Don't use environment values at certain deoptimize-instructions.

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 97 matching lines @@
   if (first_ == NULL) {
     HBlockEntry* entry = new(zone()) HBlockEntry();
     entry->InitializeAsFirst(this);
     first_ = last_ = entry;
   }
   instr->InsertAfter(last_);
   last_ = instr;
 }
 
 
-HDeoptimize* HBasicBlock::CreateDeoptimize() {
+HDeoptimize* HBasicBlock::CreateDeoptimize(
+    HDeoptimize::UseEnvironment has_uses) {
   ASSERT(HasEnvironment());
+  if (has_uses == HDeoptimize::kNoUses) return new(zone()) HDeoptimize(0);
+
   HEnvironment* environment = last_environment();
-
   HDeoptimize* instr = new(zone()) HDeoptimize(environment->length());
-
   for (int i = 0; i < environment->length(); i++) {
     HValue* val = environment->values()->at(i);
     instr->AddEnvironmentValue(val);
   }
 
   return instr;
 }
 
 
 HSimulate* HBasicBlock::CreateSimulate(int id) {
@@ skipping 2349 matching lines @@
   for (int i = 0; i < clause_count; ++i) {
     CaseClause* clause = clauses->at(i);
     if (clause->is_default()) continue;
     if (!clause->label()->IsSmiLiteral()) {
       return Bailout("SwitchStatement: non-literal switch label");
     }
 
     // Unconditionally deoptimize on the first non-smi compare.
     clause->RecordTypeFeedback(oracle());
     if (!clause->IsSmiCompare()) {
-      current_block()->FinishExitWithDeoptimization();
+      // Finish with deoptimize and add uses of enviroment values to
+      // account for invisible uses.
+      current_block()->FinishExitWithDeoptimization(HDeoptimize::kUseAll);
       set_current_block(NULL);
       break;
     }
 
     // Otherwise generate a compare and branch.
     CHECK_ALIVE(VisitForValue(clause->label()));
     HValue* label_value = Pop();
     HCompare* compare =
         new(zone()) HCompare(tag_value, label_value, Token::EQ_STRICT);
     compare->SetInputRepresentation(Representation::Integer32());
@@ skipping 726 matching lines @@
       current_block()->Goto(join);
 
       set_current_block(if_false);
     }
   }
 
   // Finish up.  Unconditionally deoptimize if we've handled all the maps we
   // know about and do not want to handle ones we've never seen.  Otherwise
   // use a generic IC.
   if (count == types->length() && FLAG_deoptimize_uncommon_cases) {
-    current_block()->FinishExitWithDeoptimization();
+    current_block()->FinishExitWithDeoptimization(HDeoptimize::kNoUses);
   } else {
     HInstruction* instr = BuildStoreNamedGeneric(object, name, value);
     instr->set_position(expr->position());
     AddInstruction(instr);
 
     if (join != NULL) {
       if (!ast_context()->IsEffect()) Push(value);
       current_block()->Goto(join);
     } else {
       // The HSimulate for the store should not see the stored value in
@@ skipping 658 matching lines @@
 
       if (current_block() != NULL) current_block()->Goto(join);
       set_current_block(if_false);
     }
   }
 
   // Finish up.  Unconditionally deoptimize if we've handled all the maps we
   // know about and do not want to handle ones we've never seen.  Otherwise
   // use a generic IC.
   if (count == types->length() && FLAG_deoptimize_uncommon_cases) {
-    current_block()->FinishExitWithDeoptimization();
+    current_block()->FinishExitWithDeoptimization(HDeoptimize::kNoUses);
   } else {
     HValue* context = environment()->LookupContext();
     HCallNamed* call = new(zone()) HCallNamed(context, name, argument_count);
     call->set_position(expr->position());
     PreProcessCall(call);
 
     if (join != NULL) {
       AddInstruction(call);
       if (!ast_context()->IsEffect()) Push(call);
       current_block()->Goto(join);
@@ skipping 2190 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify();
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal