[fpc-devel] Interesting short article about optimisation

[Wayne Sherman]

On Sat, Nov 25, 2023 at 3:10 PM J. Gareth Moreton wrote:
> I just stumbled across this article about micro-architecture-specific
> optimisations in ARM:
> https://www.phoronix.com/news/ARM64-Linux-No-Uarch-Opts
>
> They briefly mention x86_64, and I agree it's good to avoid
> micro-architecture-specific optimisations and now it makes me wonder
> where the line is drawn, like the recent introduction of the optimizer
> hint regarding LEA instructions being slow on some middle-aged CPUs.

For general optimization, direct most of the effort on the most
commonly used CPUs and architectures, while ensuring satisfactory
performance for others. Allow specific optimizations for atypical
cases, as long as they don't negatively impact the most common
scenarios. Before investing much effort, check what optimizations will
be accepted upstream (unless one is willing to maintain that code
separately).