[turbofan] Redundant branch elimination.

src/compiler/pipeline.cc

Index: src/compiler/pipeline.cc
diff --git a/src/compiler/pipeline.cc b/src/compiler/pipeline.cc
index 209ddfdf0da243c8c62cf6667cddb53e16a0054f..09ff9709aa0097a1104408f8cd17b2d1641121dc 100644
--- a/src/compiler/pipeline.cc
+++ b/src/compiler/pipeline.cc
@@ -12,6 +12,7 @@
 #include "src/compiler/ast-graph-builder.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/basic-block-instrumentor.h"
+#include "src/compiler/branch-condition-elimination.h"
 #include "src/compiler/bytecode-graph-builder.h"
 #include "src/compiler/change-lowering.h"
 #include "src/compiler/code-generator.h"
@@ -609,6 +610,22 @@ struct TypedLoweringPhase {
 };
 
 
+struct BranchConditionEliminationPhase {
+  static const char* phase_name() { return "branch condition elimination"; }
+
+  void Run(PipelineData* data, Zone* temp_zone) {
+    JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
+    BranchConditionElimination branch_condition_elimination(
+        &graph_reducer, data->jsgraph(), temp_zone);
+    DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
+                                              data->common());
+    AddReducer(data, &graph_reducer, &branch_condition_elimination);
+    AddReducer(data, &graph_reducer, &dead_code_elimination);
+    graph_reducer.ReduceGraph();
+  }
+};
+
+
 struct SimplifiedLoweringPhase {
   static const char* phase_name() { return "simplified lowering"; }
 
@@ -1117,6 +1134,9 @@ Handle<Code> Pipeline::GenerateCode() {
     Run<SimplifiedLoweringPhase>();
     RunPrintAndVerify("Lowered simplified");
 
+    Run<BranchConditionEliminationPhase>();
+    RunPrintAndVerify("Branch conditions eliminated");
+
     // Optimize control flow.
     if (FLAG_turbo_cf_optimization) {
       Run<ControlFlowOptimizationPhase>();