Hi! On Wed, Jun 25, 2025 at 02:50:14PM -0400, Michael Meissner wrote: > This is patch #1 of 3 that adds the support that can be used in developing GCC > support for potential future PowerPC processors. With all 3 patches, the > tuning > for the 'future' processor is the same as power10 and power11. It may be in > the > future this tuning will change as any future PowerPC processor evolves.
Commit messages, just like mail messages, should be at most 72 columns wide. > Patch #2 will change the tuning support in power10.md to treat -mtune=future > the > same as -mtune=power10. > > Patch #3 will add tests for -mcpu=future. Since all of the tuning stuff for Future will have to change later anyway, it would be way easier and more useful, now and in the future, to actually code "use p11 tuning" whenever asked for Future tuning. That way, when we post the real thing, we'll just have to neuter the stopgap thing in one spot, not thirty. And of course we will never have to incorrectly say "this is the tuning for future!" anywhere. > These changes are being added so that hardware designers can evaluate > potential > new features to be added to the PowerPC processors in the future. It may be > these features will be incorporated into real hardware using a different name > in > the future. Or it may be these features will not be incoporated into actual > PowerPC hardware in the future. Yup. Future is stuff that is planned for some future Power CPU, you could expect it is for the next one (but we explicitly do not say that is the case). Bla bla bla :-) Some things might be removed last minute. If that is painful to you, some potential customer, just think what it does to us! None of this is done without good reason, and we very much do care about our users. They give us money and stuff eh, if nothing else! > I added a new macro (CASE_PROCESSOR_POWER10_TUNING) that expands to a set of > PROCESSOR_<xxx> cases for processors that should be tuned like a power10 > processor. In this patch, power10, power11, and future are selected. That is 100% the wrong direction. In the future we will have proper scheduling for what then is more "current" than "future". Or "shortly" maybe :-) > I also added a new inline function (power10_tuning_p) that returns true if the > processor is to be scheduled like a power10. You do know I hate things called "_p", even things that can actually be considered to be a predicate (like this). 98% of the time it is used just to mean "a function that returns a boolean" (and some actually do return something else!) "tuning_p10", or "tuning_is_for_p10", or whatever. A predicate by definition should contain a verb (and a subject)! Segher
