Change the default implementation of DataEquals for Hydrogen instructions.

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index d1a4782a011ef4245c92a64012dae493015879d0..f89665ef00226f20314232a0d1685d8e09002c8f 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -490,7 +490,7 @@ void HInstruction::InsertAfter(HInstruction* previous) {
 
 
 #ifdef DEBUG
-void HInstruction::Verify() const {
+void HInstruction::Verify() {
   // Verify that input operands are defined before use.
   HBasicBlock* cur_block = block();
   for (int i = 0; i < OperandCount(); ++i) {
@@ -517,6 +517,11 @@ void HInstruction::Verify() const {
   if (HasSideEffects() && !IsOsrEntry()) {
     ASSERT(next()->IsSimulate());
   }
+
+  // Verify that instructions that can be eliminated by GVN have overridden
+  // HValue::DataEquals.  The default implementation is UNREACHABLE.  We
+  // don't actually care whether DataEquals returns true or false here.
+  if (CheckFlag(kUseGVN)) DataEquals(this);
 }
 #endif
 
@@ -1388,7 +1393,7 @@ HValue* HAdd::EnsureAndPropagateNotMinusZero(BitVector* visited) {
 // Node-specific verification code is only included in debug mode.
 #ifdef DEBUG
 
-void HPhi::Verify() const {
+void HPhi::Verify() {
   ASSERT(OperandCount() == block()->predecessors()->length());
   for (int i = 0; i < OperandCount(); ++i) {
     HValue* value = OperandAt(i);
@@ -1400,49 +1405,49 @@ void HPhi::Verify() const {
 }
 
 
-void HSimulate::Verify() const {
+void HSimulate::Verify() {
   HInstruction::Verify();
   ASSERT(HasAstId());
 }
 
 
-void HBoundsCheck::Verify() const {
+void HBoundsCheck::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 
-void HCheckSmi::Verify() const {
+void HCheckSmi::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 
-void HCheckNonSmi::Verify() const {
+void HCheckNonSmi::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 
-void HCheckInstanceType::Verify() const {
+void HCheckInstanceType::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 
-void HCheckMap::Verify() const {
+void HCheckMap::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 
-void HCheckFunction::Verify() const {
+void HCheckFunction::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 
-void HCheckPrototypeMaps::Verify() const {
+void HCheckPrototypeMaps::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }