On 16 December 2016 at 09:54, Hendrik Leppkes <h.lepp...@gmail.com> wrote:
> On Thu, Dec 15, 2016 at 8:43 PM, Matthew Wolenetz <wolen...@chromium.org> > wrote: > >> > >> This seems like a rather odd issue to be toolchain specific. Can you > >> please provide a configure command line that would result in a broken > >> build? > > > > > > I believe the link-time failures occurred with configs like these: > > > > IIRC, on Mac, Chromium build hit this with: > > > > - > > https://cs.chromium.org/chromium/src/third_party/ > ffmpeg/chromium/config/Chromium/mac/x64/config.h?rcl=0&l=4 > > > > On Windows, one or both of the following hit this: > > > > - > > https://cs.chromium.org/chromium/src/third_party/ > ffmpeg/chromium/config/Chromium/win/ia32/config.h?rcl=0&l=4 > > - > > https://cs.chromium.org/chromium/src/third_party/ > ffmpeg/chromium/config/Chromium/win/x64/config.h?rcl=0&l=4 > > > > DCE is needed for FFmpeg compilation, this should get fixed by Steve > >> Lhomme's > >> configure patch. > >> I find it hard to understand why wavdec.c would be the only file > >> showing this issue... > > > > > > Notably, windows still hit this (VS2015 Update 3 19.00.24213.1) *even > with > > -O2.* > > > > > > You are using a custom build system, there is no way to verify any > issues for us unless you can provide a configure commandline that > fails on our own build-system. > > The patches do look like they are trying to avoid the use of DCE - and > as Carl already pointed out, quite a lot of our code relies on DCE > being performed by the compiler/linker, so fixing it in one or two > isolated spots wouldn't really fix anything but your own customized > specific build, and make our code-base less consistent within itself. > DCE generally works fine with Visual Studio, and I do not know of any > configure setup that makes it fail - of course with the exception of > using --disable-optimizations, as that turns everything of for MSVC > right now, including DCE, which makes the build impossible. Debug builds and lto still have issues with DCE with msvc and icl. Also in an original email that mentioned a similar problem https://lists.ffmpeg.org/pipermail/ffmpeg-devel/2016-April/193454.html people also mentioned issues with clang and gold compilers due to DCE. As per the linked email thread though I dont think adding patches to fix 1 or 2 cases of DCE issues should be excepted, instead we need to work out a global solution to the issues with DCE. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
