[turbofan] Exhaustive switches for MachineRepresentation.

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

Index: src/compiler/x64/instruction-selector-x64.cc
diff --git a/src/compiler/x64/instruction-selector-x64.cc b/src/compiler/x64/instruction-selector-x64.cc
index b1e1548c17e8ab1d86fa3e3fd545f8ecd63bdacc..69f13cfb020dfc801fde1d4beabda76aef254d26 100644
--- a/src/compiler/x64/instruction-selector-x64.cc
+++ b/src/compiler/x64/instruction-selector-x64.cc
@@ -111,7 +111,7 @@ void InstructionSelector::VisitLoad(Node* node) {
   LoadRepresentation load_rep = LoadRepresentationOf(node->op());
   X64OperandGenerator g(this);
 
-  ArchOpcode opcode;
+  ArchOpcode opcode = kArchNop;
   switch (load_rep.representation()) {
     case MachineRepresentation::kFloat32:
       opcode = kX64Movss;
@@ -133,7 +133,7 @@ void InstructionSelector::VisitLoad(Node* node) {
     case MachineRepresentation::kWord64:
       opcode = kX64Movq;
       break;
-    default:
+    case MachineRepresentation::kNone:
       UNREACHABLE();
       return;
   }
@@ -197,7 +197,7 @@ void InstructionSelector::VisitStore(Node* node) {
     code |= MiscField::encode(static_cast<int>(record_write_mode));
     Emit(code, 0, nullptr, input_count, inputs, temp_count, temps);
   } else {
-    ArchOpcode opcode;
+    ArchOpcode opcode = kArchNop;
     switch (rep) {
       case MachineRepresentation::kFloat32:
         opcode = kX64Movss;
@@ -219,7 +219,7 @@ void InstructionSelector::VisitStore(Node* node) {
       case MachineRepresentation::kWord64:
         opcode = kX64Movq;
         break;
-      default:
+      case MachineRepresentation::kNone:
         UNREACHABLE();
         return;
     }
@@ -243,7 +243,7 @@ void InstructionSelector::VisitCheckedLoad(Node* node) {
   Node* const buffer = node->InputAt(0);
   Node* const offset = node->InputAt(1);
   Node* const length = node->InputAt(2);
-  ArchOpcode opcode;
+  ArchOpcode opcode = kArchNop;
   switch (load_rep.representation()) {
     case MachineRepresentation::kWord8:
       opcode = load_rep.IsSigned() ? kCheckedLoadInt8 : kCheckedLoadUint8;
@@ -263,7 +263,9 @@ void InstructionSelector::VisitCheckedLoad(Node* node) {
     case MachineRepresentation::kFloat64:
       opcode = kCheckedLoadFloat64;
       break;
-    default:
+    case MachineRepresentation::kBit:
+    case MachineRepresentation::kTagged:
+    case MachineRepresentation::kNone:
       UNREACHABLE();
       return;
   }
@@ -293,7 +295,7 @@ void InstructionSelector::VisitCheckedStore(Node* node) {
   Node* const offset = node->InputAt(1);
   Node* const length = node->InputAt(2);
   Node* const value = node->InputAt(3);
-  ArchOpcode opcode;
+  ArchOpcode opcode = kArchNop;
   switch (rep) {
     case MachineRepresentation::kWord8:
       opcode = kCheckedStoreWord8;
@@ -313,7 +315,9 @@ void InstructionSelector::VisitCheckedStore(Node* node) {
     case MachineRepresentation::kFloat64:
       opcode = kCheckedStoreFloat64;
       break;
-    default:
+    case MachineRepresentation::kBit:
+    case MachineRepresentation::kTagged:
+    case MachineRepresentation::kNone:
       UNREACHABLE();
       return;
   }