Implement _GROW_TIER2_FRAME without adding tier2_extra_size

Include/internal/pycore_frame.h

@@ -65,7 +65,6 @@ typedef struct _PyInterpreterFrame {
     _Py_CODEUNIT *instr_ptr; /* Instruction currently executing (or about to begin) */
     int stacktop;  /* Offset of TOS from localsplus  */
     uint16_t return_offset;  /* Only relevant during a function call */
-    uint16_t tier2_extra_size; /* How many extra entries is at the end of localsplus for tier 2 inlining */
     char owner;
     /* Locals and stack */
     PyObject *localsplus[1];
@@ -132,7 +131,6 @@ _PyFrame_Initialize(
     frame->instr_ptr = _PyCode_CODE(code);
     frame->return_offset = 0;
     frame->owner = FRAME_OWNED_BY_THREAD;
-    frame->tier2_extra_size = 0;
 
     for (int i = null_locals_from; i < code->co_nlocalsplus; i++) {
         frame->localsplus[i] = NULL;
@@ -260,35 +258,6 @@ _PyThreadState_PushFrame(PyThreadState *tstate, size_t size);
 
 void _PyThreadState_PopFrame(PyThreadState *tstate, _PyInterpreterFrame *frame);
 
-
-/* Converts frame for tier 2.
- * Adds stack space at the end of the current frame for Tier 2 execution.
- * The frame that is being expanded MUST be the current executing frame, and
- * it must be at the top of the datastack.
- * */
-static inline int
-_PyFrame_ConvertToTier2(PyThreadState *tstate, _PyInterpreterFrame *frame,
-                        int localsplus_grow)
-{
-    assert(localsplus_grow > 0);
-    // Already grown previously
-    if (frame->tier2_extra_size >= localsplus_grow) {
-        return 0;
-    }
-    if (frame->owner != FRAME_OWNED_BY_THREAD) {
-        return 1;
-    }
-    if (!_PyThreadState_HasStackSpace(tstate, localsplus_grow)) {
-        return 1;
-    }
-    assert(_PyThreadState_HasStackSpace(tstate, localsplus_grow));
-    assert(tstate->current_frame == frame);
-    tstate->datastack_top += localsplus_grow;
-    assert(tstate->datastack_top < tstate->datastack_limit);
-    frame->tier2_extra_size += localsplus_grow;
-    return 0;
-}
-
 /* Pushes a frame without checking for space.
  * Must be guarded by _PyThreadState_HasStackSpace()
  * Consumes reference to func. */

Lib/test/test_sys.py

@@ -1550,7 +1550,7 @@ class C(object): pass
         def func():
             return sys._getframe()
         x = func()
-        check(x, size('3Pi3c7P4ic??2P'))
+        check(x, size('3Pi3c7P2ic??2P'))
         # function
         def func(): pass
         check(func, size('15Pi'))
@@ -1567,7 +1567,7 @@ def bar(cls):
             check(bar, size('PP'))
         # generator
         def get_gen(): yield 1
-        check(get_gen(), size('PP4P4c7P4ic??2P'))
+        check(get_gen(), size('PP4P4c7P2ic??2P'))
         # iterator
         check(iter('abc'), size('lP'))
         # callable-iterator

Python/bytecodes.c

@@ -4175,7 +4175,10 @@ dummy_func(
         }
 
         op(_GROW_TIER2_FRAME, (--)) {
-            DEOPT_IF(_PyFrame_ConvertToTier2(tstate, frame, oparg));
+            DEOPT_IF(frame->owner != FRAME_OWNED_BY_THREAD);
+            DEOPT_IF(stack_pointer + oparg > tstate->datastack_limit);
+            assert(stack_pointer <= tstate->datastack_top);
+            tstate->datastack_top = stack_pointer + oparg;
         }
 
 

Python/ceval.c

@@ -1675,11 +1675,10 @@ static void
 clear_thread_frame(PyThreadState *tstate, _PyInterpreterFrame * frame)
 {
     assert(frame->owner == FRAME_OWNED_BY_THREAD);
-    // Make sure that this is, indeed, the top frame. We can't check this in
-    // _PyThreadState_PopFrame, since f_code is already cleared at that point:
-    // This doesn't apply to tier 2 frames.
-    assert(frame->tier2_extra_size ==  0 ? (PyObject **)frame + _PyFrame_GetCode(frame)->co_framesize ==
-              tstate->datastack_top : 1);
+    // // Make sure that this is, indeed, the top frame. We can't check this in
+    // // _PyThreadState_PopFrame, since f_code is already cleared at that point:
+    // assert((PyObject **)frame + _PyFrame_GetCode(frame)->co_framesize ==
+    //     tstate->datastack_top);
     tstate->c_recursion_remaining--;
     assert(frame->frame_obj == NULL || frame->frame_obj->f_frame == frame);
     _PyFrame_ClearExceptCode(frame);
@@ -1793,7 +1792,6 @@ _PyEvalFramePushAndInit_Ex(PyThreadState *tstate, PyFunctionObject *func,
     return NULL;
 }
 
-
 PyObject *
 _PyEval_Vector(PyThreadState *tstate, PyFunctionObject *func,
                PyObject *locals,