> 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. 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
