static DEC_TYPE
IEEE_FUNCTION_NAME (DEC_TYPE x)
{
decContext context;
decNumber dn_result;
DEC_TYPE result;
decNumber dn_x;
decNumber dn_one;
decNumber dn_exponent;
DEC_TYPE one = DFP_CONSTANT(1.0);
FUNC_CONVERT_TO_DN(&x, &dn_x);
FUNC_CONVERT_TO_DN(&one, &dn_one);
if (decNumberIsNaN (&dn_x))
return x+x;
if (decNumberIsInfinite (&dn_x))
return decNumberIsNegative (&dn_x) ? DFP_CONSTANT(-1.0) : x;
decContextDefault(&context, DEFAULT_CONTEXT);
decNumberExp(&dn_exponent, &dn_x, &context);
decNumberSubtract(&dn_result, &dn_exponent, &dn_one, &context);
FUNC_CONVERT_FROM_DN(&dn_result, &result, &context);
if (context.status & DEC_Overflow)
DFP_EXCEPT (FE_OVERFLOW);
return result;
}
void* decSingleExp (void* _0, const void* _1, decContext* ctx) noexcept
{
decNumber _0num;
decNumber _1num;
decSingleToNumber (_1, &_1num);
decNumberExp (&_0num, &_1num, ctx);
return decSingleFromNumber (_0, &_0num, ctx);
}
DecimalDecNumber exp(const DecimalDecNumber &val)
{
decContext contextMath;
decContextDefault(&contextMath, DEC_INIT_BASE); // initialize
contextMath.traps=0; // no traps, thank you
contextMath.digits=DECNUMDIGITS; // set precision
contextMath.emax = 1000000 - 1; // Max for mathematical functions like exp
contextMath.emin = -contextMath.emax; // Max for mathematical functions
DecimalDecNumber result;
decNumberExp(&result.m_value, &val.m_value, &contextMath);
return result;
}