diff --git a/Misc/NEWS.d/next/Core and Builtins/2019-08-23-22-46-25.bpo-37812.vsWZwS.rst b/Misc/NEWS.d/next/Core and Builtins/2019-08-23-22-46-25.bpo-37812.vsWZwS.rst new file mode 100644 index 00000000000..90c3ff3f7ef --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2019-08-23-22-46-25.bpo-37812.vsWZwS.rst @@ -0,0 +1,3 @@ +The ``CHECK_SMALL_INT`` macro used inside :file:`Object/longobject.c` has +been replaced with an explicit ``return`` at each call site, conditioned on +a ``static inline`` function ``is_small_int``. diff --git a/Objects/longobject.c b/Objects/longobject.c index 3978f5c4a16..74037be7a1e 100644 --- a/Objects/longobject.c +++ b/Objects/longobject.c @@ -41,6 +41,13 @@ PyObject *_PyLong_One = NULL; -NSMALLNEGINTS (inclusive) to NSMALLPOSINTS (not inclusive). */ static PyLongObject small_ints[NSMALLNEGINTS + NSMALLPOSINTS]; + +static inline int +is_small_int(long long ival) +{ + return -NSMALLNEGINTS <= ival && ival < NSMALLPOSINTS; +} + #ifdef COUNT_ALLOCS Py_ssize_t _Py_quick_int_allocs, _Py_quick_neg_int_allocs; #endif @@ -49,7 +56,7 @@ static PyObject * get_small_int(sdigit ival) { PyObject *v; - assert(-NSMALLNEGINTS <= ival && ival < NSMALLPOSINTS); + assert(is_small_int(ival)); v = (PyObject *)&small_ints[ival + NSMALLNEGINTS]; Py_INCREF(v); #ifdef COUNT_ALLOCS @@ -60,17 +67,13 @@ get_small_int(sdigit ival) #endif return v; } -#define CHECK_SMALL_INT(ival) \ - do if (-NSMALLNEGINTS <= ival && ival < NSMALLPOSINTS) { \ - return get_small_int((sdigit)ival); \ - } while(0) static PyLongObject * maybe_small_long(PyLongObject *v) { if (v && Py_ABS(Py_SIZE(v)) <= 1) { sdigit ival = MEDIUM_VALUE(v); - if (-NSMALLNEGINTS <= ival && ival < NSMALLPOSINTS) { + if (is_small_int(ival)) { Py_DECREF(v); return (PyLongObject *)get_small_int(ival); } @@ -78,7 +81,8 @@ maybe_small_long(PyLongObject *v) return v; } #else -#define CHECK_SMALL_INT(ival) +#define is_small_int(ival) 0 +#define get_small_int(ival) (assert(0), NULL) #define maybe_small_long(val) (val) #endif @@ -293,7 +297,9 @@ _PyLong_Copy(PyLongObject *src) i = -(i); if (i < 2) { sdigit ival = MEDIUM_VALUE(src); - CHECK_SMALL_INT(ival); + if (is_small_int(ival)) { + return get_small_int(ival); + } } result = _PyLong_New(i); if (result != NULL) { @@ -315,7 +321,9 @@ PyLong_FromLong(long ival) int ndigits = 0; int sign; - CHECK_SMALL_INT(ival); + if (is_small_int(ival)) { + return get_small_int((sdigit)ival); + } if (ival < 0) { /* negate: can't write this as abs_ival = -ival since that @@ -1146,7 +1154,10 @@ PyLong_FromLongLong(long long ival) int ndigits = 0; int negative = 0; - CHECK_SMALL_INT(ival); + if (is_small_int(ival)) { + return get_small_int((sdigit)ival); + } + if (ival < 0) { /* avoid signed overflow on negation; see comments in PyLong_FromLong above. */ @@ -1218,7 +1229,10 @@ PyLong_FromSsize_t(Py_ssize_t ival) int ndigits = 0; int negative = 0; - CHECK_SMALL_INT(ival); + if (is_small_int(ival)) { + return get_small_int((sdigit)ival); + } + if (ival < 0) { /* avoid signed overflow when ival = SIZE_T_MIN */ abs_ival = (size_t)(-1-ival)+1;