[PATCH] D37680: [X86][SSE] Add support for X86ISD::PACKSS to ComputeNumSignBitsForTargetNode

[Elena Demikhovsky via Phabricator via llvm-commits]

delena added a comment.

I want to suggest a test case without intrinsic:
define <16 x i8> @vselect_packss_opt(<16 x i16> %a0, <16 x i16> %a1, <16 x i8> %a2, <16 x i8> %a3) {

  %1 = icmp eq <16 x i16> %a0, %a1
  %x2 = sext <16 x i1> %1 to <16 x i8>
  %x6 = and <16 x i8> %x2, %a2
  %x7 = xor <16 x i8> %x2, <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>
  %x8 = and <16 x i8> %x7, %a3
  %x9 = or <16 x i8> %x6, %x8
  ret <16 x i8> %x9

}


Repository:
  rL LLVM

https://reviews.llvm.org/D37680