Wilco Dijkstra <wilco.dijks...@arm.com> writes: > Hi Richard, > >> Could you give details? I thought it was always known that trapped >> system register accesses were slow. In the previous versions, the >> checks seemed to be presented as an up-front price worth paying for >> faster atomic operations, on the systems that would use those paths. >> Now the checks are being presented as something that are good to remove >> to make the code simpler and faster. > > The system register checks came from early versions (~2 years ago) when > there was no HWCAP defined yet, so Victor added them for testing. > The idea was to leave them for a while so you could get new atomics > on an older kernel, and remove them once newer kernels became available.
Hmm, ok. But the RCPC3 one was added in June last year (so part of the current GCC 15 release cycle), and then changed to a different form by your patch in January this year. Now the proposal (two months later) is to remove it altogether. But perhaps the most constructive thing is for me to bow out of this one and leave the decision to other maintainers. Thanks, Richard
