Reduce the amount of full code generated to fill out array literals.

src/x64/code-stubs-x64.cc

 // 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 6618 matching lines @@
 
   __ bind(&need_incremental);
 
   // Fall through when we need to inform the incremental marker.
 }
 
 
 void StoreArrayLiteralElementStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- rax    : element value to store
-  //  -- rbx    : array literal
-  //  -- rdi    : map of array literal
   //  -- rcx    : element index as smi
-  //  -- rdx    : array literal index in function
   //  -- rsp[0] : return address
+  //  -- rsp[8] : array literal index in function
+  //  -- rsp[16]: array literal
+  // clobbers rbx, rdx, rdi
   // -----------------------------------
 
   Label element_done;
   Label double_elements;
   Label smi_element;
   Label slow_elements;
   Label fast_elements;
 
+  // Get array literal index, array literal and its map.
+  __ movq(rdx, Operand(rsp, 1 * kPointerSize));
+  __ movq(rbx, Operand(rsp, 2 * kPointerSize));
+  __ movq(rdi, FieldOperand(rbx, JSObject::kMapOffset));
+
   __ CheckFastElements(rdi, &double_elements);
 
   // FAST_*_SMI_ELEMENTS or FAST_*_ELEMENTS
   __ JumpIfSmi(rax, &smi_element);
   __ CheckFastSmiElements(rdi, &fast_elements);
 
   // Store into the array literal requires a elements transition. Call into
   // the runtime.
 
   __ bind(&slow_elements);
@@ skipping 432 matching lines @@
     __ jmp(generic_construct_stub, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64