[mypyc] Optimize list.__imul__, tuple.__mul__ (#18887)

https://docs.python.org/3/c-api/sequence.html#c.PySequence_Repeat
https://docs.python.org/3/c-api/sequence.html#c.PySequence_InPlaceRepeat

Author: cdce8p

mypyc/doc/list_operations.rst

@@ -33,7 +33,7 @@ Operators
 * ``lst[n]`` (get item by integer index)
 * ``lst[n:m]``, ``lst[n:]``, ``lst[:m]``, ``lst[:]`` (slicing)
 * ``lst1 + lst2``, ``lst += iter``
-* ``lst * n``, ``n * lst``
+* ``lst * n``, ``n * lst``, ``lst *= n``
 * ``obj in lst``
 
 Statements

mypyc/doc/tuple_operations.rst

@@ -22,6 +22,7 @@ Operators
 * ``tup[n]`` (integer index)
 * ``tup[n:m]``, ``tup[n:]``, ``tup[:m]`` (slicing)
 * ``tup1 + tup2``
+* ``tup * n``, ``n * tup``
 
 Statements
 ----------

mypyc/lib-rt/CPy.h

@@ -664,6 +664,7 @@ int CPyList_Remove(PyObject *list, PyObject *obj);
 CPyTagged CPyList_Index(PyObject *list, PyObject *obj);
 PyObject *CPySequence_Multiply(PyObject *seq, CPyTagged t_size);
 PyObject *CPySequence_RMultiply(CPyTagged t_size, PyObject *seq);
+PyObject *CPySequence_InPlaceMultiply(PyObject *seq, CPyTagged t_size);
 PyObject *CPyList_GetSlice(PyObject *obj, CPyTagged start, CPyTagged end);
 PyObject *CPyList_Copy(PyObject *list);
 int CPySequence_Check(PyObject *obj);

mypyc/lib-rt/list_ops.c

@@ -331,6 +331,14 @@ PyObject *CPySequence_RMultiply(CPyTagged t_size, PyObject *seq) {
     return CPySequence_Multiply(seq, t_size);
 }
 
+PyObject *CPySequence_InPlaceMultiply(PyObject *seq, CPyTagged t_size) {
+    Py_ssize_t size = CPyTagged_AsSsize_t(t_size);
+    if (size == -1 && PyErr_Occurred()) {
+        return NULL;
+    }
+    return PySequence_InPlaceRepeat(seq, size);
+}
+
 PyObject *CPyList_GetSlice(PyObject *obj, CPyTagged start, CPyTagged end) {
     if (likely(PyList_CheckExact(obj)
                && CPyTagged_CheckShort(start) && CPyTagged_CheckShort(end))) {

mypyc/primitives/list_ops.py

@@ -307,6 +307,15 @@
     error_kind=ERR_MAGIC,
 )
 
+# list *= int
+binary_op(
+    name="*=",
+    arg_types=[list_rprimitive, int_rprimitive],
+    return_type=list_rprimitive,
+    c_function_name="CPySequence_InPlaceMultiply",
+    error_kind=ERR_MAGIC,
+)
+
 # list[begin:end]
 list_slice_op = custom_op(
     arg_types=[list_rprimitive, int_rprimitive, int_rprimitive],

mypyc/primitives/tuple_ops.py

@@ -83,6 +83,24 @@
     error_kind=ERR_MAGIC,
 )
 
+# tuple * int
+binary_op(
+    name="*",
+    arg_types=[tuple_rprimitive, int_rprimitive],
+    return_type=tuple_rprimitive,
+    c_function_name="CPySequence_Multiply",
+    error_kind=ERR_MAGIC,
+)
+
+# int * tuple
+binary_op(
+    name="*",
+    arg_types=[int_rprimitive, tuple_rprimitive],
+    return_type=tuple_rprimitive,
+    c_function_name="CPySequence_RMultiply",
+    error_kind=ERR_MAGIC,
+)
+
 # tuple[begin:end]
 tuple_slice_op = custom_op(
     arg_types=[tuple_rprimitive, int_rprimitive, int_rprimitive],

mypyc/test-data/fixtures/ir.py

@@ -212,6 +212,8 @@ def __contains__(self, item: object) -> int: ...
     def __add__(self, value: Tuple[T_co, ...], /) -> Tuple[T_co, ...]: ...
     @overload
     def __add__(self, value: Tuple[_T, ...], /) -> Tuple[T_co | _T, ...]: ...
+    def __mul__(self, value: int, /) -> Tuple[T_co, ...]: ...
+    def __rmul__(self, value: int, /) -> Tuple[T_co, ...]: ...
 
 class function: pass
 
@@ -225,6 +227,7 @@ def __setitem__(self, i: int, o: _T) -> None: pass
     def __delitem__(self, i: int) -> None: pass
     def __mul__(self, i: int) -> List[_T]: pass
     def __rmul__(self, i: int) -> List[_T]: pass
+    def __imul__(self, i: int) -> List[_T]: ...
     def __iter__(self) -> Iterator[_T]: pass
     def __len__(self) -> int: pass
     def __contains__(self, item: object) -> int: ...

mypyc/test-data/irbuild-lists.test

@@ -194,6 +194,18 @@ L0:
     b = r4
     return 1
 
+[case testListIMultiply]
+from typing import List
+def f(a: List[int]) -> None:
+    a *= 2
+[out]
+def f(a):
+    a, r0 :: list
+L0:
+    r0 = CPySequence_InPlaceMultiply(a, 4)
+    a = r0
+    return 1
+
 [case testListLen]
 from typing import List
 def f(a: List[int]) -> int:

mypyc/test-data/irbuild-tuple.test

@@ -418,3 +418,38 @@ L0:
     r3 = unbox(tuple[int, int, int, int], r2)
     c = r3
     return 1
+
+[case testTupleMultiply]
+from typing import Tuple
+def f(a: Tuple[int]) -> None:
+    b = a * 2
+    c = 3 * (2,)
+def g(a: Tuple[int, ...]) -> None:
+    b = a * 2
+[out]
+def f(a):
+    a :: tuple[int]
+    r0 :: object
+    r1 :: tuple
+    r2, b :: tuple[int, int]
+    r3 :: tuple[int]
+    r4 :: object
+    r5 :: tuple
+    r6, c :: tuple[int, int, int]
+L0:
+    r0 = box(tuple[int], a)
+    r1 = CPySequence_Multiply(r0, 4)
+    r2 = unbox(tuple[int, int], r1)
+    b = r2
+    r3 = (4)
+    r4 = box(tuple[int], r3)
+    r5 = CPySequence_RMultiply(6, r4)
+    r6 = unbox(tuple[int, int, int], r5)
+    c = r6
+    return 1
+def g(a):
+    a, r0, b :: tuple
+L0:
+    r0 = CPySequence_Multiply(a, 4)
+    b = r0
+    return 1

mypyc/test-data/run-lists.test

@@ -313,6 +313,13 @@ def test_add() -> None:
     assert in_place_add({3: "", 4: ""}) == res
     assert in_place_add(range(3, 5)) == res
 
+def test_multiply() -> None:
+    l1 = [1]
+    assert l1 * 3 == [1, 1, 1]
+    assert 3 * l1 == [1, 1, 1]
+    l1 *= 3
+    assert l1 == [1, 1, 1]
+
 [case testOperatorInExpression]
 
 def tuple_in_int0(i: int) -> bool: