Yes. There are cases where cmov is a killer beast and for example it makes your browser faster. JSC goes to great efforts to select it in certain cases where i

Yes. There are cases where cmov is a killer beast and for example it makes your browser faster. JSC goes to great efforts to select it in certain cases where it’s a statistically significant overall speed up. I think the place where it’s the most effective for us is converting hole-or-undefined to undefined on array load. Even on x86 where cmov is hella weird (two operands, no immediates) it ends up being a big win.