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

src/arm/full-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 150 matching lines @@
   // MANUAL indicates that the scope shouldn't actually generate code to set up
   // the frame (that is done below).
   FrameScope frame_scope(masm_, StackFrame::MANUAL);
 
   info->set_prologue_offset(masm_->pc_offset());
   {
     PredictableCodeSizeScope predictible_code_size_scope(
         masm_, kNoCodeAgeSequenceLength * Assembler::kInstrSize);
     // The following three instructions must remain together and unmodified
     // for code aging to work properly.
-    __ stm(db_w, sp, r1.bit() | cp.bit() | fp.bit() | lr.bit());
-    __ nop(ip.code());
-    // Adjust FP to point to saved FP.
-    __ add(fp, sp, Operand(2 * kPointerSize));
+    if (FLAG_optimize_for_size) {
+      // Pre-age the code.
+      Code* stub = Code::GetPreAgedCodeAgeStub(isolate());
+      __ add(r0, pc, Operand(-8));
+      __ ldr(pc, MemOperand(pc, -4));
+      __ dd(reinterpret_cast<uint32_t>(stub->instruction_start()));
+    } else {
+      // The following three instructions must remain together and unmodified
+      // for code aging to work properly.
+      __ stm(db_w, sp, r1.bit() | cp.bit() | fp.bit() | lr.bit());
+      __ nop(ip.code());
+      // Adjust FP to point to saved FP.
+      __ add(fp, sp, Operand(2 * kPointerSize));
+    }
   }
   info->AddNoFrameRange(0, masm_->pc_offset());
 
   { Comment cmnt(masm_, "[ Allocate locals");
     int locals_count = info->scope()->num_stack_slots();
     // Generators allocate locals, if any, in context slots.
     ASSERT(!info->function()->is_generator() || locals_count == 0);
     if (locals_count > 0) {
       __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
       for (int i = 0; i < locals_count; i++) {
@@ skipping 4703 matching lines @@
   *context_length = 0;
   return previous_;
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM