ilvr.d, ilvod.d, pckod.d:
It is not possible to emit ilvr.d, or pckod.d since ilvod.d covers the
same shuffle. ilvod.d will be emitted instead.
+
+splati.w:
+ It is not possible to emit splati.w since shf.w covers the same cases.
+ shf.w will be emitted instead.