From 7a071fabd74fa6335cdbdb0ee6433e485450a816 Mon Sep 17 00:00:00 2001
From: "Nicolas B. Pierron" <nicolas.b.pierron@mozilla.com>
Date: Tue, 4 Dec 2012 17:34:38 -0800
Subject: [PATCH] Bug 810253 - Add tests and comments. r=dvander

---
 js/src/ion/IonAnalysis.cpp             | 2 ++
 js/src/jit-test/tests/ion/bug810253.js | 8 ++++++++
 2 files changed, 10 insertions(+)
 create mode 100644 js/src/jit-test/tests/ion/bug810253.js

diff --git a/js/src/ion/IonAnalysis.cpp b/js/src/ion/IonAnalysis.cpp
index c6d1880fea5..72f900ca884 100644
--- a/js/src/ion/IonAnalysis.cpp
+++ b/js/src/ion/IonAnalysis.cpp
@@ -177,6 +177,8 @@ IsPhiObservable(MPhi *phi)
     if (slot == 1)
         return true;
 
+    // If the Phi is one of the formal argument, and we are using an argument
+    // object in the function.  The phi might be observable after a bailout.
     CompileInfo &info = phi->block()->info();
     if (info.fun() && info.hasArguments()) {
         // We do not support arguments object inside inline frames yet.
diff --git a/js/src/jit-test/tests/ion/bug810253.js b/js/src/jit-test/tests/ion/bug810253.js
new file mode 100644
index 00000000000..2c8685fd919
--- /dev/null
+++ b/js/src/jit-test/tests/ion/bug810253.js
@@ -0,0 +1,8 @@
+function f(x) {
+    // Enter via OSR.
+    for (var j = 0; j < 100; j++) { };
+
+    for (var i = 0; i < arguments.length; i++)
+        assertEq(arguments[i], i);
+};
+f(0, 1, 2, 3);