[PATCH] Use broadcasts to optimize overall size when loading constant splat vectors (x86-64 with AVX or AVX2)

[Elena Demikhovsky]

I tried this :
let Predicates = [OptForSize, UseAVX] in {
  def : Pat<(v2f64 (X86VBroadcast (loadf64 addr:$src))),
            (VMOVDDUPrm addr:$src)>;
  def : Pat<(v2i64 (X86VBroadcast (loadi64 addr:$src))),
            (VMOVDDUPrm addr:$src)>;
}

It solves Q64 test in avx2-broadcast.ll.

-  Elena

http://reviews.llvm.org/D5347