ARM64: Optimize AllocateHeapNumber to use STP.

src/arm64/codegen-arm64.cc

 // Copyright 2013 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 321 matching lines @@
 
   {
     Label loop, convert_hole;
     __ Bind(&loop);
     __ Ldr(x13, MemOperand(src_elements, kPointerSize, PostIndex));
     __ Cmp(x13, kHoleNanInt64);
     __ B(eq, &convert_hole);
 
     // Non-hole double, copy value into a heap number.
     Register heap_num = x5;
-    __ AllocateHeapNumber(heap_num, &gc_required, x6, x4, heap_num_map);
-    __ Str(x13, FieldMemOperand(heap_num, HeapNumber::kValueOffset));
+    __ AllocateHeapNumber(heap_num, &gc_required, x6, x4,
+                          x13, heap_num_map);
     __ Mov(x13, dst_elements);
     __ Str(heap_num, MemOperand(dst_elements, kPointerSize, PostIndex));
     __ RecordWrite(array, x13, heap_num, kLRHasBeenSaved, kDontSaveFPRegs,
                    EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
 
     __ B(&entry);
 
     // Replace the-hole NaN with the-hole pointer.
     __ Bind(&convert_hole);
     __ Str(the_hole, MemOperand(dst_elements, kPointerSize, PostIndex));
@@ skipping 252 matching lines @@
   __ Fmul(result, double_temp3, double_temp1);
 
   __ Bind(&done);
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64