Make HDeoptimize to explicitly use environment values....

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 95 matching lines @@
   if (first_ == NULL) {
     HBlockEntry* entry = new HBlockEntry();
     entry->InitializeAsFirst(this);
     first_ = last_ = entry;
   }
   instr->InsertAfter(last_);
   last_ = instr;
 }
 
 
+HDeoptimize* HBasicBlock::CreateDeoptimize() {
+  ASSERT(HasEnvironment());
+  HEnvironment* environment = last_environment();
+
+  HDeoptimize* instr = new 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) {
   ASSERT(HasEnvironment());
   HEnvironment* environment = last_environment();
   ASSERT(id == AstNode::kNoNumber ||
          environment->closure()->shared()->VerifyBailoutId(id));
 
   int push_count = environment->push_count();
   int pop_count = environment->pop_count();
 
   int length = environment->length();
@@ skipping 2362 matching lines @@
     clause->RecordTypeFeedback(oracle());
     if (!clause->IsSmiCompare()) {
       if (current_block() == first_test_block) {
         // If the first test is the one that deopts and if the tag value is
         // a phi, we need to have some use of that phi to prevent phi
         // elimination from removing it.  This HSimulate is such a use.
         Push(tag_value);
         AddSimulate(stmt->EntryId());
         Drop(1);
       }
-      current_block()->Finish(new HDeoptimize());
+
+      current_block()->FinishWithDeoptimization();

[Kevin Millikin (Chromium), 2011/03/17 05:31:02]

We had code to try to handle this issue with a hack (which obviously didn't
work.  We inserted HSimulate immediate before HDeoptimize to create uses of all
environment values).  That code is immediately above what you just wrote.

Delete it please :)

       set_current_block(NULL);
       break;
     }
 
     // Otherwise generate a compare and branch.
     VISIT_FOR_VALUE(clause->label());
     HValue* label_value = Pop();
     HCompare* compare = new HCompare(tag_value, label_value, Token::EQ_STRICT);
     compare->SetInputRepresentation(Representation::Integer32());
     ASSERT(!compare->HasSideEffects());
@@ skipping 599 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()->FinishExit(new HDeoptimize);
+    current_block()->FinishExitWithDeoptimization();
   } 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 327 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()->FinishExit(new HDeoptimize);
+    current_block()->FinishExitWithDeoptimization();
   } else {
     HInstruction* instr = BuildLoadNamedGeneric(object, expr);
     instr->set_position(expr->position());
 
     if (join != NULL) {
       AddInstruction(instr);
       if (!ast_context()->IsEffect()) Push(instr);
       current_block()->Goto(join);
     } else {
       ast_context()->ReturnInstruction(instr, expr->id());
@@ skipping 344 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()->FinishExit(new HDeoptimize);
+    current_block()->FinishExitWithDeoptimization();
   } else {
     HContext* context = new HContext;
     AddInstruction(context);
     HCallNamed* call = new HCallNamed(context, name, argument_count);
     call->set_position(expr->position());
     PreProcessCall(call);
 
     if (join != NULL) {
       AddInstruction(call);
       if (!ast_context()->IsEffect()) Push(call);
@@ skipping 2083 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify();
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal