4 ms·

What's the deal with pidigits? Losing out bad to PHP here even.

by Rickasaurus 13y ago

iopq 13y ago
because it's not using GMP
- saidajigumi 13y ago
  So if I understand correctly, the pidigits test in this case this isn't a self-contained, fully ported microbenchmark, but rather a test of some random Rust code vs. an optimized library[1]? If that's true, then what's the point of including pidigits if the entire algorithm isn't going to be ported into all target languages? [1] GMP, The GNU Multiple Precision Arithemtic Library: https://gmplib.org/ https://gmplib.org/
  - iopq 13y ago
    It's more of a "testing the platform" rather than the language. You can write a Rust program that runs at exactly the same speed as a C program (the difference here would be clang backend vs. gcc moreso than the choice of language).
    - wmf 13y ago
      That becomes more of a pass/fail test (either you're using the fastest known library or you aren't) which isn't very interesting as a benchmark.
  - pcwalton 13y ago
    As I understand it, the rule is "if your language comes with a bignum implementation, you must use it, otherwise you may use GMP". I've been seriously tempted to suggest removing our bignum implementation for this reason (though I won't).
    - qbproger 13y ago
      Python uses GMP while having a bignum implementation. I believe any language is allowed to use it. Python: http://benchmarksgame.alioth.debian.org/u64/program.php?test=pidigits&lang=python3&id=2 http://benchmarksgame.alioth.debian.org/u64/program.php?test... Ruby: http://benchmarksgame.alioth.debian.org/u64/benchmark.php?test=pidigits&lang=yarv&id=2&data=u64 http://benchmarksgame.alioth.debian.org/u64/benchmark.php?te...
    - igouy 13y ago
      There is no such rule. When someone contributes a Rust pi-digits program that uses GMP it will be shown (as long as it uses the same algorithm). We get to see both programs that use GMP and programs that don't.
legulere 13y ago
Bignum math isn't optimized for performance yet. See this discussion: http://www.reddit.com/r/rust/comments/1xcq1q/c_gcc_vs_rust_wtf/ http://www.reddit.com/r/rust/comments/1xcq1q/c_gcc_vs_rust_w... There are also already some patches making rust a lot less worse: https://github.com/mozilla/rust/pull/12209 https://github.com/mozilla/rust/pull/12209
pcwalton 13y ago
A fix is in the queue. It was a tiny thing. Currently there is an Android buildbot issue that is preventing anything from landing, but hopefully that will be resolved today.

What's the deal with pidigits? Losing out bad to PHP here even.

iopq 13y ago

because it's not using GMP

saidajigumi 13y ago
So if I understand correctly, the pidigits test in this case this isn't a self-contained, fully ported microbenchmark, but rather a test of some random Rust code vs. an optimized library[1]? If that's true, then what's the point of including pidigits if the entire algorithm isn't going to be ported into all target languages? [1] GMP, The GNU Multiple Precision Arithemtic Library: https://gmplib.org/ https://gmplib.org/
- iopq 13y ago
  It's more of a "testing the platform" rather than the language. You can write a Rust program that runs at exactly the same speed as a C program (the difference here would be clang backend vs. gcc moreso than the choice of language).
  - wmf 13y ago
    That becomes more of a pass/fail test (either you're using the fastest known library or you aren't) which isn't very interesting as a benchmark.
- pcwalton 13y ago
  As I understand it, the rule is "if your language comes with a bignum implementation, you must use it, otherwise you may use GMP". I've been seriously tempted to suggest removing our bignum implementation for this reason (though I won't).
  - qbproger 13y ago
    Python uses GMP while having a bignum implementation. I believe any language is allowed to use it. Python: http://benchmarksgame.alioth.debian.org/u64/program.php?test=pidigits&lang=python3&id=2 http://benchmarksgame.alioth.debian.org/u64/program.php?test... Ruby: http://benchmarksgame.alioth.debian.org/u64/benchmark.php?test=pidigits&lang=yarv&id=2&data=u64 http://benchmarksgame.alioth.debian.org/u64/benchmark.php?te...
  - igouy 13y ago
    There is no such rule. When someone contributes a Rust pi-digits program that uses GMP it will be shown (as long as it uses the same algorithm). We get to see both programs that use GMP and programs that don't.

legulere 13y ago

Bignum math isn't optimized for performance yet. See this discussion: http://www.reddit.com/r/rust/comments/1xcq1q/c_gcc_vs_rust_wtf/ http://www.reddit.com/r/rust/comments/1xcq1q/c_gcc_vs_rust_w... There are also already some patches making rust a lot less worse: https://github.com/mozilla/rust/pull/12209 https://github.com/mozilla/rust/pull/12209

pcwalton 13y ago

A fix is in the queue. It was a tiny thing. Currently there is an Android buildbot issue that is preventing anything from landing, but hopefully that will be resolved today.