James Almer: > On 7/27/2022 2:34 PM, Swinney, Jonathan wrote: >> I recognize that this patch is going to be somewhat controversial. I'm >> submitting it mostly to see what the opinions are and evaluate >> options. I am working on improving performance for aarch64. On that >> architecture, there are fewer hand written assembly implementations of >> hot functions than there are for x86_64 and allowing gcc to >> auto-vectorize yields noticeable improvements. >> >> Gcc vectorization has improved recently and it hasn't been evaluated >> on the mailing list for a few years. This is the latest discussion I >> found in my searches: >> http://ffmpeg.org/pipermail/ffmpeg-devel/2016-May/193977.html > > Every time this was done, it was inevitably reverted after complains and > crash reports started piling up because gcc can't really handle all the > inline code our codebase has, among other things. > >> >> If the community is not comfortable accepting a patch like this >> outright, would you be willing to accept a new option to the configure >> script, something like --enable-auto-vectorization? > > --extra-cflags can be used for this. >
No, it can't, because what is given via --extra-cflags is inserted at the start of CFLAGS, so that the automatically added -fno-tree-vectorize overwrites it. - Andreas _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
