exp2(), exp2f(), exp2l()

Synopsis:

#include <math.h>

double exp2( double x );

float exp2f( float x );

long double exp2l(long double x );

libm: The general-purpose math library.
libm-sve: (QNX Neutrino 7.1 or later) A library that optimizes the code for ARMv8.2 chips that have Scalable Vector Extension hardware.

Your system requirements will determine how you should work with these libraries:

If you want only selected processes to run with the SVE version, you can include both libraries in your OS image and use the -l m or -l m-sve option to qcc to link explicitly against the appropriate one.
If you want all processes to use the SVE version, include libm-sve.so in your OS image and set up a symbolic link from libm.so to libm-sve.so. Use the -l m option to qcc to link against the library.

Note: Compile your program with the -fno-builtin option to prevent the compiler from using a built-in version of the function.

The exp2(), exp2f(), and exp2l() functions compute the base-2 exponential function of x (i.e., 2^x).

To check for error situations, use feclearexcept() and fetestexcept(). For example:

Call feclearexcept(FE_ALL_EXCEPT) before calling exp2(), exp2f(), or exp2l().
On return, if fetestexcept(FE_ALL_EXCEPT) is nonzero, then an error has occurred.

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.