On Wed, Nov 17, 2021 at 02:00:02PM -0600, Segher Boessenkool wrote: > On Wed, Nov 17, 2021 at 11:45:02AM -0600, Paul A. Clarke wrote: > > I guess I'm being pedantic. "requires -mcpu=power8 and -mvsx" is not > > accurate from a user's point a view, as "-mcpu=power8" is sufficient, > > since "-mvsx" is enabled when "-mcpu=power8" is specified. > > To be really pedantic, -mcpu=power8 isn't required either: anythng that > enable the subset of ISA 2.07 that is needed is enough already. But we > don't want to encourage users to use those interfaces. > > > The real "requires" is "-mcpu=power8" and no "-mno-vsx". > > And no -mno-altivec. And and and. There is a huge web. > > > It's not a strong objection, since specifying "-mno-vsx" should be > > uncommon. (Right?) And, specifying "-mcpu=power8 -mvsx" is harmless. > > Maybe the warning could say "requires -mcpu=power8 (and -mvsx)"? Is > that clearer, to your eye?
Hrm. No, but let me withdraw my expression of concern. Both "power8" and "vsx" are required, and those two options get that explicitly. That "-mcpu=power8" also pulls in "-mvsx" is a subtlety that is perhaps not terribly relevant. Thanks for entertaining my concern, but we've spent too much time on it already. :-) PC
