On Jan 14, 2013, at 4:00 AM, Tim Northover <[email protected]> wrote:
> Hi, > > As suggested by John in his review of the AArch64 backend, I'm splitting this > change into a separate thread. > > I'd like to make the ARM NEON polynomial types be based on unsigned variants > (unsigned char, unsigned short) rather than the present signed ones. > > The AArch32 (i.e. "ARM") procedure call standard leaves this detail > unspecified, merely saying that they represent polynomials over GF(2). > However, the AArch64 PCS says that they correspond to unsigned types. > > Since the 32-bit ABI is compatible with this, I think it would be better to > bring them into alignment rather than adding unnecessary target > conditionalisation to Clang. > > Ok to commit? This makes me a little nervous. What do GCC and other ARM compilers use? If all the other ARM compilers use unsigned poly types, then it is probably a good thing to bring Clang in sync with them. If other compilers use signed poly types, then I think it would be better to conditionalize this for AArch64. This will also break compatibility due the C++ mangling. The poly vector mangling won't be affected, but any poly8_t and poly16_t types will change. _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
