diff options
| -rw-r--r-- | Lib/test/test_capi/test_opt.py | 30 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Core_and_Builtins/2025-05-25-19-32-15.gh-issue-131798.f5h8aI.rst | 1 | ||||
| -rw-r--r-- | Python/optimizer_bytecodes.c | 14 | ||||
| -rw-r--r-- | Python/optimizer_cases.c.h | 13 |
4 files changed, 55 insertions, 3 deletions
diff --git a/Lib/test/test_capi/test_opt.py b/Lib/test/test_capi/test_opt.py index ee8d261685d..8a3819dabe4 100644 --- a/Lib/test/test_capi/test_opt.py +++ b/Lib/test/test_capi/test_opt.py @@ -1666,13 +1666,11 @@ class TestUopsOptimization(unittest.TestCase): self.assertIn("_CONTAINS_OP_DICT", uops) self.assertNotIn("_TO_BOOL_BOOL", uops) - def test_remove_guard_for_known_type_str(self): def f(n): for i in range(n): false = i == TIER2_THRESHOLD empty = "X"[:false] - empty += "" # Make JIT realize this is a string. if empty: return 1 return 0 @@ -2249,6 +2247,34 @@ class TestUopsOptimization(unittest.TestCase): self.assertNotIn("_LOAD_ATTR_METHOD_NO_DICT", uops) self.assertNotIn("_LOAD_ATTR_METHOD_LAZY_DICT", uops) + def test_remove_guard_for_slice_list(self): + def f(n): + for i in range(n): + false = i == TIER2_THRESHOLD + sliced = [1, 2, 3][:false] + if sliced: + return 1 + return 0 + + res, ex = self._run_with_optimizer(f, TIER2_THRESHOLD) + self.assertEqual(res, 0) + self.assertIsNotNone(ex) + uops = get_opnames(ex) + self.assertIn("_TO_BOOL_LIST", uops) + self.assertNotIn("_GUARD_TOS_LIST", uops) + + def test_remove_guard_for_slice_tuple(self): + def f(n): + for i in range(n): + false = i == TIER2_THRESHOLD + a, b = (1, 2, 3)[: false + 2] + + _, ex = self._run_with_optimizer(f, TIER2_THRESHOLD) + self.assertIsNotNone(ex) + uops = get_opnames(ex) + self.assertIn("_UNPACK_SEQUENCE_TWO_TUPLE", uops) + self.assertNotIn("_GUARD_TOS_TUPLE", uops) + def global_identity(x): return x diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-05-25-19-32-15.gh-issue-131798.f5h8aI.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-05-25-19-32-15.gh-issue-131798.f5h8aI.rst new file mode 100644 index 00000000000..6ecbfb8d9cf --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-05-25-19-32-15.gh-issue-131798.f5h8aI.rst @@ -0,0 +1 @@ +Make the JIT optimizer understand that slicing a string/list/tuple returns the same type. diff --git a/Python/optimizer_bytecodes.c b/Python/optimizer_bytecodes.c index 12efaacd8f0..fbf4dfd3db6 100644 --- a/Python/optimizer_bytecodes.c +++ b/Python/optimizer_bytecodes.c @@ -1237,6 +1237,20 @@ dummy_func(void) { sym_set_const(callable, list_append); } + op(_BINARY_SLICE, (container, start, stop -- res)) { + // Slicing a string/list/tuple always returns the same type. + PyTypeObject *type = sym_get_type(container); + if (type == &PyUnicode_Type || + type == &PyList_Type || + type == &PyTuple_Type) + { + res = sym_new_type(ctx, type); + } + else { + res = sym_new_not_null(ctx); + } + } + // END BYTECODES // } diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h index 1a2d49973ee..b42f47c75ea 100644 --- a/Python/optimizer_cases.c.h +++ b/Python/optimizer_cases.c.h @@ -568,8 +568,19 @@ } case _BINARY_SLICE: { + JitOptSymbol *container; JitOptSymbol *res; - res = sym_new_not_null(ctx); + container = stack_pointer[-3]; + PyTypeObject *type = sym_get_type(container); + if (type == &PyUnicode_Type || + type == &PyList_Type || + type == &PyTuple_Type) + { + res = sym_new_type(ctx, type); + } + else { + res = sym_new_not_null(ctx); + } stack_pointer[-3] = res; stack_pointer += -2; assert(WITHIN_STACK_BOUNDS()); |