expd32(), expd64(), expd128() — Calculate exponential function
Standards
| Standards / Extensions | C or C++ | Dependencies |
|---|---|---|
| C/C++ DFP | both | z/OS® V1.8 |
Format
#define __STDC_WANT_DEC_FP__
#include <math.h>
_Decimal32 expd32(_Decimal32 x);
_Decimal64 expd64(_Decimal64 x);
_Decimal128 expd128(_Decimal128 x);
_Decimal32 exp(_Decimal32 x); /* C++ only */
_Decimal64 exp(_Decimal64 x); /* C++ only */
_Decimal128 exp(_Decimal128 x); /* C++ only */General description
Calculates the exponent
of x, defined as e**x, where e equals 2.17128128....
Notes:
- To use IEEE decimal floating-point, the hardware must have the Decimal Floating-Point Facility installed.
- These functions work in IEEE decimal floating-point format. See IEEE binary floating-point for more information
Returned value
If successful, the function returns the calculated value.
If an overflow occurs, the function returns HUGE_VAL_D32, HUGE_VAL_D64, or HUGE_VAL_D128. If an underflow occurs, it returns 0. Both overflow and underflow set errno to ERANGE.
Example
/* CELEBE11
This example illustrates the expd64() function.
*/
#define __STDC_WANT_DEC_FP__
#include <math.h>
#include <stdio.h>
int main(void)
{
_Decimal64 x, y;
x = 5.0DD;
y = expd64(x);
printf("expd64(%Df) = %Df\n", x, y);
}