kc3-lang/libtommath/bn_mp_2expt.c

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• Hash : 99c84acc
  Author :
  Date : 2015-11-13T10:28:23
  

  add parentheses for explicit operator precedence

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• bn_mp_2expt.c

• #include <tommath_private.h>
  #ifdef BN_MP_2EXPT_C
  /* LibTomMath, multiple-precision integer library -- Tom St Denis
   *
   * LibTomMath is a library that provides multiple-precision
   * integer arithmetic as well as number theoretic functionality.
   *
   * The library was designed directly after the MPI library by
   * Michael Fromberger but has been written from scratch with
   * additional optimizations in place.
   *
   * The library is free for all purposes without any express
   * guarantee it works.
   *
   * Tom St Denis, tstdenis82@gmail.com, http://libtom.org
   */
  
  /* computes a = 2**b 
   *
   * Simple algorithm which zeroes the int, grows it then just sets one bit
   * as required.
   */
  int
  mp_2expt (mp_int * a, int b)
  {
    int     res;
  
    /* zero a as per default */
    mp_zero (a);
  
    /* grow a to accomodate the single bit */
    if ((res = mp_grow (a, (b / DIGIT_BIT) + 1)) != MP_OKAY) {
      return res;
    }
  
    /* set the used count of where the bit will go */
    a->used = (b / DIGIT_BIT) + 1;
  
    /* put the single bit in its place */
    a->dp[b / DIGIT_BIT] = ((mp_digit)1) << (b % DIGIT_BIT);
  
    return MP_OKAY;
  }
  #endif
  
  /* $Source$ */
  /* $Revision$ */
  /* $Date$ */
  

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