gh-115480: Type propagate _BINARY_OP_ADD_UNICODE

Lib/test/test_capi/test_opt.py

@@ -795,11 +795,14 @@ def test_float_add_constant_propagation(self):
  def testfunc(n):
  a = 1.0
  for _ in range(n):
- a = a + 0.1
+ a = a + 0.25
+ a = a + 0.25
+ a = a + 0.25
+ a = a + 0.25
  return a
 
  res, ex = self._run_with_optimizer(testfunc, 32)
- self.assertAlmostEqual(res, 4.2)
+ self.assertAlmostEqual(res, 33.0)
  self.assertIsNotNone(ex)
  uops = get_opnames(ex)
  guard_both_float_count = [opname for opname in iter_opnames(ex) if opname == "_GUARD_BOTH_FLOAT"]
@@ -812,11 +815,14 @@ def test_float_subtract_constant_propagation(self):
  def testfunc(n):
  a = 1.0
  for _ in range(n):
- a = a - 0.1
+ a = a - 0.25
+ a = a - 0.25
+ a = a - 0.25
+ a = a - 0.25
  return a
 
  res, ex = self._run_with_optimizer(testfunc, 32)
- self.assertAlmostEqual(res, -2.2)
+ self.assertAlmostEqual(res, -31.0)
  self.assertIsNotNone(ex)
  uops = get_opnames(ex)
  guard_both_float_count = [opname for opname in iter_opnames(ex) if opname == "_GUARD_BOTH_FLOAT"]
@@ -829,11 +835,14 @@ def test_float_multiply_constant_propagation(self):
  def testfunc(n):
  a = 1.0
  for _ in range(n):
- a = a * 2.0
+ a = a * 1.0
+ a = a * 1.0
+ a = a * 1.0
+ a = a * 1.0
  return a
 
  res, ex = self._run_with_optimizer(testfunc, 32)
- self.assertAlmostEqual(res, 2 ** 32)
+ self.assertAlmostEqual(res, 1.0)
  self.assertIsNotNone(ex)
  uops = get_opnames(ex)
  guard_both_float_count = [opname for opname in iter_opnames(ex) if opname == "_GUARD_BOTH_FLOAT"]
@@ -842,6 +851,24 @@ def testfunc(n):
  # We'll also need to verify that propagation actually occurs.
  self.assertIn("_BINARY_OP_MULTIPLY_FLOAT", uops)
 
+ def test_add_unicode_propagation(self):
+ def testfunc(n):
+ a = ""
+ for _ in range(n):
+ a + a
+ a + a
+ a + a
+ a + a
+ return a
+
+ res, ex = self._run_with_optimizer(testfunc, 32)
+ self.assertEqual(res, "")
+ self.assertIsNotNone(ex)
+ uops = get_opnames(ex)
+ guard_both_unicode_count = [opname for opname in iter_opnames(ex) if opname == "_GUARD_BOTH_UNICODE"]
+ self.assertLessEqual(len(guard_both_unicode_count), 1)
+ self.assertIn("_BINARY_OP_ADD_UNICODE", uops)
+
  def test_compare_op_type_propagation_float(self):
  def testfunc(n):
  a = 1.0

Python/optimizer_bytecodes.c

@@ -254,6 +254,22 @@ dummy_func(void) {
  }
  }
 
+ op(_BINARY_OP_ADD_UNICODE, (left, right -- res)) {
+ if (sym_is_const(left) && sym_is_const(right) &&
+ sym_matches_type(left, &PyUnicode_Type) && sym_matches_type(right, &PyUnicode_Type)) {
+ PyObject *temp = PyUnicode_Concat(sym_get_const(left), sym_get_const(right));
+ if (temp == NULL) {
+ goto error;
+ }
+ res = sym_new_const(ctx, temp);
+ Py_DECREF(temp);
+ OUT_OF_SPACE_IF_NULL(res);
+ }
+ else {
+ OUT_OF_SPACE_IF_NULL(res = sym_new_type(ctx, &PyUnicode_Type));
+ }
+ }
+
  op(_TO_BOOL, (value -- res)) {
  (void)value;
  res = sym_new_type(ctx, &PyBool_Type);