alt Hacker NewsARM is a big target, there could be cpus where lsl is 1 cycle and add is 2+.
Without knowing about specific compiler targets/settings this looks reasonable.
Dumb in the majority case? Absolutely, but smart on the lowest common denominator.
ARM is a big target, there could be cpus where lsl is 1 cycle and add is 2+.
Without knowing about specific compiler targets/settings this looks reasonable.
Dumb in the majority case? Absolutely, but smart on the lowest common denominator.
> Without knowing about specific compiler targets/settings this looks reasonable.
But we do, armv8-a clang 21.1.0 with O3, and it doesn't.
> […] but smart on the lowest common denominator.
No, that would be the single add instruction.