[turbofan] Exhaustive switches for MachineRepresentation.

src/compiler/ia32/instruction-selector-ia32.cc

Index: src/compiler/ia32/instruction-selector-ia32.cc
diff --git a/src/compiler/ia32/instruction-selector-ia32.cc b/src/compiler/ia32/instruction-selector-ia32.cc
index 857bb4d5785c19953981c74dfcd09d3fd9141552..74d5b591ccbc14a1366bdd5078c97c7b22f16317 100644
--- a/src/compiler/ia32/instruction-selector-ia32.cc
+++ b/src/compiler/ia32/instruction-selector-ia32.cc
@@ -171,7 +171,7 @@ void VisitFloatUnop(InstructionSelector* selector, Node* node, Node* input,
 void InstructionSelector::VisitLoad(Node* node) {
   LoadRepresentation load_rep = LoadRepresentationOf(node->op());
 
-  ArchOpcode opcode;
+  ArchOpcode opcode = kArchNop;
   switch (load_rep.representation()) {
     case MachineRepresentation::kFloat32:
       opcode = kIA32Movss;
@@ -190,7 +190,8 @@ void InstructionSelector::VisitLoad(Node* node) {
     case MachineRepresentation::kWord32:
       opcode = kIA32Movl;
       break;
-    default:
+    case MachineRepresentation::kWord64:  // Fall through.
+    case MachineRepresentation::kNone:
       UNREACHABLE();
       return;
   }
@@ -255,7 +256,7 @@ 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 = kIA32Movss;
@@ -274,7 +275,8 @@ void InstructionSelector::VisitStore(Node* node) {
       case MachineRepresentation::kWord32:
         opcode = kIA32Movl;
         break;
-      default:
+      case MachineRepresentation::kWord64:  // Fall through.
+      case MachineRepresentation::kNone:
         UNREACHABLE();
         return;
     }
@@ -307,7 +309,7 @@ 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;
@@ -324,7 +326,10 @@ void InstructionSelector::VisitCheckedLoad(Node* node) {
     case MachineRepresentation::kFloat64:
       opcode = kCheckedLoadFloat64;
       break;
-    default:
+    case MachineRepresentation::kBit:     // Fall through.
+    case MachineRepresentation::kTagged:  // Fall through.
+    case MachineRepresentation::kWord64:  // Fall through.
+    case MachineRepresentation::kNone:
       UNREACHABLE();
       return;
   }
@@ -350,7 +355,7 @@ 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;
@@ -367,7 +372,10 @@ void InstructionSelector::VisitCheckedStore(Node* node) {
     case MachineRepresentation::kFloat64:
       opcode = kCheckedStoreFloat64;
       break;
-    default:
+    case MachineRepresentation::kBit:     // Fall through.
+    case MachineRepresentation::kTagged:  // Fall through.
+    case MachineRepresentation::kWord64:  // Fall through.
+    case MachineRepresentation::kNone:
       UNREACHABLE();
       return;
   }