_RETURN_TYPE
INTERNAL_FUNCTION_NAME (DEC_TYPE x)
{
DEC_TYPE result;
decContext context;
decNumber dn_result;
decNumber dn_x;
decNumber dn_absx;
decNumber dn_logx;
decNumber dn_one;
decNumber dn_cmp;
enum rounding round;
FUNC_CONVERT_TO_DN (&x, &dn_x);
if (decNumberIsZero (&dn_x))
{
DFP_EXCEPT (FE_INVALID);
DFP_ERRNO (EDOM);
return _FBLOG0;
}
if (decNumberIsInfinite (&dn_x))
{
DFP_EXCEPT (FE_INVALID);
DFP_ERRNO (EDOM);
return decNumberIsNegative (&dn_x) ? _MIN_VALUE : _MAX_VALUE;
}
if (decNumberIsNaN (&dn_x))
{
DFP_EXCEPT (FE_INVALID);
DFP_ERRNO (EDOM);
return _FBLOGNAN;
}
decContextDefault (&context, DEFAULT_CONTEXT);
decNumberAbs (&dn_absx, &dn_x, &context);
/* For DFP, we use radix 10 instead of whatever FLT_RADIX happens to be */
decNumberLog10 (&dn_logx, &dn_absx, &context);
/* Capture the case where truncation will return the wrong result,
by rounding up if -1.0 < x < 1.0 */
round = DEC_ROUND_DOWN;
decNumberFromInt32 (&dn_one, 1);
decNumberCompare (&dn_cmp, &dn_x, &dn_one, &context);
if (-decNumberIsNegative(&dn_cmp))
{
decNumberFromInt32 (&dn_one, -1);
decNumberCompare (&dn_cmp, &dn_x, &dn_one, &context);
if (!decNumberIsNegative(&dn_cmp) && !decNumberIsZero(&dn_cmp))
round = DEC_ROUND_UP;
}
context.round = round;
decNumberToIntegralValue (&dn_result, &dn_logx, &context);
FUNC_CONVERT_FROM_DN (&dn_result, &result, &context);
/* Use _Decimal* to int casting. */
return (_RETURN_TYPE) result;
}
void* decSingleLog10 (void* _0, const void* _1, decContext* ctx) noexcept
{
decNumber _0num;
decNumber _1num;
decSingleToNumber (_1, &_1num);
decNumberLog10 (&_0num, &_1num, ctx);
return decSingleFromNumber (_0, &_0num, ctx);
}
DEC_TYPE
INTERNAL_FUNCTION_NAME (DEC_TYPE x)
{
decContext context;
decNumber dn_result;
DEC_TYPE result;
decNumber dn_x;
decNumber dn_tmp;
decNumber dn_log10;
decNumber dn_one;
decNumber dn_cmp;
enum rounding round;
FUNC_CONVERT_TO_DN (&x, &dn_x);
if (decNumberIsNaN (&dn_x))
return x+x;
if (decNumberIsInfinite (&dn_x)) /* +-Inf: Inf */
return DEC_INFINITY;
if (decNumberIsZero (&dn_x)) /* Pole Error if x==0 */
{
DFP_ERRNO (ERANGE);
DFP_EXCEPT (FE_DIVBYZERO);
return -DFP_HUGE_VAL;
}
if (decNumberIsInfinite (&dn_x) && decNumberIsNegative (&dn_x))
return -x;
decContextDefault (&context, DEFAULT_CONTEXT);
decNumberAbs (&dn_tmp, &dn_x, &context);
/* For DFP, we use radix 10 instead of whatever FLT_RADIX
happens to be */
decNumberLog10 (&dn_log10, &dn_tmp, &context);
/* Capture the case where truncation will return the wrong result,
by rounding up if -1.0 < x < 1.0 */
round = DEC_ROUND_DOWN;
decNumberFromInt32 (&dn_one, 1);
decNumberCompare (&dn_cmp, &dn_x, &dn_one, &context);
if (-decNumberIsNegative(&dn_cmp))
{
decNumberFromInt32 (&dn_one, -1);
decNumberCompare (&dn_cmp, &dn_x, &dn_one, &context);
if (!decNumberIsNegative(&dn_cmp) && !decNumberIsZero(&dn_cmp))
round = DEC_ROUND_UP;
}
context.round = round;
decNumberToIntegralValue (&dn_result, &dn_log10, &context);
FUNC_CONVERT_FROM_DN (&dn_result, &result, &context);
return result;
}
