MIPS: DoNumberTagD performance improvement

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 926b3bfbb4e690b8b43905ee72b8c94173581ec0..ca83174e5928490d9dc57007fccc42712368f7b5 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -3215,7 +3215,8 @@ void MacroAssembler::AllocateHeapNumber(Register result,
                                         Register scratch1,
                                         Register scratch2,
                                         Register heap_number_map,
-                                        Label* need_gc) {
+                                        Label* need_gc,
+                                        TaggingMode tagging_mode) {
   // Allocate an object in the heap for the heap number and tag it as a heap
   // object.
   AllocateInNewSpace(HeapNumber::kSize,
@@ -3223,11 +3224,16 @@ void MacroAssembler::AllocateHeapNumber(Register result,
                      scratch1,
                      scratch2,
                      need_gc,
-                     TAG_OBJECT);
+                     tagging_mode == TAG_RESULT ? TAG_OBJECT :
+                                                  NO_ALLOCATION_FLAGS);
 
   // Store heap number map in the allocated object.
   AssertRegisterIsRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
-  sw(heap_number_map, FieldMemOperand(result, HeapObject::kMapOffset));
+  if (tagging_mode == TAG_RESULT) {
+    sw(heap_number_map, FieldMemOperand(result, HeapObject::kMapOffset));
+  } else {
+    sw(heap_number_map, MemOperand(result, HeapObject::kMapOffset));
+  }
 }