kc3-lang/libtommath/mp_grow.c

• Show log

  Commit

• Hash : 795cd201
  Author :
  Date : 2019-10-29T21:48:50
  

  simplifications: add s_mp_zero_(digs|buf) and s_mp_copy_digs
  
  Originally I made those as macros. However we have many
  other small functions like mp_clamp, mp_exch which are also not implemented
  as macros right now.
  
  If we would use c99, I would implement them as private static inline
  functions. And mp_exch would be a public static inline function.
  
  But since we are bound to c89, we simply use normal functions.
  To achieve optimal performance one should either use link time
  optimization or amalgamation.
  

Download

• mp_grow.c

• #include "tommath_private.h"
  #ifdef MP_GROW_C
  /* LibTomMath, multiple-precision integer library -- Tom St Denis */
  /* SPDX-License-Identifier: Unlicense */
  
  /* grow as required */
  mp_err mp_grow(mp_int *a, int size)
  {
     /* if the alloc size is smaller alloc more ram */
     if (a->alloc < size) {
        /* reallocate the array a->dp
         *
         * We store the return in a temporary variable
         * in case the operation failed we don't want
         * to overwrite the dp member of a.
         */
        mp_digit *dp = (mp_digit *) MP_REALLOC(a->dp,
                                               (size_t)a->alloc * sizeof(mp_digit),
                                               (size_t)size * sizeof(mp_digit));
        if (dp == NULL) {
           /* reallocation failed but "a" is still valid [can be freed] */
           return MP_MEM;
        }
  
        /* reallocation succeeded so set a->dp */
        a->dp = dp;
  
        /* zero excess digits */
        s_mp_zero_digs(a->dp + a->alloc, size - a->alloc);
        a->alloc = size;
     }
     return MP_OKAY;
  }
  #endif
  

Download