Reland: Introducing the LLVM greedy register allocator.

src/compiler/pipeline.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/compiler/pipeline.h"
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
 
 #include "src/base/platform/elapsed-timer.h"
@@ skipping 226 matching lines @@
     sequence_ = new (instruction_zone()) InstructionSequence(
         info()->isolate(), instruction_zone(), instruction_blocks);
   }
 
   void InitializeRegisterAllocator(Zone* local_zone,
                                    const RegisterConfiguration* config,
                                    const char* debug_name) {
     DCHECK(!register_allocator_);
     DCHECK(!frame_);
     frame_ = new (instruction_zone()) Frame();
-    register_allocator_ = new (instruction_zone())
-        RegisterAllocator(config, local_zone, frame(), sequence(), debug_name);
+    if (FLAG_turbo_greedy_regalloc) {
+      register_allocator_ = new (instruction_zone()) RegisterAllocatorGreedy(
+          config, local_zone, frame(), sequence(), debug_name);
+    } else {
+      register_allocator_ = new (instruction_zone()) RegisterAllocatorLinear(
+          config, local_zone, frame(), sequence(), debug_name);
+    }
   }
 
  private:
   Isolate* isolate_;
   CompilationInfo* info_;
   Zone* outer_zone_;
   ZonePool* const zone_pool_;
   PipelineStatistics* pipeline_statistics_;
   bool compilation_failed_;
   Handle<Code> code_;
@@ skipping 1003 matching lines @@
 
   if (FLAG_trace_turbo && !data->MayHaveUnverifiableGraph()) {
     TurboCfgFile tcf(data->isolate());
     tcf << AsC1VAllocator("CodeGen", data->register_allocator());
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8