fabs(), fabsf(), fabsl()

Synopsis:

#include <math.h>

double fabs( double x );

float fabsf( float x );

long double fabsl( long double x );

libm

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

The fabs(), fabsf(), and fabsl() functions compute the absolute value of x.

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

Call feclearexcept(FE_ALL_EXCEPT) before calling fabs(), fabsf(), or fabsl().
On return, if fetestexcept(FE_ALL_EXCEPT) is nonzero, then an error has occurred.

The absolute value of x.

These functions raise FE_INEXACT if the FPU reports that the result can't be exactly represented as a floating-point number.

#include <stdio.h>
#include <math.h>
#include <stdlib.h>

int main( void )
{
    printf( "%f %f\n", fabs(.5), fabs(-.5) );
    return EXIT_SUCCESS;
}

produces the output:

0.500000 0.500000