Allow direct allocation in old pointer space.

src/x64/macro-assembler-x64.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 994 matching lines @@
                                 Register key,
                                 Register r0,
                                 Register r1,
                                 Register r2,
                                 Register result);
 
 
   // ---------------------------------------------------------------------------
   // Allocation support
 
-  // Allocate an object in new space. If the new space is exhausted control
-  // continues at the gc_required label. The allocated object is returned in
-  // result and end of the new object is returned in result_end. The register
-  // scratch can be passed as no_reg in which case an additional object
-  // reference will be added to the reloc info. The returned pointers in result
-  // and result_end have not yet been tagged as heap objects. If
-  // result_contains_top_on_entry is true the content of result is known to be
-  // the allocation top on entry (could be result_end from a previous call to
-  // AllocateInNewSpace). If result_contains_top_on_entry is true scratch
+  // Allocate an object in new space or old pointer space. If the given space
+  // is exhausted control continues at the gc_required label. The allocated
+  // object is returned in result and end of the new object is returned in
+  // result_end. The register scratch can be passed as no_reg in which case
+  // an additional object reference will be added to the reloc info. The
+  // returned pointers in result and result_end have not yet been tagged as
+  // heap objects. If result_contains_top_on_entry is true the content of
+  // result is known to be the allocation top on entry (could be result_end
+  // from a previous call). If result_contains_top_on_entry is true scratch
   // should be no_reg as it is never used.
-  void AllocateInNewSpace(int object_size,
-                          Register result,
-                          Register result_end,
-                          Register scratch,
-                          Label* gc_required,
-                          AllocationFlags flags);
+  enum AllocationTarget {
+    NEW_SPACE,
+    OLD_POINTER_SPACE
+  };
+
+  void Allocate(int object_size,
+                Register result,
+                Register result_end,
+                Register scratch,
+                Label* gc_required,
+                AllocationFlags flags,
+                AllocationTarget target);
 
   void AllocateInNewSpace(int header_size,
                           ScaleFactor element_size,
                           Register element_count,
                           Register result,
                           Register result_end,
                           Register scratch,
                           Label* gc_required,
                           AllocationFlags flags);
 
@@ skipping 320 matching lines @@
                       CallKind call_kind = CALL_AS_METHOD);
 
   void EnterExitFramePrologue(bool save_rax);
 
   // Allocates arg_stack_space * kPointerSize memory (not GCed) on the stack
   // accessible via StackSpaceOperand.
   void EnterExitFrameEpilogue(int arg_stack_space, bool save_doubles);
 
   void LeaveExitFrameEpilogue();
 
+  ExternalReference GetTopAddress(AllocationTarget target);
+  ExternalReference GetLimitAddress(AllocationTarget target);
+
   // Allocation support helpers.
   // Loads the top of new-space into the result register.
   // Otherwise the address of the new-space top is loaded into scratch (if
   // scratch is valid), and the new-space top is loaded into result.
   void LoadAllocationTopHelper(Register result,
                                Register scratch,
-                               AllocationFlags flags);
+                               AllocationFlags flags,
+                               AllocationTarget target);
   // Update allocation top with value in result_end register.
   // If scratch is valid, it contains the address of the allocation top.
-  void UpdateAllocationTopHelper(Register result_end, Register scratch);
+  void UpdateAllocationTopHelper(Register result_end,
+                                 Register scratch,
+                                 AllocationTarget target);
 
   // Helper for PopHandleScope.  Allowed to perform a GC and returns
   // NULL if gc_allowed.  Does not perform a GC if !gc_allowed, and
   // possibly returns a failure object indicating an allocation failure.
   Object* PopHandleScopeHelper(Register saved,
                                Register scratch,
                                bool gc_allowed);
 
   // Helper for implementing JumpIfNotInNewSpace and JumpIfInNewSpace.
   void InNewSpace(Register object,
@@ skipping 102 matching lines @@
     masm->popfq();                                                           \
   }                                                                          \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_MACRO_ASSEMBLER_X64_H_