[Bug libstdc++/85466] Performance is slow when doing 'branchless' conditional style math operations

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85466

--- Comment #18 from Marc Glisse <glisse at gcc dot gnu.org> ---
For the "if" case, llvm turns:

if (myVector[n] > 0.5){
    result[n] = 0.8f;
}
else {
    result[n] = 0.1f;
}

into

const float tab[2] = { .8f, .1f };
result[n] = tab[item > .5f];