On 2014-06-22, at 23:31 , Daniel Micay <danielmi...@gmail.com> wrote: > On 22/06/14 05:09 PM, Rick Richardson wrote: >> Apologies if this has been suggested, but would it be possible to have a >> compiler switch that can add runtime checks and abort on >> overflow/underflow/carry for debugging purposes, but the default >> behavior is no check? IMO this would be the best of both worlds, >> because I would assume that one would really only care about checked >> math during testing and dev. > > You would need to build an entirely separate set of standard libraries > with checked overflow.
>From my understanding, everything would be built with checked overflow (unless explicitly disabled/bypassed), and the overflow check could be disabled at compile-time/. I don't think that's a good solution, but that's what Swift's `-Ofast` does, it completely removes a number of checks (including overflow checking), essentially making the language unsafe but much faster. As a side-question, were the performances of ftrapv (in clang) ever actually tested? There were some discussion on testing the impact in Firefox, but that ended up with GCC's ftrapv being broken and not doing anything, and Firefox not working with clang -ftrapv. I've not seen any numbers since, just lots of assertions that it's far too slow to be an option. _______________________________________________ Rust-dev mailing list Rust-dev@mozilla.org https://mail.mozilla.org/listinfo/rust-dev
