Age code to allow reclaiming old unexecuted functions

src/ia32/builtins-ia32.cc

Index: src/ia32/builtins-ia32.cc
diff --git a/src/ia32/builtins-ia32.cc b/src/ia32/builtins-ia32.cc
index 9bc15e90986c54048aa950b7bac9b3391ba0c0be..01785bb53e25400eda7668ffd94fb3e12088a374 100644
--- a/src/ia32/builtins-ia32.cc
+++ b/src/ia32/builtins-ia32.cc
@@ -538,6 +538,42 @@ void Builtins::Generate_LazyRecompile(MacroAssembler* masm) {
 }
 
 
+static void GenerateMakeCodeYoungAgainCommon(MacroAssembler* masm) {
+  // For now, we are relying on the fact that make_code_young doesn't do any
+  // garbage collection which allows us to save/restore the registers without
+  // worrying about which of them contain pointers. We also don't build an
+  // internal frame to make the code faster, since we shouldn't have to do stack
+  // crawls in MakeCodeYoung. This seems a bit fragile.
+
+  // Re-execute the code that was patched back to the young age when
+  // the stub returns.
+  __ sub(Operand(esp, 0), Immediate(5));
+  __ pushad();
+  __ mov(eax, Operand(esp, 8 * kPointerSize));
+  {
+    FrameScope scope(masm, StackFrame::MANUAL);
+    __ PrepareCallCFunction(1, ebx);
+    __ mov(Operand(esp, 0), eax);
+    __ CallCFunction(
+        ExternalReference::get_make_code_young_function(masm->isolate()), 1);
+  }
+  __ popad();
+  __ ret(0);
+}
+
+#define DEFINE_CODE_AGE_BUILTIN_GENERATOR(C)                 \
+void Builtins::Generate_Make##C##CodeYoungAgainEvenMarking(  \
+    MacroAssembler* masm) {                                  \
+  GenerateMakeCodeYoungAgainCommon(masm);                    \
+}                                                            \
+void Builtins::Generate_Make##C##CodeYoungAgainOddMarking(   \
+    MacroAssembler* masm) {                                  \
+  GenerateMakeCodeYoungAgainCommon(masm);                    \
+}
+CODE_AGE_LIST(DEFINE_CODE_AGE_BUILTIN_GENERATOR)
+#undef DEFINE_CODE_AGE_BUILTIN_GENERATOR
+
+
 static void Generate_NotifyDeoptimizedHelper(MacroAssembler* masm,
                                              Deoptimizer::BailoutType type) {
   {