Chandler Carruth fe05f61e5d [x86] Add handling for splat-like widenings of v16i8 shuffles.
These show up really frequently, not the least with actual splats. =] We
lowered these quite badly before. The new code path tries to widen i8
shuffles to i16 shuffles in a splat-like way. There are still some
inefficiencies in our i16 splat logic though, so we aren't really done
here.

Also, for certain patterns (bit of a gather-and-splat) we still
generate pretty silly code, and I've left a fixme for addressing it.
However, I'm not actually worried about this code pattern as much. The
old shuffle lowering generates a 29 instruction monstrosity for it that
should execute much more slowly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211974 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-28 05:16:40 +00:00
..
2014-06-24 22:45:16 +00:00
2014-06-24 15:45:59 +00:00