On Tue, Sep 3, 2019 at 10:49 AM Torbjörn Granlund <t...@gmplib.org> wrote: > > ni...@lysator.liu.se (Niels Möller) writes: > > And this on a laptop with an Intel U4100 (5 years old?), so I'd assume > it doesn't have a particularly fast div instruction. Should we just > delete div1 ? On which architectures can we expect it to be beneficial? > It should be fairly easy to find out, if we define a HGCD_DIV1_METHOD > known to tuneup, to select between plain division and the div1 function. > > Interesting but not too surprising results. > > Intel ark doesn't seem to know any processor called "U4100" so I cannot > figure out what generation it belongs to.
That most likely is 4100U, a 4th generation chip (aka Haswell). > IIRC, Intel has not improved plain 64b/64b division since Haswell, which > is older than 5 years. > > Again, if IIRC, small quotients may result in 16 cycle latency. That's > the lowest possible timing. > > > > -- > Torbjörn > Please encrypt, key id 0xC8601622 > _______________________________________________ > gmp-devel mailing list > gmp-devel@gmplib.org > https://gmplib.org/mailman/listinfo/gmp-devel _______________________________________________ gmp-devel mailing list gmp-devel@gmplib.org https://gmplib.org/mailman/listinfo/gmp-devel