diff --git a/Lib/test/test_capi/test_opt.py b/Lib/test/test_capi/test_opt.py index 2a9b777862c84a..44cfb8685e98a8 100644 --- a/Lib/test/test_capi/test_opt.py +++ b/Lib/test/test_capi/test_opt.py @@ -1437,6 +1437,37 @@ def crash_addition(): crash_addition() + def test_narrow_type_to_constant_int_zero(self): + def f(n): + trace = [] + for i in range(n): + # zero is always (int) 0, but we can only prove that it's a integer: + zero = i - i + trace.append("A") + if not zero: # Kept. + trace.append("B") + if not zero: # Removed! + trace.append("C") + trace.append("D") + if zero: # Removed! + trace.append("X") + trace.append("E") + trace.append("F") + if zero: # Removed! + trace.append("X") + trace.append("G") + return trace + + trace, ex = self._run_with_optimizer(f, TIER2_THRESHOLD) + self.assertEqual(trace, list("ABCDEFG") * TIER2_THRESHOLD) + self.assertIsNotNone(ex) + uops = get_opnames(ex) + # Only one guard remains: + self.assertEqual(uops.count("_GUARD_IS_FALSE_POP"), 1) + self.assertEqual(uops.count("_GUARD_IS_TRUE_POP"), 0) + # But all of the appends we care about are still there: + self.assertEqual(uops.count("_CALL_LIST_APPEND"), len("ABCDEFG")) + def global_identity(x): return x diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-02-22-23-03-13.gh-issue-130415.ibOV6B.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-02-22-23-03-13.gh-issue-130415.ibOV6B.rst new file mode 100644 index 00000000000000..e85760a2501c93 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-02-22-23-03-13.gh-issue-130415.ibOV6B.rst @@ -0,0 +1 @@ +Improve the JIT's understanding of integers in boolean contexts. diff --git a/Python/optimizer_bytecodes.c b/Python/optimizer_bytecodes.c index 41eb59c931aaa7..ffb080f2d88535 100644 --- a/Python/optimizer_bytecodes.c +++ b/Python/optimizer_bytecodes.c @@ -407,6 +407,19 @@ dummy_func(void) { sym_set_type(value, &PyLong_Type); res = sym_new_type(ctx, &PyBool_Type); } + if (!sym_is_const(value)) { + assert(sym_matches_type(value, &PyLong_Type)); + int next_opcode = (this_instr + 1)->opcode; + assert(next_opcode == _CHECK_VALIDITY_AND_SET_IP); + next_opcode = (this_instr + 2)->opcode; + // If the next uop is a guard, we can narrow value. However, we + // *can't* narrow res, since that would cause the guard to be + // removed and the narrowed value to be invalid: + if (next_opcode == _GUARD_IS_FALSE_POP) { + sym_set_const(value, Py_GetConstant(Py_CONSTANT_ZERO)); + res = sym_new_type(ctx, &PyBool_Type); + } + } } op(_TO_BOOL_LIST, (value -- res)) { diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h index fd8486785ed8db..608d9a8635acaf 100644 --- a/Python/optimizer_cases.c.h +++ b/Python/optimizer_cases.c.h @@ -177,6 +177,24 @@ sym_set_type(value, &PyLong_Type); res = sym_new_type(ctx, &PyBool_Type); } + if (!sym_is_const(value)) { + assert(sym_matches_type(value, &PyLong_Type)); + int next_opcode = (this_instr + 1)->opcode; + assert(next_opcode == _CHECK_VALIDITY_AND_SET_IP); + next_opcode = (this_instr + 2)->opcode; + // If the next uop is a guard, we can narrow value. However, we + // *can't* narrow res, since that would cause the guard to be + // removed and the narrowed value to be invalid: + if (next_opcode == _GUARD_IS_FALSE_POP) { + stack_pointer[-1] = res; + sym_set_const(value, Py_GetConstant(Py_CONSTANT_ZERO)); + res = sym_new_type(ctx, &PyLong_Type); + } + // else if (next_opcode == _GUARD_IS_TRUE_POP) { + // sym_set_const(value, Py_True); + // res = sym_new_type(ctx, &PyBool_Type); + // } + } stack_pointer[-1] = res; break; }