Monday, January 9, 2012

What's inlined by -xlibmil

The compiler flag -xlibmil provides inline templates for some critical maths functions, but it comes with the optimisation that it does not set errno for these functions. The functions it inlines can vary from release to release, so it's useful to be able to see which functions are inlined, and determine whether you care that they don't set errno. You can see the list of functions using the command:

grep inline /compilerpath/prod/lib/
        .inline sqrtf,1
        .inline sqrt,2
        .inline ceil,2
        .inline ceilf,1
        .inline floor,2
        .inline floorf,1
        .inline rint,2
        .inline rintf,1

From a cursory glance at the list I got when I did this just now, I can only see sqrt as a function that sets errno. So if you use sqrt and you care about whether it set errno, then don't use -xlibmil.