bpo-44990: Change layout of evaluation frames. "Layout B" (GH-27933)

Places the locals between the specials and stack. This is the more "natural" layout for a C struct, makes the code simpler and gives a slight speedup (~1%)

1 files changed, 3 insertions, 7 deletions

diff --git a/Objects/genobject.c b/Objects/genobject.c
index 86cd9cf725..7a687ce7f7 100644
--- a/Objects/genobject.c
+++ b/Objects/genobject.c
@@ -190,8 +190,7 @@ gen_send_ex2(PyGenObject *gen, PyObject *arg, PyObject **presult,
     /* Push arg onto the frame's value stack */
     result = arg ? arg : Py_None;
     Py_INCREF(result);
-    frame->stack[frame->stackdepth] = result;
-    frame->stackdepth++;
+    _PyFrame_StackPush(frame, result);
 
     frame->previous = tstate->frame;
 
@@ -350,8 +349,7 @@ _PyGen_yf(PyGenObject *gen)
 
         if (code[(frame->f_lasti+1)*sizeof(_Py_CODEUNIT)] != YIELD_FROM)
             return NULL;
-        assert(frame->stackdepth > 0);
-        yf = frame->stack[frame->stackdepth-1];
+        yf = _PyFrame_StackPeek(frame);
         Py_INCREF(yf);
     }
 
@@ -469,9 +467,7 @@ _gen_throw(PyGenObject *gen, int close_on_genexit,
         if (!ret) {
             PyObject *val;
             /* Pop subiterator from stack */
-            assert(gen->gi_xframe->stackdepth > 0);
-            gen->gi_xframe->stackdepth--;
-            ret = gen->gi_xframe->stack[gen->gi_xframe->stackdepth];
+            ret = _PyFrame_StackPop(gen->gi_xframe);
             assert(ret == yf);
             Py_DECREF(ret);
             /* Termination repetition of YIELD_FROM */