https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56253
--- Comment #14 from Marc Glisse <glisse at gcc dot gnu.org> --- (In reply to Agner Fog from comment #13) > Is it possible to do the same optimization with boolean vector intrinsics, > such as _mm_and_epi32 and _mm_or_ps to enable optimizations such as > algebraic reduction and constant propagation? Anything we already do with vector extensions should be easy, and that includes constant propagation in & and |. The sightly harder part is transformations that are only valid if v is a "bool vector" (like replacing v!=0 with just v), i.e. each component is either 0 or -1. We can test constants, we know the result of comparisons is boolean, we know &, | and ^ preserve that property, but it isn't a purely local property so it requires a bit more work.
