Add phase zone to CompilationInfo and use it in GVN pass.

src/compiler.h

Index: src/compiler.h
diff --git a/src/compiler.h b/src/compiler.h
index f53feb954a49c53016d0eece13f3425b117b1619..779acbc35166df282b87bf8023e18e2e3256a2c7 100644
--- a/src/compiler.h
+++ b/src/compiler.h
@@ -57,7 +57,7 @@ struct OffsetRange {
 // is constructed based on the resources available at compile-time.
 class CompilationInfo {
  public:
-  CompilationInfo(Handle<JSFunction> closure, Zone* zone);
+  CompilationInfo(Handle<JSFunction> closure, Zone* zone, Zone* phase_zone);
   virtual ~CompilationInfo();
 
   Isolate* isolate() {
@@ -65,6 +65,7 @@ class CompilationInfo {
     return isolate_;
   }
   Zone* zone() { return zone_; }
+  Zone* phase_zone() { return phase_zone_; }
   bool is_lazy() const { return IsLazy::decode(flags_); }
   bool is_eval() const { return IsEval::decode(flags_); }
   bool is_global() const { return IsGlobal::decode(flags_); }
@@ -300,9 +301,16 @@ class CompilationInfo {
   }
 
  protected:
-  CompilationInfo(Handle<Script> script, Zone* zone);
-  CompilationInfo(Handle<SharedFunctionInfo> shared_info, Zone* zone);
-  CompilationInfo(HydrogenCodeStub* stub, Isolate* isolate, Zone* zone);
+  CompilationInfo(Handle<Script> script,
+                  Zone* zone,
+                  Zone* phase_zone);
+  CompilationInfo(Handle<SharedFunctionInfo> shared_info,
+                  Zone* zone,
+                  Zone* phase_zone);
+  CompilationInfo(HydrogenCodeStub* stub,
+                  Isolate* isolate,
+                  Zone* zone,
+                  Zone* phase_zone);
 
  private:
   Isolate* isolate_;
@@ -320,7 +328,7 @@ class CompilationInfo {
     DEPENDENT_MAP_ABORT
   };
 
-  void Initialize(Isolate* isolate, Mode mode, Zone* zone);
+  void Initialize(Isolate* isolate, Mode mode, Zone* zone, Zone* phase_zone);
 
   void SetMode(Mode mode) {
     ASSERT(V8::UseCrankshaft());
@@ -394,6 +402,9 @@ class CompilationInfo {
   // The zone from which the compilation pipeline working on this
   // CompilationInfo allocates.
   Zone* zone_;
+  // The phase zone where allocations local to a specific phase are
+  // performed; be aware that this zone is cleared after each phase
+  Zone* phase_zone_;
 
   DeferredHandles* deferred_handles_;
 
@@ -428,21 +439,25 @@ class CompilationInfo {
 class CompilationInfoWithZone: public CompilationInfo {
  public:
   explicit CompilationInfoWithZone(Handle<Script> script)
-      : CompilationInfo(script, &zone_),
+      : CompilationInfo(script, &zone_, &phase_zone_),
         zone_(script->GetIsolate()),
-        zone_scope_(&zone_, DELETE_ON_EXIT) {}
+        zone_scope_(&zone_, DELETE_ON_EXIT),
+        phase_zone_(script->GetIsolate()) {}
   explicit CompilationInfoWithZone(Handle<SharedFunctionInfo> shared_info)
-      : CompilationInfo(shared_info, &zone_),
+      : CompilationInfo(shared_info, &zone_, &phase_zone_),
         zone_(shared_info->GetIsolate()),
-        zone_scope_(&zone_, DELETE_ON_EXIT) {}
+        zone_scope_(&zone_, DELETE_ON_EXIT),
+        phase_zone_(shared_info->GetIsolate()) {}
   explicit CompilationInfoWithZone(Handle<JSFunction> closure)
-      : CompilationInfo(closure, &zone_),
+      : CompilationInfo(closure, &zone_, &phase_zone_),
         zone_(closure->GetIsolate()),
-        zone_scope_(&zone_, DELETE_ON_EXIT) {}
+        zone_scope_(&zone_, DELETE_ON_EXIT),
+        phase_zone_(closure->GetIsolate()) {}
   CompilationInfoWithZone(HydrogenCodeStub* stub, Isolate* isolate)
-      : CompilationInfo(stub, isolate, &zone_),
+      : CompilationInfo(stub, isolate, &zone_, &phase_zone_),
         zone_(isolate),
-        zone_scope_(&zone_, DELETE_ON_EXIT) {}
+        zone_scope_(&zone_, DELETE_ON_EXIT),
+        phase_zone_(isolate) {}
 
   // Virtual destructor because a CompilationInfoWithZone has to exit the
   // zone scope and get rid of dependent maps even when the destructor is
@@ -454,6 +469,7 @@ class CompilationInfoWithZone: public CompilationInfo {
  private:
   Zone zone_;
   ZoneScope zone_scope_;
+  Zone phase_zone_;
 };