Inlining especially is call-site dependent. Little of the benefit of inlining comes from eliminating the call overhead on a modern processor. But quite often,

Inlining especially is call-site dependent. Little of the benefit of inlining comes from eliminating the call overhead on a modern processor. But quite often, functions are called with one or more parameters constant. So that enables a bunch of constant folding for that call site -- the compiler is good at noticing that if(1<7) is always going to be true, and dropping out the whole else branch, which can enable code motion and more common subexpressions... so inlining is often a win but often people misunderstand exactly why.