Allow bailing out of the register allocator when running out of virtual registers.

src/compiler.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 176 matching lines @@
   Handle<Code> code(info->shared_info()->code());
   ASSERT(code->kind() == Code::FUNCTION);
 
   // We should never arrive here if optimization has been disabled on the
   // shared function info.
   ASSERT(!info->shared_info()->optimization_disabled());
 
   // Fall back to using the full code generator if it's not possible
   // to use the Hydrogen-based optimizing compiler. We already have
   // generated code for this from the shared function object.
-  if (AlwaysFullCompiler() || !FLAG_use_hydrogen) {
+  if (AlwaysFullCompiler()) {
     info->SetCode(code);
     return true;
   }
 
   // Limit the number of times we re-compile a functions with
   // the optimizing compiler.
   const int kMaxOptCount =
       FLAG_deopt_every_n_times == 0 ? Compiler::kDefaultMaxOptCount : 1000;
   if (info->shared_info()->opt_count() > kMaxOptCount) {
     info->AbortOptimization();
@@ skipping 76 matching lines @@
   Handle<Context> global_context(info->closure()->context()->global_context());
   TypeFeedbackOracle oracle(code, global_context, info->isolate());
   HGraphBuilder builder(info, &oracle);
   HPhase phase(HPhase::kTotal);
   HGraph* graph = builder.CreateGraph();
   if (info->isolate()->has_pending_exception()) {
     info->SetCode(Handle<Code>::null());
     return false;
   }
 
-  if (graph != NULL && FLAG_build_lithium) {
+  if (graph != NULL) {
     Handle<Code> optimized_code = graph->Compile(info);
     if (!optimized_code.is_null()) {
       info->SetCode(optimized_code);
       FinishOptimization(info->closure(), start);
       return true;
     }
   }
 
   // Keep using the shared code.
   info->AbortOptimization();
@@ skipping 481 matching lines @@
     }
   }
 
   GDBJIT(AddCode(Handle<String>(shared->DebugName()),
                  Handle<Script>(info->script()),
                  Handle<Code>(info->code()),
                  info));
 }
 
 } }  // namespace v8::internal