commit e6003f466e6f5b7eddd01740666230b62ab5a872
author Damien George <damien.p.george@gmail.com> Mon Feb 13 15:44:31 2017 +1100
committer Damien George <damien.p.george@gmail.com> Thu Feb 16 19:11:34 2017 +1100
tree 01dabf002737d9960c822623f9f54316a8143c4a
parent 019048a6dc0783515e7fba4255dd2b22265d1059

py: De-optimise some uses of mp_getiter, so they don't use the C stack.

In these cases the heap is anyway used to create a new object so no real
need to use the C stack for iterating.  It saves a few bytes of code size.

py/objdict.c

diff --git a/py/objdict.c b/py/objdict.c
index c52403f..013cc0a 100644
--- a/py/objdict.c
+++ b/py/objdict.c
@@ -250,8 +250,7 @@
 
 // this is a classmethod
 STATIC mp_obj_t dict_fromkeys(size_t n_args, const mp_obj_t *args) {
-    mp_obj_iter_buf_t iter_buf;
-    mp_obj_t iter = mp_getiter(args[1], &iter_buf);
+    mp_obj_t iter = mp_getiter(args[1], NULL);
     mp_obj_t value = mp_const_none;
     mp_obj_t next = MP_OBJ_NULL;
 
@@ -377,12 +376,10 @@
             }
         } else {
             // update from a generic iterable of pairs
-            mp_obj_iter_buf_t iter_buf;
-            mp_obj_t iter = mp_getiter(args[1], &iter_buf);
+            mp_obj_t iter = mp_getiter(args[1], NULL);
             mp_obj_t next = MP_OBJ_NULL;
             while ((next = mp_iternext(iter)) != MP_OBJ_STOP_ITERATION) {
-                mp_obj_iter_buf_t inner_iter_buf;
-                mp_obj_t inneriter = mp_getiter(next, &inner_iter_buf);
+                mp_obj_t inneriter = mp_getiter(next, NULL);
                 mp_obj_t key = mp_iternext(inneriter);
                 mp_obj_t value = mp_iternext(inneriter);
                 mp_obj_t stop = mp_iternext(inneriter);