gh-107674: Improve performance of `sys.settrace` (GH-117133)

* Check tracing in RESUME_CHECK

* Only change to RESUME_CHECK if not tracing

1 files changed, 17 insertions, 11 deletions

diff --git a/Python/ceval.c b/Python/ceval.c
index 59498bc826e..11874690990 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -808,17 +808,23 @@ resume_frame:
     {
         _Py_CODEUNIT *prev = frame->instr_ptr;
         _Py_CODEUNIT *here = frame->instr_ptr = next_instr;
-        _PyFrame_SetStackPointer(frame, stack_pointer);
-        int original_opcode = _Py_call_instrumentation_line(
-                tstate, frame, here, prev);
-        stack_pointer = _PyFrame_GetStackPointer(frame);
-        if (original_opcode < 0) {
-            next_instr = here+1;
-            goto error;
-        }
-        next_instr = frame->instr_ptr;
-        if (next_instr != here) {
-            DISPATCH();
+        int original_opcode = 0;
+        if (tstate->tracing) {
+            PyCodeObject *code = _PyFrame_GetCode(frame);
+            original_opcode = code->_co_monitoring->lines[(int)(here - _PyCode_CODE(code))].original_opcode;
+        } else {
+            _PyFrame_SetStackPointer(frame, stack_pointer);
+            original_opcode = _Py_call_instrumentation_line(
+                    tstate, frame, here, prev);
+            stack_pointer = _PyFrame_GetStackPointer(frame);
+            if (original_opcode < 0) {
+                next_instr = here+1;
+                goto error;
+            }
+            next_instr = frame->instr_ptr;
+            if (next_instr != here) {
+                DISPATCH();
+            }
         }
         if (_PyOpcode_Caches[original_opcode]) {
             _PyBinaryOpCache *cache = (_PyBinaryOpCache *)(next_instr+1);