On 1/9/19 9:45 AM, Kyrill Tkachov wrote: > Hi Kay, > > On 09/01/19 08:29, Kay F. Jahnke wrote: >> Hi there! >> >> I am developing software which tries to deliberately exploit the >> compiler's autovectorization facilities by feeding data in >> autovectorization-friendly loops. I'm currently using both g++ and >> clang++ to see how well this approach works. Using simple arithmetic, I >> often get good results. To widen the scope of my work, I was looking for >> documentation on which constructs would be recognized by the >> autovectorization stage, and found >> >> https://www.gnu.org/software/gcc/projects/tree-ssa/vectorization.html >> > > Yeah, that page hasn't been updated in ages AFAIK. > >> By the looks of it, this document has not seen any changes for several >> years. Has development on the autovectorization stage stopped, or is >> there simply no documentation? >> > > There's plenty of work being done on auto-vectorisation in GCC. > Auto-vectorisation is a performance optimisation and as such is not really > a user-visible feature that absolutely requires user documentation.
I don't agree. Sometimes vectorization is critical. It would be nice to have a warning which would fire if vectorization failed. That would surely help the OP. -- Andrew Haley Java Platform Lead Engineer Red Hat UK Ltd. <https://www.redhat.com> EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671
