[wasm] implement simd lowering for replaceLane, load, store and test for phi

src/compiler/simd-scalar-lowering.h

Index: src/compiler/simd-scalar-lowering.h
diff --git a/src/compiler/simd-scalar-lowering.h b/src/compiler/simd-scalar-lowering.h
index 39449f4b9ff54d01a82fc25cf204bab9efa23812..4f7db85d88befe811dd1a282d1fd1016e55af063 100644
--- a/src/compiler/simd-scalar-lowering.h
+++ b/src/compiler/simd-scalar-lowering.h
@@ -53,6 +53,7 @@ class SimdScalarLowering {
   SimdType ReplacementType(Node* node);
   void PreparePhiReplacement(Node* phi);
   void SetLoweredType(Node* node, Node* output);
+  void GetIndexNodes(Node* index, Node** new_indices);

[Mircea Trofin, 2016/11/15 16:21:27]

Is 'Index' part of the SIMD nomenclature? It sounds a bit too general.

[aseemgarg, 2016/11/19 01:56:54]

It isn't. it represents index for load or store. This function simply gives
replacement (in case of simd, it will be original index, and 3 more 4 bytes
apart). 

 
   struct NodeState {
     Node* node;