Make it possible to assert that certain instance types are compatible wrt HAllocate.

src/hydrogen-instructions.h

 // 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 5410 matching lines @@
     SetAllSideEffects();
   }
 
   Handle<Object> name_;
   bool for_typeof_;
 };
 
 
 class HAllocate V8_FINAL : public HTemplateInstruction<2> {
  public:
+  static bool CompatibleInstanceTypes(InstanceType type1,
+                                      InstanceType type2) {
+    return ComputeFlags(TENURED, type1) == ComputeFlags(TENURED, type2) &&
+        ComputeFlags(NOT_TENURED, type1) == ComputeFlags(NOT_TENURED, type2);
+  }
+
   static HAllocate* New(Zone* zone,
                         HValue* context,
                         HValue* size,
                         HType type,
                         PretenureFlag pretenure_flag,
                         InstanceType instance_type,
                         Handle<AllocationSite> allocation_site =
                             Handle<AllocationSite>::null()) {
     return new(zone) HAllocate(context, size, type, pretenure_flag,
         instance_type, allocation_site);
@@ skipping 38 matching lines @@
   }
 
   bool MustPrefillWithFiller() const {
     return (flags_ & PREFILL_WITH_FILLER) != 0;
   }
 
   void MakePrefillWithFiller() {
     flags_ = static_cast<HAllocate::Flags>(flags_ | PREFILL_WITH_FILLER);
   }
 
+  bool MustClearNextMapWord() const {
+    return (flags_ & CLEAR_NEXT_MAP_WORD) != 0;
+  }
+
   void MakeDoubleAligned() {
     flags_ = static_cast<HAllocate::Flags>(flags_ | ALLOCATE_DOUBLE_ALIGNED);
   }
 
   virtual void HandleSideEffectDominator(GVNFlag side_effect,
                                          HValue* dominator) V8_OVERRIDE;
 
   virtual void PrintDataTo(StringStream* stream) V8_OVERRIDE;
 
   DECLARE_CONCRETE_INSTRUCTION(Allocate)
 
  private:
   enum Flags {
     ALLOCATE_IN_NEW_SPACE = 1 << 0,
     ALLOCATE_IN_OLD_DATA_SPACE = 1 << 1,
     ALLOCATE_IN_OLD_POINTER_SPACE = 1 << 2,
     ALLOCATE_DOUBLE_ALIGNED = 1 << 3,
-    PREFILL_WITH_FILLER = 1 << 4
+    PREFILL_WITH_FILLER = 1 << 4,
+    CLEAR_NEXT_MAP_WORD = 1 << 5
   };
 
   HAllocate(HValue* context,
             HValue* size,
             HType type,
             PretenureFlag pretenure_flag,
             InstanceType instance_type,
             Handle<AllocationSite> allocation_site =
                 Handle<AllocationSite>::null())
       : HTemplateInstruction<2>(type),
+        flags_(ComputeFlags(pretenure_flag, instance_type)),
         dominating_allocate_(NULL),
-        filler_free_space_size_(NULL),
-        clear_next_map_word_(false) {
+        filler_free_space_size_(NULL) {
     SetOperandAt(0, context);
     SetOperandAt(1, size);
     set_representation(Representation::Tagged());
     SetFlag(kTrackSideEffectDominators);
     SetGVNFlag(kChangesNewSpacePromotion);
     SetGVNFlag(kDependsOnNewSpacePromotion);
-    flags_ = pretenure_flag == TENURED
+
+    if (FLAG_trace_pretenuring) {
+      PrintF("HAllocate with AllocationSite %p %s\n",
+             allocation_site.is_null()
+                 ? static_cast<void*>(NULL)
+                 : static_cast<void*>(*allocation_site),
+             pretenure_flag == TENURED ? "tenured" : "not tenured");
+    }
+  }
+
+  static Flags ComputeFlags(PretenureFlag pretenure_flag,
+                            InstanceType instance_type) {
+    Flags flags = pretenure_flag == TENURED
         ? (Heap::TargetSpaceId(instance_type) == OLD_POINTER_SPACE
             ? ALLOCATE_IN_OLD_POINTER_SPACE : ALLOCATE_IN_OLD_DATA_SPACE)
         : ALLOCATE_IN_NEW_SPACE;
     if (instance_type == FIXED_DOUBLE_ARRAY_TYPE) {
-      flags_ = static_cast<HAllocate::Flags>(flags_ | ALLOCATE_DOUBLE_ALIGNED);
+      flags = static_cast<Flags>(flags | ALLOCATE_DOUBLE_ALIGNED);
     }
     // We have to fill the allocated object with one word fillers if we do
     // not use allocation folding since some allocations may depend on each
     // other, i.e., have a pointer to each other. A GC in between these
     // allocations may leave such objects behind in a not completely initialized
     // state.
     if (!FLAG_use_gvn || !FLAG_use_allocation_folding) {
-      flags_ = static_cast<HAllocate::Flags>(flags_ | PREFILL_WITH_FILLER);
+      flags = static_cast<Flags>(flags | PREFILL_WITH_FILLER);
     }
-    clear_next_map_word_ = pretenure_flag == NOT_TENURED &&
-        AllocationSite::CanTrack(instance_type);
+    if (pretenure_flag == NOT_TENURED &&
+        AllocationSite::CanTrack(instance_type)) {
+      flags = static_cast<Flags>(flags | CLEAR_NEXT_MAP_WORD);
+    }
+    return flags;
+  }
 
-    if (FLAG_trace_pretenuring) {
-      PrintF("HAllocate with AllocationSite %p %s\n",
-             allocation_site.is_null()
-                 ? static_cast<void*>(NULL)
-                 : static_cast<void*>(*allocation_site),
-             pretenure_flag == TENURED ? "tenured" : "not tenured");
-    }
+  void UpdateClearNextMapWord(bool clear_next_map_word) {
+    flags_ = static_cast<Flags>(clear_next_map_word
+                                ? flags_ | CLEAR_NEXT_MAP_WORD
+                                : flags_ & ~CLEAR_NEXT_MAP_WORD);
   }
 
   void UpdateSize(HValue* size) {
     SetOperandAt(1, size);
   }
 
   HAllocate* GetFoldableDominator(HAllocate* dominator);
 
   void UpdateFreeSpaceFiller(int32_t filler_size);
 
   void CreateFreeSpaceFiller(int32_t filler_size);
 
   bool IsFoldable(HAllocate* allocate) {
     return (IsNewSpaceAllocation() && allocate->IsNewSpaceAllocation()) ||
         (IsOldDataSpaceAllocation() && allocate->IsOldDataSpaceAllocation()) ||
         (IsOldPointerSpaceAllocation() &&
             allocate->IsOldPointerSpaceAllocation());
   }
 
   void ClearNextMapWord(int offset);
 
   Flags flags_;
   Handle<Map> known_initial_map_;
   HAllocate* dominating_allocate_;
   HStoreNamedField* filler_free_space_size_;
-  bool clear_next_map_word_;
 };
 
 
 class HStoreCodeEntry V8_FINAL: public HTemplateInstruction<2> {
  public:
   static HStoreCodeEntry* New(Zone* zone,
                               HValue* context,
                               HValue* function,
                               HValue* code) {
     return new(zone) HStoreCodeEntry(function, code);
@@ skipping 1906 matching lines @@
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_