Calculate the base-2 exponential of a number
#include <math.h> double exp2( double x ); float exp2f( float x ); long double exp2l(long double x );
The exp2(), exp2f(), and exp2l() functions compute the base-2 exponential function of x (i.e., 2x).
To check for error situations, use feclearexcept() and fetestexcept(). For example:
The base-2 exponential function of x.
If x is: | These functions return: | Errors: |
---|---|---|
±0.0 | 1 | — |
A value that would cause overflow | Inf | FE_OVERFLOW |
A value that would cause underflow | 0.0 | FE_UNDERFLOW |
-Inf | 0.0 | — |
Inf | Inf | — |
NaN | NaN | — |
These functions raise FE_INEXACT if the FPU reports that the result can't be exactly represented as a floating-point number.
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | No |
Signal handler | No |
Thread | Yes |