[turbofan] Introduce separate SelectLowering reducer.

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"
 #include "src/compiler/ast-graph-builder.h"
 #include "src/compiler/basic-block-instrumentor.h"
 #include "src/compiler/change-lowering.h"
 #include "src/compiler/code-generator.h"
 #include "src/compiler/control-reducer.h"
 #include "src/compiler/graph-replay.h"
 #include "src/compiler/graph-visualizer.h"
 #include "src/compiler/instruction.h"
 #include "src/compiler/instruction-selector.h"
 #include "src/compiler/js-context-specialization.h"
 #include "src/compiler/js-generic-lowering.h"
 #include "src/compiler/js-inlining.h"
 #include "src/compiler/js-typed-lowering.h"
 #include "src/compiler/machine-operator-reducer.h"
 #include "src/compiler/pipeline-statistics.h"
 #include "src/compiler/register-allocator.h"
 #include "src/compiler/schedule.h"
 #include "src/compiler/scheduler.h"
+#include "src/compiler/select-lowering.h"
 #include "src/compiler/simplified-lowering.h"
 #include "src/compiler/simplified-operator-reducer.h"
 #include "src/compiler/typer.h"
 #include "src/compiler/value-numbering-reducer.h"
 #include "src/compiler/verifier.h"
 #include "src/compiler/zone-pool.h"
 #include "src/ostreams.h"
 #include "src/utils.h"
 
 namespace v8 {
@@ skipping 404 matching lines @@
 
       VerifyAndPrintGraph(data.graph(), "Late Control reduced");
     }
   }
 
   {
     // Lower any remaining generic JSOperators.
     PhaseScope phase_scope(pipeline_statistics.get(), "generic lowering");
     SourcePositionTable::Scope pos(data.source_positions(),
                                    SourcePosition::Unknown());
-    JSGenericLowering lowering(info(), data.jsgraph());
+    JSGenericLowering generic(info(), data.jsgraph());
+    SelectLowering select(data.jsgraph()->graph(), data.jsgraph()->common());
     GraphReducer graph_reducer(data.graph());
-    graph_reducer.AddReducer(&lowering);
+    graph_reducer.AddReducer(&generic);
+    graph_reducer.AddReducer(&select);
     graph_reducer.ReduceGraph();
 
     // TODO(jarin, rossberg): Remove UNTYPED once machine typing works.
     VerifyAndPrintGraph(data.graph(), "Lowered generic", true);
   }
 
   if (!pipeline_statistics.is_empty()) {
     pipeline_statistics->BeginPhaseKind("block building");
   }
 
@@ skipping 164 matching lines @@
 }
 
 
 void Pipeline::TearDown() {
   InstructionOperand::TearDownCaches();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8