| #ifndef Py_LONGINTREPR_H |
| #define Py_LONGINTREPR_H |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| /*********************************************************** |
| Copyright (c) 2000, BeOpen.com. |
| Copyright (c) 1995-2000, Corporation for National Research Initiatives. |
| Copyright (c) 1990-1995, Stichting Mathematisch Centrum. |
| All rights reserved. |
| |
| See the file "Misc/COPYRIGHT" for information on usage and |
| redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES. |
| ******************************************************************/ |
| |
| /* 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 any way. |
| Note: 'digit' should be able to hold 2*MASK+1, and 'twodigits' |
| should be able to hold the intermediate results in 'mul' |
| (at most MASK << SHIFT). |
| 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. */ |
| |
| typedef unsigned short digit; |
| typedef unsigned int wdigit; /* digit widened to parameter size */ |
| typedef unsigned long twodigits; |
| typedef long stwodigits; /* signed variant of twodigits */ |
| |
| #define SHIFT 15 |
| #define BASE ((digit)1 << SHIFT) |
| #define MASK ((int)(BASE - 1)) |
| |
| /* 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 fuction takes care of allocating extra memory |
| so that ob_digit[0] ... ob_digit[abs(ob_size)-1] are actually available. */ |
| |
| struct _longobject { |
| PyObject_HEAD |
| int ob_size; |
| digit ob_digit[1]; |
| }; |
| |
| DL_IMPORT(PyLongObject *) _PyLong_New(int); |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| #endif /* !Py_LONGINTREPR_H */ |