Alan Lawrence <alan.lawre...@arm.com> writes: > Patches 7-11 migrate migrate ARM, x86, IA64 (I think), and mostly PowerPC, > to > the new reduc_(plus|[us](min|max))_scal_optab. I have not managed to work > out > how to do the same for MIPS (specifically what I need to add to > mips_expand_vec_reduc), and have had no response from the maintainers, so > am
Sorry, I was looking at this but failed to send an email saying so. The lack of vec_extract appears to be the stumbling point here so at the very least we need to add a naïve version of that I believe. > (2) also renaming reduc_..._scal_optab back to reduc_..._optab; would > break the > MIPS backend if something were not done with it's existing patterns. I suspect we can deal with this in time to make a rename OK. One thing occurred to me about this change in general which is that on the whole the reduction to a scalar seems good for an epilogue but is there a problem if the result is then replicated across a vector for further processing. I.e. a vector is reduced to a scalar, which moves the value from a SIMD register to a GP register (because scalar modes are not supported in SIMD registers generally) and then gets moved back to a SIMD register to form part of a new vector? Would you expect the redundant moves to get eliminated? Thanks, Matthew
