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v0.5.1
v0.5.1
https://github.com/python/cpython
Tip revision: 74f4bd53e03ded8408bcc2de67cf0f5a4ac5b1a1 authored by Barry Warsaw on 23 February 2012, 15:59:38 UTC
Bump some more copyright years (as per PEP 101), since this is the first
Bump some more copyright years (as per PEP 101), since this is the first
Tip revision: 74f4bd5
longintrepr.h
#ifndef Py_LONGINTREPR_H
#define Py_LONGINTREPR_H
#ifdef __cplusplus
extern "C" {
#endif
/* This is published for the benefit of "friend" marshal.c only. */
/* Parameters of the long integer representation.
These shouldn't have to be changed as C should guarantee that a short
contains at least 16 bits, but it's made changeable anyway.
Note: 'digit' should be able to hold 2*MASK+1, and 'twodigits'
should be able to hold the intermediate results in 'mul'
(at most (BASE-1)*(2*BASE+1) == MASK*(2*MASK+3)).
Also, x_sub assumes that 'digit' is an unsigned type, and overflow
is handled by taking the result mod 2**N for some N > SHIFT.
And, at some places it is assumed that MASK fits in an int, as well.
long_pow() requires that SHIFT be divisible by 5. */
typedef unsigned short digit;
typedef unsigned int wdigit; /* digit widened to parameter size */
#define BASE_TWODIGITS_TYPE long
typedef unsigned BASE_TWODIGITS_TYPE twodigits;
typedef BASE_TWODIGITS_TYPE stwodigits; /* signed variant of twodigits */
#define PyLong_SHIFT 15
#define PyLong_BASE ((digit)1 << PyLong_SHIFT)
#define PyLong_MASK ((int)(PyLong_BASE - 1))
/* b/w compatibility with Python 2.5 */
#define SHIFT PyLong_SHIFT
#define BASE PyLong_BASE
#define MASK PyLong_MASK
#if PyLong_SHIFT % 5 != 0
#error "longobject.c requires that PyLong_SHIFT be divisible by 5"
#endif
/* Long integer representation.
The absolute value of a number is equal to
SUM(for i=0 through abs(ob_size)-1) ob_digit[i] * 2**(SHIFT*i)
Negative numbers are represented with ob_size < 0;
zero is represented by ob_size == 0.
In a normalized number, ob_digit[abs(ob_size)-1] (the most significant
digit) is never zero. Also, in all cases, for all valid i,
0 <= ob_digit[i] <= MASK.
The allocation function takes care of allocating extra memory
so that ob_digit[0] ... ob_digit[abs(ob_size)-1] are actually available.
CAUTION: Generic code manipulating subtypes of PyVarObject has to
aware that longs abuse ob_size's sign bit.
*/
struct _longobject {
PyObject_VAR_HEAD
digit ob_digit[1];
};
PyAPI_FUNC(PyLongObject *) _PyLong_New(Py_ssize_t);
/* Return a copy of src. */
PyAPI_FUNC(PyObject *) _PyLong_Copy(PyLongObject *src);
#ifdef __cplusplus
}
#endif
#endif /* !Py_LONGINTREPR_H */