[PATCH] D8136: Generation of PSAD in LoopVectorizer

[Cong Hou via llvm-commits]

congh added a comment.

Based on the discussion and link above, it is not clear to me how PSAD can be implemented through ABSDIFF and HSUM. Take doing PSAD on 2 x v16i8 -> v?i32 for example: currently v16i8 will be widened before DIFF and ABS, so is ABSDIFF for the widened type (v16i16 or v16i32) or for v16i8 here? How HSUM is used to represent PSAD?


Repository:
  rL LLVM

http://reviews.llvm.org/D8136