POP TOP

python · savannahostrowski · Sep 15, 2025 · Jul 26, 2025 · Jul 29, 2025 · Jul 31, 2025
commit e75ca80cff4fac57cebd1aee8ee2f84db93620cb
diff --git a/Lib/test/test_capi/test_opt.py b/Lib/test/test_capi/test_opt.py
@@ -1614,6 +1614,55 @@ def f(n):
         # But all of the appends we care about are still there:
         self.assertEqual(uops.count("_CALL_LIST_APPEND"), len("ABCDEFG"))
 
+    def test_replace_with_true_pop_top_load_const_inline_borrow(self):
+        def testfunc(n):
+            x = 0
+            for _ in range(n):
+                a = 42
+                result = bool(a)
+                if result:
+                    x += 1
+            return x
+        res, ex = self._run_with_optimizer(testfunc, TIER2_THRESHOLD)
+        self.assertEqual(res, TIER2_THRESHOLD)
+        self.assertIsNotNone(ex)
+        uops = get_opnames(ex)
+        self.assertNotIn("_REPLACE_WITH_TRUE", uops)
+        self.assertNotIn("_POP_TOP_LOAD_CONST_INLINE_BORROW", uops)
+
+    def test_to_bool_none_pop_top_load_const_inline_borrow(self):
+        def testfunc(n):
+            x = 0
+            for _ in range(n):
+                a = None
+                result = bool(a)
+                if result:
+                    x += 1
+            return x
+        res, ex = self._run_with_optimizer(testfunc, TIER2_THRESHOLD)
+        self.assertEqual(res, 0)
+        self.assertIsNotNone(ex)
+        uops = get_opnames(ex)
+        self.assertNotIn("_TO_BOOL_NONE", uops)
+        self.assertNotIn("_POP_TOP_LOAD_CONST_INLINE_BORROW", uops)
+
+    def test_get_len_pop_top_load_const_inline_borrow(self):
+        def testfunc(n):
+            x = 0
+            for _ in range(n):
+                a = "foo"
+                result = len(a)
+                if result:
+                    x += 1
+            return x
+
+        res, ex = self._run_with_optimizer(testfunc, TIER2_THRESHOLD)
+        self.assertEqual(res, TIER2_THRESHOLD)
+        self.assertIsNotNone(ex)
+        uops = get_opnames(ex)
+        self.assertNotIn("_GET_LEN", uops)
+        self.assertNotIn("_POP_TOP_LOAD_CONST_INLINE_BORROW", uops)
+
     def test_compare_op_pop_two_load_const_inline_borrow(self):
         def testfunc(n):
             x = 0

@@ -362,6 +362,7 @@ dummy_func(void) {
     }
 
     op(_TO_BOOL_NONE, (value -- res)) {
+        REPLACE_OPCODE_IF_EVALUATES_PURE(value);
         int already_bool = optimize_to_bool(this_instr, ctx, value, &res);
         if (!already_bool) {
             sym_set_const(value, Py_None);

diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h