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#ifndef Py_LIMITED_API

#ifndef Py_LONGINTREPR_H

#define Py_LONGINTREPR_H

#ifdef __cplusplus

extern "C" {

#endif

/* This is published for the benefit of "friends" marshal.c and _decimal.c. */

/* Parameters of the integer representation. There are two different

sets of parameters: one set for 30-bit digits, stored in an unsigned 32-bit

integer type, and one set for 15-bit digits with each digit stored in an

unsigned short. The value of PYLONG_BITS_IN_DIGIT, defined either at

configure time or in pyport.h, is used to decide which digit size to use.

Type 'digit' should be able to hold 2*PyLong_BASE-1, and type 'twodigits'

should be an unsigned integer type able to hold all integers up to

PyLong_BASE*PyLong_BASE-1. x_sub assumes that 'digit' is an unsigned type,

and that overflow is handled by taking the result modulo 2**N for some N >

PyLong_SHIFT. The majority of the code doesn't care about the precise

value of PyLong_SHIFT, but there are some notable exceptions:

- PyLong_{As,From}ByteArray require that PyLong_SHIFT be at least 8

- long_hash() requires that PyLong_SHIFT is *strictly* less than the number

of bits in an unsigned long, as do the PyLong <-> long (or unsigned long)

conversion functions

- the Python int <-> size_t/Py_ssize_t conversion functions expect that

PyLong_SHIFT is strictly less than the number of bits in a size_t

- the marshal code currently expects that PyLong_SHIFT is a multiple of 15

- NSMALLNEGINTS and NSMALLPOSINTS should be small enough to fit in a single

digit; with the current values this forces PyLong_SHIFT >= 9

The values 15 and 30 should fit all of the above requirements, on any

platform.

#if PYLONG_BITS_IN_DIGIT == 30

typedef uint32_t digit;

typedef int32_t sdigit; /* signed variant of digit */

typedef uint64_t twodigits;

typedef int64_t stwodigits; /* signed variant of twodigits */

#define PyLong_SHIFT 30

#define _PyLong_DECIMAL_SHIFT 9 /* max(e such that 10**e fits in a digit) */

#define _PyLong_DECIMAL_BASE ((digit)1000000000) /* 10 ** DECIMAL_SHIFT */

#elif PYLONG_BITS_IN_DIGIT == 15

typedef unsigned short digit;

typedef short sdigit; /* signed variant of digit */

typedef unsigned long twodigits;

typedef long stwodigits; /* signed variant of twodigits */

#define PyLong_SHIFT 15

#define _PyLong_DECIMAL_SHIFT 4 /* max(e such that 10**e fits in a digit) */

#define _PyLong_DECIMAL_BASE ((digit)10000) /* 10 ** DECIMAL_SHIFT */

#else

#error "PYLONG_BITS_IN_DIGIT should be 15 or 30"

#endif

#define PyLong_BASE ((digit)1 << PyLong_SHIFT)

#define PyLong_MASK ((digit)(PyLong_BASE - 1))

/* Long integer representation.

Long integers are made up of a number of 30- or 15-bit digits, depending on

the platform. The number of digits (ndigits) is stored in the high bits of

the lv_tag field (lvtag >> _PyLong_NON_SIZE_BITS).

The absolute value of a number is equal to

SUM(for i=0 through ndigits-1) ob_digit[i] * 2**(PyLong_SHIFT*i)

The sign of the value is stored in the lower 2 bits of lv_tag.

- 0: Positive

- 1: Zero

- 2: Negative

The third lowest bit of lv_tag is

set to 1 for the small ints.

In a normalized number, ob_digit[ndigits-1] (the most significant

digit) is never zero. Also, in all cases, for all valid i,

0 <= ob_digit[i] <= PyLong_MASK.

The allocation function takes care of allocating extra memory

so that ob_digit[0] ... ob_digit[ndigits-1] are actually available.

We always allocate memory for at least one digit, so accessing ob_digit[0]

is always safe. However, in the case ndigits == 0, the contents of

ob_digit[0] may be undefined.

typedef struct _PyLongValue {

uintptr_t lv_tag; /* Number of digits, sign and flags */

digit ob_digit[1];

} _PyLongValue;

struct _longobject {

PyObject_HEAD

_PyLongValue long_value;

};

Py_DEPRECATED(3.14) PyAPI_FUNC(PyLongObject*) _PyLong_New(Py_ssize_t);

// Return a copy of src.

PyAPI_FUNC(PyObject*) _PyLong_Copy(PyLongObject *src);

Py_DEPRECATED(3.14) PyAPI_FUNC(PyLongObject*) _PyLong_FromDigits(

int negative,

Py_ssize_t digit_count,

digit *digits);

/* Inline some internals for speed. These should be in pycore_long.h

* if user code didn't need them inlined. */

#define _PyLong_SIGN_MASK 3

#define _PyLong_NON_SIZE_BITS 3

static inline int

_PyLong_IsCompact(const PyLongObject* op) {

assert(PyType_HasFeature(op->ob_base.ob_type, Py_TPFLAGS_LONG_SUBCLASS));

return op->long_value.lv_tag < (2 << _PyLong_NON_SIZE_BITS);

}

#define PyUnstable_Long_IsCompact _PyLong_IsCompact

static inline Py_ssize_t

_PyLong_CompactValue(const PyLongObject *op)

{

Py_ssize_t sign;

assert(PyType_HasFeature(op->ob_base.ob_type, Py_TPFLAGS_LONG_SUBCLASS));

assert(PyUnstable_Long_IsCompact(op));

sign = 1 - (op->long_value.lv_tag & _PyLong_SIGN_MASK);

return sign * (Py_ssize_t)op->long_value.ob_digit[0];

}

#define PyUnstable_Long_CompactValue _PyLong_CompactValue

/* --- Import/Export API -------------------------------------------------- */

typedef struct PyLongLayout {

uint8_t bits_per_digit;

uint8_t digit_size;

int8_t digits_order;

int8_t digit_endianness;

} PyLongLayout;

PyAPI_FUNC(const PyLongLayout*) PyLong_GetNativeLayout(void);

typedef struct PyLongExport {

int64_t value;

uint8_t negative;

Py_ssize_t ndigits;

const void *digits;

// Member used internally, must not be used for other purpose.

Py_uintptr_t _reserved;

} PyLongExport;

PyAPI_FUNC(int) PyLong_Export(

PyObject *obj,

PyLongExport *export_long);

PyAPI_FUNC(void) PyLong_FreeExport(

PyLongExport *export_long);

/* --- PyLongWriter API --------------------------------------------------- */

typedef struct PyLongWriter PyLongWriter;

PyAPI_FUNC(PyLongWriter*) PyLongWriter_Create(

int negative,

Py_ssize_t ndigits,

void **digits);

PyAPI_FUNC(PyObject*) PyLongWriter_Finish(PyLongWriter *writer);

PyAPI_FUNC(void) PyLongWriter_Discard(PyLongWriter *writer);

#ifdef __cplusplus

}

#endif

#endif /* !Py_LONGINTREPR_H */

#endif /* Py_LIMITED_API */

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