Merge pull request #998 from MoonchildProductions/master

Merge master into Sync-weave

27 files changed, 126 insertions, 510 deletions

diff --git a/js/src/frontend/Parser.cpp b/js/src/frontend/Parser.cpp
index 7bfab87a3..209265a58 100644
--- a/js/src/frontend/Parser.cpp
+++ b/js/src/frontend/Parser.cpp
@@ -3463,7 +3463,6 @@ Parser<ParseHandler>::functionFormalParametersAndBody(InHandling inHandling,
 
         if (kind != Arrow) {
 #if JS_HAS_EXPR_CLOSURES
-            addTelemetry(JSCompartment::DeprecatedExpressionClosure);
             if (!warnOnceAboutExprClosure())
                 return false;
 #else
@@ -5545,7 +5544,6 @@ Parser<ParseHandler>::forStatement(YieldHandling yieldHandling)
         if (matched) {
             iflags = JSITER_FOREACH;
             isForEach = true;
-            addTelemetry(JSCompartment::DeprecatedForEach);
             if (!warnOnceAboutForEach())
                 return null();
         }
@@ -6077,7 +6075,6 @@ Parser<ParseHandler>::yieldExpression(InHandling inHandling)
         }
 
         pc->functionBox()->setGeneratorKind(LegacyGenerator);
-        addTelemetry(JSCompartment::DeprecatedLegacyGenerator);
 
         MOZ_FALLTHROUGH;
 
@@ -9589,16 +9586,6 @@ Parser<ParseHandler>::exprInParens(InHandling inHandling, YieldHandling yieldHan
 }
 
 template <typename ParseHandler>
-void
-Parser<ParseHandler>::addTelemetry(JSCompartment::DeprecatedLanguageExtension e)
-{
-    JSContext* cx = context->maybeJSContext();
-    if (!cx)
-        return;
-    cx->compartment()->addTelemetry(getFilename(), e);
-}
-
-template <typename ParseHandler>
 bool
 Parser<ParseHandler>::warnOnceAboutExprClosure()
 {
diff --git a/js/src/frontend/Parser.h b/js/src/frontend/Parser.h
index b58b021cd..12642fad8 100644
--- a/js/src/frontend/Parser.h
+++ b/js/src/frontend/Parser.h
@@ -1420,8 +1420,6 @@ class Parser final : private JS::AutoGCRooter, public StrictModeGetter
 
     bool asmJS(Node list);
 
-    void addTelemetry(JSCompartment::DeprecatedLanguageExtension e);
-
     bool warnOnceAboutExprClosure();
     bool warnOnceAboutForEach();
 };
diff --git a/js/src/gc/Nursery.cpp b/js/src/gc/Nursery.cpp
index 55ca5a059..ea4350fb8 100644
--- a/js/src/gc/Nursery.cpp
+++ b/js/src/gc/Nursery.cpp
@@ -530,7 +530,6 @@ js::Nursery::collect(JSRuntime* rt, JS::gcreason::Reason reason)
     // the nursery is full, look for object groups that are getting promoted
     // excessively and try to pretenure them.
     maybeStartProfile(ProfileKey::Pretenure);
-    uint32_t pretenureCount = 0;
     if (promotionRate > 0.8 || reason == JS::gcreason::FULL_STORE_BUFFER) {
         JSContext* cx = rt->contextFromMainThread();
         for (auto& entry : tenureCounts.entries) {
@@ -539,7 +538,6 @@ js::Nursery::collect(JSRuntime* rt, JS::gcreason::Reason reason)
                 if (group->canPreTenure()) {
                     AutoCompartment ac(cx, group->compartment());
                     group->setShouldPreTenure(cx);
-                    pretenureCount++;
                 }
             }
         }
@@ -556,12 +554,6 @@ js::Nursery::collect(JSRuntime* rt, JS::gcreason::Reason reason)
     minorGcCount_++;
 
     int64_t totalTime = profileTimes_[ProfileKey::Total];
-    rt->addTelemetry(JS_TELEMETRY_GC_MINOR_US, totalTime);
-    rt->addTelemetry(JS_TELEMETRY_GC_MINOR_REASON, reason);
-    if (totalTime > 1000)
-        rt->addTelemetry(JS_TELEMETRY_GC_MINOR_REASON_LONG, reason);
-    rt->addTelemetry(JS_TELEMETRY_GC_NURSERY_BYTES, sizeOfHeapCommitted());
-    rt->addTelemetry(JS_TELEMETRY_GC_PRETENURE_COUNT, pretenureCount);
 
     rt->gc.stats.endNurseryCollection(reason);
     TraceMinorGCEnd();
diff --git a/js/src/gc/Statistics.cpp b/js/src/gc/Statistics.cpp
index 19f9986dd..8a9f4e135 100644
--- a/js/src/gc/Statistics.cpp
+++ b/js/src/gc/Statistics.cpp
@@ -34,13 +34,6 @@ using mozilla::MakeRange;
 using mozilla::PodArrayZero;
 using mozilla::PodZero;
 
-/*
- * If this fails, then you can either delete this assertion and allow all
- * larger-numbered reasons to pile up in the last telemetry bucket, or switch
- * to GC_REASON_3 and bump the max value.
- */
-JS_STATIC_ASSERT(JS::gcreason::NUM_TELEMETRY_REASONS >= JS::gcreason::NUM_REASONS);
-
 const char*
 js::gcstats::ExplainInvocationKind(JSGCInvocationKind gckind)
 {
@@ -92,7 +85,6 @@ struct PhaseInfo
     Phase index;
     const char* name;
     Phase parent;
-    const uint8_t telemetryBucket;
 };
 
 // The zeroth entry in the timing arrays is used for phases that have a
@@ -134,78 +126,74 @@ struct DagChildEdge {
  */
 
 static const PhaseInfo phases[] = {
-    { PHASE_MUTATOR, "Mutator Running", PHASE_NO_PARENT, 0 },
-    { PHASE_GC_BEGIN, "Begin Callback", PHASE_NO_PARENT, 1 },
-    { PHASE_WAIT_BACKGROUND_THREAD, "Wait Background Thread", PHASE_NO_PARENT, 2 },
-    { PHASE_MARK_DISCARD_CODE, "Mark Discard Code", PHASE_NO_PARENT, 3 },
-    { PHASE_RELAZIFY_FUNCTIONS, "Relazify Functions", PHASE_NO_PARENT, 4 },
-    { PHASE_PURGE, "Purge", PHASE_NO_PARENT, 5 },
-    { PHASE_MARK, "Mark", PHASE_NO_PARENT, 6 },
-        { PHASE_UNMARK, "Unmark", PHASE_MARK, 7 },
+    { PHASE_MUTATOR, "Mutator Running", PHASE_NO_PARENT },
+    { PHASE_GC_BEGIN, "Begin Callback", PHASE_NO_PARENT },
+    { PHASE_WAIT_BACKGROUND_THREAD, "Wait Background Thread", PHASE_NO_PARENT },
+    { PHASE_MARK_DISCARD_CODE, "Mark Discard Code", PHASE_NO_PARENT },
+    { PHASE_RELAZIFY_FUNCTIONS, "Relazify Functions", PHASE_NO_PARENT },
+    { PHASE_PURGE, "Purge", PHASE_NO_PARENT },
+    { PHASE_MARK, "Mark", PHASE_NO_PARENT },
+        { PHASE_UNMARK, "Unmark", PHASE_MARK },
         /* PHASE_MARK_ROOTS */
-        { PHASE_MARK_DELAYED, "Mark Delayed", PHASE_MARK, 8 },
-    { PHASE_SWEEP, "Sweep", PHASE_NO_PARENT, 9 },
-        { PHASE_SWEEP_MARK, "Mark During Sweeping", PHASE_SWEEP, 10 },
-            { PHASE_SWEEP_MARK_TYPES, "Mark Types During Sweeping", PHASE_SWEEP_MARK, 11 },
-            { PHASE_SWEEP_MARK_INCOMING_BLACK, "Mark Incoming Black Pointers", PHASE_SWEEP_MARK, 12 },
-            { PHASE_SWEEP_MARK_WEAK, "Mark Weak", PHASE_SWEEP_MARK, 13 },
-            { PHASE_SWEEP_MARK_INCOMING_GRAY, "Mark Incoming Gray Pointers", PHASE_SWEEP_MARK, 14 },
-            { PHASE_SWEEP_MARK_GRAY, "Mark Gray", PHASE_SWEEP_MARK, 15 },
-            { PHASE_SWEEP_MARK_GRAY_WEAK, "Mark Gray and Weak", PHASE_SWEEP_MARK, 16 },
-        { PHASE_FINALIZE_START, "Finalize Start Callbacks", PHASE_SWEEP, 17 },
-            { PHASE_WEAK_ZONEGROUP_CALLBACK, "Per-Slice Weak Callback", PHASE_FINALIZE_START, 57 },
-            { PHASE_WEAK_COMPARTMENT_CALLBACK, "Per-Compartment Weak Callback", PHASE_FINALIZE_START, 58 },
-        { PHASE_SWEEP_ATOMS, "Sweep Atoms", PHASE_SWEEP, 18 },
-        { PHASE_SWEEP_SYMBOL_REGISTRY, "Sweep Symbol Registry", PHASE_SWEEP, 19 },
-        { PHASE_SWEEP_COMPARTMENTS, "Sweep Compartments", PHASE_SWEEP, 20 },
-            { PHASE_SWEEP_DISCARD_CODE, "Sweep Discard Code", PHASE_SWEEP_COMPARTMENTS, 21 },
-            { PHASE_SWEEP_INNER_VIEWS, "Sweep Inner Views", PHASE_SWEEP_COMPARTMENTS, 22 },
-            { PHASE_SWEEP_CC_WRAPPER, "Sweep Cross Compartment Wrappers", PHASE_SWEEP_COMPARTMENTS, 23 },
-            { PHASE_SWEEP_BASE_SHAPE, "Sweep Base Shapes", PHASE_SWEEP_COMPARTMENTS, 24 },
-            { PHASE_SWEEP_INITIAL_SHAPE, "Sweep Initial Shapes", PHASE_SWEEP_COMPARTMENTS, 25 },
-            { PHASE_SWEEP_TYPE_OBJECT, "Sweep Type Objects", PHASE_SWEEP_COMPARTMENTS, 26 },
-            { PHASE_SWEEP_BREAKPOINT, "Sweep Breakpoints", PHASE_SWEEP_COMPARTMENTS, 27 },
-            { PHASE_SWEEP_REGEXP, "Sweep Regexps", PHASE_SWEEP_COMPARTMENTS, 28 },
-            { PHASE_SWEEP_MISC, "Sweep Miscellaneous", PHASE_SWEEP_COMPARTMENTS, 29 },
-            { PHASE_SWEEP_TYPES, "Sweep type information", PHASE_SWEEP_COMPARTMENTS, 30 },
-                { PHASE_SWEEP_TYPES_BEGIN, "Sweep type tables and compilations", PHASE_SWEEP_TYPES, 31 },
-                { PHASE_SWEEP_TYPES_END, "Free type arena", PHASE_SWEEP_TYPES, 32 },
-        { PHASE_SWEEP_OBJECT, "Sweep Object", PHASE_SWEEP, 33 },
-        { PHASE_SWEEP_STRING, "Sweep String", PHASE_SWEEP, 34 },
-        { PHASE_SWEEP_SCRIPT, "Sweep Script", PHASE_SWEEP, 35 },
-        { PHASE_SWEEP_SCOPE, "Sweep Scope", PHASE_SWEEP, 59 },
-        { PHASE_SWEEP_SHAPE, "Sweep Shape", PHASE_SWEEP, 36 },
-        { PHASE_SWEEP_JITCODE, "Sweep JIT code", PHASE_SWEEP, 37 },
-        { PHASE_FINALIZE_END, "Finalize End Callback", PHASE_SWEEP, 38 },
-        { PHASE_DESTROY, "Deallocate", PHASE_SWEEP, 39 },
-    { PHASE_COMPACT, "Compact", PHASE_NO_PARENT, 40 },
-        { PHASE_COMPACT_MOVE, "Compact Move", PHASE_COMPACT, 41 },
-        { PHASE_COMPACT_UPDATE, "Compact Update", PHASE_COMPACT, 42 },
+        { PHASE_MARK_DELAYED, "Mark Delayed", PHASE_MARK },
+    { PHASE_SWEEP, "Sweep", PHASE_NO_PARENT },
+        { PHASE_SWEEP_MARK, "Mark During Sweeping", PHASE_SWEEP },
+            { PHASE_SWEEP_MARK_TYPES, "Mark Types During Sweeping", PHASE_SWEEP_MARK },
+            { PHASE_SWEEP_MARK_INCOMING_BLACK, "Mark Incoming Black Pointers", PHASE_SWEEP_MARK },
+            { PHASE_SWEEP_MARK_WEAK, "Mark Weak", PHASE_SWEEP_MARK },
+            { PHASE_SWEEP_MARK_INCOMING_GRAY, "Mark Incoming Gray Pointers", PHASE_SWEEP_MARK },
+            { PHASE_SWEEP_MARK_GRAY, "Mark Gray", PHASE_SWEEP_MARK },
+            { PHASE_SWEEP_MARK_GRAY_WEAK, "Mark Gray and Weak", PHASE_SWEEP_MARK },
+        { PHASE_FINALIZE_START, "Finalize Start Callbacks", PHASE_SWEEP },
+            { PHASE_WEAK_ZONEGROUP_CALLBACK, "Per-Slice Weak Callback", PHASE_FINALIZE_START },
+            { PHASE_WEAK_COMPARTMENT_CALLBACK, "Per-Compartment Weak Callback", PHASE_FINALIZE_START },
+        { PHASE_SWEEP_ATOMS, "Sweep Atoms", PHASE_SWEEP },
+        { PHASE_SWEEP_SYMBOL_REGISTRY, "Sweep Symbol Registry", PHASE_SWEEP },
+        { PHASE_SWEEP_COMPARTMENTS, "Sweep Compartments", PHASE_SWEEP },
+            { PHASE_SWEEP_DISCARD_CODE, "Sweep Discard Code", PHASE_SWEEP_COMPARTMENTS },
+            { PHASE_SWEEP_INNER_VIEWS, "Sweep Inner Views", PHASE_SWEEP_COMPARTMENTS },
+            { PHASE_SWEEP_CC_WRAPPER, "Sweep Cross Compartment Wrappers", PHASE_SWEEP_COMPARTMENTS },
+            { PHASE_SWEEP_BASE_SHAPE, "Sweep Base Shapes", PHASE_SWEEP_COMPARTMENTS },
+            { PHASE_SWEEP_INITIAL_SHAPE, "Sweep Initial Shapes", PHASE_SWEEP_COMPARTMENTS },
+            { PHASE_SWEEP_TYPE_OBJECT, "Sweep Type Objects", PHASE_SWEEP_COMPARTMENTS },
+            { PHASE_SWEEP_BREAKPOINT, "Sweep Breakpoints", PHASE_SWEEP_COMPARTMENTS },
+            { PHASE_SWEEP_REGEXP, "Sweep Regexps", PHASE_SWEEP_COMPARTMENTS },
+            { PHASE_SWEEP_MISC, "Sweep Miscellaneous", PHASE_SWEEP_COMPARTMENTS },
+            { PHASE_SWEEP_TYPES, "Sweep type information", PHASE_SWEEP_COMPARTMENTS },
+                { PHASE_SWEEP_TYPES_BEGIN, "Sweep type tables and compilations", PHASE_SWEEP_TYPES },
+                { PHASE_SWEEP_TYPES_END, "Free type arena", PHASE_SWEEP_TYPES },
+        { PHASE_SWEEP_OBJECT, "Sweep Object", PHASE_SWEEP },
+        { PHASE_SWEEP_STRING, "Sweep String", PHASE_SWEEP },
+        { PHASE_SWEEP_SCRIPT, "Sweep Script", PHASE_SWEEP },
+        { PHASE_SWEEP_SCOPE, "Sweep Scope", PHASE_SWEEP },
+        { PHASE_SWEEP_SHAPE, "Sweep Shape", PHASE_SWEEP },
+        { PHASE_SWEEP_JITCODE, "Sweep JIT code", PHASE_SWEEP },
+        { PHASE_FINALIZE_END, "Finalize End Callback", PHASE_SWEEP },
+        { PHASE_DESTROY, "Deallocate", PHASE_SWEEP },
+    { PHASE_COMPACT, "Compact", PHASE_NO_PARENT },
+        { PHASE_COMPACT_MOVE, "Compact Move", PHASE_COMPACT },
+        { PHASE_COMPACT_UPDATE, "Compact Update", PHASE_COMPACT },
             /* PHASE_MARK_ROOTS */
-            { PHASE_COMPACT_UPDATE_CELLS, "Compact Update Cells", PHASE_COMPACT_UPDATE, 43 },
-    { PHASE_GC_END, "End Callback", PHASE_NO_PARENT, 44 },
-    { PHASE_MINOR_GC, "All Minor GCs", PHASE_NO_PARENT, 45 },
+            { PHASE_COMPACT_UPDATE_CELLS, "Compact Update Cells", PHASE_COMPACT_UPDATE },
+    { PHASE_GC_END, "End Callback", PHASE_NO_PARENT },
+    { PHASE_MINOR_GC, "All Minor GCs", PHASE_NO_PARENT },
         /* PHASE_MARK_ROOTS */
-    { PHASE_EVICT_NURSERY, "Minor GCs to Evict Nursery", PHASE_NO_PARENT, 46 },
+    { PHASE_EVICT_NURSERY, "Minor GCs to Evict Nursery", PHASE_NO_PARENT },
         /* PHASE_MARK_ROOTS */
-    { PHASE_TRACE_HEAP, "Trace Heap", PHASE_NO_PARENT, 47 },
+    { PHASE_TRACE_HEAP, "Trace Heap", PHASE_NO_PARENT },
         /* PHASE_MARK_ROOTS */
-    { PHASE_BARRIER, "Barriers", PHASE_NO_PARENT, 55 },
-        { PHASE_UNMARK_GRAY, "Unmark gray", PHASE_BARRIER, 56 },
-    { PHASE_MARK_ROOTS, "Mark Roots", PHASE_MULTI_PARENTS, 48 },
-        { PHASE_BUFFER_GRAY_ROOTS, "Buffer Gray Roots", PHASE_MARK_ROOTS, 49 },
-        { PHASE_MARK_CCWS, "Mark Cross Compartment Wrappers", PHASE_MARK_ROOTS, 50 },
-        { PHASE_MARK_STACK, "Mark C and JS stacks", PHASE_MARK_ROOTS, 51 },
-        { PHASE_MARK_RUNTIME_DATA, "Mark Runtime-wide Data", PHASE_MARK_ROOTS, 52 },
-        { PHASE_MARK_EMBEDDING, "Mark Embedding", PHASE_MARK_ROOTS, 53 },
-        { PHASE_MARK_COMPARTMENTS, "Mark Compartments", PHASE_MARK_ROOTS, 54 },
-    { PHASE_PURGE_SHAPE_TABLES, "Purge ShapeTables", PHASE_NO_PARENT, 60 },
-
-    { PHASE_LIMIT, nullptr, PHASE_NO_PARENT, 60 }
-
-    // Current number of telemetryBuckets is 60. If you insert new phases
-    // somewhere, start at that number and count up. Do not change any existing
-    // numbers.
+    { PHASE_BARRIER, "Barriers", PHASE_NO_PARENT },
+        { PHASE_UNMARK_GRAY, "Unmark gray", PHASE_BARRIER },
+    { PHASE_MARK_ROOTS, "Mark Roots", PHASE_MULTI_PARENTS },
+        { PHASE_BUFFER_GRAY_ROOTS, "Buffer Gray Roots", PHASE_MARK_ROOTS },
+        { PHASE_MARK_CCWS, "Mark Cross Compartment Wrappers", PHASE_MARK_ROOTS },
+        { PHASE_MARK_STACK, "Mark C and JS stacks", PHASE_MARK_ROOTS },
+        { PHASE_MARK_RUNTIME_DATA, "Mark Runtime-wide Data", PHASE_MARK_ROOTS },
+        { PHASE_MARK_EMBEDDING, "Mark Embedding", PHASE_MARK_ROOTS },
+        { PHASE_MARK_COMPARTMENTS, "Mark Compartments", PHASE_MARK_ROOTS },
+    { PHASE_PURGE_SHAPE_TABLES, "Purge ShapeTables", PHASE_NO_PARENT },
+
+    { PHASE_LIMIT, nullptr, PHASE_NO_PARENT }
 };
 
 static ExtraPhaseInfo phaseExtra[PHASE_LIMIT] = { { 0, 0 } };
@@ -845,12 +833,6 @@ Statistics::~Statistics()
 /* static */ bool
 Statistics::initialize()
 {
-    for (size_t i = 0; i < PHASE_LIMIT; i++) {
-        MOZ_ASSERT(phases[i].index == i);
-        for (size_t j = 0; j < PHASE_LIMIT; j++)
-            MOZ_ASSERT_IF(i != j, phases[i].telemetryBucket != phases[j].telemetryBucket);
-    }
-
     // Create a static table of descendants for every phase with multiple
     // children. This assumes that all descendants come linearly in the
     // list, which is reasonable since full dags are not supported; any
@@ -925,32 +907,6 @@ Statistics::getMaxGCPauseSinceClear()
     return maxPauseInInterval;
 }
 
-// Sum up the time for a phase, including instances of the phase with different
-// parents.
-static int64_t
-SumPhase(Phase phase, const Statistics::PhaseTimeTable times)
-{
-    int64_t sum = 0;
-    for (auto i : MakeRange(Statistics::NumTimingArrays))
-        sum += times[i][phase];
-    return sum;
-}
-
-static Phase
-LongestPhase(const Statistics::PhaseTimeTable times)
-{
-    int64_t longestTime = 0;
-    Phase longestPhase = PHASE_NONE;
-    for (size_t i = 0; i < PHASE_LIMIT; ++i) {
-        int64_t phaseTime = SumPhase(Phase(i), times);
-        if (phaseTime > longestTime) {
-            longestTime = phaseTime;
-            longestPhase = Phase(i);
-        }
-    }
-    return longestPhase;
-}
-
 void
 Statistics::printStats()
 {
@@ -985,34 +941,6 @@ Statistics::endGC()
     int64_t total, longest;
     gcDuration(&total, &longest);
 
-    int64_t sccTotal, sccLongest;
-    sccDurations(&sccTotal, &sccLongest);
-
-    runtime->addTelemetry(JS_TELEMETRY_GC_IS_ZONE_GC, !zoneStats.isCollectingAllZones());
-    runtime->addTelemetry(JS_TELEMETRY_GC_MS, t(total));
-    runtime->addTelemetry(JS_TELEMETRY_GC_MAX_PAUSE_MS, t(longest));
-    int64_t markTotal = SumPhase(PHASE_MARK, phaseTimes);
-    int64_t markRootsTotal = SumPhase(PHASE_MARK_ROOTS, phaseTimes);
-    runtime->addTelemetry(JS_TELEMETRY_GC_MARK_MS, t(markTotal));
-    runtime->addTelemetry(JS_TELEMETRY_GC_SWEEP_MS, t(phaseTimes[PHASE_DAG_NONE][PHASE_SWEEP]));
-    if (runtime->gc.isCompactingGc()) {
-        runtime->addTelemetry(JS_TELEMETRY_GC_COMPACT_MS,
-                              t(phaseTimes[PHASE_DAG_NONE][PHASE_COMPACT]));
-    }
-    runtime->addTelemetry(JS_TELEMETRY_GC_MARK_ROOTS_MS, t(markRootsTotal));
-    runtime->addTelemetry(JS_TELEMETRY_GC_MARK_GRAY_MS, t(phaseTimes[PHASE_DAG_NONE][PHASE_SWEEP_MARK_GRAY]));
-    runtime->addTelemetry(JS_TELEMETRY_GC_NON_INCREMENTAL, nonincremental());
-    if (nonincremental())
-        runtime->addTelemetry(JS_TELEMETRY_GC_NON_INCREMENTAL_REASON, uint32_t(nonincrementalReason_));
-    runtime->addTelemetry(JS_TELEMETRY_GC_INCREMENTAL_DISABLED, !runtime->gc.isIncrementalGCAllowed());
-    runtime->addTelemetry(JS_TELEMETRY_GC_SCC_SWEEP_TOTAL_MS, t(sccTotal));
-    runtime->addTelemetry(JS_TELEMETRY_GC_SCC_SWEEP_MAX_PAUSE_MS, t(sccLongest));
-
-    if (!aborted) {
-        double mmu50 = computeMMU(50 * PRMJ_USEC_PER_MSEC);
-        runtime->addTelemetry(JS_TELEMETRY_GC_MMU_50, mmu50 * 100);
-    }
-
     if (fp)
         printStats();
 
@@ -1061,8 +989,6 @@ Statistics::beginSlice(const ZoneGCStats& zoneStats, JSGCInvocationKind gckind,
         return;
     }
 
-    runtime->addTelemetry(JS_TELEMETRY_GC_REASON, reason);
-
     // Slice callbacks should only fire for the outermost level.
     if (gcDepth == 1) {
         bool wasFullGC = zoneStats.isCollectingAllZones();
@@ -1082,25 +1008,6 @@ Statistics::endSlice()
         slices.back().endFaults = GetPageFaultCount();
         slices.back().finalState = runtime->gc.state();
 
-        int64_t sliceTime = slices.back().end - slices.back().start;
-        runtime->addTelemetry(JS_TELEMETRY_GC_SLICE_MS, t(sliceTime));
-        runtime->addTelemetry(JS_TELEMETRY_GC_RESET, slices.back().wasReset());
-        if (slices.back().wasReset())
-            runtime->addTelemetry(JS_TELEMETRY_GC_RESET_REASON, uint32_t(slices.back().resetReason));
-
-        if (slices.back().budget.isTimeBudget()) {
-            int64_t budget_ms = slices.back().budget.timeBudget.budget;
-            runtime->addTelemetry(JS_TELEMETRY_GC_BUDGET_MS, budget_ms);
-            if (budget_ms == runtime->gc.defaultSliceBudget())
-                runtime->addTelemetry(JS_TELEMETRY_GC_ANIMATION_MS, t(sliceTime));
-
-            // Record any phase that goes more than 2x over its budget.
-            if (sliceTime > 2 * budget_ms * 1000) {
-                Phase longest = LongestPhase(slices.back().phaseTimes);
-                runtime->addTelemetry(JS_TELEMETRY_GC_SLOW_PHASE, phases[longest].telemetryBucket);
-            }
-        }
-
         sliceCount_++;
     }
 
diff --git a/js/src/jsapi.h b/js/src/jsapi.h
index 30c4a835a..005d2278e 100644
--- a/js/src/jsapi.h
+++ b/js/src/jsapi.h
@@ -2154,6 +2154,13 @@ namespace JS {
 extern JS_PUBLIC_API(bool)
 OrdinaryHasInstance(JSContext* cx, HandleObject objArg, HandleValue v, bool* bp);
 
+// Implementation of
+// https://www.ecma-international.org/ecma-262/6.0/#sec-instanceofoperator
+// This is almost identical to JS_HasInstance, except the latter may call a
+// custom hasInstance class op instead of InstanceofOperator.
+extern JS_PUBLIC_API(bool)
+InstanceofOperator(JSContext* cx, HandleObject obj, HandleValue v, bool* bp);
+
 } // namespace JS
 
 extern JS_PUBLIC_API(void*)
@@ -6566,7 +6573,7 @@ struct JS_PUBLIC_API(PerformanceGroup) {
     uint64_t refCount_;
 };
 
-using PerformanceGroupVector = mozilla::Vector<RefPtr<js::PerformanceGroup>, 0, SystemAllocPolicy>;
+using PerformanceGroupVector = mozilla::Vector<RefPtr<js::PerformanceGroup>, 8, SystemAllocPolicy>;
 
 /**
  * Commit any Performance Monitoring data.
@@ -6605,10 +6612,6 @@ SetStopwatchIsMonitoringJank(JSContext*, bool);
 extern JS_PUBLIC_API(bool)
 GetStopwatchIsMonitoringJank(JSContext*);
 
-// Extract the CPU rescheduling data.
-extern JS_PUBLIC_API(void)
-GetPerfMonitoringTestCpuRescheduling(JSContext*, uint64_t* stayed, uint64_t* moved);
-
 
 /**
  * Add a number of microseconds to the time spent waiting on CPOWs
diff --git a/js/src/jscompartment.cpp b/js/src/jscompartment.cpp
index 4e4ccdf2a..a48bb0ffe 100644
--- a/js/src/jscompartment.cpp
+++ b/js/src/jscompartment.cpp
@@ -41,7 +41,6 @@ using namespace js::gc;
 using namespace js::jit;
 
 using mozilla::DebugOnly;
-using mozilla::PodArrayZero;
 
 JSCompartment::JSCompartment(Zone* zone, const JS::CompartmentOptions& options = JS::CompartmentOptions())
   : creationOptions_(options.creationOptions()),
@@ -91,7 +90,6 @@ JSCompartment::JSCompartment(Zone* zone, const JS::CompartmentOptions& options =
     unmappedArgumentsTemplate_(nullptr),
     lcovOutput()
 {
-    PodArrayZero(sawDeprecatedLanguageExtension);
     runtime_->numCompartments++;
     MOZ_ASSERT_IF(creationOptions_.mergeable(),
                   creationOptions_.invisibleToDebugger());
@@ -99,8 +97,6 @@ JSCompartment::JSCompartment(Zone* zone, const JS::CompartmentOptions& options =
 
 JSCompartment::~JSCompartment()
 {
-    reportTelemetry();
-
     // Write the code coverage information in a file.
     JSRuntime* rt = runtimeFromMainThread();
     if (rt->lcovOutput.isEnabled())
@@ -1268,39 +1264,6 @@ JSCompartment::addSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf,
         *privateData += callback(mallocSizeOf, this);
 }
 
-void
-JSCompartment::reportTelemetry()
-{
-    // Only report telemetry for web content and add-ons, not chrome JS.
-    if (isSystem_)
-        return;
-
-    // Hazard analysis can't tell that the telemetry callbacks don't GC.
-    JS::AutoSuppressGCAnalysis nogc;
-
-    int id = creationOptions_.addonIdOrNull()
-             ? JS_TELEMETRY_DEPRECATED_LANGUAGE_EXTENSIONS_IN_ADDONS
-             : JS_TELEMETRY_DEPRECATED_LANGUAGE_EXTENSIONS_IN_CONTENT;
-
-    // Call back into Firefox's Telemetry reporter.
-    for (size_t i = 0; i < DeprecatedLanguageExtensionCount; i++) {
-        if (sawDeprecatedLanguageExtension[i])
-            runtime_->addTelemetry(id, i);
-    }
-}
-
-void
-JSCompartment::addTelemetry(const char* filename, DeprecatedLanguageExtension e)
-{
-    // Only report telemetry for web content and add-ons, not chrome JS.
-    if (isSystem_)
-        return;
-    if (!creationOptions_.addonIdOrNull() && (!filename || strncmp(filename, "http", 4) != 0))
-        return;
-
-    sawDeprecatedLanguageExtension[e] = true;
-}
-
 HashNumber
 JSCompartment::randomHashCode()
 {
diff --git a/js/src/jscompartment.h b/js/src/jscompartment.h
index 7bfeee1f6..98c8fe200 100644
--- a/js/src/jscompartment.h
+++ b/js/src/jscompartment.h
@@ -344,13 +344,6 @@ struct JSCompartment
         isAtomsCompartment_ = true;
     }
 
-    // Used to approximate non-content code when reporting telemetry.
-    inline bool isProbablySystemOrAddonCode() const {
-        if (creationOptions_.addonIdOrNull())
-            return true;
-
-        return isSystem_;
-    }
   private:
     JSPrincipals*                principals_;
     bool                         isSystem_;
@@ -879,34 +872,10 @@ struct JSCompartment
         return jitCompartment_;
     }
 
-    enum DeprecatedLanguageExtension {
-        DeprecatedForEach = 0,              // JS 1.6+
-        // NO LONGER USING 1
-        DeprecatedLegacyGenerator = 2,      // JS 1.7+
-        DeprecatedExpressionClosure = 3,    // Added in JS 1.8
-        // NO LONGER USING 4
-        // NO LONGER USING 5
-        // NO LONGER USING 6
-        // NO LONGER USING 7
-        // NO LONGER USING 8
-        // NO LONGER USING 9
-        DeprecatedBlockScopeFunRedecl = 10,
-        DeprecatedLanguageExtensionCount
-    };
-
     js::ArgumentsObject* getOrCreateArgumentsTemplateObject(JSContext* cx, bool mapped);
 
     js::ArgumentsObject* maybeArgumentsTemplateObject(bool mapped) const;
 
-  private:
-    // Used for collecting telemetry on SpiderMonkey's deprecated language extensions.
-    bool sawDeprecatedLanguageExtension[DeprecatedLanguageExtensionCount];
-
-    void reportTelemetry();
-
-  public:
-    void addTelemetry(const char* filename, DeprecatedLanguageExtension e);
-
   public:
     // Aggregated output used to collect JSScript hit counts when code coverage
     // is enabled.
diff --git a/js/src/jsexn.cpp b/js/src/jsexn.cpp
index 9a8e364ed..1e70a3890 100644
--- a/js/src/jsexn.cpp
+++ b/js/src/jsexn.cpp
@@ -707,67 +707,6 @@ ErrorReport::~ErrorReport()
 {
 }
 
-void
-ErrorReport::ReportAddonExceptionToTelementry(JSContext* cx)
-{
-    MOZ_ASSERT(exnObject);
-    RootedObject unwrapped(cx, UncheckedUnwrap(exnObject));
-    MOZ_ASSERT(unwrapped, "UncheckedUnwrap failed?");
-
-    // There is not much we can report if the exception is not an ErrorObject, let's ignore those.
-    if (!unwrapped->is<ErrorObject>())
-        return;
-
-    Rooted<ErrorObject*> errObj(cx, &unwrapped->as<ErrorObject>());
-    RootedObject stack(cx, errObj->stack());
-
-    // Let's ignore TOP level exceptions. For regular add-ons those will not be reported anyway,
-    // for SDK based once it should not be a valid case either.
-    // At this point the frame stack is unwound but the exception object stored the stack so let's
-    // use that for getting the function name.
-    if (!stack)
-        return;
-
-    JSCompartment* comp = stack->compartment();
-    JSAddonId* addonId = comp->creationOptions().addonIdOrNull();
-
-    // We only want to send the report if the scope that just have thrown belongs to an add-on.
-    // Let's check the compartment of the youngest function on the stack, to determine that.
-    if (!addonId)
-        return;
-
-    RootedString funnameString(cx);
-    JS::SavedFrameResult result = GetSavedFrameFunctionDisplayName(cx, stack, &funnameString);
-    // AccessDenied should never be the case here for add-ons but let's not risk it.
-    JSAutoByteString bytes;
-    const char* funname = nullptr;
-    bool denied = result == JS::SavedFrameResult::AccessDenied;
-    funname = denied ? "unknown"
-                     : funnameString ? AtomToPrintableString(cx,
-                                                             &funnameString->asAtom(),
-                                                             &bytes)
-                                     : "anonymous";
-
-    UniqueChars addonIdChars(JS_EncodeString(cx, addonId));
-
-    const char* filename = nullptr;
-    if (reportp && reportp->filename) {
-        filename = strrchr(reportp->filename, '/');
-        if (filename)
-            filename++;
-    }
-    if (!filename) {
-        filename = "FILE_NOT_FOUND";
-    }
-    char histogramKey[64];
-    SprintfLiteral(histogramKey, "%s %s %s %u",
-                   addonIdChars.get(),
-                   funname,
-                   filename,
-                   (reportp ? reportp->lineno : 0) );
-    cx->runtime()->addTelemetry(JS_TELEMETRY_ADDON_EXCEPTIONS, 1, histogramKey);
-}
-
 bool
 ErrorReport::init(JSContext* cx, HandleValue exn,
                   SniffingBehavior sniffingBehavior)
@@ -786,10 +725,6 @@ ErrorReport::init(JSContext* cx, HandleValue exn,
                                       JSMSG_ERR_DURING_THROW);
             return false;
         }
-
-        // Let's see if the exception is from add-on code, if so, it should be reported
-        // to telementry.
-        ReportAddonExceptionToTelementry(cx);
     }
 
 
diff --git a/js/src/jsfriendapi.cpp b/js/src/jsfriendapi.cpp
index 595a21410..f5cd56a9b 100644
--- a/js/src/jsfriendapi.cpp
+++ b/js/src/jsfriendapi.cpp
@@ -543,11 +543,6 @@ js::SetPreserveWrapperCallback(JSContext* cx, PreserveWrapperCallback callback)
     cx->preserveWrapperCallback = callback;
 }
 
-/*
- * The below code is for temporary telemetry use. It can be removed when
- * sufficient data has been harvested.
- */
-
 namespace js {
 // Defined in vm/GlobalObject.cpp.
 extern size_t sSetProtoCalled;
@@ -643,12 +638,6 @@ js::StringToLinearStringSlow(JSContext* cx, JSString* str)
     return str->ensureLinear(cx);
 }
 
-JS_FRIEND_API(void)
-JS_SetAccumulateTelemetryCallback(JSContext* cx, JSAccumulateTelemetryDataCallback callback)
-{
-    cx->setTelemetryCallback(cx, callback);
-}
-
 JS_FRIEND_API(JSObject*)
 JS_CloneObject(JSContext* cx, HandleObject obj, HandleObject protoArg)
 {
diff --git a/js/src/jsfriendapi.h b/js/src/jsfriendapi.h
index 722085549..d29285483 100644
--- a/js/src/jsfriendapi.h
+++ b/js/src/jsfriendapi.h
@@ -105,46 +105,6 @@ JS_TraceShapeCycleCollectorChildren(JS::CallbackTracer* trc, JS::GCCellPtr shape
 extern JS_FRIEND_API(void)
 JS_TraceObjectGroupCycleCollectorChildren(JS::CallbackTracer* trc, JS::GCCellPtr group);
 
-enum {
-    JS_TELEMETRY_GC_REASON,
-    JS_TELEMETRY_GC_IS_ZONE_GC,
-    JS_TELEMETRY_GC_MS,
-    JS_TELEMETRY_GC_BUDGET_MS,
-    JS_TELEMETRY_GC_ANIMATION_MS,
-    JS_TELEMETRY_GC_MAX_PAUSE_MS,
-    JS_TELEMETRY_GC_MARK_MS,
-    JS_TELEMETRY_GC_SWEEP_MS,
-    JS_TELEMETRY_GC_COMPACT_MS,
-    JS_TELEMETRY_GC_MARK_ROOTS_MS,
-    JS_TELEMETRY_GC_MARK_GRAY_MS,
-    JS_TELEMETRY_GC_SLICE_MS,
-    JS_TELEMETRY_GC_SLOW_PHASE,
-    JS_TELEMETRY_GC_MMU_50,
-    JS_TELEMETRY_GC_RESET,
-    JS_TELEMETRY_GC_RESET_REASON,
-    JS_TELEMETRY_GC_INCREMENTAL_DISABLED,
-    JS_TELEMETRY_GC_NON_INCREMENTAL,
-    JS_TELEMETRY_GC_NON_INCREMENTAL_REASON,
-    JS_TELEMETRY_GC_SCC_SWEEP_TOTAL_MS,
-    JS_TELEMETRY_GC_SCC_SWEEP_MAX_PAUSE_MS,
-    JS_TELEMETRY_GC_MINOR_REASON,
-    JS_TELEMETRY_GC_MINOR_REASON_LONG,
-    JS_TELEMETRY_GC_MINOR_US,
-    JS_TELEMETRY_GC_NURSERY_BYTES,
-    JS_TELEMETRY_GC_PRETENURE_COUNT,
-    JS_TELEMETRY_DEPRECATED_LANGUAGE_EXTENSIONS_IN_CONTENT,
-    JS_TELEMETRY_DEPRECATED_LANGUAGE_EXTENSIONS_IN_ADDONS,
-    JS_TELEMETRY_ADDON_EXCEPTIONS,
-    JS_TELEMETRY_AOT_USAGE,
-    JS_TELEMETRY_END
-};
-
-typedef void
-(*JSAccumulateTelemetryDataCallback)(int id, uint32_t sample, const char* key);
-
-extern JS_FRIEND_API(void)
-JS_SetAccumulateTelemetryCallback(JSContext* cx, JSAccumulateTelemetryDataCallback callback);
-
 extern JS_FRIEND_API(bool)
 JS_GetIsSecureContext(JSCompartment* compartment);
 
@@ -1456,9 +1416,6 @@ struct MOZ_STACK_CLASS JS_FRIEND_API(ErrorReport)
     bool populateUncaughtExceptionReportUTF8(JSContext* cx, ...);
     bool populateUncaughtExceptionReportUTF8VA(JSContext* cx, va_list ap);
 
-    // Reports exceptions from add-on scopes to telementry.
-    void ReportAddonExceptionToTelementry(JSContext* cx);
-
     // We may have a provided JSErrorReport, so need a way to represent that.
     JSErrorReport* reportp;
 
diff --git a/js/src/jsfun.cpp b/js/src/jsfun.cpp
index bcb0da80b..863871df9 100644
--- a/js/src/jsfun.cpp
+++ b/js/src/jsfun.cpp
@@ -690,7 +690,7 @@ js::fun_symbolHasInstance(JSContext* cx, unsigned argc, Value* vp)
 }
 
 /*
- * ES6 (4-25-16) 7.3.19 OrdinaryHasInstance
+ * ES6 7.3.19 OrdinaryHasInstance
  */
 bool
 JS::OrdinaryHasInstance(JSContext* cx, HandleObject objArg, HandleValue v, bool* bp)
@@ -707,7 +707,7 @@ JS::OrdinaryHasInstance(JSContext* cx, HandleObject objArg, HandleValue v, bool*
     if (obj->is<JSFunction>() && obj->isBoundFunction()) {
         /* Steps 2a-b. */
         obj = obj->as<JSFunction>().getBoundFunctionTarget();
-        return InstanceOfOperator(cx, obj, v, bp);
+        return InstanceofOperator(cx, obj, v, bp);
     }
 
     /* Step 3. */
@@ -716,12 +716,12 @@ JS::OrdinaryHasInstance(JSContext* cx, HandleObject objArg, HandleValue v, bool*
         return true;
     }
 
-    /* Step 4. */
+    /* Step 4-5. */
     RootedValue pval(cx);
     if (!GetProperty(cx, obj, obj, cx->names().prototype, &pval))
         return false;
 
-    /* Step 5. */
+    /* Step 6. */
     if (pval.isPrimitive()) {
         /*
          * Throw a runtime error if instanceof is called on a function that
@@ -732,7 +732,7 @@ JS::OrdinaryHasInstance(JSContext* cx, HandleObject objArg, HandleValue v, bool*
         return false;
     }
 
-    /* Step 6. */
+    /* Step 7. */
     RootedObject pobj(cx, &pval.toObject());
     bool isDelegate;
     if (!IsDelegate(cx, pobj, v, &isDelegate))
diff --git a/js/src/jsgc.cpp b/js/src/jsgc.cpp
index 3d4dae9bb..8cee9ec09 100644
--- a/js/src/jsgc.cpp
+++ b/js/src/jsgc.cpp
@@ -2310,22 +2310,27 @@ GCRuntime::updateCellPointers(MovingTracer* trc, Zone* zone, AllocKinds kinds, s
 //  2) typed object type descriptor objects
 //  3) all other objects
 //
+// Also, there can be data races calling IsForwarded() on the new location of a
+// cell that is being updated in parallel on another thread. This can be avoided
+// by updating some kinds of cells in different phases. This is done for JSScripts
+// and LazyScripts, and JSScripts and Scopes.
+//
 // Since we want to minimize the number of phases, we put everything else into
 // the first phase and label it the 'misc' phase.
 
 static const AllocKinds UpdatePhaseMisc {
     AllocKind::SCRIPT,
-    AllocKind::LAZY_SCRIPT,
     AllocKind::BASE_SHAPE,
     AllocKind::SHAPE,
     AllocKind::ACCESSOR_SHAPE,
     AllocKind::OBJECT_GROUP,
     AllocKind::STRING,
-    AllocKind::JITCODE,
-    AllocKind::SCOPE
+    AllocKind::JITCODE
 };
 
 static const AllocKinds UpdatePhaseObjects {
+    AllocKind::LAZY_SCRIPT,
+    AllocKind::SCOPE,
     AllocKind::FUNCTION,
     AllocKind::FUNCTION_EXTENDED,
     AllocKind::OBJECT0,
diff --git a/js/src/jsstr.cpp b/js/src/jsstr.cpp
index 4151d012b..e3b5708ca 100644
--- a/js/src/jsstr.cpp
+++ b/js/src/jsstr.cpp
@@ -3070,8 +3070,11 @@ js::ValueToSource(JSContext* cx, HandleValue v)
 
         return ToString<CanGC>(cx, v);
     }
-
+#if JS_HAS_TOSOURCE
     return ObjectToSource(cx, obj);
+#else
+    return ToString<CanGC>(cx, v);
+#endif
 }
 
 JSString*
diff --git a/js/src/jswrapper.h b/js/src/jswrapper.h
index 3c73979f8..84ebe2732 100644
--- a/js/src/jswrapper.h
+++ b/js/src/jswrapper.h
@@ -270,6 +270,8 @@ class JS_FRIEND_API(OpaqueCrossCompartmentWrapper) : public CrossCompartmentWrap
     virtual bool getBuiltinClass(JSContext* cx, HandleObject wrapper, ESClass* cls) const override;
     virtual bool isArray(JSContext* cx, HandleObject obj,
                          JS::IsArrayAnswer* answer) const override;
+    virtual bool hasInstance(JSContext* cx, HandleObject wrapper,
+                             MutableHandleValue v, bool* bp) const override;
     virtual const char* className(JSContext* cx, HandleObject wrapper) const override;
     virtual JSString* fun_toString(JSContext* cx, HandleObject proxy, unsigned indent) const override;
 
diff --git a/js/src/old-configure.in b/js/src/old-configure.in
index 8abea5956..45108ee59 100644
--- a/js/src/old-configure.in
+++ b/js/src/old-configure.in
@@ -206,10 +206,6 @@ case "$target" in
 
             # -Zc:sizedDealloc- disables C++14 global sized deallocation (see bug 1160146)
             CXXFLAGS="$CXXFLAGS -Zc:sizedDealloc-"
-
-            # Disable C++11 thread-safe statics due to crashes on XP (bug 1204752)
-            # See https://connect.microsoft.com/VisualStudio/feedback/details/1789709/visual-c-2015-runtime-broken-on-windows-server-2003-c-11-magic-statics
-            CXXFLAGS="$CXXFLAGS -Zc:threadSafeInit-"
             ;;
         esac
         AC_SUBST(MSVS_VERSION)
diff --git a/js/src/proxy/OpaqueCrossCompartmentWrapper.cpp b/js/src/proxy/OpaqueCrossCompartmentWrapper.cpp
index ff3f4145c..02bf237ff 100644
--- a/js/src/proxy/OpaqueCrossCompartmentWrapper.cpp
+++ b/js/src/proxy/OpaqueCrossCompartmentWrapper.cpp
@@ -175,6 +175,14 @@ OpaqueCrossCompartmentWrapper::isArray(JSContext* cx, HandleObject obj,
     return true;
 }
 
+bool OpaqueCrossCompartmentWrapper::hasInstance(JSContext* cx,
+                                                HandleObject wrapper,
+                                                MutableHandleValue v,
+                                                bool* bp) const {
+  *bp = false;
+  return true;
+}
+
 const char*
 OpaqueCrossCompartmentWrapper::className(JSContext* cx,
                                          HandleObject proxy) const
diff --git a/js/src/proxy/ScriptedProxyHandler.cpp b/js/src/proxy/ScriptedProxyHandler.cpp
index 776547337..0e25f470c 100644
--- a/js/src/proxy/ScriptedProxyHandler.cpp
+++ b/js/src/proxy/ScriptedProxyHandler.cpp
@@ -8,8 +8,6 @@
 
 #include "jsapi.h"
 
-#include "vm/Interpreter.h" // For InstanceOfOperator
-
 #include "jsobjinlines.h"
 #include "vm/NativeObject-inl.h"
 
@@ -1230,7 +1228,7 @@ bool
 ScriptedProxyHandler::hasInstance(JSContext* cx, HandleObject proxy, MutableHandleValue v,
                                   bool* bp) const
 {
-    return InstanceOfOperator(cx, proxy, v, bp);
+    return InstanceofOperator(cx, proxy, v, bp);
 }
 
 bool
diff --git a/js/src/tests/user.js b/js/src/tests/user.js
index 732bbbd1a..e75593ab1 100755
--- a/js/src/tests/user.js
+++ b/js/src/tests/user.js
@@ -22,7 +22,6 @@ user_pref("javascript.options.strict", false);
 user_pref("javascript.options.werror", false);
 user_pref("toolkit.startup.max_resumed_crashes", -1);
 user_pref("security.turn_off_all_security_so_that_viruses_can_take_over_this_computer", true);
-user_pref("toolkit.telemetry.enabled", false);
 user_pref("browser.safebrowsing.phishing.enabled", false);
 user_pref("browser.safebrowsing.malware.enabled", false);
 user_pref("browser.safebrowsing.forbiddenURIs.enabled", false);
diff --git a/js/src/vm/Interpreter.cpp b/js/src/vm/Interpreter.cpp
index b747e4d7a..e6d6630c4 100644
--- a/js/src/vm/Interpreter.cpp
+++ b/js/src/vm/Interpreter.cpp
@@ -718,14 +718,14 @@ js::Execute(JSContext* cx, HandleScript script, JSObject& envChainArg, Value* rv
 }
 
 /*
- * ES6 (4-25-16) 12.10.4 InstanceofOperator
+ * ES6 12.9.4 InstanceofOperator
  */
 extern bool
-js::InstanceOfOperator(JSContext* cx, HandleObject obj, HandleValue v, bool* bp)
+JS::InstanceofOperator(JSContext* cx, HandleObject obj, HandleValue v, bool* bp)
 {
     /* Step 1. is handled by caller. */
 
-    /* Step 2. */
+    /* Step 2-3. */
     RootedValue hasInstance(cx);
     RootedId id(cx, SYMBOL_TO_JSID(cx->wellKnownSymbols().hasInstance));
     if (!GetProperty(cx, obj, obj, id, &hasInstance))
@@ -735,7 +735,7 @@ js::InstanceOfOperator(JSContext* cx, HandleObject obj, HandleValue v, bool* bp)
         if (!IsCallable(hasInstance))
             return ReportIsNotFunction(cx, hasInstance);
 
-        /* Step 3. */
+        /* Step 4. */
         RootedValue rval(cx);
         if (!Call(cx, hasInstance, obj, v, &rval))
             return false;
@@ -743,13 +743,13 @@ js::InstanceOfOperator(JSContext* cx, HandleObject obj, HandleValue v, bool* bp)
         return true;
     }
 
-    /* Step 4. */
+    /* Step 5. */
     if (!obj->isCallable()) {
         RootedValue val(cx, ObjectValue(*obj));
         return ReportIsNotFunction(cx, val);
     }
 
-    /* Step 5. */
+    /* Step 6. */
     return OrdinaryHasInstance(cx, obj, v, bp);
 }
 
@@ -760,7 +760,7 @@ js::HasInstance(JSContext* cx, HandleObject obj, HandleValue v, bool* bp)
     RootedValue local(cx, v);
     if (JSHasInstanceOp hasInstance = clasp->getHasInstance())
         return hasInstance(cx, obj, &local, bp);
-    return js::InstanceOfOperator(cx, obj, local, bp);
+    return JS::InstanceofOperator(cx, obj, local, bp);
 }
 
 static inline bool
diff --git a/js/src/vm/Interpreter.h b/js/src/vm/Interpreter.h
index 330dbef5f..9fefd75cc 100644
--- a/js/src/vm/Interpreter.h
+++ b/js/src/vm/Interpreter.h
@@ -323,9 +323,6 @@ extern JSType
 TypeOfValue(const Value& v);
 
 extern bool
-InstanceOfOperator(JSContext* cx, HandleObject obj, HandleValue v, bool* bp);
-
-extern bool
 HasInstance(JSContext* cx, HandleObject obj, HandleValue v, bool* bp);
 
 // Unwind environment chain and iterator to match the scope corresponding to
diff --git a/js/src/vm/Runtime.cpp b/js/src/vm/Runtime.cpp
index 174e23594..8eb997c71 100644
--- a/js/src/vm/Runtime.cpp
+++ b/js/src/vm/Runtime.cpp
@@ -147,7 +147,6 @@ JSRuntime::JSRuntime(JSRuntime* parentRuntime)
     updateChildRuntimeCount(parentRuntime),
 #endif
     interrupt_(false),
-    telemetryCallback(nullptr),
     handlingSegFault(false),
     handlingJitInterrupt_(false),
     interruptCallbackDisabled(false),
@@ -452,19 +451,6 @@ JSRuntime::destroyRuntime()
 }
 
 void
-JSRuntime::addTelemetry(int id, uint32_t sample, const char* key)
-{
-    if (telemetryCallback)
-        (*telemetryCallback)(id, sample, key);
-}
-
-void
-JSRuntime::setTelemetryCallback(JSRuntime* rt, JSAccumulateTelemetryDataCallback callback)
-{
-    rt->telemetryCallback = callback;
-}
-
-void
 JSRuntime::addSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf, JS::RuntimeSizes* rtSizes)
 {
     // Several tables in the runtime enumerated below can be used off thread.
diff --git a/js/src/vm/Runtime.h b/js/src/vm/Runtime.h
index f354d2069..e60371e38 100644
--- a/js/src/vm/Runtime.h
+++ b/js/src/vm/Runtime.h
@@ -577,17 +577,7 @@ struct JSRuntime : public JS::shadow::Runtime,
 #endif
 
     mozilla::Atomic<uint32_t, mozilla::Relaxed> interrupt_;
-
-    /* Call this to accumulate telemetry data. */
-    JSAccumulateTelemetryDataCallback telemetryCallback;
   public:
-    // Accumulates data for Firefox telemetry. |id| is the ID of a JS_TELEMETRY_*
-    // histogram. |key| provides an additional key to identify the histogram.
-    // |sample| is the data to add to the histogram.
-    void addTelemetry(int id, uint32_t sample, const char* key = nullptr);
-
-    void setTelemetryCallback(JSRuntime* rt, JSAccumulateTelemetryDataCallback callback);
-
     enum InterruptMode {
         RequestInterruptUrgent,
         RequestInterruptCanWait
diff --git a/js/src/vm/SelfHosting.cpp b/js/src/vm/SelfHosting.cpp
index 08670c833..328a960b6 100644
--- a/js/src/vm/SelfHosting.cpp
+++ b/js/src/vm/SelfHosting.cpp
@@ -1904,23 +1904,6 @@ intrinsic_RuntimeDefaultLocale(JSContext* cx, unsigned argc, Value* vp)
 }
 
 static bool
-intrinsic_AddContentTelemetry(JSContext* cx, unsigned argc, Value* vp)
-{
-    CallArgs args = CallArgsFromVp(argc, vp);
-    MOZ_ASSERT(args.length() == 2);
-
-    int id = args[0].toInt32();
-    MOZ_ASSERT(id < JS_TELEMETRY_END);
-    MOZ_ASSERT(id >= 0);
-
-    if (!cx->compartment()->isProbablySystemOrAddonCode())
-        cx->runtime()->addTelemetry(id, args[1].toInt32());
-
-    args.rval().setUndefined();
-    return true;
-}
-
-static bool
 intrinsic_ConstructFunction(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
@@ -2273,7 +2256,6 @@ static const JSFunctionSpec intrinsic_functions[] = {
     JS_FN("DecompileArg",            intrinsic_DecompileArg,            2,0),
     JS_FN("_FinishBoundFunctionInit", intrinsic_FinishBoundFunctionInit, 3,0),
     JS_FN("RuntimeDefaultLocale",    intrinsic_RuntimeDefaultLocale,    0,0),
-    JS_FN("AddContentTelemetry",     intrinsic_AddContentTelemetry,     2,0),
 
     JS_INLINABLE_FN("_IsConstructing", intrinsic_IsConstructing,        0,0,
                     IntrinsicIsConstructing),
diff --git a/js/src/vm/Stopwatch.cpp b/js/src/vm/Stopwatch.cpp
index 28632c2a1..684846f00 100644
--- a/js/src/vm/Stopwatch.cpp
+++ b/js/src/vm/Stopwatch.cpp
@@ -20,6 +20,7 @@
 #include "gc/Zone.h"
 #include "vm/Runtime.h"
 
+
 namespace js {
 
 bool
@@ -136,6 +137,9 @@ PerformanceMonitoring::start()
 bool
 PerformanceMonitoring::commit()
 {
+    // Maximal initialization size, in elements for the vector of groups.
+    static const size_t MAX_GROUPS_INIT_CAPACITY = 1024;
+
 #if !defined(MOZ_HAVE_RDTSC)
     // The AutoStopwatch is only executed if `MOZ_HAVE_RDTSC`.
     return false;
@@ -152,13 +156,24 @@ PerformanceMonitoring::commit()
         return true;
     }
 
-    PerformanceGroupVector recentGroups;
-    recentGroups_.swap(recentGroups);
+    // The move operation is generally constant time, unless
+    // `recentGroups_.length()` is very small, in which case
+    // it's fast just because it's small.
+    PerformanceGroupVector recentGroups(Move(recentGroups_));
+    recentGroups_ = PerformanceGroupVector(); // Reconstruct after `Move`.
 
     bool success = true;
     if (stopwatchCommitCallback)
         success = stopwatchCommitCallback(iteration_, recentGroups, stopwatchCommitClosure);
 
+    // Heuristic: we expect to have roughly the same number of groups as in
+    // the previous iteration.
+    const size_t capacity = recentGroups.capacity() < MAX_GROUPS_INIT_CAPACITY ?
+                            recentGroups.capacity() :
+                            MAX_GROUPS_INIT_CAPACITY;
+    success = recentGroups_.reserve(capacity)
+            && success;
+
     // Reset immediately, to make sure that we're not hit by the end
     // of a nested event loop (which would cause `commit` to be called
     // twice in succession).
@@ -227,7 +242,7 @@ AutoStopwatch::AutoStopwatch(JSContext* cx MOZ_GUARD_OBJECT_NOTIFIER_PARAM_IN_IM
     MOZ_GUARD_OBJECT_NOTIFIER_INIT;
 
     JSCompartment* compartment = cx_->compartment();
-    if (compartment->scheduledForDestruction)
+    if (MOZ_UNLIKELY(compartment->scheduledForDestruction))
         return;
 
     JSRuntime* runtime = cx_->runtime();
@@ -266,11 +281,11 @@ AutoStopwatch::~AutoStopwatch()
     }
 
     JSCompartment* compartment = cx_->compartment();
-    if (compartment->scheduledForDestruction)
+    if (MOZ_UNLIKELY(compartment->scheduledForDestruction))
         return;
 
     JSRuntime* runtime = cx_->runtime();
-    if (iteration_ != runtime->performanceMonitoring.iteration()) {
+    if (MOZ_UNLIKELY(iteration_ != runtime->performanceMonitoring.iteration())) {
         // We have entered a nested event loop at some point.
         // Any information we may have is obsolete.
         return;
@@ -319,11 +334,6 @@ AutoStopwatch::exit()
             const uint64_t cyclesEnd = getCycles(runtime);
             cyclesDelta = cyclesEnd - cyclesStart_; // Always >= 0 by definition of `getCycles`.
         }
-#if WINVER >= 0x600
-        updateTelemetry(cpuStart_, cpuEnd);
-#elif defined(__linux__)
-        updateTelemetry(cpuStart_, cpuEnd);
-#endif // WINVER >= 0x600 || _linux__
     }
 
     uint64_t CPOWTimeDelta = 0;
@@ -335,17 +345,6 @@ AutoStopwatch::exit()
     return addToGroups(cyclesDelta, CPOWTimeDelta);
 }
 
-void
-AutoStopwatch::updateTelemetry(const cpuid_t& cpuStart_, const cpuid_t& cpuEnd)
-{
-  JSRuntime* runtime = cx_->runtime();
-
-    if (isSameCPU(cpuStart_, cpuEnd))
-        runtime->performanceMonitoring.testCpuRescheduling.stayed += 1;
-    else
-        runtime->performanceMonitoring.testCpuRescheduling.moved += 1;
-}
-
 PerformanceGroup*
 AutoStopwatch::acquireGroup(PerformanceGroup* group)
 {
@@ -638,13 +637,6 @@ GetStopwatchIsMonitoringCPOW(JSContext* cx)
 }
 
 JS_PUBLIC_API(void)
-GetPerfMonitoringTestCpuRescheduling(JSContext* cx, uint64_t* stayed, uint64_t* moved)
-{
-    *stayed = cx->performanceMonitoring.testCpuRescheduling.stayed;
-    *moved = cx->performanceMonitoring.testCpuRescheduling.moved;
-}
-
-JS_PUBLIC_API(void)
 AddCPOWPerformanceDelta(JSContext* cx, uint64_t delta)
 {
     cx->performanceMonitoring.totalCPOWTime += delta;
diff --git a/js/src/vm/Stopwatch.h b/js/src/vm/Stopwatch.h
index 38a3eb801..d7f299594 100644
--- a/js/src/vm/Stopwatch.h
+++ b/js/src/vm/Stopwatch.h
@@ -217,33 +217,6 @@ struct PerformanceMonitoring {
      */
     uint64_t monotonicReadTimestampCounter();
 
-    /**
-     * Data extracted by the AutoStopwatch to determine how often
-     * we reschedule the process to a different CPU during the
-     * execution of JS.
-     *
-     * Warning: These values are incremented *only* on platforms
-     * that offer a syscall/libcall to check on which CPU a
-     * process is currently executed.
-     */
-    struct TestCpuRescheduling
-    {
-        // Incremented once we have finished executing code
-        // in a group, if the CPU on which we started
-        // execution is the same as the CPU on which
-        // we finished.
-        uint64_t stayed;
-        // Incremented once we have finished executing code
-        // in a group, if the CPU on which we started
-        // execution is different from the CPU on which
-        // we finished.
-        uint64_t moved;
-        TestCpuRescheduling()
-            : stayed(0),
-              moved(0)
-        { }
-    };
-    TestCpuRescheduling testCpuRescheduling;
   private:
     PerformanceMonitoring(const PerformanceMonitoring&) = delete;
     PerformanceMonitoring& operator=(const PerformanceMonitoring&) = delete;
@@ -375,9 +348,6 @@ class AutoStopwatch final {
     // Add recent changes to a single group. Mark the group as changed recently.
     bool addToGroup(JSRuntime* runtime, uint64_t cyclesDelta, uint64_t CPOWTimeDelta, PerformanceGroup* group);
 
-    // Update telemetry statistics.
-    void updateTelemetry(const cpuid_t& a, const cpuid_t& b);
-
     // Perform a subtraction for a quantity that should be monotonic
     // but is not guaranteed to be so.
     //
diff --git a/js/src/wasm/WasmBinaryConstants.h b/js/src/wasm/WasmBinaryConstants.h
index fd3bd1264..9aa5091f6 100644
--- a/js/src/wasm/WasmBinaryConstants.h
+++ b/js/src/wasm/WasmBinaryConstants.h
@@ -434,15 +434,6 @@ enum class Op
     Limit
 };
 
-// Telemetry sample values for the JS_AOT_USAGE key, indicating whether asm.js
-// or WebAssembly is used.
-
-enum class Telemetry
-{
-    ASMJS = 0,
-    WASM = 1
-};
-
 } // namespace wasm
 } // namespace js
 
diff --git a/js/src/wasm/WasmModule.cpp b/js/src/wasm/WasmModule.cpp
index b24e01a40..f1ecd8620 100644
--- a/js/src/wasm/WasmModule.cpp
+++ b/js/src/wasm/WasmModule.cpp
@@ -1066,8 +1066,5 @@ Module::instantiate(JSContext* cx,
             return false;
     }
 
-    uint32_t mode = uint32_t(metadata().isAsmJS() ? Telemetry::ASMJS : Telemetry::WASM);
-    cx->runtime()->addTelemetry(JS_TELEMETRY_AOT_USAGE, mode);
-
     return true;
 }