Unify MachineType and RepType.

test/cctest/compiler/test-representation-change.cc

Index: test/cctest/compiler/test-representation-change.cc
diff --git a/test/cctest/compiler/test-representation-change.cc b/test/cctest/compiler/test-representation-change.cc
index 092a5f7d90cab204aa9fe1a055240f87d382b0f4..080ccd66383b349cc7df2f79e2ceeaea62b12afe 100644
--- a/test/cctest/compiler/test-representation-change.cc
+++ b/test/cctest/compiler/test-representation-change.cc
@@ -65,16 +65,16 @@ class RepresentationChangerTester : public HandleAndZoneScope,
     return graph()->NewNode(common()->Parameter(index), graph()->start());
   }
 
-  void CheckTypeError(RepTypeUnion from, RepTypeUnion to) {
+  void CheckTypeError(MachineTypeUnion from, MachineTypeUnion to) {
     changer()->testing_type_errors_ = true;
     changer()->type_error_ = false;
     Node* n = Parameter(0);
     Node* c = changer()->GetRepresentationFor(n, from, to);
-    CHECK_EQ(n, c);
     CHECK(changer()->type_error_);
+    CHECK_EQ(n, c);
   }
 
-  void CheckNop(RepTypeUnion from, RepTypeUnion to) {
+  void CheckNop(MachineTypeUnion from, MachineTypeUnion to) {
     Node* n = Parameter(0);
     Node* c = changer()->GetRepresentationFor(n, from, to);
     CHECK_EQ(n, c);
@@ -85,7 +85,8 @@ class RepresentationChangerTester : public HandleAndZoneScope,
 }  // namespace v8::internal::compiler
 
 
-static const RepType all_reps[] = {rBit, rWord32, rWord64, rFloat64, rTagged};
+static const MachineType all_reps[] = {rBit, rWord32, rWord64, rFloat64,
+                                       rTagged};
 
 
 // TODO(titzer): lift this to ValueHelper
@@ -156,8 +157,8 @@ TEST(ToTagged_constant) {
 }
 
 
-static void CheckChange(IrOpcode::Value expected, RepTypeUnion from,
-                        RepTypeUnion to) {
+static void CheckChange(IrOpcode::Value expected, MachineTypeUnion from,
+                        MachineTypeUnion to) {
   RepresentationChangerTester r;
 
   Node* n = r.Parameter();
@@ -214,7 +215,20 @@ TEST(Nops) {
   r.CheckNop(rWord64, rBit);
   r.CheckNop(rWord64, rBit | tBool);
 
+  // 32-bit words can be used as smaller word sizes and vice versa, because
+  // loads from memory implicitly sign or zero extend the value to the
+  // full machine word size, and stores implicitly truncate.
+  r.CheckNop(rWord32, rWord8);
+  r.CheckNop(rWord32, rWord16);
+  r.CheckNop(rWord32, rWord32);
+  r.CheckNop(rWord8, rWord32);
+  r.CheckNop(rWord16, rWord32);
+
   // rBit (result of comparison) is implicitly a wordish thing.
+  r.CheckNop(rBit, rWord8);
+  r.CheckNop(rBit | tBool, rWord8);
+  r.CheckNop(rBit, rWord16);
+  r.CheckNop(rBit | tBool, rWord16);
   r.CheckNop(rBit, rWord32);
   r.CheckNop(rBit | tBool, rWord32);
   r.CheckNop(rBit, rWord64);