp_obj_t *args) {