From bef63d2fb81ae28760040157ea589541bed47d02 Mon Sep 17 00:00:00 2001 From: Savannah Ostrowski Date: Mon, 15 Dec 2025 15:18:44 -0800 Subject: [PATCH] GH-134584: Remove redundant refcount from `_STORE_ATTR_SLOT` (#142729) --- Include/internal/pycore_opcode_metadata.h | 2 +- Include/internal/pycore_uop_ids.h | 2 +- Include/internal/pycore_uop_metadata.h | 6 +++--- Lib/test/test_capi/test_opt.py | 20 +++++++++++++++++++- Python/bytecodes.c | 8 +++++--- Python/executor_cases.c.h | 14 ++++++++++---- Python/generated_cases.c.h | 15 +++++++++++++-- Python/optimizer_bytecodes.c | 6 ++++++ Python/optimizer_cases.c.h | 14 ++++++++++++-- 9 files changed, 70 insertions(+), 17 deletions(-) diff --git a/Include/internal/pycore_opcode_metadata.h b/Include/internal/pycore_opcode_metadata.h index cbbbbcedf2be..ce8a26c551bf 100644 --- a/Include/internal/pycore_opcode_metadata.h +++ b/Include/internal/pycore_opcode_metadata.h @@ -1483,7 +1483,7 @@ _PyOpcode_macro_expansion[256] = { [SET_UPDATE] = { .nuops = 1, .uops = { { _SET_UPDATE, OPARG_SIMPLE, 0 } } }, [STORE_ATTR] = { .nuops = 1, .uops = { { _STORE_ATTR, OPARG_SIMPLE, 3 } } }, [STORE_ATTR_INSTANCE_VALUE] = { .nuops = 4, .uops = { { _GUARD_TYPE_VERSION_AND_LOCK, 2, 1 }, { _GUARD_DORV_NO_DICT, OPARG_SIMPLE, 3 }, { _STORE_ATTR_INSTANCE_VALUE, 1, 3 }, { _POP_TOP, OPARG_SIMPLE, 4 } } }, - [STORE_ATTR_SLOT] = { .nuops = 2, .uops = { { _GUARD_TYPE_VERSION, 2, 1 }, { _STORE_ATTR_SLOT, 1, 3 } } }, + [STORE_ATTR_SLOT] = { .nuops = 3, .uops = { { _GUARD_TYPE_VERSION, 2, 1 }, { _STORE_ATTR_SLOT, 1, 3 }, { _POP_TOP, OPARG_SIMPLE, 4 } } }, [STORE_ATTR_WITH_HINT] = { .nuops = 2, .uops = { { _GUARD_TYPE_VERSION, 2, 1 }, { _STORE_ATTR_WITH_HINT, 1, 3 } } }, [STORE_DEREF] = { .nuops = 1, .uops = { { _STORE_DEREF, OPARG_SIMPLE, 0 } } }, [STORE_FAST] = { .nuops = 1, .uops = { { _STORE_FAST, OPARG_SIMPLE, 0 } } }, diff --git a/Include/internal/pycore_uop_ids.h b/Include/internal/pycore_uop_ids.h index 69bd9af09916..df623f49b0d5 100644 --- a/Include/internal/pycore_uop_ids.h +++ b/Include/internal/pycore_uop_ids.h @@ -1035,7 +1035,7 @@ extern "C" { #define _START_EXECUTOR_r00 1228 #define _STORE_ATTR_r20 1229 #define _STORE_ATTR_INSTANCE_VALUE_r21 1230 -#define _STORE_ATTR_SLOT_r20 1231 +#define _STORE_ATTR_SLOT_r21 1231 #define _STORE_ATTR_WITH_HINT_r20 1232 #define _STORE_DEREF_r10 1233 #define _STORE_FAST_r10 1234 diff --git a/Include/internal/pycore_uop_metadata.h b/Include/internal/pycore_uop_metadata.h index d06eba97ccf7..f600468c3216 100644 --- a/Include/internal/pycore_uop_metadata.h +++ b/Include/internal/pycore_uop_metadata.h @@ -1846,7 +1846,7 @@ const _PyUopCachingInfo _PyUop_Caching[MAX_UOP_ID+1] = { .entries = { { -1, -1, -1 }, { -1, -1, -1 }, - { 0, 2, _STORE_ATTR_SLOT_r20 }, + { 1, 2, _STORE_ATTR_SLOT_r21 }, { -1, -1, -1 }, }, }, @@ -3545,7 +3545,7 @@ const uint16_t _PyUop_Uncached[MAX_UOP_REGS_ID+1] = { [_GUARD_DORV_NO_DICT_r33] = _GUARD_DORV_NO_DICT, [_STORE_ATTR_INSTANCE_VALUE_r21] = _STORE_ATTR_INSTANCE_VALUE, [_STORE_ATTR_WITH_HINT_r20] = _STORE_ATTR_WITH_HINT, - [_STORE_ATTR_SLOT_r20] = _STORE_ATTR_SLOT, + [_STORE_ATTR_SLOT_r21] = _STORE_ATTR_SLOT, [_COMPARE_OP_r21] = _COMPARE_OP, [_COMPARE_OP_FLOAT_r01] = _COMPARE_OP_FLOAT, [_COMPARE_OP_FLOAT_r11] = _COMPARE_OP_FLOAT, @@ -4780,7 +4780,7 @@ const char *const _PyOpcode_uop_name[MAX_UOP_REGS_ID+1] = { [_STORE_ATTR_INSTANCE_VALUE] = "_STORE_ATTR_INSTANCE_VALUE", [_STORE_ATTR_INSTANCE_VALUE_r21] = "_STORE_ATTR_INSTANCE_VALUE_r21", [_STORE_ATTR_SLOT] = "_STORE_ATTR_SLOT", - [_STORE_ATTR_SLOT_r20] = "_STORE_ATTR_SLOT_r20", + [_STORE_ATTR_SLOT_r21] = "_STORE_ATTR_SLOT_r21", [_STORE_ATTR_WITH_HINT] = "_STORE_ATTR_WITH_HINT", [_STORE_ATTR_WITH_HINT_r20] = "_STORE_ATTR_WITH_HINT_r20", [_STORE_DEREF] = "_STORE_DEREF", diff --git a/Lib/test/test_capi/test_opt.py b/Lib/test/test_capi/test_opt.py index 5a52d7609d2c..0fa74b9e8fae 100644 --- a/Lib/test/test_capi/test_opt.py +++ b/Lib/test/test_capi/test_opt.py @@ -2612,7 +2612,25 @@ class TestUopsOptimization(unittest.TestCase): self.assertNotIn("_POP_TOP_INT", uops) self.assertIn("_POP_TOP_NOP", uops) - def test_store_susbscr_dict(self): + def test_store_attr_slot(self): + class C: + __slots__ = ('x',) + + def testfunc(n): + c = C() + for _ in range(n): + c.x = 42 + y = c.x + return y + + res, ex = self._run_with_optimizer(testfunc, TIER2_THRESHOLD) + self.assertEqual(res, 42) + self.assertIsNotNone(ex) + uops = get_opnames(ex) + self.assertIn("_STORE_ATTR_SLOT", uops) + self.assertIn("_POP_TOP_NOP", uops) + + def test_store_subscr_dict(self): def testfunc(n): d = {} for _ in range(n): diff --git a/Python/bytecodes.c b/Python/bytecodes.c index 8420d09e8190..0dbfe962684e 100644 --- a/Python/bytecodes.c +++ b/Python/bytecodes.c @@ -2640,7 +2640,7 @@ dummy_func( _GUARD_TYPE_VERSION + _STORE_ATTR_WITH_HINT; - op(_STORE_ATTR_SLOT, (index/1, value, owner --)) { + op(_STORE_ATTR_SLOT, (index/1, value, owner -- o)) { PyObject *owner_o = PyStackRef_AsPyObjectBorrow(owner); DEOPT_IF(!LOCK_OBJECT(owner_o)); @@ -2649,14 +2649,16 @@ dummy_func( PyObject *old_value = *(PyObject **)addr; FT_ATOMIC_STORE_PTR_RELEASE(*(PyObject **)addr, PyStackRef_AsPyObjectSteal(value)); UNLOCK_OBJECT(owner_o); - PyStackRef_CLOSE(owner); + INPUTS_DEAD(); + o = owner; Py_XDECREF(old_value); } macro(STORE_ATTR_SLOT) = unused/1 + _GUARD_TYPE_VERSION + - _STORE_ATTR_SLOT; + _STORE_ATTR_SLOT + + POP_TOP; family(COMPARE_OP, INLINE_CACHE_ENTRIES_COMPARE_OP) = { COMPARE_OP_FLOAT, diff --git a/Python/executor_cases.c.h b/Python/executor_cases.c.h index b4d4684f8785..b2ce7d0d1822 100644 --- a/Python/executor_cases.c.h +++ b/Python/executor_cases.c.h @@ -8786,11 +8786,12 @@ break; } - case _STORE_ATTR_SLOT_r20: { + case _STORE_ATTR_SLOT_r21: { CHECK_CURRENT_CACHED_VALUES(2); assert(WITHIN_STACK_BOUNDS_IGNORING_CACHE()); _PyStackRef owner; _PyStackRef value; + _PyStackRef o; _PyStackRef _stack_item_0 = _tos_cache0; _PyStackRef _stack_item_1 = _tos_cache1; owner = _stack_item_1; @@ -8809,14 +8810,19 @@ PyObject *old_value = *(PyObject **)addr; FT_ATOMIC_STORE_PTR_RELEASE(*(PyObject **)addr, PyStackRef_AsPyObjectSteal(value)); UNLOCK_OBJECT(owner_o); + o = owner; + stack_pointer[0] = o; + stack_pointer += 1; + ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__); _PyFrame_SetStackPointer(frame, stack_pointer); - PyStackRef_CLOSE(owner); Py_XDECREF(old_value); stack_pointer = _PyFrame_GetStackPointer(frame); - _tos_cache0 = PyStackRef_ZERO_BITS; + _tos_cache0 = o; _tos_cache1 = PyStackRef_ZERO_BITS; _tos_cache2 = PyStackRef_ZERO_BITS; - SET_CURRENT_CACHED_VALUES(0); + SET_CURRENT_CACHED_VALUES(1); + stack_pointer += -1; + 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 3b8ad4565af9..2811a2ec8ac8 100644 --- a/Python/generated_cases.c.h +++ b/Python/generated_cases.c.h @@ -10678,6 +10678,7 @@ static_assert(INLINE_CACHE_ENTRIES_STORE_ATTR == 4, "incorrect cache size"); _PyStackRef owner; _PyStackRef value; + _PyStackRef o; /* Skip 1 cache entry */ // _GUARD_TYPE_VERSION { @@ -10706,13 +10707,23 @@ PyObject *old_value = *(PyObject **)addr; FT_ATOMIC_STORE_PTR_RELEASE(*(PyObject **)addr, PyStackRef_AsPyObjectSteal(value)); UNLOCK_OBJECT(owner_o); - stack_pointer += -2; + o = owner; + stack_pointer[-2] = o; + stack_pointer += -1; ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__); _PyFrame_SetStackPointer(frame, stack_pointer); - PyStackRef_CLOSE(owner); Py_XDECREF(old_value); stack_pointer = _PyFrame_GetStackPointer(frame); } + // _POP_TOP + { + value = o; + stack_pointer += -1; + ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__); + _PyFrame_SetStackPointer(frame, stack_pointer); + PyStackRef_XCLOSE(value); + stack_pointer = _PyFrame_GetStackPointer(frame); + } DISPATCH(); } diff --git a/Python/optimizer_bytecodes.c b/Python/optimizer_bytecodes.c index b97b4c35d9aa..decf98865aea 100644 --- a/Python/optimizer_bytecodes.c +++ b/Python/optimizer_bytecodes.c @@ -114,6 +114,12 @@ dummy_func(void) { ss = sub_st; } + op(_STORE_ATTR_SLOT, (index/1, value, owner -- o)) { + (void)index; + (void)value; + o = owner; + } + op(_STORE_SUBSCR_DICT, (value, dict_st, sub -- st)) { (void)value; st = dict_st; diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h index 0d56464ea91c..cdab0fd2ef87 100644 --- a/Python/optimizer_cases.c.h +++ b/Python/optimizer_cases.c.h @@ -1698,8 +1698,18 @@ } case _STORE_ATTR_SLOT: { - CHECK_STACK_BOUNDS(-2); - stack_pointer += -2; + JitOptRef owner; + JitOptRef value; + JitOptRef o; + owner = stack_pointer[-1]; + value = stack_pointer[-2]; + uint16_t index = (uint16_t)this_instr->operand0; + (void)index; + (void)value; + o = owner; + CHECK_STACK_BOUNDS(-1); + stack_pointer[-2] = o; + stack_pointer += -1; ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__); break; } -- 2.47.3