exp2(), exp2f(), exp2l()

Calculate the base-2 exponential of a number

Synopsis:

#include <math.h>

double exp2( double x );

float exp2f( float x );

long double exp2l(long double x );

Arguments:

x
The number that you want to calculate the base-2 exponential of.

Library:

libm

Use the -l m option to qcc to link against this library.

Description:

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:

Returns:

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.

Classification:

ANSI, POSIX 1003.1

Safety:  
Cancellation point No
Interrupt handler No
Signal handler No
Thread Yes