pythonGH-131798: Add _POP_CALL_TWO_LOAD_CONST_INLINE_BORROW (pythonGH-134268)

Author: tomasr8

Include/internal/pycore_uop_ids.h

@@ -1955,9 +1955,10 @@ def testfunc(n):
         self.assertEqual(res, TIER2_THRESHOLD)
         self.assertIsNotNone(ex)
         uops = get_opnames(ex)
-        self.assertIn("_CALL_ISINSTANCE", uops)
+        self.assertNotIn("_CALL_ISINSTANCE", uops)
         self.assertNotIn("_GUARD_THIRD_NULL", uops)
         self.assertNotIn("_GUARD_CALLABLE_ISINSTANCE", uops)
+        self.assertIn("_POP_CALL_TWO_LOAD_CONST_INLINE_BORROW", uops)
 
     def test_call_list_append(self):
         def testfunc(n):
@@ -1987,9 +1988,10 @@ def testfunc(n):
         self.assertEqual(res, TIER2_THRESHOLD)
         self.assertIsNotNone(ex)
         uops = get_opnames(ex)
-        self.assertIn("_CALL_ISINSTANCE", uops)
+        self.assertNotIn("_CALL_ISINSTANCE", uops)
         self.assertNotIn("_TO_BOOL_BOOL", uops)
         self.assertNotIn("_GUARD_IS_TRUE_POP", uops)
+        self.assertIn("_POP_CALL_TWO_LOAD_CONST_INLINE_BORROW", uops)
 
     def test_call_isinstance_is_false(self):
         def testfunc(n):
@@ -2004,9 +2006,10 @@ def testfunc(n):
         self.assertEqual(res, TIER2_THRESHOLD)
         self.assertIsNotNone(ex)
         uops = get_opnames(ex)
-        self.assertIn("_CALL_ISINSTANCE", uops)
+        self.assertNotIn("_CALL_ISINSTANCE", uops)
         self.assertNotIn("_TO_BOOL_BOOL", uops)
         self.assertNotIn("_GUARD_IS_FALSE_POP", uops)
+        self.assertIn("_POP_CALL_TWO_LOAD_CONST_INLINE_BORROW", uops)
 
     def test_call_isinstance_subclass(self):
         def testfunc(n):
@@ -2021,9 +2024,10 @@ def testfunc(n):
         self.assertEqual(res, TIER2_THRESHOLD)
         self.assertIsNotNone(ex)
         uops = get_opnames(ex)
-        self.assertIn("_CALL_ISINSTANCE", uops)
+        self.assertNotIn("_CALL_ISINSTANCE", uops)
         self.assertNotIn("_TO_BOOL_BOOL", uops)
         self.assertNotIn("_GUARD_IS_TRUE_POP", uops)
+        self.assertIn("_POP_CALL_TWO_LOAD_CONST_INLINE_BORROW", uops)
 
     def test_call_isinstance_unknown_object(self):
         def testfunc(n):

Include/internal/pycore_uop_metadata.h

@@ -0,0 +1,2 @@
+Add ``_POP_CALL_TWO_LOAD_CONST_INLINE_BORROW`` and use it to further
+optimize ``CALL_ISINSTANCE``.

Lib/test/test_capi/test_opt.py

@@ -5342,6 +5342,15 @@ dummy_func(
             value = PyStackRef_FromPyObjectImmortal(ptr);
         }
 
+        tier2 pure op(_POP_CALL_TWO_LOAD_CONST_INLINE_BORROW, (ptr/4, callable, null, pop1, pop2 -- value)) {
+            PyStackRef_CLOSE(pop2);
+            PyStackRef_CLOSE(pop1);
+            (void)null; // Silence compiler warnings about unused variables
+            DEAD(null);
+            PyStackRef_CLOSE(callable);
+            value = PyStackRef_FromPyObjectImmortal(ptr);
+        }
+
         tier2 op(_CHECK_FUNCTION, (func_version/2 -- )) {
             assert(PyStackRef_FunctionCheck(frame->f_funcobj));
             PyFunctionObject *func = (PyFunctionObject *)PyStackRef_AsPyObjectBorrow(frame->f_funcobj);

Misc/NEWS.d/next/Core_and_Builtins/2025-05-19-20-52-53.gh-issue-134268.HPKX1e.rst

@@ -550,6 +550,10 @@ dummy_func(void) {
         value = sym_new_const(ctx, ptr);
     }
 
+    op(_POP_CALL_TWO_LOAD_CONST_INLINE_BORROW, (ptr/4, unused, unused, unused, unused -- value)) {
+        value = sym_new_const(ctx, ptr);
+    }
+
     op(_COPY, (bottom, unused[oparg-1] -- bottom, unused[oparg-1], top)) {
         assert(oparg > 0);
         top = bottom;
@@ -901,12 +905,12 @@ dummy_func(void) {
             // known types, meaning we can deduce either True or False
 
             // The below check is equivalent to PyObject_TypeCheck(inst, cls)
+            PyObject *out = Py_False;
             if (inst_type == cls_o || PyType_IsSubtype(inst_type, cls_o)) {
-                sym_set_const(res, Py_True);
-            }
-            else {
-                sym_set_const(res, Py_False);
+                out = Py_True;
             }
+            sym_set_const(res, out);
+            REPLACE_OP(this_instr, _POP_CALL_TWO_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)out);
         }
     }