From fdf1a2fc6d628a3a21df4b9be4ffb84cca46185f Mon Sep 17 00:00:00 2001
From: Guido van Rossum <guido@python.org>
Date: Wed, 1 Nov 2023 08:17:58 -0700
Subject: [PATCH] Move `_EXIT_TRACE` logic to a separate label

Using `GOTO_TIER_ONE()` macro. This should make things simpler
for Justin.
---
 Python/bytecodes.c        |  5 +----
 Python/ceval.c            | 11 +++++++++++
 Python/ceval_macros.h     |  2 ++
 Python/executor_cases.c.h |  5 +----
 4 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/Python/bytecodes.c b/Python/bytecodes.c
index 6c668c36166bd7..98af114a72fa60 100644
--- a/Python/bytecodes.c
+++ b/Python/bytecodes.c
@@ -4024,10 +4024,7 @@ dummy_func(
 
         op(_EXIT_TRACE, (--)) {
             TIER_TWO_ONLY
-            _PyFrame_SetStackPointer(frame, stack_pointer);
-            Py_DECREF(current_executor);
-            OPT_HIST(trace_uop_execution_counter, trace_run_length_hist);
-            goto enter_tier_one;
+            GOTO_TIER_ONE();
         }
 
         op(_INSERT, (unused[oparg], top -- top, unused[oparg])) {
diff --git a/Python/ceval.c b/Python/ceval.c
index e1c9a2e0b03ef0..6e156ab2009468 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1027,6 +1027,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
         }
     }
 
+// Jump here from ERROR_IF(..., unbound_local_error)
 unbound_local_error_tier_two:
     _PyEval_FormatExcCheckArg(tstate, PyExc_UnboundLocalError,
         UNBOUNDLOCAL_ERROR_MSG,
@@ -1034,6 +1035,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
     );
     goto error_tier_two;
 
+// JUMP to any of these from ERROR_IF(..., error)
 pop_4_error_tier_two:
     STACK_SHRINK(1);
 pop_3_error_tier_two:
@@ -1050,6 +1052,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
     Py_DECREF(current_executor);
     goto resume_with_error;
 
+// Jump here from DEOPT_IF()
 deoptimize:
     // On DEOPT_IF we just repeat the last instruction.
     // This presumes nothing was popped from the stack (nor pushed).
@@ -1058,10 +1061,18 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
     frame->return_offset = 0;  // Dispatch to frame->instr_ptr
     _PyFrame_SetStackPointer(frame, stack_pointer);
     Py_DECREF(current_executor);
+    // Fall through
+// Jump here from ENTER_EXECUTOR
 enter_tier_one:
     next_instr = frame->instr_ptr;
     goto resume_frame;
 
+// Jump here from _EXIT_TRACE
+exit_trace:
+    _PyFrame_SetStackPointer(frame, stack_pointer);
+    Py_DECREF(current_executor);
+    OPT_HIST(trace_uop_execution_counter, trace_run_length_hist);
+    goto enter_tier_one;
 }
 #if defined(__GNUC__)
 #  pragma GCC diagnostic pop
diff --git a/Python/ceval_macros.h b/Python/ceval_macros.h
index d22075169b8199..546adbe5f438d1 100644
--- a/Python/ceval_macros.h
+++ b/Python/ceval_macros.h
@@ -395,3 +395,5 @@ stack_pointer = _PyFrame_GetStackPointer(frame);
 /* Tier-switching macros. */
 
 #define GOTO_TIER_TWO() goto enter_tier_two;
+
+#define GOTO_TIER_ONE() goto exit_trace;
diff --git a/Python/executor_cases.c.h b/Python/executor_cases.c.h
index 94005285ec7ee8..fdf3e4b01a88b3 100644
--- a/Python/executor_cases.c.h
+++ b/Python/executor_cases.c.h
@@ -3261,10 +3261,7 @@
 
         case _EXIT_TRACE: {
             TIER_TWO_ONLY
-            _PyFrame_SetStackPointer(frame, stack_pointer);
-            Py_DECREF(current_executor);
-            OPT_HIST(trace_uop_execution_counter, trace_run_length_hist);
-            goto enter_tier_one;
+            GOTO_TIER_ONE();
             break;
         }