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 146 matching lines @@
     __ bind(&ok);
   }
 
   // Open a frame scope to indicate that there is a frame on the stack.  The
   // 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(

[danno, 2013/10/14 18:53:14]

For this and other platforms, can you please consolidate the logic for emitting
the prologue into the macros assembler? Everything from PredictableCodeSizeScope
to the end of your change is the same for full codegen and crankshaft. You will
probably need a single parameter "for_generated_stub" to distinguish the
JSFunction pointer.

[rmcilroy, 2013/10/15 17:03:44]

Done.

         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 && FLAG_age_code) {
+      // 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 {
+      __ 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 4786 matching lines @@
   ASSERT(Memory::uint32_at(interrupt_address_pointer) ==
          reinterpret_cast<uint32_t>(
              isolate->builtins()->OsrAfterStackCheck()->entry()));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM