> On Nov 2, 2017, at 4:35 PM, Johannes Weiß via swift-dev <swift-dev@swift.org> > wrote: >> On 2 Nov 2017, at 1:33 pm, Erik Eckstein <eeckst...@apple.com> wrote: >> >> >> >>> On Nov 2, 2017, at 10:51 AM, Johannes Weiß <johanneswe...@apple.com> wrote: >>> >>> Definitely a +1 from me, a haven't recently seen much of a difference >>> either. >>> >>> Said that I do sometimes use it in a micro-benchmark just to convince >>> myself we don't lose much performance on the checks. Usually it turns out >>> fine, I'm happy and move on. But I guess there's some value in being able >>> to elide a lot of checks just to see how much of a difference it does. And >>> if there's a big difference then I'd try to optimise the program and elide >>> unnecessary checks myself. Clearly -Ounchecked should never be used in any >>> real code but I find having a baseline when optimising performance very >>> helpful and -Ounchecked sometimes seemed like a cheap, automatic baseline >>> for some code ;). >>> >>> And lastly I always thought having it as an 'optimisation' is a misnomer, >>> it's not an optimisation as it clearly changes the semantics of the program >>> quite a bit. I thought '-unsafe-remove-checks' or something describes it >>> better, a bit like '-assume-single-threaded’. >> >> I like that idea. We could add such an option. > > awesome, that's be a +💯 from me then 🙂
Yeah, if the proposal is really just to provide a separate option for turning off safety checks instead of conflating it into the -O option, that seems totally unobjectionable. John. > >> >> Daniel, I think that’s also what you were asking for. >> >> >>> But probably the 'no checks' mode adds too much complexity to just keep it >>> around for a questionable way to do performance baselines. >>> >>>> On 2 Nov 2017, at 9:52 am, Erik Eckstein via swift-dev >>>> <swift-dev@swift.org> wrote: >>>> >>>> Hi, >>>> >>>> I’d like to propose to deprecate the -Ounchecked swift optimization mode. >>>> >>>> The -Ounchecked mode actually contradicts one of the main goals of swift: >>>> to be a safe language. >>>> In the past we didn’t see lot of significant performance differences >>>> compared to -O (there were some improvements but also some regressions). >>>> Also, we want to reduce the effort of maintaining too many different >>>> optimization modes, especially because we recently added -Osize. >>>> >>>> Deprecating would mean that we map -Ounchecked to -O. >>>> >>>> If you have any comments or concerns, please let me know >>>> >>>> Thanks, >>>> Erik >>>> >>>> >>>> >>>> _______________________________________________ >>>> swift-dev mailing list >>>> swift-dev@swift.org >>>> https://lists.swift.org/mailman/listinfo/swift-dev > > _______________________________________________ > swift-dev mailing list > swift-dev@swift.org > https://lists.swift.org/mailman/listinfo/swift-dev
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