From 32abf472e03f84fa4e99b5e37ae870317f190b3d Mon Sep 17 00:00:00 2001
From: Shu-yu Guo <shu@rfrn.org>
Date: Thu, 26 Mar 2015 14:16:58 -0700
Subject: [PATCH] Bug 1147224 - Only keep the optimization information of the
 last time IonBuilder visits a bytecode location. (r=djvj)

---
 js/src/jit/OptimizationTracking.cpp | 5 +++++
 js/src/jit/OptimizationTracking.h   | 6 ++++++
 2 files changed, 11 insertions(+)

diff --git a/js/src/jit/OptimizationTracking.cpp b/js/src/jit/OptimizationTracking.cpp
index be78e56a7b3..765400df58b 100644
--- a/js/src/jit/OptimizationTracking.cpp
+++ b/js/src/jit/OptimizationTracking.cpp
@@ -1040,6 +1040,11 @@ IonBuilder::startTrackingOptimizations()
             // OOMs are handled as if optimization tracking were turned off.
             if (!trackedOptimizationSites_.append(site))
                 site = nullptr;
+        } else {
+            // The same bytecode may be visited multiple times (see
+            // restartLoop). Only the last time matters, so clear any previous
+            // tracked optimizations.
+            site->optimizations()->clear();
         }
 
         if (site)
diff --git a/js/src/jit/OptimizationTracking.h b/js/src/jit/OptimizationTracking.h
index a2b65e41b47..8be16a3f4ac 100644
--- a/js/src/jit/OptimizationTracking.h
+++ b/js/src/jit/OptimizationTracking.h
@@ -107,6 +107,12 @@ class TrackedOptimizations : public TempObject
         currentAttempt_(UINT32_MAX)
     { }
 
+    void clear() {
+        types_.clear();
+        attempts_.clear();
+        currentAttempt_ = UINT32_MAX;
+    }
+
     bool trackTypeInfo(OptimizationTypeInfo &&ty);
 
     bool trackAttempt(JS::TrackedStrategy strategy);