c3-lang/libtommath/bn_mp_set_int.c

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• Hash : 4e3f1344
  Author :
  Date : 2015-11-12T01:49:07
  

  provide tommath_private.h tommath.h contains declarations for the public part of the library. tommath_private.h contains the functions which are private to ltm and should not be exposed to the public.

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• bn_mp_set_int.c

• #include <tommath_private.h>
  #ifdef BN_MP_SET_INT_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
   */
  
  /* set a 32-bit const */
  int mp_set_int (mp_int * a, unsigned long b)
  {
    int     x, res;
  
    mp_zero (a);
    
    /* set four bits at a time */
    for (x = 0; x < 8; x++) {
      /* shift the number up four bits */
      if ((res = mp_mul_2d (a, 4, a)) != MP_OKAY) {
        return res;
      }
  
      /* OR in the top four bits of the source */
      a->dp[0] |= (b >> 28) & 15;
  
      /* shift the source up to the next four bits */
      b <<= 4;
  
      /* ensure that digits are not clamped off */
      a->used += 1;
    }
    mp_clamp (a);
    return MP_OKAY;
  }
  #endif
  
  /* $Source$ */
  /* $Revision$ */
  /* $Date$ */
  

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