> On Mar 15, 2017, at 15:26 , Segher Boessenkool <seg...@kernel.crashing.org> > wrote:
> I do not think VLE can get in, not in its current shape at least. VLE > is very unlike PowerPC in many ways so it comes at a very big cost to > the port (maintenance and otherwise -- maintenance is what I care about > most). > > Since SPE and VLE only share the part of the rs6000 port that doesn't > change at all (except for a bug fix once or twice a year), and everything > else needs special cases all over the place, it seems to me it would be > best for everyone if we split the rs6000 port in two, one for SPE and VLE > and one for the rest. Both ports could then be very significantly > simplified. > > I am assuming SPE and VLE do not support AltiVec or 64-bit PowerPC, > please correct me if that is incorrect. Also, is "normal" floating > point supported at all? > > Do you (AdaCore and Mentor) think splitting the port is a good idea? That's actually an option we considered. We haven't gone very far in studying what this would entail and were still unclear on how much of a clean separation we could get without risking the introduction of (too much) instability. It seemed like avoiding code duplication (that would otherwise be a maintenance issue) might require refactoring in sensitive areas, e.g. prologue/epilogue expansion, but the perspective of getting two variants simpler to grasp on top of common code definitely sounds attractive and worth some effort. Olivier
