diff -r ce072f38628c -r fb3cd08bc7fb src/Stack.cpp
--- a/src/Stack.cpp	Sat Dec 22 16:42:20 2012 -0800
+++ b/src/Stack.cpp	Sat Dec 22 18:22:14 2012 -0800
@@ -67,7 +67,9 @@
 static inline size_t
 SizeForCodeFrame(Code *code)
 {
-    return sizeof(Frame) + sizeof(LocalSlot) * (code->nlocals() + code->maxStackDepth());
+    return sizeof(Frame) + 
+           sizeof(void *) * (code->maxLoopDepth()) +
+           sizeof(LocalSlot) * (code->nlocals() + code->maxStackDepth());
 }
 
 bool
@@ -199,6 +201,22 @@
     top_.fp = top_.fp->prev();
 }
 
+void
+Frame::enterLoop(Zone *zone)
+{
+    assert(loopDepth_ < code_->maxLoopDepth());
+    loopStack()[loopDepth_] = zone->heap().lifoPosition();
+    loopDepth_++;
+}
+
+void
+Frame::leaveLoop(Zone *zone)
+{
+    assert(loopDepth_ > 0);
+    loopDepth_--;
+    zone->heap().unwindLifo(loopStack()[loopDepth_]);
+}
+
 void
 Frame::accept(VirtualObjectVisitor *visitor)
 {