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bpo-37802: Slightly improve perfomance of PyLong_FromUnsigned*() (GH-15192)

This commit is contained in:
Sergey Fedoseev 2019-09-12 19:41:14 +05:00 committed by Gregory P. Smith
parent 8d88e8c662
commit c6734ee7c5
2 changed files with 45 additions and 77 deletions
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3
Misc/NEWS.d/next/Core and Builtins/2019-08-09-18-28-57.bpo-37802.pKxcAW.rst Normal file
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@ -0,0 +1,3 @@
Slightly improve performance of :c:func:`PyLong_FromUnsignedLong`,
:c:func:`PyLong_FromUnsignedLongLong` and :c:func:`PyLong_FromSize_t`.
Patch by Sergey Fedoseev.

119
Objects/longobject.c
View File

@ -43,6 +43,7 @@ PyObject *_PyLong_One = NULL;
static PyLongObject small_ints[NSMALLNEGINTS + NSMALLPOSINTS];
#define IS_SMALL_INT(ival) (-NSMALLNEGINTS <= (ival) && (ival) < NSMALLPOSINTS)
#define IS_SMALL_UINT(ival) ((ival) < NSMALLPOSINTS)
#ifdef COUNT_ALLOCS
Py_ssize_t _Py_quick_int_allocs, _Py_quick_neg_int_allocs;
@ -78,6 +79,7 @@ maybe_small_long(PyLongObject *v)
}
#else
#define IS_SMALL_INT(ival) 0
#define IS_SMALL_UINT(ival) 0
#define get_small_int(ival) (Py_UNREACHABLE(), NULL)
#define maybe_small_long(val) (val)
#endif
@ -378,32 +380,52 @@ PyLong_FromLong(long ival)
return (PyObject *)v;
}
#define PYLONG_FROM_UINT(INT_TYPE, ival) \
do { \
if (IS_SMALL_UINT(ival)) { \
return get_small_int((ival)); \
} \
/* Count the number of Python digits. */ \
Py_ssize_t ndigits = 0; \
INT_TYPE t = (ival); \
while (t) { \
++ndigits; \
t >>= PyLong_SHIFT; \
} \
PyLongObject *v = _PyLong_New(ndigits); \
if (v == NULL) { \
return NULL; \
} \
digit *p = v->ob_digit; \
while ((ival)) { \
*p++ = (digit)((ival) & PyLong_MASK); \
(ival) >>= PyLong_SHIFT; \
} \
return (PyObject *)v; \
} while(0)
/* Create a new int object from a C unsigned long int */
PyObject *
PyLong_FromUnsignedLong(unsigned long ival)
{
PyLongObject *v;
unsigned long t;
int ndigits = 0;
PYLONG_FROM_UINT(unsigned long, ival);
}
if (ival < PyLong_BASE)
return PyLong_FromLong(ival);
/* Count the number of Python digits. */
t = ival;
while (t) {
++ndigits;
t >>= PyLong_SHIFT;
}
v = _PyLong_New(ndigits);
if (v != NULL) {
digit *p = v->ob_digit;
while (ival) {
*p++ = (digit)(ival & PyLong_MASK);
ival >>= PyLong_SHIFT;
}
}
return (PyObject *)v;
/* Create a new int object from a C unsigned long long int. */
PyObject *
PyLong_FromUnsignedLongLong(unsigned long long ival)
{
PYLONG_FROM_UINT(unsigned long long, ival);
}
/* Create a new int object from a C size_t. */
PyObject *
PyLong_FromSize_t(size_t ival)
{
PYLONG_FROM_UINT(size_t, ival);
}
/* Create a new int object from a C double */
@ -1186,34 +1208,6 @@ PyLong_FromLongLong(long long ival)
return (PyObject *)v;
}
/* Create a new int object from a C unsigned long long int. */
PyObject *
PyLong_FromUnsignedLongLong(unsigned long long ival)
{
PyLongObject *v;
unsigned long long t;
int ndigits = 0;
if (ival < PyLong_BASE)
return PyLong_FromLong((long)ival);
/* Count the number of Python digits. */
t = ival;
while (t) {
++ndigits;
t >>= PyLong_SHIFT;
}
v = _PyLong_New(ndigits);
if (v != NULL) {
digit *p = v->ob_digit;
while (ival) {
*p++ = (digit)(ival & PyLong_MASK);
ival >>= PyLong_SHIFT;
}
}
return (PyObject *)v;
}
/* Create a new int object from a C Py_ssize_t. */
PyObject *
@ -1257,35 +1251,6 @@ PyLong_FromSsize_t(Py_ssize_t ival)
return (PyObject *)v;
}
/* Create a new int object from a C size_t. */
PyObject *
PyLong_FromSize_t(size_t ival)
{
PyLongObject *v;
size_t t;
int ndigits = 0;
if (ival < PyLong_BASE)
return PyLong_FromLong((long)ival);
/* Count the number of Python digits. */
t = ival;
while (t) {
++ndigits;
t >>= PyLong_SHIFT;
}
v = _PyLong_New(ndigits);
if (v != NULL) {
digit *p = v->ob_digit;
Py_SIZE(v) = ndigits;
while (ival) {
*p++ = (digit)(ival & PyLong_MASK);
ival >>= PyLong_SHIFT;
}
}
return (PyObject *)v;
}
/* Get a C long long int from an int object or any object that has an
__int__ method. Return -1 and set an error if overflow occurs. */