On Fri, 24 Apr 2015, Uros Bizjak wrote:
Please try to generate paradoxical subreg (V2DImode subreg of V1DImode pseudo). IIRC, there is some functionality in the compiler that is able to tell if the highpart of the paradoxical register is zeroed.
Those are not currently legal (I tried to change that) https://gcc.gnu.org/ml/gcc-patches/2013-03/msg00745.html https://gcc.gnu.org/ml/gcc-patches/2014-06/msg00769.html In this case, a subreg:V2DI of DImode should work. -- Marc Glisse
