Refactor Hydrogen GVN into an HPhase and use the phase zone.

src/hydrogen.cc

 // Copyright 2012 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 3928 matching lines @@
   int checksum = type_info->own_type_change_checksum();
   int composite_checksum = graph()->update_type_change_checksum(checksum);
   graph()->set_use_optimistic_licm(
       !type_info->matches_inlined_type_change_checksum(composite_checksum));
   type_info->set_inlined_type_change_checksum(composite_checksum);
 
   return true;
 }
 
 
-// Perform common subexpression elimination and loop-invariant code motion.
-void HGraph::GlobalValueNumbering() {
-  HPhase phase("H_Global value numbering", this);
-  HGlobalValueNumberer gvn(this, info());
-  bool removed_side_effects = gvn.Analyze();
-  // Trigger a second analysis pass to further eliminate duplicate values that
-  // could only be discovered by removing side-effect-generating instructions
-  // during the first pass.
-  if (FLAG_smi_only_arrays && removed_side_effects) {
-    removed_side_effects = gvn.Analyze();
-    ASSERT(!removed_side_effects);
-  }
-}
-
-
 bool HGraph::Optimize(SmartArrayPointer<char>* bailout_reason) {
   *bailout_reason = SmartArrayPointer<char>();
   OrderBlocks();
   AssignDominators();
 
   // We need to create a HConstant "zero" now so that GVN will fold every
   // zero-valued constant in the graph together.
   // The constant is needed to make idef-based bounds check work: the pass
   // evaluates relations with "zero" and that zero cannot be created after GVN.
   GetConstant0();
@@ skipping 48 matching lines @@
 
   InitializeInferredTypes();
 
   // Must be performed before canonicalization to ensure that Canonicalize
   // will not remove semantically meaningful ToInt32 operations e.g. BIT_OR with
   // zero.
   if (FLAG_opt_safe_uint32_operations) ComputeSafeUint32Operations();
 
   if (FLAG_use_canonicalizing) Canonicalize();
 
-  if (FLAG_use_gvn) GlobalValueNumbering();
+  if (FLAG_use_gvn) {
+    HGlobalValueNumberingPhase phase(this);
+    phase.Run();
+  }
 
   if (FLAG_use_range) {
     HRangeAnalysis rangeAnalysis(this);
     rangeAnalysis.Analyze();
   }
   ComputeMinusZeroChecks();
 
   // Eliminate redundant stack checks on backwards branches.
   HStackCheckEliminator sce(this);
   sce.Process();
@@ skipping 7511 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal