gh-148604: change ADD_OP(_POP_TOP, ...) to optimize_pop_top in optimizer_bytecodes.c (GH-148619)

Author: NekoAsakura

Lib/test/test_capi/test_opt.py

@@ -2642,6 +2642,9 @@ def testfunc(n):
         uops = get_opnames(ex)
         # When the result of type(...) is known, _CALL_TYPE_1 is decomposed.
         self.assertNotIn("_CALL_TYPE_1", uops)
+        # _CALL_TYPE_1 produces 2 _POP_TOP_NOP (callable and null)
+        # type(42) is int produces 4 _POP_TOP_NOP
+        self.assertGreaterEqual(count_ops(ex, "_POP_TOP_NOP"), 6)
 
     def test_call_type_1_result_is_const(self):
         def testfunc(n):
@@ -3453,6 +3456,10 @@ def f(n):
         self.assertEqual(res, TIER2_THRESHOLD)
         uops = get_opnames(ex)
         self.assertNotIn("_LOAD_SPECIAL", uops)
+        # __enter__/__exit__ produce 2 _POP_TOP_NOP
+        # x += 1 produces 2 _POP_TOP_NOP
+        # __exit__()'s None return produces 1 _POP_TOP_NOP
+        self.assertGreaterEqual(count_ops(ex, "_POP_TOP_NOP"), 5)
 
     def test_store_fast_refcount_elimination(self):
         def foo(x):

Python/optimizer_bytecodes.c

@@ -1480,13 +1480,13 @@ dummy_func(void) {
        next = sym_new_type(ctx, &PyLong_Type);
     }
 
-    op(_CALL_TYPE_1, (unused, unused, arg -- res, a)) {
+    op(_CALL_TYPE_1, (callable, null, arg -- res, a)) {
         PyObject* type = (PyObject *)sym_get_type(arg);
         if (type) {
             res = sym_new_const(ctx, type);
             ADD_OP(_SWAP, 3, 0);
-            ADD_OP(_POP_TOP, 0, 0);
-            ADD_OP(_POP_TOP, 0, 0);
+            optimize_pop_top(ctx, this_instr, callable);
+            optimize_pop_top(ctx, this_instr, null);
             ADD_OP(_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)type);
             ADD_OP(_SWAP, 2, 0);
         }
@@ -1509,7 +1509,7 @@ dummy_func(void) {
         a = arg;
     }
 
-    op(_CALL_ISINSTANCE, (unused, unused, instance, cls -- res)) {
+    op(_CALL_ISINSTANCE, (callable, null, instance, cls -- res)) {
         // the result is always a bool, but sometimes we can
         // narrow it down to True or False
         res = sym_new_type(ctx, &PyBool_Type);
@@ -1525,10 +1525,10 @@ dummy_func(void) {
                 out = Py_True;
             }
             sym_set_const(res, out);
-            ADD_OP(_POP_TOP, 0, 0);
-            ADD_OP(_POP_TOP, 0, 0);
-            ADD_OP(_POP_TOP_NOP, 0, 0);
-            ADD_OP(_POP_TOP, 0, 0);
+            optimize_pop_top(ctx, this_instr, cls);
+            optimize_pop_top(ctx, this_instr, instance);
+            optimize_pop_top(ctx, this_instr, null);
+            optimize_pop_top(ctx, this_instr, callable);
             ADD_OP(_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)out);
         }
     }
@@ -1902,7 +1902,7 @@ dummy_func(void) {
                 ADD_OP(immortal ? _LOAD_CONST_INLINE_BORROW : _LOAD_CONST_INLINE,
                        0, (uintptr_t)descr);
                 ADD_OP(_SWAP, 3, 0);
-                ADD_OP(_POP_TOP, 0, 0);
+                optimize_pop_top(ctx, this_instr, method_and_self[0]);
                 if ((type->tp_flags & Py_TPFLAGS_IMMUTABLETYPE) == 0) {
                     PyType_Watch(TYPE_WATCHER_ID, (PyObject *)type);
                     _Py_BloomFilter_Add(dependencies, type);