From ecc6022e880cb4cc216b775f749413237d2baf27 Mon Sep 17 00:00:00 2001
From: Phil Ringnalda <philringnalda@gmail.com>
Date: Wed, 16 Oct 2013 09:43:19 -0700
Subject: [PATCH] Backed out changeset b158656d754e (bug 921035) for test
 bustage

---
 js/src/jit-test/tests/ion/bug921035.js | 12 ------------
 js/src/jit/IonAnalysis.cpp             | 15 +++------------
 2 files changed, 3 insertions(+), 24 deletions(-)
 delete mode 100644 js/src/jit-test/tests/ion/bug921035.js

diff --git a/js/src/jit-test/tests/ion/bug921035.js b/js/src/jit-test/tests/ion/bug921035.js
deleted file mode 100644
index 41dc8aa96708..000000000000
--- a/js/src/jit-test/tests/ion/bug921035.js
+++ /dev/null
@@ -1,12 +0,0 @@
-function $ERROR() {}
-function testMultipleArgumentsObjects() {
-    var testargs = arguments;
-    var f = function (which) {
-        var args = [ testargs ];
-        return args[which][0];
-    };
-    var arr = [0, 0, 0, 0, 1];
-    for (var i = 0; i < arr.length; i++)
-        $ERROR[i] = f(arr[i]);
-}
-testMultipleArgumentsObjects()
diff --git a/js/src/jit/IonAnalysis.cpp b/js/src/jit/IonAnalysis.cpp
index c21bc213c772..a2c9f4a38f08 100644
--- a/js/src/jit/IonAnalysis.cpp
+++ b/js/src/jit/IonAnalysis.cpp
@@ -211,25 +211,16 @@ IsPhiObservable(MPhi *phi, Observability observe)
         break;
     }
 
+    // If the Phi is of the |this| value, it must always be observable.
     uint32_t slot = phi->slot();
     CompileInfo &info = phi->block()->info();
-    JSFunction *fun = info.fun();
-
-    // If the Phi is of the |this| value, it must always be observable.
-    if (fun && slot == info.thisSlot())
-        return true;
-
-    // If the function is heavyweight, and the Phi is of the |scopeChain|
-    // value, and the function may need an arguments object, then make sure
-    // to preserve the scope chain, because it may be needed to construct the
-    // arguments object during bailout.
-    if (fun && fun->isHeavyweight() && info.hasArguments() && slot == info.scopeChainSlot())
+    if (info.fun() && slot == info.thisSlot())
         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.
     // For inlined frames this is not needed, as they are captured in the inlineResumePoint.
-    if (fun && info.hasArguments()) {
+    if (info.fun() && info.hasArguments()) {
         uint32_t first = info.firstArgSlot();
         if (first <= slot && slot - first < info.nargs()) {
             // If arguments obj aliases formals, then the arg slots will never be used.