diff --git a/js/src/jscompartment.cpp b/js/src/jscompartment.cpp
index dd23e01383b..35592428010 100644
--- a/js/src/jscompartment.cpp
+++ b/js/src/jscompartment.cpp
@@ -491,7 +491,7 @@ JSCompartment::markTypes(JSTracer *trc)
 }
 
 void
-JSCompartment::discardJitCode(FreeOp *fop, bool discardConstraints)
+JSCompartment::discardJitCode(FreeOp *fop)
 {
 #ifdef JS_METHODJIT
 
@@ -527,7 +527,7 @@ JSCompartment::discardJitCode(FreeOp *fop, bool discardConstraints)
             script->resetUseCount();
         }
 
-        types.sweepCompilerOutputs(fop, discardConstraints);
+        types.sweepCompilerOutputs(fop);
     }
 
 #endif /* JS_METHODJIT */
@@ -547,7 +547,7 @@ JSCompartment::sweep(FreeOp *fop, bool releaseTypes)
 {
     {
         gcstats::AutoPhase ap(rt->gcStats, gcstats::PHASE_SWEEP_DISCARD_CODE);
-        discardJitCode(fop, !activeAnalysis && !gcPreserveCode);
+        discardJitCode(fop);
     }
 
     /* This function includes itself in PHASE_SWEEP_TABLES. */
@@ -581,7 +581,6 @@ JSCompartment::sweep(FreeOp *fop, bool releaseTypes)
     }
 
     if (!activeAnalysis && !gcPreserveCode) {
-        JS_ASSERT(!types.constrainedOutputs);
         gcstats::AutoPhase ap(rt->gcStats, gcstats::PHASE_DISCARD_ANALYSIS);
 
         /*
diff --git a/js/src/jscompartment.h b/js/src/jscompartment.h
index 9422ee8e506..0fa4993dec0 100644
--- a/js/src/jscompartment.h
+++ b/js/src/jscompartment.h
@@ -347,7 +347,7 @@ struct JSCompartment
 
     void mark(JSTracer *trc);
     void markTypes(JSTracer *trc);
-    void discardJitCode(js::FreeOp *fop, bool discardConstraints);
+    void discardJitCode(js::FreeOp *fop);
     bool isDiscardingJitCode(JSTracer *trc);
     void sweep(js::FreeOp *fop, bool releaseTypes);
     void sweepCrossCompartmentWrappers();
diff --git a/js/src/jsgc.cpp b/js/src/jsgc.cpp
index 09c6ededab3..e133346ea1e 100644
--- a/js/src/jsgc.cpp
+++ b/js/src/jsgc.cpp
@@ -3351,7 +3351,7 @@ BeginMarkPhase(JSRuntime *rt)
     if (rt->gcIsIncremental) {
         for (GCCompartmentsIter c(rt); !c.done(); c.next()) {
             gcstats::AutoPhase ap(rt->gcStats, gcstats::PHASE_MARK_DISCARD_CODE);
-            c->discardJitCode(rt->defaultFreeOp(), false);
+            c->discardJitCode(rt->defaultFreeOp());
         }
     }
 
diff --git a/js/src/jsinfer.cpp b/js/src/jsinfer.cpp
index 55094b78888..e33258f9b34 100644
--- a/js/src/jsinfer.cpp
+++ b/js/src/jsinfer.cpp
@@ -5849,16 +5849,16 @@ TypeCompartment::sweep(FreeOp *fop)
     pendingArray = NULL;
     pendingCapacity = 0;
 
-    sweepCompilerOutputs(fop, true);
+    sweepCompilerOutputs(fop);
 }
 
 void
-TypeCompartment::sweepCompilerOutputs(FreeOp *fop, bool discardConstraints)
+TypeCompartment::sweepCompilerOutputs(FreeOp *fop)
 {
     if (constrainedOutputs) {
         bool isCompiling = compiledInfo.outputIndex != RecompileInfo::NoCompilerRunning;
-        if (discardConstraints) {
-            JS_ASSERT(!isCompiling);
+        if (isCompiling && !compartment()->activeAnalysis)
+        {
 #if DEBUG
             for (unsigned i = 0; i < constrainedOutputs->length(); i++) {
                 CompilerOutput &co = (*constrainedOutputs)[i];
@@ -5869,9 +5869,10 @@ TypeCompartment::sweepCompilerOutputs(FreeOp *fop, bool discardConstraints)
             fop->delete_(constrainedOutputs);
             constrainedOutputs = NULL;
         } else {
-            // Constraints have captured an index to the constrained outputs
-            // vector.  Thus, we invalidate all compilations except the one
-            // which is potentially running now.
+            // A Compilation is running and the AutoEnterCompilation class has
+            // captured an index into the constrained outputs vector and
+            // potentially created multiple types with this index.  Instead, we
+            // invalidate all compilations except the one running now.
             size_t len = constrainedOutputs->length();
             for (unsigned i = 0; i < len; i++) {
                 if (i != compiledInfo.outputIndex) {
diff --git a/js/src/jsinfer.h b/js/src/jsinfer.h
index a746cc6db32..b39eb1cd139 100644
--- a/js/src/jsinfer.h
+++ b/js/src/jsinfer.h
@@ -1180,7 +1180,7 @@ struct TypeCompartment
     void markSetsUnknown(JSContext *cx, TypeObject *obj);
 
     void sweep(FreeOp *fop);
-    void sweepCompilerOutputs(FreeOp *fop, bool discardConstraints);
+    void sweepCompilerOutputs(FreeOp *fop);
     void finalizeObjects();
 };
 
diff --git a/js/src/jsinferinlines.h b/js/src/jsinferinlines.h
index 7bd7bf1ee38..4361480cd49 100644
--- a/js/src/jsinferinlines.h
+++ b/js/src/jsinferinlines.h
@@ -336,7 +336,6 @@ struct AutoEnterCompilation
         info(cx->compartment->types.compiledInfo),
         mode(mode)
     {
-        JS_ASSERT(cx->compartment->activeAnalysis);
         JS_ASSERT(info.outputIndex == RecompileInfo::NoCompilerRunning);
     }