Hi Vadim, Yes, exactly, what is the point of having two versions -pthreads and -win32threads when you can make -pthreads behave like -win32threads by disabling the use of pthreads etc?
Yaron 2014-09-26 22:47 GMT+03:00 Vadim Chugunov <vadi...@gmail.com>: > When LLVM's configure finds a usable <pthread.h>, it prefers to use that > rather than the home-grown stuff. However if LLVM is configured with > --disable-pthreads, both mingw flavors produce the same results. > > BTW, I've tried to quantify the slowdown: a quick test indicates that LLVM > build that uses pthreads is about 10% slower than the one which doesn't. > This is less that I remember seeing last year (something got optimized?), > but still... > > Vadim > > > On Fri, Sep 26, 2014 at 3:29 AM, Yaron Keren <yaron.ke...@gmail.com> > wrote: > >> Yes, of course. >> >> I refer to the significant slowdown of Rust compiler when compiled with >> -pthreads vs -win32threads flavor. >> If Rust can be compiled without <mutex> and <thread> on win32threads, why >> should it slow down on pthreads? >> Isn't the only difference betwen the win32threads and pthreads is the >> addition of pthreads, <mutex> and <thread>? >> >> Yaron >> >> >> 2014-09-26 11:39 GMT+03:00 Vadim Chugunov <vadi...@gmail.com>: >> >>> Hi Yaron, >>> Not sure I understand your question. Wasn't <mutex> one of the more >>> important C++11 features that LLVM would like to use? >>> >> >> On Thu, Sep 25, 2014 at 1:24 AM, Yaron Keren <yaron.ke...@gmail.com> >> wrote: >> >>> Vadim, >>> >>> Thanks for the feedback on the -win32. A dependency on a small DLL with >>> BSD license does not sound too bad, but performance regression is obviously >>> a serious problem. >>> >>> However, by disabling <mutex> use with -pthreads rust performance should >>> be same as -win32 threads? >>> Saying it another way, does the -win32 version have any feature that >>> -pthreads vesion do not have? >>> >>> Yaron >>> >>> >>> 2014-09-25 9:52 GMT+03:00 Vadim Chugunov <vadi...@gmail.com>: >>> >>>> Hi, >>>> I think I can at least answer why the Rust project prefers to use >>>> mingw-w64-win32threads: >>>> 1. It does not inject dependency on libwinpthread.dll, which is nice. >>>> 2. Those who tried building LLVM with mingw-w64-pthreads, had reported >>>> significant slowdown of the resulting Rust compiler (as compared to one >>>> linked to LLVM compiled with the win32threads flavor). Profiling seemed >>>> to point towards libpthreads' implementation of mutex. I had checked the >>>> source, and indeed, it looked not very efficient ( >>>> http://sourceforge.net/p/mingw-w64/bugs/344). It would be nice to get >>>> a second opinion, though, maybe I missed something. >>>> >>>> Vadim >>>> >>>> >>>> On Wed, Sep 24, 2014 at 10:55 AM, Chandler Carruth < >>>> chandl...@google.com> wrote: >>>> >>>>> >>>>> On Wed, Sep 24, 2014 at 10:37 AM, Óscar Fuentes <o...@wanadoo.es> >>>>> wrote: >>>>> >>>>>> The best thing for understanding their reasons is to ask them to speak >>>>>> up. >>>>>> >>>>> >>>>> I asked them directly, and this thread is a chance for them to speak >>>>> up again. I *think* I've addressed the concerns of those I've spoken to >>>>> directly, but there may be other folks or other concerns or I may have >>>>> messed it up. =] >>>>> >>>>> >>>>>> My experience on the MinGW/MinGW-w64 communities is that those who >>>>>> choose MinGW is because of ignorance about MinGW-w64 and because there >>>>>> are lots of documents on the 'net that references MinGW. MinGW is, to >>>>>> all practical effects, a zombie project and there is no reason to >>>>>> prefer >>>>>> it over MinGW-w64 nowadays. >>>>>> >>>>> >>>>> :: shrug :: >>>>> >>>>> I'm not such a user, and so I don't want to speculate as to what >>>>> motivates them. >>>>> >>>>> _______________________________________________ >>>>> LLVM Developers mailing list >>>>> llvm...@cs.uiuc.edu http://llvm.cs.uiuc.edu >>>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >>>>> >>>>> >>>> >>>> _______________________________________________ >>>> LLVM Developers mailing list >>>> llvm...@cs.uiuc.edu http://llvm.cs.uiuc.edu >>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >>>> >>>> >>> >> >
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