[turbofan] Support for %_DoubleHi, %_DoubleLo and %_ConstructDouble.

src/compiler/x64/instruction-selector-x64.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <algorithm>
 
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
@@ skipping 1353 matching lines @@
   VisitFloat64Compare(this, node, &cont);
 }
 
 
 void InstructionSelector::VisitFloat64LessThanOrEqual(Node* node) {
   FlagsContinuation cont(kUnsignedGreaterThanOrEqual, node);
   VisitFloat64Compare(this, node, &cont);
 }
 
 
+void InstructionSelector::VisitFloat64ExtractWord32(Node* node) {
+  X64OperandGenerator g(this);
+  InstructionCode opcode = (OpParameter<int>(node) == 0)
+                               ? kSSEFloat64ExtractLowWord32
+                               : kSSEFloat64ExtractHighWord32;
+  Emit(opcode, g.DefineAsRegister(node), g.Use(node->InputAt(0)));
+}
+
+
+void InstructionSelector::VisitFloat64InsertWord32(Node* node) {
+  X64OperandGenerator g(this);
+  Node* left = node->InputAt(0);
+  Node* right = node->InputAt(1);
+  InstructionCode opcode;
+  switch (OpParameter<int>(node)) {
+    case 0: {
+      Float64Matcher mleft(left);
+      if (mleft.HasValue() && (bit_cast<uint64_t>(mleft.Value()) >> 32) == 0u) {
+        Emit(kSSEFloat64LoadLowWord32, g.DefineAsRegister(node), g.Use(right));
+        return;
+      }
+      opcode = kSSEFloat64InsertLowWord32;
+      break;
+    }
+    case 1:
+      opcode = kSSEFloat64InsertHighWord32;
+      break;
+    default:
+      UNREACHABLE();
+      return;
+  }
+  Emit(opcode, g.DefineSameAsFirst(node), g.UseRegister(left), g.Use(right));
+}
+
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
   MachineOperatorBuilder::Flags flags =
       MachineOperatorBuilder::kWord32ShiftIsSafe;
   if (CpuFeatures::IsSupported(SSE4_1)) {
     flags |= MachineOperatorBuilder::kFloat64Floor |
              MachineOperatorBuilder::kFloat64Ceil |
              MachineOperatorBuilder::kFloat64RoundTruncate;
   }
   return flags;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8