Use stability to only conditionally flush information from the CheckMaps table.

BUG=
R=ishell@chromium.org

Review URL: https://codereview.chromium.org/153823003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19330 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
verwaest@chromium.org 2014-02-12 15:07:41 +00:00
parent 1512e9e678
commit 2b7d33572a
8 changed files with 133 additions and 58 deletions

View File

@ -295,7 +295,8 @@ HValue* CodeStubGraphBuilder<ToNumberStub>::BuildCodeStub() {
// Check if the parameter is already a SMI or heap number.
IfBuilder if_number(this);
if_number.If<HIsSmiAndBranch>(value);
if_number.OrIf<HCompareMap>(value, isolate()->factory()->heap_number_map());
if_number.OrIf<HCompareMap>(value, isolate()->factory()->heap_number_map(),
top_info());
if_number.Then();
// Return the number.
@ -358,7 +359,8 @@ HValue* CodeStubGraphBuilder<FastCloneShallowArrayStub>::BuildCodeStub() {
HValue* elements = AddLoadElements(boilerplate);
IfBuilder if_fixed_cow(this);
if_fixed_cow.If<HCompareMap>(elements, factory->fixed_cow_array_map());
if_fixed_cow.If<HCompareMap>(elements, factory->fixed_cow_array_map(),
top_info());
if_fixed_cow.Then();
push_value = BuildCloneShallowArray(boilerplate,
allocation_site,
@ -369,7 +371,7 @@ HValue* CodeStubGraphBuilder<FastCloneShallowArrayStub>::BuildCodeStub() {
if_fixed_cow.Else();
IfBuilder if_fixed(this);
if_fixed.If<HCompareMap>(elements, factory->fixed_array_map());
if_fixed.If<HCompareMap>(elements, factory->fixed_array_map(), top_info());
if_fixed.Then();
push_value = BuildCloneShallowArray(boilerplate,
allocation_site,

View File

@ -1185,7 +1185,7 @@ Handle<Code> Compiler::GetOptimizedCode(Handle<JSFunction> function,
if (FLAG_trace_opt) {
PrintF("[failed to optimize ");
function->PrintName();
PrintF("]\n");
PrintF(": %s]\n", GetBailoutReason(info->bailout_reason()));
}
if (isolate->has_pending_exception()) isolate->clear_pending_exception();

View File

@ -50,6 +50,7 @@ struct HCheckTableEntry {
HValue* object_; // The object being approximated. NULL => invalid entry.
HInstruction* check_; // The last check instruction.
MapSet maps_; // The set of known maps for the object.
bool is_stable_;
};
@ -103,9 +104,10 @@ class HCheckTable : public ZoneObject {
}
default: {
// If the instruction changes maps uncontrollably, drop everything.
if (instr->CheckChangesFlag(kMaps) ||
instr->CheckChangesFlag(kOsrEntries)) {
Kill();
if (instr->CheckChangesFlag(kOsrEntries)) {
Reset();
} else if (instr->CheckChangesFlag(kMaps)) {
KillUnstableEntries();
}
}
// Improvements possible:
@ -154,6 +156,7 @@ class HCheckTable : public ZoneObject {
if (old_entry->check_ != NULL &&
old_entry->check_->block()->Dominates(succ)) {
new_entry->check_ = old_entry->check_;
new_entry->is_stable_ = old_entry->is_stable_;
} else {
// Leave it NULL till we meet a new check instruction for this object
// in the control flow.
@ -175,7 +178,8 @@ class HCheckTable : public ZoneObject {
HCheckTableEntry* pred_entry = copy->Find(phi_operand);
if (pred_entry != NULL) {
// Create an entry for a phi in the table.
copy->Insert(phi, NULL, pred_entry->maps_->Copy(phase_->zone()));
copy->Insert(phi, NULL, pred_entry->maps_->Copy(phase_->zone()),
pred_entry->is_stable_);
}
}
}
@ -193,12 +197,13 @@ class HCheckTable : public ZoneObject {
if (is_true_branch) {
// Learn on the true branch of if(CompareMap(x)).
if (entry == NULL) {
copy->Insert(object, cmp, cmp->map());
copy->Insert(object, cmp, cmp->map(), cmp->is_stable());
} else {
MapSet list = new(phase_->zone()) UniqueSet<Map>();
list->Add(cmp->map(), phase_->zone());
entry->maps_ = list;
entry->check_ = cmp;
entry->is_stable_ = cmp->is_stable();
}
} else {
// Learn on the false branch of if(CompareMap(x)).
@ -217,10 +222,10 @@ class HCheckTable : public ZoneObject {
HCheckTableEntry* re = copy->Find(right);
if (le == NULL) {
if (re != NULL) {
copy->Insert(left, NULL, re->maps_->Copy(zone));
copy->Insert(left, NULL, re->maps_->Copy(zone), re->is_stable_);
}
} else if (re == NULL) {
copy->Insert(right, NULL, le->maps_->Copy(zone));
copy->Insert(right, NULL, le->maps_->Copy(zone), le->is_stable_);
} else {
MapSet intersect = le->maps_->Intersect(re->maps_, zone);
le->maps_ = intersect;
@ -247,8 +252,7 @@ class HCheckTable : public ZoneObject {
HBasicBlock* pred_block, Zone* zone) {
if (that->size_ == 0) {
// If the other state is empty, simply reset.
size_ = 0;
cursor_ = 0;
Reset();
} else {
int pred_index = succ->PredecessorIndexOf(pred_block);
bool compact = false;
@ -271,6 +275,8 @@ class HCheckTable : public ZoneObject {
} else {
this_entry->maps_ =
this_entry->maps_->Union(that_entry->maps_, phase_->zone());
this_entry->is_stable_ =
this_entry->is_stable_ && that_entry->is_stable_;
if (this_entry->check_ != that_entry->check_) {
this_entry->check_ = NULL;
}
@ -351,7 +357,8 @@ class HCheckTable : public ZoneObject {
}
} else {
// No entry; insert a new one.
Insert(object, instr, instr->map_set().Copy(phase_->zone()));
Insert(object, instr, instr->map_set().Copy(phase_->zone()),
instr->is_stable());
}
}
@ -413,7 +420,8 @@ class HCheckTable : public ZoneObject {
}
} else {
// No prior information.
Insert(object, instr, map);
// TODO(verwaest): Tag map constants with stability.
Insert(object, instr, map, false);
}
}
@ -430,12 +438,14 @@ class HCheckTable : public ZoneObject {
if (instr->has_transition()) {
// This store transitions the object to a new map.
Kill(object);
Insert(object, NULL, MapConstant(instr->transition()));
Insert(object, NULL, MapConstant(instr->transition()),
instr->is_stable());
} else if (IsMapAccess(instr->access())) {
// This is a store directly to the map field of the object.
Kill(object);
if (!instr->value()->IsConstant()) return;
Insert(object, NULL, MapConstant(instr->value()));
// TODO(verwaest): Tag with stability.
Insert(object, NULL, MapConstant(instr->value()), false);
} else {
// If the instruction changes maps, it should be handled above.
CHECK(!instr->CheckChangesFlag(kMaps));
@ -485,12 +495,26 @@ class HCheckTable : public ZoneObject {
}
}
// Kill everything in the table.
void Kill() {
// Reset the table.
void Reset() {
size_ = 0;
cursor_ = 0;
}
// Kill everything in the table.
void KillUnstableEntries() {
bool compact = false;
for (int i = 0; i < size_; i++) {
HCheckTableEntry* entry = &entries_[i];
ASSERT(entry->object_ != NULL);
if (!entry->is_stable_) {
entry->object_ = NULL;
compact = true;
}
}
if (compact) Compact();
}
// Kill everything in the table that may alias {object}.
void Kill(HValue* object) {
bool compact = false;
@ -572,17 +596,24 @@ class HCheckTable : public ZoneObject {
return entry == NULL ? NULL : entry->maps_;
}
void Insert(HValue* object, HInstruction* check, Unique<Map> map) {
void Insert(HValue* object,
HInstruction* check,
Unique<Map> map,
bool is_stable) {
MapSet list = new(phase_->zone()) UniqueSet<Map>();
list->Add(map, phase_->zone());
Insert(object, check, list);
Insert(object, check, list, is_stable);
}
void Insert(HValue* object, HInstruction* check, MapSet maps) {
void Insert(HValue* object,
HInstruction* check,
MapSet maps,
bool is_stable) {
HCheckTableEntry* entry = &entries_[cursor_++];
entry->object_ = object;
entry->check_ = check;
entry->maps_ = maps;
entry->is_stable_ = is_stable;
// If the table becomes full, wrap around and overwrite older entries.
if (cursor_ == kMaxTrackedObjects) cursor_ = 0;
if (size_ < kMaxTrackedObjects) size_++;
@ -612,8 +643,7 @@ class HCheckTable : public ZoneObject {
class HCheckMapsEffects : public ZoneObject {
public:
explicit HCheckMapsEffects(Zone* zone)
: maps_stored_(false),
stores_(5, zone) { }
: stores_(5, zone) { }
inline bool Disabled() {
return false; // Effects are _not_ disabled.
@ -621,27 +651,22 @@ class HCheckMapsEffects : public ZoneObject {
// Process a possibly side-effecting instruction.
void Process(HInstruction* instr, Zone* zone) {
switch (instr->opcode()) {
case HValue::kStoreNamedField: {
stores_.Add(HStoreNamedField::cast(instr), zone);
break;
}
case HValue::kOsrEntry: {
// Kill everything. Loads must not be hoisted past the OSR entry.
maps_stored_ = true;
}
default: {
maps_stored_ |= (instr->CheckChangesFlag(kMaps) |
instr->CheckChangesFlag(kElementsKind));
}
if (instr->IsStoreNamedField()) {
stores_.Add(HStoreNamedField::cast(instr), zone);
} else {
flags_.Add(instr->ChangesFlags());
}
}
// Apply these effects to the given check elimination table.
void Apply(HCheckTable* table) {
if (maps_stored_) {
if (flags_.Contains(kOsrEntries)) {
table->Reset();
return;
}
if (flags_.Contains(kMaps) || flags_.Contains(kElementsKind)) {
// Uncontrollable map modifications; kill everything.
table->Kill();
table->KillUnstableEntries();
return;
}
@ -656,14 +681,14 @@ class HCheckMapsEffects : public ZoneObject {
// Union these effects with the other effects.
void Union(HCheckMapsEffects* that, Zone* zone) {
maps_stored_ |= that->maps_stored_;
flags_.Add(that->flags_);
for (int i = 0; i < that->stores_.length(); i++) {
stores_.Add(that->stores_[i], zone);
}
}
private:
bool maps_stored_ : 1;
GVNFlagSet flags_;
ZoneList<HStoreNamedField*> stores_;
};
@ -680,7 +705,7 @@ void HCheckEliminationPhase::Run() {
} else {
// Perform only local analysis.
for (int i = 0; i < graph()->blocks()->length(); i++) {
table->Kill();
table->Reset();
engine.AnalyzeOneBlock(graph()->blocks()->at(i), table);
}
}

View File

@ -3107,7 +3107,7 @@ HCheckMaps* HCheckMaps::New(Zone* zone,
CompilationInfo* info,
HValue* typecheck) {
HCheckMaps* check_map = new(zone) HCheckMaps(value, zone, typecheck);
check_map->Add(map, zone);
check_map->Add(map, info, zone);
if (map->CanOmitMapChecks() &&
value->IsConstant() &&
HConstant::cast(value)->HasMap(map)) {

View File

@ -1508,8 +1508,10 @@ class HBranch V8_FINAL : public HUnaryControlInstruction {
class HCompareMap V8_FINAL : public HUnaryControlInstruction {
public:
DECLARE_INSTRUCTION_FACTORY_P2(HCompareMap, HValue*, Handle<Map>);
DECLARE_INSTRUCTION_FACTORY_P4(HCompareMap, HValue*, Handle<Map>,
DECLARE_INSTRUCTION_FACTORY_P3(HCompareMap, HValue*, Handle<Map>,
CompilationInfo*);
DECLARE_INSTRUCTION_FACTORY_P5(HCompareMap, HValue*, Handle<Map>,
CompilationInfo*,
HBasicBlock*, HBasicBlock*);
virtual bool KnownSuccessorBlock(HBasicBlock** block) V8_OVERRIDE {
@ -1535,6 +1537,10 @@ class HCompareMap V8_FINAL : public HUnaryControlInstruction {
return Representation::Tagged();
}
bool is_stable() const {
return is_stable_;
}
DECLARE_CONCRETE_INSTRUCTION(CompareMap)
protected:
@ -1543,14 +1549,22 @@ class HCompareMap V8_FINAL : public HUnaryControlInstruction {
private:
HCompareMap(HValue* value,
Handle<Map> map,
CompilationInfo* info,
HBasicBlock* true_target = NULL,
HBasicBlock* false_target = NULL)
: HUnaryControlInstruction(value, true_target, false_target),
known_successor_index_(kNoKnownSuccessorIndex), map_(Unique<Map>(map)) {
ASSERT(!map.is_null());
is_stable_ = map->is_stable();
if (FLAG_check_elimination && is_stable_) {
map->AddDependentCompilationInfo(
DependentCode::kPrototypeCheckGroup, info);
}
}
int known_successor_index_;
bool is_stable_;
Unique<Map> map_;
};
@ -2633,10 +2647,11 @@ class HCheckMaps V8_FINAL : public HTemplateInstruction<2> {
HValue* typecheck = NULL);
static HCheckMaps* New(Zone* zone, HValue* context,
HValue* value, SmallMapList* maps,
CompilationInfo* info,
HValue* typecheck = NULL) {
HCheckMaps* check_map = new(zone) HCheckMaps(value, zone, typecheck);
for (int i = 0; i < maps->length(); i++) {
check_map->Add(maps->at(i), zone);
check_map->Add(maps->at(i), info, zone);
}
return check_map;
}
@ -2668,6 +2683,10 @@ class HCheckMaps V8_FINAL : public HTemplateInstruction<2> {
return has_migration_target_;
}
bool is_stable() const {
return is_stable_;
}
DECLARE_CONCRETE_INSTRUCTION(CheckMaps)
protected:
@ -2678,8 +2697,15 @@ class HCheckMaps V8_FINAL : public HTemplateInstruction<2> {
virtual int RedefinedOperandIndex() { return 0; }
private:
void Add(Handle<Map> map, Zone* zone) {
void Add(Handle<Map> map, CompilationInfo* info, Zone* zone) {
map_set_.Add(Unique<Map>(map), zone);
is_stable_ = is_stable_ && map->is_stable();
if (FLAG_check_elimination && is_stable_) {
map->AddDependentCompilationInfo(
DependentCode::kPrototypeCheckGroup, info);
}
if (!has_migration_target_ && map->is_migration_target()) {
has_migration_target_ = true;
SetChangesFlag(kNewSpacePromotion);
@ -2689,7 +2715,7 @@ class HCheckMaps V8_FINAL : public HTemplateInstruction<2> {
// Clients should use one of the static New* methods above.
HCheckMaps(HValue* value, Zone *zone, HValue* typecheck)
: HTemplateInstruction<2>(value->type()),
omit_(false), has_migration_target_(false) {
omit_(false), has_migration_target_(false), is_stable_(true) {
SetOperandAt(0, value);
// Use the object value for the dependency if NULL is passed.
SetOperandAt(1, typecheck != NULL ? typecheck : value);
@ -2702,6 +2728,7 @@ class HCheckMaps V8_FINAL : public HTemplateInstruction<2> {
bool omit_;
bool has_migration_target_;
bool is_stable_;
UniqueSet<Map> map_set_;
};
@ -6477,6 +6504,16 @@ class HStoreNamedField V8_FINAL : public HTemplateInstruction<3> {
}
SetOperandAt(2, map_constant);
has_transition_ = true;
is_stable_ = map->is_stable();
if (FLAG_check_elimination && is_stable_) {
map->AddDependentCompilationInfo(
DependentCode::kPrototypeCheckGroup, info);
}
}
bool is_stable() const {
return is_stable_;
}
bool NeedsWriteBarrier() {
@ -6515,6 +6552,7 @@ class HStoreNamedField V8_FINAL : public HTemplateInstruction<3> {
new_space_dominator_(NULL),
write_barrier_mode_(UPDATE_WRITE_BARRIER),
has_transition_(false),
is_stable_(false),
store_mode_(store_mode) {
// Stores to a non existing in-object property are allowed only to the
// newly allocated objects (via HAllocate or HInnerAllocatedObject).
@ -6530,6 +6568,7 @@ class HStoreNamedField V8_FINAL : public HTemplateInstruction<3> {
HValue* new_space_dominator_;
WriteBarrierMode write_barrier_mode_ : 1;
bool has_transition_ : 1;
bool is_stable_ : 1;
StoreFieldOrKeyedMode store_mode_ : 1;
};

View File

@ -1390,7 +1390,8 @@ HValue* HGraphBuilder::BuildCopyElementsOnWrite(HValue* object,
IfBuilder cow_checker(this);
cow_checker.If<HCompareMap>(elements, factory->fixed_cow_array_map());
cow_checker.If<HCompareMap>(
elements, factory->fixed_cow_array_map(), top_info());
cow_checker.Then();
HValue* capacity = AddLoadFixedArrayLength(elements);
@ -1707,7 +1708,7 @@ HValue* HGraphBuilder::BuildNumberToString(HValue* object, Type* type) {
// Check if the object is a heap number.
IfBuilder if_objectisnumber(this);
HValue* objectisnumber = if_objectisnumber.If<HCompareMap>(
object, isolate()->factory()->heap_number_map());
object, isolate()->factory()->heap_number_map(), top_info());
if_objectisnumber.Then();
{
// Compute hash for heap number similar to double_get_hash().
@ -5651,13 +5652,15 @@ void HOptimizedGraphBuilder::HandlePolymorphicNamedFieldAccess(
HValue* dependency;
if (info.type()->Is(Type::Number())) {
Handle<Map> heap_number_map = isolate()->factory()->heap_number_map();
compare = New<HCompareMap>(object, heap_number_map, if_true, if_false);
compare = New<HCompareMap>(object, heap_number_map, top_info(),
if_true, if_false);
dependency = smi_check;
} else if (info.type()->Is(Type::String())) {
compare = New<HIsStringAndBranch>(object, if_true, if_false);
dependency = compare;
} else {
compare = New<HCompareMap>(object, info.map(), if_true, if_false);
compare = New<HCompareMap>(object, info.map(), top_info(),
if_true, if_false);
dependency = compare;
}
FinishCurrentBlock(compare);
@ -6297,7 +6300,7 @@ HInstruction* HOptimizedGraphBuilder::TryBuildConsolidatedElementLoad(
}
if (!has_double_maps && !has_smi_or_object_maps) return NULL;
HCheckMaps* checked_object = Add<HCheckMaps>(object, maps);
HCheckMaps* checked_object = Add<HCheckMaps>(object, maps, top_info());
// FAST_ELEMENTS is considered more general than FAST_HOLEY_SMI_ELEMENTS.
// If we've seen both, the consolidated load must use FAST_HOLEY_ELEMENTS.
ElementsKind consolidated_elements_kind = has_seen_holey_elements
@ -6395,7 +6398,7 @@ HValue* HOptimizedGraphBuilder::HandlePolymorphicElementAccess(
HBasicBlock* this_map = graph()->CreateBasicBlock();
HBasicBlock* other_map = graph()->CreateBasicBlock();
HCompareMap* mapcompare =
New<HCompareMap>(object, map, this_map, other_map);
New<HCompareMap>(object, map, top_info(), this_map, other_map);
FinishCurrentBlock(mapcompare);
set_current_block(this_map);
@ -6603,7 +6606,7 @@ HInstruction* HOptimizedGraphBuilder::BuildNamedAccess(
checked_object =
Add<HCheckInstanceType>(object, HCheckInstanceType::IS_STRING);
} else {
checked_object = Add<HCheckMaps>(object, types);
checked_object = Add<HCheckMaps>(object, types, top_info());
}
return BuildMonomorphicAccess(
&info, object, checked_object, value, ast_id, return_id);
@ -6855,11 +6858,13 @@ void HOptimizedGraphBuilder::HandlePolymorphicCallNamed(
Handle<Map> map = info.map();
if (info.type()->Is(Type::Number())) {
Handle<Map> heap_number_map = isolate()->factory()->heap_number_map();
compare = New<HCompareMap>(receiver, heap_number_map, if_true, if_false);
compare = New<HCompareMap>(receiver, heap_number_map, top_info(),
if_true, if_false);
} else if (info.type()->Is(Type::String())) {
compare = New<HIsStringAndBranch>(receiver, if_true, if_false);
} else {
compare = New<HCompareMap>(receiver, map, if_true, if_false);
compare = New<HCompareMap>(receiver, map, top_info(),
if_true, if_false);
}
FinishCurrentBlock(compare);
@ -7704,7 +7709,7 @@ bool HOptimizedGraphBuilder::TryInlineApiCall(Handle<JSFunction> function,
case kCallApiFunction:
case kCallApiMethod:
// Need to check that none of the receiver maps could have changed.
Add<HCheckMaps>(receiver, receiver_maps);
Add<HCheckMaps>(receiver, receiver_maps, top_info());
// Need to ensure the chain between receiver and api_holder is intact.
if (holder_lookup == CallOptimization::kHolderFound) {
AddCheckPrototypeMaps(api_holder, receiver_maps->first());

View File

@ -538,6 +538,7 @@ TEST(DeoptimizeCompare) {
TEST(DeoptimizeLoadICStoreIC) {
i::FLAG_concurrent_recompilation = false;
i::FLAG_check_elimination = false;
LocalContext env;
v8::HandleScope scope(env->GetIsolate());
@ -619,6 +620,7 @@ TEST(DeoptimizeLoadICStoreIC) {
TEST(DeoptimizeLoadICStoreICNested) {
i::FLAG_concurrent_recompilation = false;
i::FLAG_check_elimination = false;
LocalContext env;
v8::HandleScope scope(env->GetIsolate());

View File

@ -47,7 +47,9 @@ function g() {
var fun = g();
fun(false, c);
fun(false, c);
%OptimizeFunctionOnNextCall(fun);
fun(false, c);
%TryMigrateInstance(c);
%OptimizeFunctionOnNextCall(fun);
fun(false, c);
fun(true, c);