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| author | scoder <stefan_ml@behnel.de> | 2021-09-21 11:01:18 +0200 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-09-21 11:01:18 +0200 |
| commit | debd80403721b00423680328d6adf160a28fbff4 (patch) | |
| tree | e732523c9fdf4f49141bfd8e01052c47feecadeb /Python | |
| parent | 0bfa1106acfcddc03590e1f5d6789dbad3affe70 (diff) | |
| download | cpython3-debd80403721b00423680328d6adf160a28fbff4.tar.gz | |
bpo-24076: Inline single digit unpacking in the integer fastpath of sum() (GH-28469)
Diffstat (limited to 'Python')
| -rw-r--r-- | Python/bltinmodule.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c index 76c9f87fdf..38bdfb2766 100644 --- a/Python/bltinmodule.c +++ b/Python/bltinmodule.c @@ -2479,7 +2479,15 @@ builtin_sum_impl(PyObject *module, PyObject *iterable, PyObject *start) return PyLong_FromLong(i_result); } if (PyLong_CheckExact(item) || PyBool_Check(item)) { - long b = PyLong_AsLongAndOverflow(item, &overflow); + long b; + overflow = 0; + /* Single digits are common, fast, and cannot overflow on unpacking. */ + switch (Py_SIZE(item)) { + case -1: b = -(sdigit) ((PyLongObject*)item)->ob_digit[0]; break; + case 0: continue; + case 1: b = ((PyLongObject*)item)->ob_digit[0]; break; + default: b = PyLong_AsLongAndOverflow(item, &overflow); break; + } if (overflow == 0 && (i_result >= 0 ? (b <= LONG_MAX - i_result) : (b >= LONG_MIN - i_result))) |