ARM: Small copy optimization. Copying 64bits at a time.

src/arm/lithium-codegen-arm.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 5596 matching lines @@
   __ jmp(&allocated);
 
   __ bind(&runtime_allocate);
   __ mov(r0, Operand(Smi::FromInt(size)));
   __ Push(r1, r0);
   CallRuntime(Runtime::kAllocateInNewSpace, 1, instr);
   __ pop(r1);
 
   __ bind(&allocated);
   // Copy the content into the newly allocated memory.
-  // (Unroll copy loop once for better throughput).
-  for (int i = 0; i < size - kPointerSize; i += 2 * kPointerSize) {
-    __ ldr(r3, FieldMemOperand(r1, i));
-    __ ldr(r2, FieldMemOperand(r1, i + kPointerSize));
-    __ str(r3, FieldMemOperand(r0, i));
-    __ str(r2, FieldMemOperand(r0, i + kPointerSize));
-  }
-  if ((size % (2 * kPointerSize)) != 0) {
-    __ ldr(r3, FieldMemOperand(r1, size - kPointerSize));
-    __ str(r3, FieldMemOperand(r0, size - kPointerSize));
-  }
+  __ CopyFields(r0, r1, double_scratch0(), double_scratch0().low(),
+                size / kPointerSize);
 }
 
 
 void LCodeGen::DoFunctionLiteral(LFunctionLiteral* instr) {
   // Use the fast case closure allocation code that allocates in new
   // space for nested functions that don't need literals cloning.
   Handle<SharedFunctionInfo> shared_info = instr->shared_info();
   bool pretenure = instr->hydrogen()->pretenure();
   if (!pretenure && shared_info->num_literals() == 0) {
     FastNewClosureStub stub(shared_info->language_mode(),
@@ skipping 374 matching lines @@
   __ sub(scratch, result, Operand(index, LSL, kPointerSizeLog2 - kSmiTagSize));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal