X87: [turbofan] Exhaustive switches for MachineRepresentation.

  port 739c0187 (r33011)

  original commit message:

BUG=

Review URL: https://codereview.chromium.org/1544013002

Cr-Commit-Position: refs/heads/master@{#33018}

src/compiler/x87/instruction-selector-x87.cc

@@ -132,7 +132,7 @@ class X87OperandGenerator final : public OperandGenerator {
 void InstructionSelector::VisitLoad(Node* node) {
   LoadRepresentation load_rep = LoadRepresentationOf(node->op());
 
-  ArchOpcode opcode;
+  ArchOpcode opcode = kArchNop;
   switch (load_rep.representation()) {
     case MachineRepresentation::kFloat32:
       opcode = kX87Movss;
@@ -151,7 +151,8 @@ void InstructionSelector::VisitLoad(Node* node) {
     case MachineRepresentation::kWord32:
       opcode = kX87Movl;
       break;
-    default:
+    case MachineRepresentation::kWord64:  // Fall through.
+    case MachineRepresentation::kNone:
       UNREACHABLE();
       return;
   }
@@ -216,7 +217,7 @@ 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 = kX87Movss;
@@ -235,7 +236,8 @@ void InstructionSelector::VisitStore(Node* node) {
       case MachineRepresentation::kWord32:
         opcode = kX87Movl;
         break;
-      default:
+      case MachineRepresentation::kWord64:  // Fall through.
+      case MachineRepresentation::kNone:
         UNREACHABLE();
         return;
     }
@@ -268,7 +270,7 @@ 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;
@@ -285,7 +287,10 @@ 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;
   }
@@ -311,7 +316,7 @@ 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;
@@ -328,7 +333,10 @@ 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;
   }