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Merged
merged 4 commits into from
Jun 14, 2025
Merged

gh-135474: Specialize arithmetic only on compact ints #135479

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32b2d07
Specialize arithmetic only on compact ints
Fidget-Spinner Jun 13, 2025
8a20d78
📜🤖 Added by blurb_it.
blurb-it[bot] Jun 13, 2025
c9e93fe
Remove broken constant propagation code (for now)
Fidget-Spinner Jun 13, 2025
4019a15
Merge branch 'pylong_compactadd' of github.com:Fidget-Spinner/cpython…
Fidget-Spinner Jun 13, 2025
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4 changes: 2 additions & 2 deletions Doc/howto/perf_profiling.rst
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Original file line number Diff line number Diff line change
Expand Up @@ -92,7 +92,7 @@ Then we can use ``perf report`` to analyze the data:
| | | |
| | | |--51.67%--_PyEval_EvalFrameDefault
| | | | |
| | | | |--11.52%--_PyLong_Add
| | | | |--11.52%--_PyCompactLong_Add
| | | | | |
| | | | | |--2.97%--_PyObject_Malloc
...
Expand Down Expand Up @@ -142,7 +142,7 @@ Instead, if we run the same experiment with ``perf`` support enabled we get:
| | | |
| | | |--51.81%--_PyEval_EvalFrameDefault
| | | | |
| | | | |--13.77%--_PyLong_Add
| | | | |--13.77%--_PyCompactLong_Add
| | | | | |
| | | | | |--3.26%--_PyObject_Malloc

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6 changes: 3 additions & 3 deletions Include/internal/pycore_long.h
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Expand Up @@ -112,9 +112,9 @@ PyAPI_DATA(PyObject*) _PyLong_Rshift(PyObject *, int64_t);
// Export for 'math' shared extension
PyAPI_DATA(PyObject*) _PyLong_Lshift(PyObject *, int64_t);

PyAPI_FUNC(PyObject*) _PyLong_Add(PyLongObject *left, PyLongObject *right);
PyAPI_FUNC(PyObject*) _PyLong_Multiply(PyLongObject *left, PyLongObject *right);
PyAPI_FUNC(PyObject*) _PyLong_Subtract(PyLongObject *left, PyLongObject *right);
PyAPI_FUNC(PyObject*) _PyCompactLong_Add(PyLongObject *left, PyLongObject *right);
PyAPI_FUNC(PyObject*) _PyCompactLong_Multiply(PyLongObject *left, PyLongObject *right);
PyAPI_FUNC(PyObject*) _PyCompactLong_Subtract(PyLongObject *left, PyLongObject *right);

// Export for 'binascii' shared extension.
PyAPI_DATA(unsigned char) _PyLong_DigitValue[256];
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6 changes: 3 additions & 3 deletions Include/internal/pycore_opcode_metadata.h
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6 changes: 3 additions & 3 deletions Include/internal/pycore_uop_metadata.h
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1 change: 1 addition & 0 deletions Misc/NEWS.d/next/Core_and_Builtins/2025-06-13-16-05-24.gh-issue-135474.67nOl3.rst
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@@ -0,0 +1 @@
Specialize integer operations only on compact integers. This is a CPython internal change.
17 changes: 11 additions & 6 deletions Objects/longobject.c
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Expand Up @@ -3772,9 +3772,11 @@ long_add(PyLongObject *a, PyLongObject *b)
}

PyObject *
_PyLong_Add(PyLongObject *a, PyLongObject *b)
_PyCompactLong_Add(PyLongObject *a, PyLongObject *b)
{
return (PyObject*)long_add(a, b);
assert(_PyLong_BothAreCompact(a, b));
stwodigits z = medium_value(a) + medium_value(b);
return (PyObject *)_PyLong_FromSTwoDigits(z);
}

static PyObject *
Expand Down Expand Up @@ -3815,9 +3817,10 @@ long_sub(PyLongObject *a, PyLongObject *b)
}

PyObject *
_PyLong_Subtract(PyLongObject *a, PyLongObject *b)
_PyCompactLong_Subtract(PyLongObject *a, PyLongObject *b)
{
return (PyObject*)long_sub(a, b);
assert(_PyLong_BothAreCompact(a, b));
return (PyObject *)_PyLong_FromSTwoDigits(medium_value(a) - medium_value(b));
}

static PyObject *
Expand Down Expand Up @@ -4262,9 +4265,11 @@ long_mul(PyLongObject *a, PyLongObject *b)
}

PyObject *
_PyLong_Multiply(PyLongObject *a, PyLongObject *b)
_PyCompactLong_Multiply(PyLongObject *a, PyLongObject *b)
{
return (PyObject*)long_mul(a, b);
assert(_PyLong_BothAreCompact(a, b));
stwodigits v = medium_value(a) * medium_value(b);
return (PyObject *)_PyLong_FromSTwoDigits(v);
}

static PyObject *
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9 changes: 6 additions & 3 deletions Python/bytecodes.c
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Expand Up @@ -582,9 +582,10 @@ dummy_func(
PyObject *right_o = PyStackRef_AsPyObjectBorrow(right);
assert(PyLong_CheckExact(left_o));
assert(PyLong_CheckExact(right_o));
DEOPT_IF(!_PyLong_BothAreCompact((PyLongObject *)left_o, (PyLongObject *)right_o));
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If you narrow the checks in _GUARD_TOS_INT and _GUARD_NOS_INT to check for compact ints, we can drop the check here. That way we keep the guard and action in separate micro-ops.

Likewise for + and -. The only complexity is that optimizer_bytecodes.c will need updating to handle compact ints differently.

This change is fine for now though, if you want to do the more sophisticated change in another PR.

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Sure, I can do that.

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On second thought, it's best to leave this to another PR. We need to introduce a new type altogether (one separate from the sym_set_type(&PyLong_Type), and I want to keep this PR's change confined to longobject.c).


STAT_INC(BINARY_OP, hit);
PyObject *res_o = _PyLong_Multiply((PyLongObject *)left_o, (PyLongObject *)right_o);
PyObject *res_o = _PyCompactLong_Multiply((PyLongObject *)left_o, (PyLongObject *)right_o);
PyStackRef_CLOSE_SPECIALIZED(right, _PyLong_ExactDealloc);
PyStackRef_CLOSE_SPECIALIZED(left, _PyLong_ExactDealloc);
INPUTS_DEAD();
Expand All @@ -597,9 +598,10 @@ dummy_func(
PyObject *right_o = PyStackRef_AsPyObjectBorrow(right);
assert(PyLong_CheckExact(left_o));
assert(PyLong_CheckExact(right_o));
DEOPT_IF(!_PyLong_BothAreCompact((PyLongObject *)left_o, (PyLongObject *)right_o));

STAT_INC(BINARY_OP, hit);
PyObject *res_o = _PyLong_Add((PyLongObject *)left_o, (PyLongObject *)right_o);
PyObject *res_o = _PyCompactLong_Add((PyLongObject *)left_o, (PyLongObject *)right_o);
PyStackRef_CLOSE_SPECIALIZED(right, _PyLong_ExactDealloc);
PyStackRef_CLOSE_SPECIALIZED(left, _PyLong_ExactDealloc);
INPUTS_DEAD();
Expand All @@ -612,9 +614,10 @@ dummy_func(
PyObject *right_o = PyStackRef_AsPyObjectBorrow(right);
assert(PyLong_CheckExact(left_o));
assert(PyLong_CheckExact(right_o));
DEOPT_IF(!_PyLong_BothAreCompact((PyLongObject *)left_o, (PyLongObject *)right_o));

STAT_INC(BINARY_OP, hit);
PyObject *res_o = _PyLong_Subtract((PyLongObject *)left_o, (PyLongObject *)right_o);
PyObject *res_o = _PyCompactLong_Subtract((PyLongObject *)left_o, (PyLongObject *)right_o);
PyStackRef_CLOSE_SPECIALIZED(right, _PyLong_ExactDealloc);
PyStackRef_CLOSE_SPECIALIZED(left, _PyLong_ExactDealloc);
INPUTS_DEAD();
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24 changes: 15 additions & 9 deletions Python/executor_cases.c.h
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27 changes: 18 additions & 9 deletions Python/generated_cases.c.h
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51 changes: 3 additions & 48 deletions Python/optimizer_bytecodes.c
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Expand Up @@ -222,60 +222,15 @@ dummy_func(void) {
}

op(_BINARY_OP_ADD_INT, (left, right -- res)) {
if (sym_is_const(ctx, left) && sym_is_const(ctx, right)) {
assert(PyLong_CheckExact(sym_get_const(ctx, left)));
assert(PyLong_CheckExact(sym_get_const(ctx, right)));
PyObject *temp = _PyLong_Add((PyLongObject *)sym_get_const(ctx, left),
(PyLongObject *)sym_get_const(ctx, right));
if (temp == NULL) {
goto error;
}
res = sym_new_const(ctx, temp);
Py_DECREF(temp);
// TODO gh-115506:
// replace opcode with constant propagated one and add tests!
}
else {
res = sym_new_type(ctx, &PyLong_Type);
}
res = sym_new_type(ctx, &PyLong_Type);
}

op(_BINARY_OP_SUBTRACT_INT, (left, right -- res)) {
if (sym_is_const(ctx, left) && sym_is_const(ctx, right)) {
assert(PyLong_CheckExact(sym_get_const(ctx, left)));
assert(PyLong_CheckExact(sym_get_const(ctx, right)));
PyObject *temp = _PyLong_Subtract((PyLongObject *)sym_get_const(ctx, left),
(PyLongObject *)sym_get_const(ctx, right));
if (temp == NULL) {
goto error;
}
res = sym_new_const(ctx, temp);
Py_DECREF(temp);
// TODO gh-115506:
// replace opcode with constant propagated one and add tests!
}
else {
res = sym_new_type(ctx, &PyLong_Type);
}
res = sym_new_type(ctx, &PyLong_Type);
}

op(_BINARY_OP_MULTIPLY_INT, (left, right -- res)) {
if (sym_is_const(ctx, left) && sym_is_const(ctx, right)) {
assert(PyLong_CheckExact(sym_get_const(ctx, left)));
assert(PyLong_CheckExact(sym_get_const(ctx, right)));
PyObject *temp = _PyLong_Multiply((PyLongObject *)sym_get_const(ctx, left),
(PyLongObject *)sym_get_const(ctx, right));
if (temp == NULL) {
goto error;
}
res = sym_new_const(ctx, temp);
Py_DECREF(temp);
// TODO gh-115506:
// replace opcode with constant propagated one and add tests!
}
else {
res = sym_new_type(ctx, &PyLong_Type);
}
res = sym_new_type(ctx, &PyLong_Type);
}

op(_BINARY_OP_ADD_FLOAT, (left, right -- res)) {
Expand Down
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