gh-134584: Eliminate redundant refcounting from `_CALL_STR_1` (GH-136070)

Signed-off-by: Manjusaka <me@manjusaka.me>

diff --git a/Include/internal/pycore_opcode_metadata.h b/Include/internal/pycore_opcode_metadata.h
index 82c7cf486b1a008ed00335b57c829d02edea3197..ec2eb15151c98206da287cb14ac69ca6e29eb471 100644 (file)
--- a/Include/internal/pycore_opcode_metadata.h
+++ b/Include/internal/pycore_opcode_metadata.h
@@ -1129,7 +1129,7 @@ const struct opcode_metadata _PyOpcode_opcode_metadata[267] = {
     [CALL_NON_PY_GENERAL] = { true, INSTR_FMT_IBC00, HAS_ARG_FLAG | HAS_EVAL_BREAK_FLAG | HAS_EXIT_FLAG | HAS_ERROR_FLAG | HAS_ESCAPES_FLAG },
     [CALL_PY_EXACT_ARGS] = { true, INSTR_FMT_IBC00, HAS_ARG_FLAG | HAS_DEOPT_FLAG | HAS_EXIT_FLAG | HAS_SYNC_SP_FLAG | HAS_NEEDS_GUARD_IP_FLAG },
     [CALL_PY_GENERAL] = { true, INSTR_FMT_IBC00, HAS_ARG_FLAG | HAS_DEOPT_FLAG | HAS_EXIT_FLAG | HAS_ERROR_FLAG | HAS_ERROR_NO_POP_FLAG | HAS_ESCAPES_FLAG | HAS_SYNC_SP_FLAG | HAS_NEEDS_GUARD_IP_FLAG },
-    [CALL_STR_1] = { true, INSTR_FMT_IBC00, HAS_ARG_FLAG | HAS_EVAL_BREAK_FLAG | HAS_DEOPT_FLAG | HAS_ERROR_FLAG | HAS_ESCAPES_FLAG },
+    [CALL_STR_1] = { true, INSTR_FMT_IBC00, HAS_ARG_FLAG | HAS_EVAL_BREAK_FLAG | HAS_DEOPT_FLAG | HAS_ERROR_FLAG | HAS_ERROR_NO_POP_FLAG | HAS_ESCAPES_FLAG },
     [CALL_TUPLE_1] = { true, INSTR_FMT_IBC00, HAS_ARG_FLAG | HAS_EVAL_BREAK_FLAG | HAS_DEOPT_FLAG | HAS_ERROR_FLAG | HAS_ERROR_NO_POP_FLAG | HAS_ESCAPES_FLAG },
     [CALL_TYPE_1] = { true, INSTR_FMT_IBC00, HAS_ARG_FLAG | HAS_DEOPT_FLAG | HAS_ESCAPES_FLAG },
     [CHECK_EG_MATCH] = { true, INSTR_FMT_IX, HAS_ERROR_FLAG | HAS_ESCAPES_FLAG },
@@ -1375,7 +1375,7 @@ _PyOpcode_macro_expansion[256] = {
     [CALL_NON_PY_GENERAL] = { .nuops = 3, .uops = { { _CHECK_IS_NOT_PY_CALLABLE, OPARG_SIMPLE, 3 }, { _CALL_NON_PY_GENERAL, OPARG_SIMPLE, 3 }, { _CHECK_PERIODIC_AT_END, OPARG_REPLACED, 3 } } },
     [CALL_PY_EXACT_ARGS] = { .nuops = 8, .uops = { { _CHECK_PEP_523, OPARG_SIMPLE, 1 }, { _CHECK_FUNCTION_VERSION, 2, 1 }, { _CHECK_FUNCTION_EXACT_ARGS, OPARG_SIMPLE, 3 }, { _CHECK_STACK_SPACE, OPARG_SIMPLE, 3 }, { _CHECK_RECURSION_REMAINING, OPARG_SIMPLE, 3 }, { _INIT_CALL_PY_EXACT_ARGS, OPARG_SIMPLE, 3 }, { _SAVE_RETURN_OFFSET, OPARG_SAVE_RETURN_OFFSET, 3 }, { _PUSH_FRAME, OPARG_SIMPLE, 3 } } },
     [CALL_PY_GENERAL] = { .nuops = 6, .uops = { { _CHECK_PEP_523, OPARG_SIMPLE, 1 }, { _CHECK_FUNCTION_VERSION, 2, 1 }, { _CHECK_RECURSION_REMAINING, OPARG_SIMPLE, 3 }, { _PY_FRAME_GENERAL, OPARG_SIMPLE, 3 }, { _SAVE_RETURN_OFFSET, OPARG_SAVE_RETURN_OFFSET, 3 }, { _PUSH_FRAME, OPARG_SIMPLE, 3 } } },
-    [CALL_STR_1] = { .nuops = 4, .uops = { { _GUARD_NOS_NULL, OPARG_SIMPLE, 3 }, { _GUARD_CALLABLE_STR_1, OPARG_SIMPLE, 3 }, { _CALL_STR_1, OPARG_SIMPLE, 3 }, { _CHECK_PERIODIC_AT_END, OPARG_REPLACED, 3 } } },
+    [CALL_STR_1] = { .nuops = 5, .uops = { { _GUARD_NOS_NULL, OPARG_SIMPLE, 3 }, { _GUARD_CALLABLE_STR_1, OPARG_SIMPLE, 3 }, { _CALL_STR_1, OPARG_SIMPLE, 3 }, { _POP_TOP, OPARG_SIMPLE, 3 }, { _CHECK_PERIODIC_AT_END, OPARG_REPLACED, 3 } } },
     [CALL_TUPLE_1] = { .nuops = 5, .uops = { { _GUARD_NOS_NULL, OPARG_SIMPLE, 3 }, { _GUARD_CALLABLE_TUPLE_1, OPARG_SIMPLE, 3 }, { _CALL_TUPLE_1, OPARG_SIMPLE, 3 }, { _POP_TOP, OPARG_SIMPLE, 3 }, { _CHECK_PERIODIC_AT_END, OPARG_REPLACED, 3 } } },
     [CALL_TYPE_1] = { .nuops = 3, .uops = { { _GUARD_NOS_NULL, OPARG_SIMPLE, 3 }, { _GUARD_CALLABLE_TYPE_1, OPARG_SIMPLE, 3 }, { _CALL_TYPE_1, OPARG_SIMPLE, 3 } } },
     [CHECK_EG_MATCH] = { .nuops = 1, .uops = { { _CHECK_EG_MATCH, OPARG_SIMPLE, 0 } } },

diff --git a/Include/internal/pycore_uop_ids.h b/Include/internal/pycore_uop_ids.h
index ce1ad5a4c8a5f68be1e3adcd2ce8ad1b8fed2df5..eb8e915e6d9a9fddab6c4217dc41345c807318be 100644 (file)
--- a/Include/internal/pycore_uop_ids.h
+++ b/Include/internal/pycore_uop_ids.h
@@ -438,7 +438,7 @@ extern "C" {
 #define _CALL_METHOD_DESCRIPTOR_NOARGS_r01 631
 #define _CALL_METHOD_DESCRIPTOR_O_r01 632
 #define _CALL_NON_PY_GENERAL_r01 633
-#define _CALL_STR_1_r31 634
+#define _CALL_STR_1_r32 634
 #define _CALL_TUPLE_1_r32 635
 #define _CALL_TYPE_1_r31 636
 #define _CHECK_AND_ALLOCATE_OBJECT_r00 637

diff --git a/Include/internal/pycore_uop_metadata.h b/Include/internal/pycore_uop_metadata.h
index 0a37ce98c7eb4877e1852a0ed0ef6b103f8e8176..3bd19c82bc4eb4cf23be33aa88cee49edee683e4 100644 (file)
--- a/Include/internal/pycore_uop_metadata.h
+++ b/Include/internal/pycore_uop_metadata.h
@@ -274,7 +274,7 @@ const uint32_t _PyUop_Flags[MAX_UOP_ID+1] = {
     [_GUARD_CALLABLE_TYPE_1] = HAS_DEOPT_FLAG,
     [_CALL_TYPE_1] = HAS_ARG_FLAG | HAS_ESCAPES_FLAG,
     [_GUARD_CALLABLE_STR_1] = HAS_DEOPT_FLAG,
-    [_CALL_STR_1] = HAS_ARG_FLAG | HAS_ERROR_FLAG | HAS_ESCAPES_FLAG,
+    [_CALL_STR_1] = HAS_ARG_FLAG | HAS_ERROR_FLAG | HAS_ERROR_NO_POP_FLAG | HAS_ESCAPES_FLAG,
     [_GUARD_CALLABLE_TUPLE_1] = HAS_DEOPT_FLAG,
     [_CALL_TUPLE_1] = HAS_ARG_FLAG | HAS_ERROR_FLAG | HAS_ERROR_NO_POP_FLAG | HAS_ESCAPES_FLAG,
     [_CHECK_AND_ALLOCATE_OBJECT] = HAS_ARG_FLAG | HAS_DEOPT_FLAG | HAS_ERROR_FLAG | HAS_ERROR_NO_POP_FLAG | HAS_ESCAPES_FLAG,
@@ -2525,7 +2525,7 @@ const _PyUopCachingInfo _PyUop_Caching[MAX_UOP_ID+1] = {
             { -1, -1, -1 },
             { -1, -1, -1 },
             { -1, -1, -1 },
-            { 1, 0, _CALL_STR_1_r31 },
+            { 2, 0, _CALL_STR_1_r32 },
         },
     },
     [_GUARD_CALLABLE_TUPLE_1] = {
@@ -3734,7 +3734,7 @@ const uint16_t _PyUop_Uncached[MAX_UOP_REGS_ID+1] = {
     [_GUARD_CALLABLE_STR_1_r13] = _GUARD_CALLABLE_STR_1,
     [_GUARD_CALLABLE_STR_1_r23] = _GUARD_CALLABLE_STR_1,
     [_GUARD_CALLABLE_STR_1_r33] = _GUARD_CALLABLE_STR_1,
-    [_CALL_STR_1_r31] = _CALL_STR_1,
+    [_CALL_STR_1_r32] = _CALL_STR_1,
     [_GUARD_CALLABLE_TUPLE_1_r03] = _GUARD_CALLABLE_TUPLE_1,
     [_GUARD_CALLABLE_TUPLE_1_r13] = _GUARD_CALLABLE_TUPLE_1,
     [_GUARD_CALLABLE_TUPLE_1_r23] = _GUARD_CALLABLE_TUPLE_1,
@@ -4056,7 +4056,7 @@ const char *const _PyOpcode_uop_name[MAX_UOP_REGS_ID+1] = {
     [_CALL_NON_PY_GENERAL] = "_CALL_NON_PY_GENERAL",
     [_CALL_NON_PY_GENERAL_r01] = "_CALL_NON_PY_GENERAL_r01",
     [_CALL_STR_1] = "_CALL_STR_1",
-    [_CALL_STR_1_r31] = "_CALL_STR_1_r31",
+    [_CALL_STR_1_r32] = "_CALL_STR_1_r32",
     [_CALL_TUPLE_1] = "_CALL_TUPLE_1",
     [_CALL_TUPLE_1_r32] = "_CALL_TUPLE_1_r32",
     [_CALL_TYPE_1] = "_CALL_TYPE_1",

diff --git a/Lib/test/test_capi/test_opt.py b/Lib/test/test_capi/test_opt.py
index 0e7fd62c28a06545c4d5ffd5fded97c230c946aa..bd48db537a2f4a649e5df37d122223908bc70dbb 100644 (file)
--- a/Lib/test/test_capi/test_opt.py
+++ b/Lib/test/test_capi/test_opt.py
@@ -1957,6 +1957,20 @@ class TestUopsOptimization(unittest.TestCase):
         self.assertNotIn("_GUARD_NOS_NULL", uops)
         self.assertNotIn("_GUARD_CALLABLE_STR_1", uops)
 
+    def test_call_str_1_pop_top(self):
+        def testfunc(n):
+            x = 0
+            for _ in range(n):
+                t = str("")
+                x += 1 if len(t) == 0 else 0
+            return x
+        res, ex = self._run_with_optimizer(testfunc, TIER2_THRESHOLD)
+        self.assertEqual(res, TIER2_THRESHOLD)
+        self.assertIsNotNone(ex)
+        uops = get_opnames(ex)
+        self.assertIn("_CALL_STR_1", uops)
+        self.assertIn("_POP_TOP_NOP", uops)
+
     def test_call_str_1_result_is_str(self):
         def testfunc(n):
             x = 0

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-06-28-17-54-27.gh-issue-134584.EXgPub.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-06-28-17-54-27.gh-issue-134584.EXgPub.rst
new file mode 100644 (file)
index 0000000..638c170
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-06-28-17-54-27.gh-issue-134584.EXgPub.rst
@@ -0,0 +1 @@
+Eliminate redundant refcounting from ``_CALL_STR_1``.

diff --git a/Python/bytecodes.c b/Python/bytecodes.c
index d96a1944cd516a92ece91617cb568e150592a90f..3e76dcd77561cedaf1dff9f94e3071c5c3e08f0c 100644 (file)
--- a/Python/bytecodes.c
+++ b/Python/bytecodes.c
@@ -4040,18 +4040,17 @@ dummy_func(
             DEOPT_IF(callable_o != (PyObject *)&PyUnicode_Type);
         }
 
-        op(_CALL_STR_1, (callable, null, arg -- res)) {
+        op(_CALL_STR_1, (callable, null, arg -- res, a)) {
             PyObject *arg_o = PyStackRef_AsPyObjectBorrow(arg);
 
             assert(oparg == 1);
             STAT_INC(CALL, hit);
             PyObject *res_o = PyObject_Str(arg_o);
-            DEAD(null);
-            DEAD(callable);
-            (void)callable; // Silence compiler warnings about unused variables
-            (void)null;
-            PyStackRef_CLOSE(arg);
-            ERROR_IF(res_o == NULL);
+            if (res_o == NULL) {
+                ERROR_NO_POP();
+            }
+            a = arg;
+            INPUTS_DEAD();
             res = PyStackRef_FromPyObjectSteal(res_o);
         }
 
@@ -4061,6 +4060,7 @@ dummy_func(
             _GUARD_NOS_NULL +
             _GUARD_CALLABLE_STR_1 +
             _CALL_STR_1 +
+            POP_TOP +
             _CHECK_PERIODIC_AT_END;
 
         op(_GUARD_CALLABLE_TUPLE_1, (callable, unused, unused -- callable, unused, unused)) {

diff --git a/Python/executor_cases.c.h b/Python/executor_cases.c.h
index fab23f358682eb7ef221677474e51fc46bcb889e..ff73b55bc6aaba316c6eab533fb5cded44ade7c5 100644 (file)
--- a/Python/executor_cases.c.h
+++ b/Python/executor_cases.c.h
@@ -12755,47 +12755,40 @@
             break;
         }
 
-        case _CALL_STR_1_r31: {
+        case _CALL_STR_1_r32: {
             CHECK_CURRENT_CACHED_VALUES(3);
             assert(WITHIN_STACK_BOUNDS_WITH_CACHE());
             _PyStackRef arg;
-            _PyStackRef null;
-            _PyStackRef callable;
             _PyStackRef res;
+            _PyStackRef a;
             _PyStackRef _stack_item_0 = _tos_cache0;
             _PyStackRef _stack_item_1 = _tos_cache1;
             _PyStackRef _stack_item_2 = _tos_cache2;
             oparg = CURRENT_OPARG();
             arg = _stack_item_2;
-            null = _stack_item_1;
-            callable = _stack_item_0;
             PyObject *arg_o = PyStackRef_AsPyObjectBorrow(arg);
             assert(oparg == 1);
             STAT_INC(CALL, hit);
-            stack_pointer[0] = callable;
-            stack_pointer[1] = null;
+            stack_pointer[0] = _stack_item_0;
+            stack_pointer[1] = _stack_item_1;
             stack_pointer[2] = arg;
             stack_pointer += 3;
             ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             _PyFrame_SetStackPointer(frame, stack_pointer);
             PyObject *res_o = PyObject_Str(arg_o);
             stack_pointer = _PyFrame_GetStackPointer(frame);
-            (void)callable;
-            (void)null;
-            stack_pointer += -3;
-            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
-            _PyFrame_SetStackPointer(frame, stack_pointer);
-            PyStackRef_CLOSE(arg);
-            stack_pointer = _PyFrame_GetStackPointer(frame);
             if (res_o == NULL) {
                 SET_CURRENT_CACHED_VALUES(0);
                 JUMP_TO_ERROR();
             }
+            a = arg;
             res = PyStackRef_FromPyObjectSteal(res_o);
+            _tos_cache1 = a;
             _tos_cache0 = res;
-            _tos_cache1 = PyStackRef_ZERO_BITS;
             _tos_cache2 = PyStackRef_ZERO_BITS;
-            SET_CURRENT_CACHED_VALUES(1);
+            SET_CURRENT_CACHED_VALUES(2);
+            stack_pointer += -3;
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             assert(WITHIN_STACK_BOUNDS_WITH_CACHE());
             break;
         }

diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h
index 413593386583a815995a2d316c8e696390e09d01..1d8c01bd1b350133818f9239333d1bd5af26d535 100644 (file)
--- a/Python/generated_cases.c.h
+++ b/Python/generated_cases.c.h
@@ -3968,6 +3968,8 @@
             _PyStackRef callable;
             _PyStackRef arg;
             _PyStackRef res;
+            _PyStackRef a;
+            _PyStackRef value;
             /* Skip 1 cache entry */
             /* Skip 2 cache entries */
             // _GUARD_NOS_NULL
@@ -3998,23 +4000,24 @@
                 _PyFrame_SetStackPointer(frame, stack_pointer);
                 PyObject *res_o = PyObject_Str(arg_o);
                 stack_pointer = _PyFrame_GetStackPointer(frame);
-                (void)callable;
-                (void)null;
-                stack_pointer += -3;
-                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
-                _PyFrame_SetStackPointer(frame, stack_pointer);
-                PyStackRef_CLOSE(arg);
-                stack_pointer = _PyFrame_GetStackPointer(frame);
                 if (res_o == NULL) {
                     JUMP_TO_LABEL(error);
                 }
+                a = arg;
                 res = PyStackRef_FromPyObjectSteal(res_o);
             }
-            // _CHECK_PERIODIC_AT_END
+            // _POP_TOP
             {
-                stack_pointer[0] = res;
-                stack_pointer += 1;
+                value = a;
+                stack_pointer[-3] = res;
+                stack_pointer += -2;
                 ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
+                _PyFrame_SetStackPointer(frame, stack_pointer);
+                PyStackRef_XCLOSE(value);
+                stack_pointer = _PyFrame_GetStackPointer(frame);
+            }
+            // _CHECK_PERIODIC_AT_END
+            {
                 _PyFrame_SetStackPointer(frame, stack_pointer);
                 int err = check_periodics(tstate);
                 stack_pointer = _PyFrame_GetStackPointer(frame);

diff --git a/Python/optimizer_bytecodes.c b/Python/optimizer_bytecodes.c
index 9e767464500d459c6e37db0048215306e01ca85a..071f4ca31ba7a47ae932065339da85c3f077a67b 100644 (file)
--- a/Python/optimizer_bytecodes.c
+++ b/Python/optimizer_bytecodes.c
@@ -951,7 +951,7 @@ dummy_func(void) {
         }
     }
 
-    op(_CALL_STR_1, (unused, unused, arg -- res)) {
+    op(_CALL_STR_1, (unused, unused, arg -- res, a)) {
         if (sym_matches_type(arg, &PyUnicode_Type)) {
             // e.g. str('foo') or str(foo) where foo is known to be a string
             // Note: we must strip the reference information because it goes
@@ -961,6 +961,7 @@ dummy_func(void) {
         else {
             res = sym_new_type(ctx, &PyUnicode_Type);
         }
+        a = arg;
     }
 
     op(_CALL_ISINSTANCE, (unused, unused, instance, cls -- res)) {

diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h
index c3f122215ed7bd8c54a65da62efb29cb21290349..d3cff14be70aac4433e6d9b812c99885adc8a953 100644 (file)
--- a/Python/optimizer_cases.c.h
+++ b/Python/optimizer_cases.c.h
@@ -2855,6 +2855,7 @@
         case _CALL_STR_1: {
             JitOptRef arg;
             JitOptRef res;
+            JitOptRef a;
             arg = stack_pointer[-1];
             if (sym_matches_type(arg, &PyUnicode_Type)) {
                 res = PyJitRef_StripReferenceInfo(arg);
@@ -2862,9 +2863,11 @@
             else {
                 res = sym_new_type(ctx, &PyUnicode_Type);
             }
-            CHECK_STACK_BOUNDS(-2);
+            a = arg;
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-3] = res;
-            stack_pointer += -2;
+            stack_pointer[-2] = a;
+            stack_pointer += -1;
             ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }