GH-120619: Clean up `RETURN_VALUE` instruction (GH-120624)

* Rename _POP_FRAME to _RETURN_VALUE as it returns a value as well as popping a frame.

* Remove remaining _POP_FRAMEs

7 files changed, 26 insertions, 20 deletions

diff --git a/Python/bytecodes.c b/Python/bytecodes.c
index 05c17ac..31db284 100644
--- a/Python/bytecodes.c
+++ b/Python/bytecodes.c
@@ -827,7 +827,7 @@ dummy_func(
         // We definitely pop the return value off the stack on entry.
         // We also push it onto the stack on exit, but that's a
         // different frame, and it's accounted for by _PUSH_FRAME.
-        op(_POP_FRAME, (retval --)) {
+        inst(RETURN_VALUE, (retval -- res)) {
             #if TIER_ONE
             assert(frame != &entry_frame);
             #endif
@@ -839,15 +839,12 @@ dummy_func(
             _PyInterpreterFrame *dying = frame;
             frame = tstate->current_frame = dying->previous;
             _PyEval_FrameClearAndPop(tstate, dying);
-            _PyFrame_StackPush(frame, retval);
             LOAD_SP();
             LOAD_IP(frame->return_offset);
+            res = retval;
             LLTRACE_RESUME_FRAME();
         }
 
-        macro(RETURN_VALUE) =
-            _POP_FRAME;
-
         inst(INSTRUMENTED_RETURN_VALUE, (retval --)) {
             int err = _Py_call_instrumentation_arg(
                     tstate, PY_MONITORING_EVENT_PY_RETURN,
@@ -869,7 +866,7 @@ dummy_func(
 
         macro(RETURN_CONST) =
             LOAD_CONST +
-            _POP_FRAME;
+            RETURN_VALUE;
 
         inst(INSTRUMENTED_RETURN_CONST, (--)) {
             PyObject *retval = GETITEM(FRAME_CO_CONSTS, oparg);
diff --git a/Python/executor_cases.c.h b/Python/executor_cases.c.h
index 470c82d..d390c9f 100644
--- a/Python/executor_cases.c.h
+++ b/Python/executor_cases.c.h
@@ -971,8 +971,9 @@
             break;
         }
 
-        case _POP_FRAME: {
+        case _RETURN_VALUE: {
             PyObject *retval;
+            PyObject *res;
             retval = stack_pointer[-1];
             #if TIER_ONE
             assert(frame != &entry_frame);
@@ -985,10 +986,12 @@
             _PyInterpreterFrame *dying = frame;
             frame = tstate->current_frame = dying->previous;
             _PyEval_FrameClearAndPop(tstate, dying);
-            _PyFrame_StackPush(frame, retval);
             LOAD_SP();
             LOAD_IP(frame->return_offset);
+            res = retval;
             LLTRACE_RESUME_FRAME();
+            stack_pointer[0] = res;
+            stack_pointer += 1;
             break;
         }
 
diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h
index 0274f8b..8a6f5ff 100644
--- a/Python/generated_cases.c.h
+++ b/Python/generated_cases.c.h
@@ -5202,12 +5202,13 @@
             INSTRUCTION_STATS(RETURN_CONST);
             PyObject *value;
             PyObject *retval;
+            PyObject *res;
             // _LOAD_CONST
             {
                 value = GETITEM(FRAME_CO_CONSTS, oparg);
                 Py_INCREF(value);
             }
-            // _POP_FRAME
+            // _RETURN_VALUE
             retval = value;
             {
                 #if TIER_ONE
@@ -5220,11 +5221,13 @@
                 _PyInterpreterFrame *dying = frame;
                 frame = tstate->current_frame = dying->previous;
                 _PyEval_FrameClearAndPop(tstate, dying);
-                _PyFrame_StackPush(frame, retval);
                 LOAD_SP();
                 LOAD_IP(frame->return_offset);
+                res = retval;
                 LLTRACE_RESUME_FRAME();
             }
+            stack_pointer[0] = res;
+            stack_pointer += 1;
             DISPATCH();
         }
 
@@ -5265,6 +5268,7 @@
             next_instr += 1;
             INSTRUCTION_STATS(RETURN_VALUE);
             PyObject *retval;
+            PyObject *res;
             retval = stack_pointer[-1];
             #if TIER_ONE
             assert(frame != &entry_frame);
@@ -5277,10 +5281,12 @@
             _PyInterpreterFrame *dying = frame;
             frame = tstate->current_frame = dying->previous;
             _PyEval_FrameClearAndPop(tstate, dying);
-            _PyFrame_StackPush(frame, retval);
             LOAD_SP();
             LOAD_IP(frame->return_offset);
+            res = retval;
             LLTRACE_RESUME_FRAME();
+            stack_pointer[0] = res;
+            stack_pointer += 1;
             DISPATCH();
         }
 
diff --git a/Python/optimizer.c b/Python/optimizer.c
index 4dc3438..c9b187d 100644
--- a/Python/optimizer.c
+++ b/Python/optimizer.c
@@ -537,7 +537,7 @@ add_to_trace(
 // Reserve space for N uops, plus 3 for _SET_IP, _CHECK_VALIDITY and _EXIT_TRACE
 #define RESERVE(needed) RESERVE_RAW((needed) + 3, _PyUOpName(opcode))
 
-// Trace stack operations (used by _PUSH_FRAME, _POP_FRAME)
+// Trace stack operations (used by _PUSH_FRAME, _RETURN_VALUE)
 #define TRACE_STACK_PUSH() \
     if (trace_stack_depth >= TRACE_STACK_SIZE) { \
         DPRINTF(2, "Trace stack overflow\n"); \
@@ -748,10 +748,10 @@ top:  // Jump here after _PUSH_FRAME or likely branches
                     int nuops = expansion->nuops;
                     RESERVE(nuops + 1); /* One extra for exit */
                     int16_t last_op = expansion->uops[nuops-1].uop;
-                    if (last_op == _POP_FRAME || last_op == _RETURN_GENERATOR || last_op == _YIELD_VALUE) {
+                    if (last_op == _RETURN_VALUE || last_op == _RETURN_GENERATOR || last_op == _YIELD_VALUE) {
                         // Check for trace stack underflow now:
                         // We can't bail e.g. in the middle of
-                        // LOAD_CONST + _POP_FRAME.
+                        // LOAD_CONST + _RETURN_VALUE.
                         if (trace_stack_depth == 0) {
                             DPRINTF(2, "Trace stack underflow\n");
                             OPT_STAT_INC(trace_stack_underflow);
@@ -810,7 +810,7 @@ top:  // Jump here after _PUSH_FRAME or likely branches
                                 Py_FatalError("garbled expansion");
                         }
 
-                        if (uop == _POP_FRAME || uop == _RETURN_GENERATOR || uop == _YIELD_VALUE) {
+                        if (uop == _RETURN_VALUE || uop == _RETURN_GENERATOR || uop == _YIELD_VALUE) {
                             TRACE_STACK_POP();
                             /* Set the operand to the function or code object returned to,
                              * to assist optimization passes. (See _PUSH_FRAME below.)
diff --git a/Python/optimizer_analysis.c b/Python/optimizer_analysis.c
index 75d1d9f..0e45bd8 100644
--- a/Python/optimizer_analysis.c
+++ b/Python/optimizer_analysis.c
@@ -265,7 +265,7 @@ remove_globals(_PyInterpreterFrame *frame, _PyUOpInstruction *buffer,
                 }
                 break;
             }
-            case _POP_FRAME:
+            case _RETURN_VALUE:
             {
                 builtins_watched >>= 1;
                 globals_watched >>= 1;
@@ -365,13 +365,13 @@ eliminate_pop_guard(_PyUOpInstruction *this_instr, bool exit)
     }
 }
 
-/* _PUSH_FRAME/_POP_FRAME's operand can be 0, a PyFunctionObject *, or a
+/* _PUSH_FRAME/_RETURN_VALUE's operand can be 0, a PyFunctionObject *, or a
  * PyCodeObject *. Retrieve the code object if possible.
  */
 static PyCodeObject *
 get_code(_PyUOpInstruction *op)
 {
-    assert(op->opcode == _PUSH_FRAME || op->opcode == _POP_FRAME || op->opcode == _RETURN_GENERATOR);
+    assert(op->opcode == _PUSH_FRAME || op->opcode == _RETURN_VALUE || op->opcode == _RETURN_GENERATOR);
     PyCodeObject *co = NULL;
     uint64_t operand = op->operand;
     if (operand == 0) {
diff --git a/Python/optimizer_bytecodes.c b/Python/optimizer_bytecodes.c
index e6fb85a..121ca92 100644
--- a/Python/optimizer_bytecodes.c
+++ b/Python/optimizer_bytecodes.c
@@ -606,7 +606,7 @@ dummy_func(void) {
         ctx->done = true;
     }
 
-    op(_POP_FRAME, (retval -- res)) {
+    op(_RETURN_VALUE, (retval -- res)) {
         SYNC_SP();
         ctx->frame->stack_pointer = stack_pointer;
         frame_pop(ctx);
diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h
index 18f3ca4..53959a3 100644
--- a/Python/optimizer_cases.c.h
+++ b/Python/optimizer_cases.c.h
@@ -558,7 +558,7 @@
             break;
         }
 
-        case _POP_FRAME: {
+        case _RETURN_VALUE: {
             _Py_UopsSymbol *retval;
             _Py_UopsSymbol *res;
             retval = stack_pointer[-1];