Use direct jump and call instruction for X64 when the deoptimization entries are in the code range

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 223 matching lines @@
     // Everything after runtime_entry (inclusive) is not GC'ed.
     RUNTIME_ENTRY,
     JS_RETURN,  // Marks start of the ExitJSFrame code.
     COMMENT,
     POSITION,  // See comment for kNoPosition above.
     STATEMENT_POSITION,  // See comment for kNoPosition above.
     DEBUG_BREAK_SLOT,  // Additional code inserted for debug break slot.
     EXTERNAL_REFERENCE,  // The address of an external C++ function.
     INTERNAL_REFERENCE,  // An address inside the same function.
 
+#if defined(V8_TARGET_ARCH_X64)

[Sven Panne, 2012/12/14 08:20:11]

Similar to the comment in the related CL, I will strongly object any change in
this area which is architecture-dependent.

+    // Marks a deopt entry. Only used on X64.
+    // It uses a custom noncompact encoding.
+    DEOPT_ENTRY,
+#else
     // Marks a constant pool. Only used on ARM.
     // It uses a custom noncompact encoding.
     CONST_POOL,
+#endif
 
     // add more as needed
     // Pseudo-types
     NUMBER_OF_MODES,  // There are at most 15 modes with noncompact encoding.
     NONE,  // never recorded
     CODE_AGE_SEQUENCE,  // Not stored in RelocInfo array, used explictly by
                         // code aging.
     FIRST_REAL_RELOC_MODE = CODE_TARGET,
+#if defined(V8_TARGET_ARCH_X64)

[Sven Panne, 2012/12/14 08:20:11]

see above

+    LAST_REAL_RELOC_MODE = DEOPT_ENTRY,
+#else
     LAST_REAL_RELOC_MODE = CONST_POOL,
+#endif
     FIRST_PSEUDO_RELOC_MODE = CODE_AGE_SEQUENCE,
     LAST_PSEUDO_RELOC_MODE = CODE_AGE_SEQUENCE,
     LAST_CODE_ENUM = DEBUG_BREAK,
     LAST_GCED_ENUM = GLOBAL_PROPERTY_CELL,
     // Modes <= LAST_COMPACT_ENUM are guaranteed to have compact encoding.
     LAST_COMPACT_ENUM = CODE_TARGET_WITH_ID,
     LAST_STANDARD_NONCOMPACT_ENUM = INTERNAL_REFERENCE
   };
 
 
@@ skipping 24 matching lines @@
   // Is the relocation mode affected by GC?
   static inline bool IsGCRelocMode(Mode mode) {
     return mode <= LAST_GCED_ENUM;
   }
   static inline bool IsJSReturn(Mode mode) {
     return mode == JS_RETURN;
   }
   static inline bool IsComment(Mode mode) {
     return mode == COMMENT;
   }
+#if defined(V8_TARGET_ARCH_X64)

[Sven Panne, 2012/12/14 08:20:11]

see above

+  static inline bool IsDeoptEntry(Mode mode) {
+    return mode == DEOPT_ENTRY;
+  }
+#else
   static inline bool IsConstPool(Mode mode) {
     return mode == CONST_POOL;
   }
+#endif
   static inline bool IsPosition(Mode mode) {
     return mode == POSITION || mode == STATEMENT_POSITION;
   }
   static inline bool IsStatementPosition(Mode mode) {
     return mode == STATEMENT_POSITION;
   }
   static inline bool IsExternalReference(Mode mode) {
     return mode == EXTERNAL_REFERENCE;
   }
   static inline bool IsInternalReference(Mode mode) {
@@ skipping 23 matching lines @@
   bool IsCodedSpecially();
 
   // Read/modify the code target in the branch/call instruction
   // this relocation applies to;
   // can only be called if IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY
   INLINE(Address target_address());
   INLINE(void set_target_address(Address target,
                                  WriteBarrierMode mode = UPDATE_WRITE_BARRIER));
   INLINE(Object* target_object());
   INLINE(Handle<Object> target_object_handle(Assembler* origin));
+#if defined(V8_TARGET_ARCH_X64)

[Sven Panne, 2012/12/14 08:20:11]

see above

+  INLINE(Address target_deopt_entry(Assembler* origin));
+#endif
   INLINE(Object** target_object_address());
   INLINE(void set_target_object(Object* target,
                                 WriteBarrierMode mode = UPDATE_WRITE_BARRIER));
   INLINE(JSGlobalPropertyCell* target_cell());
   INLINE(Handle<JSGlobalPropertyCell> target_cell_handle());
   INLINE(void set_target_cell(JSGlobalPropertyCell* cell,
                               WriteBarrierMode mode = UPDATE_WRITE_BARRIER));
   INLINE(Code* code_age_stub());
   INLINE(void set_code_age_stub(Code* stub));
 
@@ skipping 114 matching lines @@
   // On ia32 and arm this is 1 + 4 + 1 + 1 + 1 + 4 = 12.
   // On x64 this is 1 + 4 + 1 + 1 + 1 + 8 == 16;
   // Here we use the maximum of the two.
   static const int kMaxSize = 16;
 
  private:
   inline uint32_t WriteVariableLengthPCJump(uint32_t pc_delta);
   inline void WriteTaggedPC(uint32_t pc_delta, int tag);
   inline void WriteExtraTaggedPC(uint32_t pc_delta, int extra_tag);
   inline void WriteExtraTaggedIntData(int data_delta, int top_tag);
+#if !defined(V8_TARGET_ARCH_X64)

[Sven Panne, 2012/12/14 08:20:11]

see above

   inline void WriteExtraTaggedConstPoolData(int data);
+#else
+  inline void WriteExtraTaggedDeoptEntryData(int data);
+#endif
   inline void WriteExtraTaggedData(intptr_t data_delta, int top_tag);
   inline void WriteTaggedData(intptr_t data_delta, int tag);
   inline void WriteExtraTag(int extra_tag, int top_tag);
 
   byte* pos_;
   byte* last_pc_;
   int last_id_;
   int last_position_;
   DISALLOW_COPY_AND_ASSIGN(RelocInfoWriter);
 };
@@ skipping 465 matching lines @@
  public:
   NullCallWrapper() { }
   virtual ~NullCallWrapper() { }
   virtual void BeforeCall(int call_size) const { }
   virtual void AfterCall() const { }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ASSEMBLER_H_