Disable aggressive optimizations on the last optimization attempt.

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 669 matching lines @@
       next_block_id_(0),
       info_(info),
       blocks_(8),
       values_(16),
       phi_list_(NULL) {
   start_environment_ = new HEnvironment(NULL, info->scope(), info->closure());
   start_environment_->set_ast_id(info->function()->id());
 }
 
 
+bool HGraph::AllowAggressiveOptimizations() const {
+  return info()->shared_info()->opt_count() + 1 < kDefaultMaxOptCount;
+}
+
+
 Handle<Code> HGraph::Compile() {
   int values = GetMaximumValueID();
   if (values > LAllocator::max_initial_value_ids()) {
     if (FLAG_trace_bailout) PrintF("Function is too big\n");
     return Handle<Code>::null();
   }
 
   LAllocator allocator(values, this);
   LChunkBuilder builder(this, &allocator);
   LChunk* chunk = builder.Build();
@@ skipping 746 matching lines @@
   }
 }
 
 // Only move instructions that postdominate the loop header (i.e. are
 // always executed inside the loop). This is to avoid unnecessary
 // deoptimizations assuming the loop is executed at least once.
 // TODO(fschneider): Better type feedback should give us information
 // about code that was never executed.
 bool HGlobalValueNumberer::ShouldMove(HInstruction* instr,
                                       HBasicBlock* loop_header) {
-  if (!instr->IsChange() &&
-      FLAG_aggressive_loop_invariant_motion) return true;
+  if (FLAG_aggressive_loop_invariant_motion &&
+      !instr->IsChange() &&
+      (!instr->CanDeoptimize() || graph_->AllowAggressiveOptimizations())) {
+    return true;
+  }
   HBasicBlock* block = instr->block();
   bool result = true;
   if (block != loop_header) {
     for (int i = 1; i < loop_header->predecessors()->length(); ++i) {
       bool found = false;
       HBasicBlock* pred = loop_header->predecessors()->at(i);
       while (pred != loop_header) {
         if (pred == block) found = true;
         pred = pred->dominator();
       }
@@ skipping 4339 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify();
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal