Date: Wed, 29 Jan 2014 15:34:17 -0800 From: Steve Kargl <sgk@troutmask.apl.washington.edu> To: Dmitry Marakasov <amdmi3@amdmi3.ru> Cc: freebsd-current@FreeBSD.org Subject: Re: libm lacks C99 functions -> no c++11 cmath in libstdc++ Message-ID: <20140129233417.GA90062@troutmask.apl.washington.edu> In-Reply-To: <20140129222325.GA9806@hades.panopticon> References: <20140129164136.GA3489@hades.panopticon> <20140129172307.GA88757@troutmask.apl.washington.edu> <20140129184735.GA63095@hades.panopticon> <20140129215928.GA89714@troutmask.apl.washington.edu> <20140129222325.GA9806@hades.panopticon>
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On Thu, Jan 30, 2014 at 02:23:25AM +0400, Dmitry Marakasov wrote: > * Steve Kargl (sgk@troutmask.apl.washington.edu) wrote: > > > > > > - bad enough by itself, it affects libstdc++ from ports' gcc in such a > > > > > way that it disables C++11 math completely (along with a lot more > > > > > other more widely used math functions) > > > > > > > > > > > > > > > - we may probably implement these by calling less-precise > > > > > erf erfc lgamma tgamma as we do with other functions as we alredy > > > > > do with some others > > > > > > > > This, unfortuantely, has already been done, although it may only > > > > be available in FreeBSD-current. See src/lib/msun/src/imprecise.c. > > > > > > I know, it's available on 10.0 as well. However that's not the case for > > > 9.x, for which it's impossible to build c++11 math using software (even > > > if it doesn't use unimplemented functions), neither with system gcc > > > nor with gcc from ports. > > > > > > > It's not impossible. Add whatever C++-fu you need > > that is equivalent to > > > > #include <math.h> > > #ifndef fool > > #define fool(x) foo((double)(x)) > > #endif > > The point was that one should not be required to do something like this > to build std::hypot - using software on FreeBSD. > My point is that specifically adding this #define kludge to whatever software needs it is preferrable to the travesty foisted on libm by msun/src/imprecise.c. What imprecise.c does is not documented. -- steve
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