On Thu, Jul 18, 2013 at 6:11 PM, Craig Topper <[email protected]>wrote:
> Would __builtin_shufflevector(__a, __a, 0, 1, -1, -1) work? > Personally, I would prefer a defined way to produce an undef input in general... but if folks are worried about exposing such an interface, then sure, we could just allow the shuffle builtin itself to designate an "undef" input with goofy indices. > > > On Thu, Jul 18, 2013 at 5:42 PM, Chandler Carruth <[email protected]>wrote: > >> >> On Thu, Jul 18, 2013 at 5:32 PM, Katya Romanova < >> [email protected]> wrote: >> >>> - __m128d __zero = _mm_setzero_pd(); >>> - return __builtin_shufflevector(__a, __zero, 0, 1, 2, 2); >>> + return (__m256d)__builtin_ia32_pd256_pd((__v2df)__a); >>> >> >> I think this is the wrong approach. >> >> Rather than switching these to use an x86-specific builtin, instead it >> would be better to provide some generic form to produce an undef input to a >> shufflevector. That is a generally useful and completely target independent >> concept. >> >> _______________________________________________ >> cfe-commits mailing list >> [email protected] >> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits >> >> > > > -- > ~Craig >
_______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
