text: /* Copyright (c) 2018, 2019, Oracle and/or its affiliates.
   * Copyright (C) 1996-2017 Python Software Foundation
   *
   * Licensed under the PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2
   */
  #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:
  
     - long_pow() requires that PyLong_SHIFT be divisible by 5
  
     - 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))
  
  #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 ints 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 */
  #endif /* Py_LIMITED_API */
  