Alexander, on Wed, 31 May 2023 20:09:29 +0300 (MSK) you (Alexander Monakov ) wrote: > On Wed, 31 May 2023, Jens Gustedt wrote: > > > So what? On the arch where it exist, it is used and useful. (And I > > also think that implementations improved over the state from 20 > > years ago that you describe.) > > Sorry, I'm not sure what you meant in the parenthetical statement. > Improved in what sense? In the sense that depending on your -march=xxx settings they use all low level operations that are available. IIRC, bit operation support is e.g already quite good on most current x86_64, there is specialization for multiplying or dividing a 128 bit integer with/by a 64 bit integer, and when I did these patches I have seen that division by a small constant is quite good. The composition of 64 bit operations is still used as a fallback where no such native processor support is available, though. Jₑₙₛ -- :: ICube :::::::::::::::::::::::::::::: deputy director :: :: Université de Strasbourg :::::::::::::::::::::: ICPS :: :: INRIA Nancy Grand Est :::::::::::::::::::::::: Camus :: :: :::::::::::::::::::::::::::::::::::: ☎ +33 368854536 :: :: https://icube-icps.unistra.fr/index.php/Jens_Gustedt ::