Make special RPO computation iterative during scheduling.

test/unittests/compiler/register-allocator-unittest.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/base/utils/random-number-generator.h"
 #include "src/compiler/register-allocator.h"
 #include "test/unittests/test-utils.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
 namespace v8 {
@@ skipping 79 matching lines @@
                                Rpo loop_end = Rpo::Invalid()) {
     CHECK(current_block_ == NULL);
     BasicBlock::Id block_id =
         BasicBlock::Id::FromSize(instruction_blocks_.size());
     BasicBlock* basic_block = new (zone()) BasicBlock(zone(), block_id);
     basic_block->set_rpo_number(block_id.ToInt());
     basic_block->set_ao_number(block_id.ToInt());
     if (loop_header.IsValid()) {
       basic_block->set_loop_depth(1);
       basic_block->set_loop_header(basic_blocks_[loop_header.ToSize()]);
-      basic_block->set_loop_end(loop_end.ToInt());
+      basic_block->set_loop_end(basic_blocks_[loop_end.ToSize()]);
     }
     InstructionBlock* instruction_block =
         new (zone()) InstructionBlock(zone(), basic_block);
     basic_blocks_.push_back(basic_block);
     instruction_blocks_.push_back(instruction_block);
     current_block_ = instruction_block;
     sequence()->StartBlock(basic_block);
     return instruction_block;
   }
 
@@ skipping 79 matching lines @@
   EndBlock();
 
   Allocate();
 
   ASSERT_TRUE(res->OutputAt(0)->IsRegister());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8