On Fri, Feb 26, 2021 at 11:52:39AM -0800, Josh Don wrote: > From: Clement Courbet <cour...@google.com> > > A significant portion of __calc_delta time is spent in the loop > shifting a u64 by 32 bits. Use a __builtin_clz instead of iterating. > > This is ~7x faster on benchmarks.
Have you tried on hardware without such fancy instructions?
