Front page | perl.perl5.porters |
Postings from January 2022
On Mon, 17 Jan 2022 18:28:19 +0000 "Paul \"LeoNerd\" Evans" <leonerd@leonerd.org.uk> wrote: > Next up, a perl built from my discourage-defav-in-sigsub branch (this > is significantly slower than the release perl above in absolute terms, > because it's an unoptimised debug build; but ignore that): ilmari points out that using an unoptimised debug build is unlikely to give useful results. I've rebuilt these tests using non-debug -O3, and also running the actual code for 4 times longer to reduce timing jitter/noise: > $ ./perl -Ilib benchmark-entersub.pl > full: 9.0413s > bare: 7.0131s (speedup x1.29) > sigs: 6.4964s (speedup x1.39) $ ./perl -Ilib benchmark-entersub.pl full: 4.2597s bare: 3.5885s (speedup x1.19) sigs: 3.5397s (speedup x1.20) $ ./perl -Ilib benchmark-entersub.pl full: 4.3395s bare: 3.6818s (speedup x1.18) sigs: 3.5970s (speedup x1.21) $ ./perl -Ilib benchmark-entersub.pl full: 4.0384s bare: 3.3404s (speedup x1.21) sigs: 3.4798s (speedup x1.16) So both bare and sigs are "about 20% faster", though not much difference between them. I seem to be getting more noisy results this time around though, so maybe harder to interpret. This is why I'm posting three separate runs. > Finally, by noticing that the example code we're benchmarking doesn't > really depend on the values it returns, I decided to break perl by > doing *even less work* than would actually be required to make the > args give the right answers, just to get an upper bound on the highest > possible speedup that could be achieved. In this broken version, I > don't set up GvAV(PL_defav), nor do I set up the AV in PAD_SVl(0). I > don't copy the arguments anywhere at all. OP_ARGELEM now can't find > them and will just return undef. I even had to stub out the contents > of pp_argcheck so it doesn't even perform an arity check. To be > clear: this version of perl is totally useless, but should be even > faster than it is possible to achieve for real, because any real perl > would have to do more work than this version: > > $ ./perl -Ilib benchmark-entersub.pl > full: 8.7818s > bare: 6.9137s (speedup x1.27) > sigs: 6.7048s (speedup x1.31) Now (on three separate runs): $ ./perl -Ilib benchmark-entersub.pl full: 4.0394s bare: 3.3806s (speedup x1.19) sigs: 3.3622s (speedup x1.20) $ ./perl -Ilib benchmark-entersub.pl full: 3.9630s bare: 3.2788s (speedup x1.21) sigs: 3.2075s (speedup x1.24) $ ./perl -Ilib benchmark-entersub.pl full: 4.0202s bare: 3.6163s (speedup x1.11) sigs: 3.3566s (speedup x1.20) Again fairly noisy (especially this last one), but still quite indistinguishable from the first runs; or indeed from those of a plain unpatched bleadperl: $ ./perl -Ilib benchmark-entersub.pl full: 3.3048s bare: 2.6910s (speedup x1.23) sigs: 2.5559s (speedup x1.29) $ ./perl -Ilib benchmark-entersub.pl full: 3.4209s bare: 2.7970s (speedup x1.22) sigs: 2.6608s (speedup x1.29) $ ./perl -Ilib benchmark-entersub.pl full: 3.2664s bare: 2.6584s (speedup x1.23) sigs: 2.5078s (speedup x1.30) In fact if anything, I'd say these plain bleadperls are running even more efficiently than the patched versions. -- Paul "LeoNerd" Evans leonerd@leonerd.org.uk | https://metacpan.org/author/PEVANS http://www.leonerd.org.uk/ | https://www.tindie.com/stores/leonerd/Thread Previous | Thread Next