[PATCH] X86: sink splat-shuffle into block doing a shift.

[Nadav Rotem]

  Hi Tim,

  This function answers the question: are vector shifts expensive? AFAIK 8bit shifts are expensive, so I don’t understand why there is a different handling for 8bit and 16bit shifts.  Everything else LGTM.

  Thanks,
  Nadav

http://llvm-reviews.chandlerc.com/D2816