[wasm] Add native x64 implementations for I32x4Splat, I32x4ExtractLane

src/compiler/wasm-compiler.cc

Index: src/compiler/wasm-compiler.cc
diff --git a/src/compiler/wasm-compiler.cc b/src/compiler/wasm-compiler.cc
index e92a434d1df4d9700532fbf83df6e5e08ae6f9e6..4b454b6b547828e147208eb90fdbeac7e87fb82b 100644
--- a/src/compiler/wasm-compiler.cc
+++ b/src/compiler/wasm-compiler.cc
@@ -2866,6 +2866,12 @@ void WasmGraphBuilder::SetSourcePosition(Node* node,
     source_position_table_->SetSourcePosition(node, pos);
 }
 
+Node* WasmGraphBuilder::DefaultS128Value() {
+  return graph()->NewNode(jsgraph()->machine()->CreateInt32x4(),

[titzer, 2016/08/23 13:06:40]

Can you add a TODO that we should just introduce a SimdConstant to
src/compiler/common-operator.h?

[gdeepti, 2016/08/23 19:53:34]

I have a partical CL that introduces a Simd128Constant, but the decision was to
defer till we see a strong need for it. Looked at some SIMD code with
bradnelson@, bbudge@ - conclusion was that SIMD constants are rarely used in
practice and we would only be introducing them for ease of
representation/testing. Added a TODO for now. I can clean up the experimental
patch and send it out for review if we decide that having a Simd128Constant is
necessary. 

+                          Int32Constant(0), Int32Constant(0), Int32Constant(0),
+                          Int32Constant(0));
+}
+
 Node* WasmGraphBuilder::SimdOp(wasm::WasmOpcode opcode,
                                const NodeVector& inputs) {
   switch (opcode) {
@@ -2873,8 +2879,8 @@ Node* WasmGraphBuilder::SimdOp(wasm::WasmOpcode opcode,
       return graph()->NewNode(jsgraph()->machine()->Int32x4ExtractLane(),
                               inputs[0], inputs[1]);
     case wasm::kExprI32x4Splat:
-      return graph()->NewNode(jsgraph()->machine()->Int32x4ExtractLane(),
-                              inputs[0], inputs[0], inputs[0], inputs[0]);
+      return graph()->NewNode(jsgraph()->machine()->CreateInt32x4(), inputs[0],
+                              inputs[0], inputs[0], inputs[0]);
     default:
       return graph()->NewNode(UnsupportedOpcode(opcode), nullptr);
   }