DoNumberTagD performance improvement

src/arm/macro-assembler-arm.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 50 matching lines @@
   // Return the pointer to the allocated already tagged as a heap object.
   TAG_OBJECT = 1 << 0,
   // The content of the result register already contains the allocation top in
   // new space.
   RESULT_CONTAINS_TOP = 1 << 1,
   // Specify that the requested size of the space to allocate is specified in
   // words instead of bytes.
   SIZE_IN_WORDS = 1 << 2
 };
 
+// Flags used for AllocateHeapNumber
+enum TaggingMode {
+  // Tag the result.
+  TAG_RESULT,
+  // Don't tag
+  DONT_TAG_RESULT
+};
 
 // Flags used for the ObjectToDoubleVFPRegister function.
 enum ObjectToDoubleFlags {
   // No special flags.
   NO_OBJECT_TO_DOUBLE_FLAGS = 0,
   // Object is known to be a non smi.
   OBJECT_NOT_SMI = 1 << 0,
   // Don't load NaNs or infinities, branch to the non number case instead.
   AVOID_NANS_AND_INFINITIES = 1 << 1
 };
@@ skipping 643 matching lines @@
                                  Register scratch2,
                                  Label* gc_required);
 
   // Allocates a heap number or jumps to the gc_required label if the young
   // space is full and a scavenge is needed. All registers are clobbered also
   // when control continues at the gc_required label.
   void AllocateHeapNumber(Register result,
                           Register scratch1,
                           Register scratch2,
                           Register heap_number_map,
-                          Label* gc_required);
+                          Label* gc_required,
+                          TaggingMode tagging_mode = TAG_RESULT);
   void AllocateHeapNumberWithValue(Register result,
                                    DwVfpRegister value,
                                    Register scratch1,
                                    Register scratch2,
                                    Register heap_number_map,
                                    Label* gc_required);
 
   // Copies a fixed number of fields of heap objects from src to dst.
   void CopyFields(Register dst, Register src, RegList temps, int field_count);
 
@@ skipping 657 matching lines @@
 #define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
 #define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_MACRO_ASSEMBLER_ARM_H_