Turn {mov,add}q into {mov,add}l.

src/x64/codegen-x64.cc

 // Copyright 2010 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 4374 matching lines @@
 
     // Fill out the elements FixedArray.
     // rax: JSArray.
     // rcx: FixedArray.
     // rbx: Number of elements in array as int32.
 
     // Set map.
     __ Move(FieldOperand(rcx, HeapObject::kMapOffset),
             Factory::fixed_array_map());
     // Set length.
-    __ movq(FieldOperand(rcx, FixedArray::kLengthOffset), rbx);
+    __ movl(FieldOperand(rcx, FixedArray::kLengthOffset), rbx);
     // Fill contents of fixed-array with the-hole.
     __ Move(rdx, Factory::the_hole_value());
     __ lea(rcx, FieldOperand(rcx, FixedArray::kHeaderSize));
     // Fill fixed array elements with hole.
     // rax: JSArray.
     // rbx: Number of elements in array that remains to be filled, as int32.
     // rcx: Start of elements in FixedArray.
     // rdx: the hole.
     Label loop;
     __ testl(rbx, rbx);
@@ skipping 4541 matching lines @@
   // Get the parameters pointer from the stack and untag the length.
   __ movq(rdx, Operand(rsp, 2 * kPointerSize));
   __ SmiToInteger32(rcx, rcx);
 
   // Setup the elements pointer in the allocated arguments object and
   // initialize the header in the elements fixed array.
   __ lea(rdi, Operand(rax, Heap::kArgumentsObjectSize));
   __ movq(FieldOperand(rax, JSObject::kElementsOffset), rdi);
   __ LoadRoot(kScratchRegister, Heap::kFixedArrayMapRootIndex);
   __ movq(FieldOperand(rdi, FixedArray::kMapOffset), kScratchRegister);
-  __ movq(FieldOperand(rdi, FixedArray::kLengthOffset), rcx);
+  __ movl(FieldOperand(rdi, FixedArray::kLengthOffset), rcx);
 
   // Copy the fixed array slots.
   Label loop;
   __ bind(&loop);
   __ movq(kScratchRegister, Operand(rdx, -1 * kPointerSize));  // Skip receiver.
   __ movq(FieldOperand(rdi, FixedArray::kHeaderSize), kScratchRegister);
   __ addq(rdi, Immediate(kPointerSize));
   __ subq(rdx, Immediate(kPointerSize));
   __ decq(rcx);
   __ j(not_zero, &loop);
@@ skipping 2489 matching lines @@
   // Call the function from C++.
   return FUNCTION_CAST<ModuloFunction>(buffer);
 }
 
 #endif
 
 
 #undef __
 
 } }  // namespace v8::internal