On 25 October 2017 at 07:15, Dale Curtis <dalecur...@chromium.org> wrote:
> Technically _tzcnt* intrinsics are only available when the BMI > instruction set is present. However the instruction encoding > degrades to "rep bsf" on older processors. > > Clang for Windows debatably restricts the _tzcnt* instrinics behind > the __BMI__ architecture define, so check for its presence or > exclude the usage of these intrinics when clang is present. > > See also: > https://ffmpeg.org/pipermail/ffmpeg-devel/2015-November/183404.html > https://bugs.llvm.org/show_bug.cgi?id=30506 > http://lists.llvm.org/pipermail/cfe-dev/2016-October/051034.html > > Signed-off-by: Dale Curtis <dalecur...@chromium.org LGTM _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
