kc3-lang/libtommath/mp_set_double.c

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• Hash : 9cfb6c32
  Author :
  Date : 2019-11-06T11:52:42
  

  use type-cast in stead of UINT64_C

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• mp_set_double.c

• #include "tommath_private.h"
  #ifdef MP_SET_DOUBLE_C
  /* LibTomMath, multiple-precision integer library -- Tom St Denis */
  /* SPDX-License-Identifier: Unlicense */
  
  #if defined(__STDC_IEC_559__) || defined(__GCC_IEC_559)
  mp_err mp_set_double(mp_int *a, double b)
  {
     uint64_t frac;
     int exp;
     mp_err err;
     union {
        double   dbl;
        uint64_t bits;
     } cast;
     cast.dbl = b;
  
     exp = (int)((unsigned)(cast.bits >> 52) & 0x7FFu);
     frac = (cast.bits & (((uint64_t)1 << 52) - (uint64_t)1)) | ((uint64_t)1 << 52);
  
     if (exp == 0x7FF) { /* +-inf, NaN */
        return MP_VAL;
     }
     exp -= 1023 + 52;
  
     mp_set_u64(a, frac);
  
     err = (exp < 0) ? mp_div_2d(a, -exp, a, NULL) : mp_mul_2d(a, exp, a);
     if (err != MP_OKAY) {
        return err;
     }
  
     if (((cast.bits >> 63) != 0u) && !mp_iszero(a)) {
        a->sign = MP_NEG;
     }
  
     return MP_OKAY;
  }
  #else
  /* pragma message() not supported by several compilers (in mostly older but still used versions) */
  #  ifdef _MSC_VER
  #    pragma message("mp_set_double implementation is only available on platforms with IEEE754 floating point format")
  #  else
  #    warning "mp_set_double implementation is only available on platforms with IEEE754 floating point format"
  #  endif
  #endif
  #endif
  

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