[TTI] Add generic cost handling of SK_Reverse shuffles

These can be treated as a general permute.

This required a fix for missing reverse patterns on ARM

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@345015 91177308-0d34-0410-b5e6-96231b3b80d8

Author: RKSimon

include/llvm/CodeGen/BasicTTIImpl.h

@@ -555,6 +555,7 @@ class BasicTTIImplBase : public TargetTransformInfoImplCRTPBase<T> {
                           Type *SubTp) {
     switch (Kind) {
     case TTI::SK_Select:
+    case TTI::SK_Reverse:
     case TTI::SK_Transpose:
     case TTI::SK_PermuteSingleSrc:
     case TTI::SK_PermuteTwoSrc:

lib/Target/ARM/ARMTargetTransformInfo.cpp

@@ -412,6 +412,8 @@ int ARMTTIImpl::getShuffleCost(TTI::ShuffleKind Kind, Type *Tp, int Index,
         {ISD::VECTOR_SHUFFLE, MVT::v2f32, 1},
         {ISD::VECTOR_SHUFFLE, MVT::v2i64, 1},
         {ISD::VECTOR_SHUFFLE, MVT::v2f64, 1},
+        {ISD::VECTOR_SHUFFLE, MVT::v4i16, 1},
+        {ISD::VECTOR_SHUFFLE, MVT::v8i8,  1},
 
         {ISD::VECTOR_SHUFFLE, MVT::v4i32, 2},
         {ISD::VECTOR_SHUFFLE, MVT::v4f32, 2},