On Jan 14, 2013, at 11:00 AM, Tim Northover <[email protected]> wrote:
> Hi Bob, > >> What is the motivation for switching to unsigned? > > I personally believe it's a more sane for a polynomial, by quite a > margin. For example it means that casting a poly8_t to a poly16_t will > use the natural embedding rather than converting (say) x^7 into x^15 + > x^14 + ... + x^7. OK. That makes sense. > >> Is there something different about AArch64 that makes you >> want to diverge from the de facto standard for those types? > > I wouldn't call 2/3 a de facto standard, just a mess. > >> If not, it really sounds to me like it might be best to just >> switch everything (including your AArch64 ABI) to use >> signed poly types. > > That's not really a viable option at this stage. We're fixing bugs > (not that we expect any, fingers crossed), but not changing the ABI > for things like this. So you're more willing to change the 32-bit ABI(s) than the 64-bit ABI? That doesn't make sense to me. I'm really not necessarily opposed to the change and your explanation above makes a lot of sense, but I don't think AArch64 compatibility is a good justification for an ABI-breaking change to the 32-bit targets. _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
