gh-144005: Eliminate redundant refcounting in the JIT for BINARY_OP_EXTEND (#144006)

diff --git a/Include/internal/pycore_opcode_metadata.h b/Include/internal/pycore_opcode_metadata.h
index ce6324d0a8e0b933e850fd05f5ea0b4aea3bdf7a..80c11b753be7e6d66a8848a3bf817e56ec2912b9 100644 (file)
--- a/Include/internal/pycore_opcode_metadata.h
+++ b/Include/internal/pycore_opcode_metadata.h
@@ -1094,7 +1094,7 @@ const struct opcode_metadata _PyOpcode_opcode_metadata[267] = {
     [BINARY_OP_ADD_FLOAT] = { true, INSTR_FMT_IXC0000, HAS_EXIT_FLAG | HAS_ERROR_FLAG | HAS_ERROR_NO_POP_FLAG },
     [BINARY_OP_ADD_INT] = { true, INSTR_FMT_IXC0000, HAS_EXIT_FLAG },
     [BINARY_OP_ADD_UNICODE] = { true, INSTR_FMT_IXC0000, HAS_EXIT_FLAG | HAS_ERROR_FLAG | HAS_ERROR_NO_POP_FLAG },
-    [BINARY_OP_EXTEND] = { true, INSTR_FMT_IXC0000, HAS_DEOPT_FLAG | HAS_ERROR_FLAG | HAS_ESCAPES_FLAG },
+    [BINARY_OP_EXTEND] = { true, INSTR_FMT_IXC0000, HAS_DEOPT_FLAG | HAS_ERROR_FLAG | HAS_ERROR_NO_POP_FLAG | HAS_ESCAPES_FLAG },
     [BINARY_OP_INPLACE_ADD_UNICODE] = { true, INSTR_FMT_IXC0000, HAS_LOCAL_FLAG | HAS_DEOPT_FLAG | HAS_EXIT_FLAG | HAS_ERROR_FLAG | HAS_ESCAPES_FLAG },
     [BINARY_OP_MULTIPLY_FLOAT] = { true, INSTR_FMT_IXC0000, HAS_EXIT_FLAG | HAS_ERROR_FLAG | HAS_ERROR_NO_POP_FLAG },
     [BINARY_OP_MULTIPLY_INT] = { true, INSTR_FMT_IXC0000, HAS_EXIT_FLAG },
@@ -1347,7 +1347,7 @@ _PyOpcode_macro_expansion[256] = {
     [BINARY_OP_ADD_FLOAT] = { .nuops = 5, .uops = { { _GUARD_TOS_FLOAT, OPARG_SIMPLE, 0 }, { _GUARD_NOS_FLOAT, OPARG_SIMPLE, 0 }, { _BINARY_OP_ADD_FLOAT, OPARG_SIMPLE, 5 }, { _POP_TOP_FLOAT, OPARG_SIMPLE, 5 }, { _POP_TOP_FLOAT, OPARG_SIMPLE, 5 } } },
     [BINARY_OP_ADD_INT] = { .nuops = 5, .uops = { { _GUARD_TOS_INT, OPARG_SIMPLE, 0 }, { _GUARD_NOS_INT, OPARG_SIMPLE, 0 }, { _BINARY_OP_ADD_INT, OPARG_SIMPLE, 5 }, { _POP_TOP_INT, OPARG_SIMPLE, 5 }, { _POP_TOP_INT, OPARG_SIMPLE, 5 } } },
     [BINARY_OP_ADD_UNICODE] = { .nuops = 5, .uops = { { _GUARD_TOS_UNICODE, OPARG_SIMPLE, 0 }, { _GUARD_NOS_UNICODE, OPARG_SIMPLE, 0 }, { _BINARY_OP_ADD_UNICODE, OPARG_SIMPLE, 5 }, { _POP_TOP_UNICODE, OPARG_SIMPLE, 5 }, { _POP_TOP_UNICODE, OPARG_SIMPLE, 5 } } },
-    [BINARY_OP_EXTEND] = { .nuops = 2, .uops = { { _GUARD_BINARY_OP_EXTEND, 4, 1 }, { _BINARY_OP_EXTEND, 4, 1 } } },
+    [BINARY_OP_EXTEND] = { .nuops = 4, .uops = { { _GUARD_BINARY_OP_EXTEND, 4, 1 }, { _BINARY_OP_EXTEND, 4, 1 }, { _POP_TOP, OPARG_SIMPLE, 5 }, { _POP_TOP, OPARG_SIMPLE, 5 } } },
     [BINARY_OP_INPLACE_ADD_UNICODE] = { .nuops = 3, .uops = { { _GUARD_TOS_UNICODE, OPARG_SIMPLE, 0 }, { _GUARD_NOS_UNICODE, OPARG_SIMPLE, 0 }, { _BINARY_OP_INPLACE_ADD_UNICODE, OPARG_SIMPLE, 5 } } },
     [BINARY_OP_MULTIPLY_FLOAT] = { .nuops = 5, .uops = { { _GUARD_TOS_FLOAT, OPARG_SIMPLE, 0 }, { _GUARD_NOS_FLOAT, OPARG_SIMPLE, 0 }, { _BINARY_OP_MULTIPLY_FLOAT, OPARG_SIMPLE, 5 }, { _POP_TOP_FLOAT, OPARG_SIMPLE, 5 }, { _POP_TOP_FLOAT, OPARG_SIMPLE, 5 } } },
     [BINARY_OP_MULTIPLY_INT] = { .nuops = 5, .uops = { { _GUARD_TOS_INT, OPARG_SIMPLE, 0 }, { _GUARD_NOS_INT, OPARG_SIMPLE, 0 }, { _BINARY_OP_MULTIPLY_INT, OPARG_SIMPLE, 5 }, { _POP_TOP_INT, OPARG_SIMPLE, 5 }, { _POP_TOP_INT, OPARG_SIMPLE, 5 } } },

diff --git a/Include/internal/pycore_uop_ids.h b/Include/internal/pycore_uop_ids.h
index 5cda407ba89d9305a7ac47c2d272fa89d08fff21..ccdcc27f903cb9f9ed0f91f8d2ea8155ddac7ae4 100644 (file)
--- a/Include/internal/pycore_uop_ids.h
+++ b/Include/internal/pycore_uop_ids.h
@@ -389,7 +389,7 @@ extern "C" {
 #define _BINARY_OP_ADD_UNICODE_r03 586
 #define _BINARY_OP_ADD_UNICODE_r13 587
 #define _BINARY_OP_ADD_UNICODE_r23 588
-#define _BINARY_OP_EXTEND_r21 589
+#define _BINARY_OP_EXTEND_r23 589
 #define _BINARY_OP_INPLACE_ADD_UNICODE_r21 590
 #define _BINARY_OP_MULTIPLY_FLOAT_r03 591
 #define _BINARY_OP_MULTIPLY_FLOAT_r13 592

diff --git a/Include/internal/pycore_uop_metadata.h b/Include/internal/pycore_uop_metadata.h
index c2e0f4a2c391edf716bc2346d8508d3825dd73da..d51ed9c697ab8c1e9ddd460c125b7bc4622ecb6e 100644 (file)
--- a/Include/internal/pycore_uop_metadata.h
+++ b/Include/internal/pycore_uop_metadata.h
@@ -115,7 +115,7 @@ const uint32_t _PyUop_Flags[MAX_UOP_ID+1] = {
     [_BINARY_OP_ADD_UNICODE] = HAS_ERROR_FLAG | HAS_ERROR_NO_POP_FLAG | HAS_PURE_FLAG,
     [_BINARY_OP_INPLACE_ADD_UNICODE] = HAS_LOCAL_FLAG | HAS_DEOPT_FLAG | HAS_ERROR_FLAG | HAS_ESCAPES_FLAG,
     [_GUARD_BINARY_OP_EXTEND] = HAS_DEOPT_FLAG | HAS_ESCAPES_FLAG,
-    [_BINARY_OP_EXTEND] = HAS_ERROR_FLAG | HAS_ESCAPES_FLAG,
+    [_BINARY_OP_EXTEND] = HAS_ERROR_FLAG | HAS_ERROR_NO_POP_FLAG | HAS_ESCAPES_FLAG,
     [_BINARY_SLICE] = HAS_ERROR_FLAG | HAS_ESCAPES_FLAG,
     [_STORE_SLICE] = HAS_ERROR_FLAG | HAS_ESCAPES_FLAG,
     [_BINARY_OP_SUBSCR_LIST_INT] = HAS_DEOPT_FLAG | HAS_ESCAPES_FLAG,
@@ -1113,7 +1113,7 @@ const _PyUopCachingInfo _PyUop_Caching[MAX_UOP_ID+1] = {
         .entries = {
             { -1, -1, -1 },
             { -1, -1, -1 },
-            { 1, 2, _BINARY_OP_EXTEND_r21 },
+            { 3, 2, _BINARY_OP_EXTEND_r23 },
             { -1, -1, -1 },
         },
     },
@@ -3670,7 +3670,7 @@ const uint16_t _PyUop_Uncached[MAX_UOP_REGS_ID+1] = {
     [_BINARY_OP_ADD_UNICODE_r23] = _BINARY_OP_ADD_UNICODE,
     [_BINARY_OP_INPLACE_ADD_UNICODE_r21] = _BINARY_OP_INPLACE_ADD_UNICODE,
     [_GUARD_BINARY_OP_EXTEND_r22] = _GUARD_BINARY_OP_EXTEND,
-    [_BINARY_OP_EXTEND_r21] = _BINARY_OP_EXTEND,
+    [_BINARY_OP_EXTEND_r23] = _BINARY_OP_EXTEND,
     [_BINARY_SLICE_r31] = _BINARY_SLICE,
     [_STORE_SLICE_r30] = _STORE_SLICE,
     [_BINARY_OP_SUBSCR_LIST_INT_r23] = _BINARY_OP_SUBSCR_LIST_INT,
@@ -4239,7 +4239,7 @@ const char *const _PyOpcode_uop_name[MAX_UOP_REGS_ID+1] = {
     [_BINARY_OP_ADD_UNICODE_r13] = "_BINARY_OP_ADD_UNICODE_r13",
     [_BINARY_OP_ADD_UNICODE_r23] = "_BINARY_OP_ADD_UNICODE_r23",
     [_BINARY_OP_EXTEND] = "_BINARY_OP_EXTEND",
-    [_BINARY_OP_EXTEND_r21] = "_BINARY_OP_EXTEND_r21",
+    [_BINARY_OP_EXTEND_r23] = "_BINARY_OP_EXTEND_r23",
     [_BINARY_OP_INPLACE_ADD_UNICODE] = "_BINARY_OP_INPLACE_ADD_UNICODE",
     [_BINARY_OP_INPLACE_ADD_UNICODE_r21] = "_BINARY_OP_INPLACE_ADD_UNICODE_r21",
     [_BINARY_OP_MULTIPLY_FLOAT] = "_BINARY_OP_MULTIPLY_FLOAT",

diff --git a/Lib/test/test_capi/test_opt.py b/Lib/test/test_capi/test_opt.py
index 7c33320e9f1785690ae2e79ba78440b21bdd1468..5a0a379e31a962b6c740d903fa8973959e988ac8 100644 (file)
--- a/Lib/test/test_capi/test_opt.py
+++ b/Lib/test/test_capi/test_opt.py
@@ -2897,6 +2897,23 @@ class TestUopsOptimization(unittest.TestCase):
         self.assertIn("_POP_TOP_NOP", uops)
         self.assertLessEqual(count_ops(ex, "_POP_TOP"), 2)
 
+    def test_binary_op_extend_float_long_add_refcount_elimination(self):
+        def testfunc(n):
+            a = 1.5
+            b = 2
+            res = 0.0
+            for _ in range(n):
+                res = a + b
+            return res
+
+        res, ex = self._run_with_optimizer(testfunc, TIER2_THRESHOLD)
+        self.assertEqual(res, 3.5)
+        self.assertIsNotNone(ex)
+        uops = get_opnames(ex)
+        self.assertIn("_BINARY_OP_EXTEND", uops)
+        self.assertIn("_POP_TOP_NOP", uops)
+        self.assertLessEqual(count_ops(ex, "_POP_TOP"), 2)
+
     def test_remove_guard_for_slice_list(self):
         def f(n):
             for i in range(n):

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-01-19-01-26-12.gh-issue-144005.Z3O33m.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-01-19-01-26-12.gh-issue-144005.Z3O33m.rst
new file mode 100644 (file)
index 0000000..b358219
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-01-19-01-26-12.gh-issue-144005.Z3O33m.rst
@@ -0,0 +1 @@
+Eliminate redundant refcounting from ``BINARY_OP_EXTEND``.

diff --git a/Modules/_testinternalcapi/test_cases.c.h b/Modules/_testinternalcapi/test_cases.c.h
index c02d236fc3e8ac610462d3751d85e31bfd62ab9e..a7d589dbe7b274dead743df5326b07990f664132 100644 (file)
--- a/Modules/_testinternalcapi/test_cases.c.h
+++ b/Modules/_testinternalcapi/test_cases.c.h
@@ -317,6 +317,9 @@
             _PyStackRef left;
             _PyStackRef right;
             _PyStackRef res;
+            _PyStackRef l;
+            _PyStackRef r;
+            _PyStackRef value;
             /* Skip 1 cache entry */
             // _GUARD_BINARY_OP_EXTEND
             {
@@ -348,25 +351,32 @@
                 STAT_INC(BINARY_OP, hit);
                 _PyFrame_SetStackPointer(frame, stack_pointer);
                 PyObject *res_o = d->action(left_o, right_o);
-                _PyStackRef tmp = right;
-                right = PyStackRef_NULL;
-                stack_pointer[-1] = right;
-                PyStackRef_CLOSE(tmp);
-                tmp = left;
-                left = PyStackRef_NULL;
-                stack_pointer[-2] = left;
-                PyStackRef_CLOSE(tmp);
                 stack_pointer = _PyFrame_GetStackPointer(frame);
-                stack_pointer += -2;
-                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 if (res_o == NULL) {
                     JUMP_TO_LABEL(error);
                 }
                 res = PyStackRef_FromPyObjectSteal(res_o);
+                l = left;
+                r = right;
+            }
+            // _POP_TOP
+            {
+                value = r;
+                stack_pointer[-2] = res;
+                stack_pointer[-1] = l;
+                _PyFrame_SetStackPointer(frame, stack_pointer);
+                PyStackRef_XCLOSE(value);
+                stack_pointer = _PyFrame_GetStackPointer(frame);
+            }
+            // _POP_TOP
+            {
+                value = l;
+                stack_pointer += -1;
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
+                _PyFrame_SetStackPointer(frame, stack_pointer);
+                PyStackRef_XCLOSE(value);
+                stack_pointer = _PyFrame_GetStackPointer(frame);
             }
-            stack_pointer[0] = res;
-            stack_pointer += 1;
-            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             DISPATCH();
         }
 

diff --git a/Python/bytecodes.c b/Python/bytecodes.c
index cef368e9b0721a2a0f6f82e4d36d2112bc87f706..36df991e84dc2c44c2addefc811929439d219d26 100644 (file)
--- a/Python/bytecodes.c
+++ b/Python/bytecodes.c
@@ -829,7 +829,7 @@ dummy_func(
             DEOPT_IF(!res);
         }
 
-       op(_BINARY_OP_EXTEND, (descr/4, left, right -- res)) {
+       op(_BINARY_OP_EXTEND, (descr/4, left, right -- res, l, r)) {
             PyObject *left_o = PyStackRef_AsPyObjectBorrow(left);
             PyObject *right_o = PyStackRef_AsPyObjectBorrow(right);
             assert(INLINE_CACHE_ENTRIES_BINARY_OP == 5);
@@ -838,13 +838,18 @@ dummy_func(
             STAT_INC(BINARY_OP, hit);
 
             PyObject *res_o = d->action(left_o, right_o);
-            DECREF_INPUTS();
-            ERROR_IF(res_o == NULL);
+            if (res_o == NULL) {
+                ERROR_NO_POP();
+            }
             res = PyStackRef_FromPyObjectSteal(res_o);
+            l = left;
+            r = right;
+            DEAD(left);
+            DEAD(right);
         }
 
         macro(BINARY_OP_EXTEND) =
-            unused/1 + _GUARD_BINARY_OP_EXTEND + rewind/-4 + _BINARY_OP_EXTEND;
+            unused/1 + _GUARD_BINARY_OP_EXTEND + rewind/-4 + _BINARY_OP_EXTEND + POP_TOP + POP_TOP;
 
         macro(BINARY_OP_INPLACE_ADD_UNICODE) =
             _GUARD_TOS_UNICODE + _GUARD_NOS_UNICODE + unused/5 + _BINARY_OP_INPLACE_ADD_UNICODE;

diff --git a/Python/executor_cases.c.h b/Python/executor_cases.c.h
index 4d4084971c75ad806ae76468340c8c5f9656d718..9098bd219ed5061b407937ffa6245a42f7b6d22d 100644 (file)
--- a/Python/executor_cases.c.h
+++ b/Python/executor_cases.c.h
@@ -5143,12 +5143,14 @@
             break;
         }
 
-        case _BINARY_OP_EXTEND_r21: {
+        case _BINARY_OP_EXTEND_r23: {
             CHECK_CURRENT_CACHED_VALUES(2);
             assert(WITHIN_STACK_BOUNDS_IGNORING_CACHE());
             _PyStackRef right;
             _PyStackRef left;
             _PyStackRef res;
+            _PyStackRef l;
+            _PyStackRef r;
             _PyStackRef _stack_item_0 = _tos_cache0;
             _PyStackRef _stack_item_1 = _tos_cache1;
             right = _stack_item_1;
@@ -5165,26 +5167,20 @@
             ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             _PyFrame_SetStackPointer(frame, stack_pointer);
             PyObject *res_o = d->action(left_o, right_o);
-            _PyStackRef tmp = right;
-            right = PyStackRef_NULL;
-            stack_pointer[-1] = right;
-            PyStackRef_CLOSE(tmp);
-            tmp = left;
-            left = PyStackRef_NULL;
-            stack_pointer[-2] = left;
-            PyStackRef_CLOSE(tmp);
             stack_pointer = _PyFrame_GetStackPointer(frame);
-            stack_pointer += -2;
-            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             if (res_o == NULL) {
                 SET_CURRENT_CACHED_VALUES(0);
                 JUMP_TO_ERROR();
             }
             res = PyStackRef_FromPyObjectSteal(res_o);
+            l = left;
+            r = right;
+            _tos_cache2 = r;
+            _tos_cache1 = l;
             _tos_cache0 = res;
-            _tos_cache1 = PyStackRef_ZERO_BITS;
-            _tos_cache2 = PyStackRef_ZERO_BITS;
-            SET_CURRENT_CACHED_VALUES(1);
+            SET_CURRENT_CACHED_VALUES(3);
+            stack_pointer += -2;
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             assert(WITHIN_STACK_BOUNDS_IGNORING_CACHE());
             break;
         }

diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h
index 194fbe4f268cb4b8ba6866f8501a9b7a32b035b7..9df6b2f70f96df4b8e0668ffcbcd4fdf12130fdb 100644 (file)
--- a/Python/generated_cases.c.h
+++ b/Python/generated_cases.c.h
@@ -317,6 +317,9 @@
             _PyStackRef left;
             _PyStackRef right;
             _PyStackRef res;
+            _PyStackRef l;
+            _PyStackRef r;
+            _PyStackRef value;
             /* Skip 1 cache entry */
             // _GUARD_BINARY_OP_EXTEND
             {
@@ -348,25 +351,32 @@
                 STAT_INC(BINARY_OP, hit);
                 _PyFrame_SetStackPointer(frame, stack_pointer);
                 PyObject *res_o = d->action(left_o, right_o);
-                _PyStackRef tmp = right;
-                right = PyStackRef_NULL;
-                stack_pointer[-1] = right;
-                PyStackRef_CLOSE(tmp);
-                tmp = left;
-                left = PyStackRef_NULL;
-                stack_pointer[-2] = left;
-                PyStackRef_CLOSE(tmp);
                 stack_pointer = _PyFrame_GetStackPointer(frame);
-                stack_pointer += -2;
-                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 if (res_o == NULL) {
                     JUMP_TO_LABEL(error);
                 }
                 res = PyStackRef_FromPyObjectSteal(res_o);
+                l = left;
+                r = right;
+            }
+            // _POP_TOP
+            {
+                value = r;
+                stack_pointer[-2] = res;
+                stack_pointer[-1] = l;
+                _PyFrame_SetStackPointer(frame, stack_pointer);
+                PyStackRef_XCLOSE(value);
+                stack_pointer = _PyFrame_GetStackPointer(frame);
+            }
+            // _POP_TOP
+            {
+                value = l;
+                stack_pointer += -1;
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
+                _PyFrame_SetStackPointer(frame, stack_pointer);
+                PyStackRef_XCLOSE(value);
+                stack_pointer = _PyFrame_GetStackPointer(frame);
             }
-            stack_pointer[0] = res;
-            stack_pointer += 1;
-            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             DISPATCH();
         }
 

diff --git a/Python/optimizer_bytecodes.c b/Python/optimizer_bytecodes.c
index 1584e731d1b2d448c42798f6d5d9260b41123893..de7a2313f9220a8af7a2872661566963b3be3065 100644 (file)
--- a/Python/optimizer_bytecodes.c
+++ b/Python/optimizer_bytecodes.c
@@ -311,6 +311,12 @@ dummy_func(void) {
         r = right;
     }
 
+    op(_BINARY_OP_EXTEND, (left, right -- res, l, r)) {
+        res = sym_new_not_null(ctx);
+        l = left;
+        r = right;
+    }
+
     op(_BINARY_OP_INPLACE_ADD_UNICODE, (left, right -- res)) {
         if (sym_is_const(ctx, left) && sym_is_const(ctx, right)) {
             assert(PyUnicode_CheckExact(sym_get_const(ctx, left)));

diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h
index 341805d51e24cd9b2ed98e1dbdcc34085202a17f..5fca69462669b5260b09573c62ae3583b68353b0 100644 (file)
--- a/Python/optimizer_cases.c.h
+++ b/Python/optimizer_cases.c.h
@@ -882,11 +882,22 @@
         }
 
         case _BINARY_OP_EXTEND: {
+            JitOptRef right;
+            JitOptRef left;
             JitOptRef res;
+            JitOptRef l;
+            JitOptRef r;
+            right = stack_pointer[-1];
+            left = stack_pointer[-2];
+            PyObject *descr = (PyObject *)this_instr->operand0;
             res = sym_new_not_null(ctx);
-            CHECK_STACK_BOUNDS(-1);
+            l = left;
+            r = right;
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[-2] = res;
-            stack_pointer += -1;
+            stack_pointer[-1] = l;
+            stack_pointer[0] = r;
+            stack_pointer += 1;
             ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }