Messages in this thread | | | From | Nick Desaulniers <> | Date | Thu, 12 Nov 2020 13:55:36 -0800 | Subject | Re: [PATCH 2/2] arm: lib: xor-neon: disable clang vectorization |
| |
On Thu, Nov 12, 2020 at 1:50 PM Arvind Sankar <nivedita@alum.mit.edu> wrote: > > On Wed, Nov 11, 2020 at 04:15:59PM +0200, Adrian Ratiu wrote: > > On Tue, 10 Nov 2020, Nick Desaulniers <ndesaulniers@google.com> > > wrote: > > > > > > Yes, though additionally Arvind points out that this code is > > > kind of curious if there was overlap; maybe the parameters > > > should just be restrict-qualified. > > > > > > > For now I think I'll just re-send the GCC changes and leave the > > Clang optimization as is, until we better understand what's > > happening and what's the best way to enable it. > > > > Note that the __restrict__ keywords also help GCC -- it saves it from > having to emit the non-vectorized version and switch between the two at > runtime. If we can verify it's safe, it's a good thing to add all > around.
100% agree. Even a BUILD_BUG_ON or WARN_ON in callers to validate such an invariant might be nice. -- Thanks, ~Nick Desaulniers
| |