I know, hardly authoritative. But it matches precisely what I remember from when I was hacking on perl with an eye to performance at the time.
Maybe drop that bit regarding 'register'? The rest of that section is still perfectly valid. That is, assuming the compiler doesn't actually perform the local variable/keep in register optimisation itself, but I think it can't do that at least in the general case. I only remember vague things about this. At least aliasing may defeat the compiler optimisation.
Caveat: Like yourself, I picked this stuff up without studying it as part of a degree. Anybody with a proper compiler background want to jump in and enlighten maybe?
I know, hardly authoritative. But it matches precisely what I remember from when I was hacking on perl with an eye to performance at the time.
Maybe drop that bit regarding 'register'? The rest of that section is still perfectly valid. That is, assuming the compiler doesn't actually perform the local variable/keep in register optimisation itself, but I think it can't do that at least in the general case. I only remember vague things about this. At least aliasing may defeat the compiler optimisation.
Caveat: Like yourself, I picked this stuff up without studying it as part of a degree. Anybody with a proper compiler background want to jump in and enlighten maybe?