[ARM64] [turbofan] Improve construction of doubles.

src/compiler/arm64/code-generator-arm64.cc

Index: src/compiler/arm64/code-generator-arm64.cc
diff --git a/src/compiler/arm64/code-generator-arm64.cc b/src/compiler/arm64/code-generator-arm64.cc
index 349950fee2635df529250867e9416b8f041b5b9a..fa821f58ca0975ee509c6ca0fedc5a65db08d5b9 100644
--- a/src/compiler/arm64/code-generator-arm64.cc
+++ b/src/compiler/arm64/code-generator-arm64.cc
@@ -588,6 +588,10 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       __ Ubfx(i.OutputRegister32(), i.InputRegister32(0), i.InputInt8(1),
               i.InputInt8(2));
       break;
+    case kArm64Bfi:
+      __ Bfi(i.OutputRegister(), i.InputRegister(1), i.InputInt6(2),
+             i.InputInt6(3));
+      break;
     case kArm64TestAndBranch32:
     case kArm64TestAndBranch:
       // Pseudo instructions turned into tbz/tbnz in AssembleArchBranch.
@@ -697,10 +701,12 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       __ Fmov(i.OutputRegister32(), i.InputFloat32Register(0));
       break;
     case kArm64Float64ExtractHighWord32:
+      // TODO(arm64): This should use MOV (to general) when NEON is supported.
       __ Fmov(i.OutputRegister(), i.InputFloat64Register(0));
       __ Lsr(i.OutputRegister(), i.OutputRegister(), 32);
       break;
     case kArm64Float64InsertLowWord32: {
+      // TODO(arm64): This should use MOV (from general) when NEON is supported.
       UseScratchRegisterScope scope(masm());
       Register tmp = scope.AcquireX();
       __ Fmov(tmp, i.InputFloat64Register(0));
@@ -709,6 +715,7 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       break;
     }
     case kArm64Float64InsertHighWord32: {
+      // TODO(arm64): This should use MOV (from general) when NEON is supported.
       UseScratchRegisterScope scope(masm());
       Register tmp = scope.AcquireX();
       __ Fmov(tmp.W(), i.InputFloat32Register(0));
@@ -716,6 +723,10 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       __ Fmov(i.OutputFloat64Register(), tmp);
       break;
     }
+    case kArm64Float64MoveU64: {
+      __ Fmov(i.OutputFloat64Register(), i.InputRegister(0));
+      break;
+    }
     case kArm64Ldrb:
       __ Ldrb(i.OutputRegister(), i.MemoryOperand());
       break;