On Thu, Aug 13, 2020 at 11:09:10AM -0700, Carl Love wrote: > The builtins > > vector signed int vec_signexti (vector signed char a) > vector signed long long vec_signextll (vector signed char a) > vector signed int vec_signexti (vector signed short a) > vector signed long long vec_signextll (vector signed short a) > vector signed long long vec_signextll (vector signed int a) > > were defined in the function prototypes directory in box called "RFC > 2608 - 128-bit Binary Integer Operations". The document the new P10 > builtins. However, this subset of the newly defined builtins for P10 > can be implemented with existing Power 9 instructions. That was the > point of the comment.
Ah, I see :-) > That is probably a level of detail that is not > really needed in the GCC code comment. Probably best to just change > the comment to read something like "ISA 3.0 sign extend builtins". Sounds good. > My thought for calling it out is that they could be back ported to an > earlier GCC version since they use Power 9 instructions but it is > probably not worth the effort unless there is an explicit request for > them. Yeah. Thanks for the explanation! Segher
