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

src/mips/macro-assembler-mips.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 4567 matching lines @@
   LoadRoot(at, Heap::kUndefinedValueRootIndex);
   Branch(not_int32, ne, object, Operand(at));
   // |undefined| is truncated to 0.
   li(dst, Operand(Smi::FromInt(0)));
   // Fall through.
 
   bind(&done);
 }
 
 
+void MacroAssembler::Prologue(PrologueFrameMode frame_mode) {
+  if (frame_mode == BUILD_STUB_FRAME) {
+    Push(ra, fp, cp);
+    Push(Smi::FromInt(StackFrame::STUB));
+    // Adjust FP to point to saved FP.
+    Addu(fp, sp, Operand(2 * kPointerSize));
+  } else {
+    PredictableCodeSizeScope predictible_code_size_scope(
+      this, kNoCodeAgeSequenceLength * Assembler::kInstrSize);
+    // The following three instructions must remain together and unmodified
+    // for code aging to work properly.
+    if (FLAG_optimize_for_size && FLAG_age_code) {
+      // Pre-age the code.
+      Code* stub = Code::GetPreAgedCodeAgeStub(isolate());
+      nop(Assembler::CODE_AGE_MARKER_NOP);
+      // Save the function's original return address
+      // (it will be clobbered by Call(t9))
+      mov(at, ra);
+      // Load the stub address to t9 and call it
+      li(t9,
+         Operand(reinterpret_cast<uint32_t>(stub->instruction_start())));
+      Call(t9);
+      // Record the stub address in the empty space for GetCodeAgeAndParity()
+      dd(reinterpret_cast<uint32_t>(stub->instruction_start()));
+    } else {
+      Push(ra, fp, cp, a1);
+      nop(Assembler::CODE_AGE_SEQUENCE_NOP);
+      // Adjust fp to point to caller's fp.
+      Addu(fp, sp, Operand(2 * kPointerSize));
+    }
+  }
+}
+
+
 void MacroAssembler::EnterFrame(StackFrame::Type type) {
   addiu(sp, sp, -5 * kPointerSize);
   li(t8, Operand(Smi::FromInt(type)));
   li(t9, Operand(CodeObject()), CONSTANT_SIZE);
   sw(ra, MemOperand(sp, 4 * kPointerSize));
   sw(fp, MemOperand(sp, 3 * kPointerSize));
   sw(cp, MemOperand(sp, 2 * kPointerSize));
   sw(t8, MemOperand(sp, 1 * kPointerSize));
   sw(t9, MemOperand(sp, 0 * kPointerSize));
   addiu(fp, sp, 3 * kPointerSize);
@@ skipping 1077 matching lines @@
        opcode == BGTZL);
   opcode = (cond == eq) ? BEQ : BNE;
   instr = (instr & ~kOpcodeMask) | opcode;
   masm_.emit(instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS