On Wed, 6 Nov 2024 at 13:52, Michael Paquier <mich...@paquier.xyz> wrote: > > On Wed, Nov 06, 2024 at 01:38:50PM +1300, David Rowley wrote: > > We could just write it that way and leave it up to the compiler to > > decide whether to use SIMD or not. Going by [1], gcc with -O2 uses > > SIMD instructions from 14.1 and clang with -O2 does it from version > > 8.0.0. gcc 14.1 was release in May 2024, so still quite new. It'll be > > quite a bit older once PG18 is out. Using the bitwise-OR method, more > > and more people will benefit as gcc14.1 and beyond becomes more > > mainstream. > > > > Clang 8.0.0 is from March 2019, so quite old already. > > Okay, WFM to keep things the way they are in the patch.
I'm not sure if I'm clear on what works for you. The latest patch I saw did 1 size_t per iteration. Are you saying we should do just size_t per loop? or we should form the code in a way that allows the compiler to use SIMD instructions? David