Enable preaging of code objects when --optimize-for-size.

src/x64/codegen-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 660 matching lines @@
   __ subsd(result, double_scratch);
   __ addsd(result, Operand(kScratchRegister, 8 * kDoubleSize));
   __ mulsd(result, input);
 
   __ bind(&done);
 }
 
 #undef __
 
 
-static const int kNoCodeAgeSequenceLength = 6;
-
 static byte* GetNoCodeAgeSequence(uint32_t* length) {
   static bool initialized = false;
   static byte sequence[kNoCodeAgeSequenceLength];
   *length = kNoCodeAgeSequenceLength;
   if (!initialized) {
     // The sequence of instructions that is patched out for aging code is the
     // following boilerplate stack-building prologue that is found both in
     // FUNCTION and OPTIMIZED_FUNCTION code:
     CodePatcher patcher(sequence, kNoCodeAgeSequenceLength);
     patcher.masm()->push(rbp);
@@ skipping 36 matching lines @@
                                 MarkingParity parity) {
   uint32_t young_length;
   byte* young_sequence = GetNoCodeAgeSequence(&young_length);
   if (age == kNoAge) {
     CopyBytes(sequence, young_sequence, young_length);
     CPU::FlushICache(sequence, young_length);
   } else {
     Code* stub = GetCodeAgeStub(isolate, age, parity);
     CodePatcher patcher(sequence, young_length);
     patcher.masm()->call(stub->instruction_start());
-    for (int i = 0;
-         i < kNoCodeAgeSequenceLength - Assembler::kShortCallInstructionLength;
-         i++) {
-      patcher.masm()->nop();
-    }
+    patcher.masm()->Nop(
+        kNoCodeAgeSequenceLength - Assembler::kShortCallInstructionLength);
   }
 }
 
 
 Operand StackArgumentsAccessor::GetArgumentOperand(int index) {
   ASSERT(index >= 0);
   int receiver = (receiver_mode_ == ARGUMENTS_CONTAIN_RECEIVER) ? 1 : 0;
   int displacement_to_last_argument = base_reg_.is(rsp) ?
       kPCOnStackSize : kFPOnStackSize + kPCOnStackSize;
   displacement_to_last_argument += extra_displacement_to_last_argument_;
   if (argument_count_reg_.is(no_reg)) {
     // argument[0] is at base_reg_ + displacement_to_last_argument +
     // (argument_count_immediate_ + receiver - 1) * kPointerSize.
     ASSERT(argument_count_immediate_ + receiver > 0);
     return Operand(base_reg_, displacement_to_last_argument +
         (argument_count_immediate_ + receiver - 1 - index) * kPointerSize);
   } else {
     // argument[0] is at base_reg_ + displacement_to_last_argument +
     // argument_count_reg_ * times_pointer_size + (receiver - 1) * kPointerSize.
     return Operand(base_reg_, argument_count_reg_, times_pointer_size,
         displacement_to_last_argument + (receiver - 1 - index) * kPointerSize);
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64