Remove unnecessary AST node for ++ and -- operations.

src/hydrogen.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4594 matching lines @@
         break;
       default:
         BAILOUT("Value: unsupported unary operation");
         break;
     }
     ast_context()->ReturnInstruction(instr, expr->id());
   }
 }
 
 
-void HGraphBuilder::VisitIncrementOperation(IncrementOperation* expr) {
-  // IncrementOperation is never visited by the visitor. It only
-  // occurs as a subexpression of CountOperation.
-  UNREACHABLE();
-}
-
-
 HInstruction* HGraphBuilder::BuildIncrement(HValue* value, bool increment) {
   HConstant* delta = increment
       ? graph_->GetConstant1()
       : graph_->GetConstantMinus1();
   HInstruction* instr = new(zone()) HAdd(value, delta);
   AssumeRepresentation(instr,  Representation::Integer32());
   return instr;
 }
 
 
 void HGraphBuilder::VisitCountOperation(CountOperation* expr) {
-  IncrementOperation* increment = expr->increment();
-  Expression* target = increment->expression();
+  Expression* target = expr->expression();
   VariableProxy* proxy = target->AsVariableProxy();
   Variable* var = proxy->AsVariable();
   Property* prop = target->AsProperty();
   ASSERT(var == NULL || prop == NULL);
   bool inc = expr->op() == Token::INC;
 
   if (var != NULL) {
     VISIT_FOR_VALUE(target);
 
     // Match the full code generator stack by simulating an extra stack
@@ skipping 40 matching lines @@
 
       HInstruction* load = NULL;
       if (prop->IsMonomorphic()) {
         Handle<String> name = prop->key()->AsLiteral()->AsPropertyName();
         Handle<Map> map = prop->GetReceiverTypes()->first();
         load = BuildLoadNamed(obj, prop, map, name);
       } else {
         load = BuildLoadNamedGeneric(obj, prop);
       }
       PushAndAdd(load);
-      if (load->HasSideEffects()) AddSimulate(increment->id());
+      if (load->HasSideEffects()) AddSimulate(expr->CountId());
 
       HValue* before = Pop();
       // There is no deoptimization to after the increment, so we don't need
       // to simulate the expression stack after this instruction.
       HInstruction* after = BuildIncrement(before, inc);
       AddInstruction(after);
 
       HInstruction* store = BuildStoreNamed(obj, after, prop);
       AddInstruction(store);
 
@@ skipping 20 matching lines @@
       HValue* obj = environment()->ExpressionStackAt(1);
       HValue* key = environment()->ExpressionStackAt(0);
 
       bool is_fast_elements = prop->IsMonomorphic() &&
           prop->GetMonomorphicReceiverType()->has_fast_elements();
 
       HInstruction* load = is_fast_elements
           ? BuildLoadKeyedFastElement(obj, key, prop)
           : BuildLoadKeyedGeneric(obj, key);
       PushAndAdd(load);
-      if (load->HasSideEffects()) AddSimulate(increment->id());
+      if (load->HasSideEffects()) AddSimulate(expr->CountId());
 
       HValue* before = Pop();
       // There is no deoptimization to after the increment, so we don't need
       // to simulate the expression stack after this instruction.
       HInstruction* after = BuildIncrement(before, inc);
       AddInstruction(after);
 
       HInstruction* store = is_fast_elements
           ? BuildStoreKeyedFastElement(obj, key, after, prop)
           : BuildStoreKeyedGeneric(obj, key, after);
@@ skipping 1255 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify();
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal