Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(389)

Unified Diff: src/hydrogen.cc

Issue 10170030: Implement tracking and optimizations of packed arrays (Closed) Base URL: https://v8.googlecode.com/svn/branches/bleeding_edge
Patch Set: Review feedback Created 8 years, 7 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « src/hydrogen.h ('k') | src/hydrogen-instructions.h » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 99beda097bbea97a5d537c982dcfb3c96decdfc2..b9ad8af529d82a9f078d61c0d88af6594b61ac64 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -1709,23 +1709,23 @@ void HGlobalValueNumberer::ProcessLoopBlock(
bool can_hoist = !instr->gvn_flags().ContainsAnyOf(depends_flags);
if (instr->IsTransitionElementsKind()) {
// It's possible to hoist transitions out of a loop as long as the
- // hoisting wouldn't move the transition past a DependsOn of one of it's
- // changes or any instructions that might change an objects map or
- // elements contents.
- GVNFlagSet changes = instr->ChangesFlags();
+ // hoisting wouldn't move the transition past an instruction that has a
+ // DependsOn flag for anything it changes.
GVNFlagSet hoist_depends_blockers =
- HValue::ConvertChangesToDependsFlags(changes);
- // In addition to not hoisting transitions above other instructions that
- // change dependencies that the transition changes, it must not be
- // hoisted above map changes and stores to an elements backing store
- // that the transition might change.
- GVNFlagSet hoist_change_blockers = changes;
- hoist_change_blockers.Add(kChangesMaps);
+ HValue::ConvertChangesToDependsFlags(instr->ChangesFlags());
+
+ // In addition, the transition must not be hoisted above elements kind
+ // changes, or if the transition is destructive to the elements buffer,
+ // changes to array pointer or array contents.
+ GVNFlagSet hoist_change_blockers;
+ hoist_change_blockers.Add(kChangesElementsKind);
HTransitionElementsKind* trans = HTransitionElementsKind::cast(instr);
if (trans->original_map()->has_fast_double_elements()) {
+ hoist_change_blockers.Add(kChangesElementsPointer);
hoist_change_blockers.Add(kChangesDoubleArrayElements);
}
if (trans->transitioned_map()->has_fast_double_elements()) {
+ hoist_change_blockers.Add(kChangesElementsPointer);
hoist_change_blockers.Add(kChangesArrayElements);
}
if (FLAG_trace_gvn) {
@@ -3966,7 +3966,7 @@ void HGraphBuilder::VisitForInStatement(ForInStatement* stmt) {
new(zone()) HLoadKeyedFastElement(
environment()->ExpressionStackAt(2), // Enum cache.
environment()->ExpressionStackAt(0), // Iteration index.
- HLoadKeyedFastElement::OMIT_HOLE_CHECK));
+ OMIT_HOLE_CHECK));
// Check if the expected map still matches that of the enumerable.
// If not just deoptimize.
@@ -4257,7 +4257,7 @@ static bool IsFastLiteral(Handle<JSObject> boilerplate,
elements->map() != boilerplate->GetHeap()->fixed_cow_array_map()) {
if (boilerplate->HasFastDoubleElements()) {
*total_size += FixedDoubleArray::SizeFor(elements->length());
- } else if (boilerplate->HasFastElements()) {
+ } else if (boilerplate->HasFastObjectElements()) {
Handle<FixedArray> fast_elements = Handle<FixedArray>::cast(elements);
int length = elements->length();
for (int i = 0; i < length; i++) {
@@ -4464,11 +4464,13 @@ void HGraphBuilder::VisitArrayLiteral(ArrayLiteral* expr) {
Representation::Integer32()));
switch (boilerplate_elements_kind) {
- case FAST_SMI_ONLY_ELEMENTS:
+ case FAST_SMI_ELEMENTS:
+ case FAST_HOLEY_SMI_ELEMENTS:
// Smi-only arrays need a smi check.
AddInstruction(new(zone()) HCheckSmi(value));
// Fall through.
case FAST_ELEMENTS:
+ case FAST_HOLEY_ELEMENTS:
AddInstruction(new(zone()) HStoreKeyedFastElement(
elements,
key,
@@ -4476,6 +4478,7 @@ void HGraphBuilder::VisitArrayLiteral(ArrayLiteral* expr) {
boilerplate_elements_kind));
break;
case FAST_DOUBLE_ELEMENTS:
+ case FAST_HOLEY_DOUBLE_ELEMENTS:
AddInstruction(new(zone()) HStoreKeyedFastDoubleElement(elements,
key,
value));
@@ -5233,9 +5236,12 @@ HInstruction* HGraphBuilder::BuildExternalArrayElementAccess(
case EXTERNAL_FLOAT_ELEMENTS:
case EXTERNAL_DOUBLE_ELEMENTS:
break;
- case FAST_SMI_ONLY_ELEMENTS:
+ case FAST_SMI_ELEMENTS:
case FAST_ELEMENTS:
case FAST_DOUBLE_ELEMENTS:
+ case FAST_HOLEY_SMI_ELEMENTS:
+ case FAST_HOLEY_ELEMENTS:
+ case FAST_HOLEY_DOUBLE_ELEMENTS:
case DICTIONARY_ELEMENTS:
case NON_STRICT_ARGUMENTS_ELEMENTS:
UNREACHABLE();
@@ -5260,13 +5266,16 @@ HInstruction* HGraphBuilder::BuildFastElementAccess(HValue* elements,
ASSERT(val != NULL);
switch (elements_kind) {
case FAST_DOUBLE_ELEMENTS:
+ case FAST_HOLEY_DOUBLE_ELEMENTS:
return new(zone()) HStoreKeyedFastDoubleElement(
elements, checked_key, val);
- case FAST_SMI_ONLY_ELEMENTS:
+ case FAST_SMI_ELEMENTS:
+ case FAST_HOLEY_SMI_ELEMENTS:
// Smi-only arrays need a smi check.
AddInstruction(new(zone()) HCheckSmi(val));
// Fall through.
case FAST_ELEMENTS:
+ case FAST_HOLEY_ELEMENTS:
return new(zone()) HStoreKeyedFastElement(
elements, checked_key, val, elements_kind);
default:
@@ -5275,10 +5284,13 @@ HInstruction* HGraphBuilder::BuildFastElementAccess(HValue* elements,
}
}
// It's an element load (!is_store).
- if (elements_kind == FAST_DOUBLE_ELEMENTS) {
- return new(zone()) HLoadKeyedFastDoubleElement(elements, checked_key);
- } else { // FAST_ELEMENTS or FAST_SMI_ONLY_ELEMENTS.
- return new(zone()) HLoadKeyedFastElement(elements, checked_key);
+ HoleCheckMode mode = IsFastPackedElementsKind(elements_kind) ?
+ OMIT_HOLE_CHECK :
+ PERFORM_HOLE_CHECK;
+ if (IsFastDoubleElementsKind(elements_kind)) {
+ return new(zone()) HLoadKeyedFastDoubleElement(elements, checked_key, mode);
+ } else { // Smi or Object elements.
+ return new(zone()) HLoadKeyedFastElement(elements, checked_key, mode);
}
}
@@ -5286,15 +5298,30 @@ HInstruction* HGraphBuilder::BuildFastElementAccess(HValue* elements,
HInstruction* HGraphBuilder::BuildMonomorphicElementAccess(HValue* object,
HValue* key,
HValue* val,
+ HValue* dependency,
Handle<Map> map,
bool is_store) {
- HInstruction* mapcheck = AddInstruction(new(zone()) HCheckMaps(object, map));
- bool fast_smi_only_elements = map->has_fast_smi_only_elements();
- bool fast_elements = map->has_fast_elements();
+ HInstruction* mapcheck =
+ AddInstruction(new(zone()) HCheckMaps(object, map, dependency));
+ // No GVNFlag is necessary for ElementsKind if there is an explicit dependency
+ // on a HElementsTransition instruction. The flag can also be removed if the
+ // map to check has FAST_HOLEY_ELEMENTS, since there can be no further
+ // ElementsKind transitions. Finally, the dependency can be removed for stores
+ // for FAST_ELEMENTS, since a transition to HOLEY elements won't change the
+ // generated store code.
+ if (dependency ||
+ (map->elements_kind() == FAST_HOLEY_ELEMENTS) ||
+ (map->elements_kind() == FAST_ELEMENTS && is_store)) {
+ mapcheck->ClearGVNFlag(kDependsOnElementsKind);
+ }
+ bool fast_smi_only_elements = map->has_fast_smi_elements();
+ bool fast_elements = map->has_fast_object_elements();
HInstruction* elements = AddInstruction(new(zone()) HLoadElements(object));
if (is_store && (fast_elements || fast_smi_only_elements)) {
- AddInstruction(new(zone()) HCheckMaps(
- elements, isolate()->factory()->fixed_array_map()));
+ HCheckMaps* check_cow_map = new(zone()) HCheckMaps(
+ elements, isolate()->factory()->fixed_array_map());
+ check_cow_map->ClearGVNFlag(kDependsOnElementsKind);
+ AddInstruction(check_cow_map);
}
HInstruction* length = NULL;
HInstruction* checked_key = NULL;
@@ -5347,8 +5374,8 @@ HValue* HGraphBuilder::HandlePolymorphicElementAccess(HValue* object,
for (int i = 0; i < maps->length(); ++i) {
Handle<Map> map = maps->at(i);
ElementsKind elements_kind = map->elements_kind();
- if (elements_kind == FAST_DOUBLE_ELEMENTS ||
- elements_kind == FAST_ELEMENTS) {
+ if (IsFastElementsKind(elements_kind) &&
+ elements_kind != GetInitialFastElementsKind()) {
possible_transitioned_maps.Add(map);
}
}
@@ -5362,12 +5389,17 @@ HValue* HGraphBuilder::HandlePolymorphicElementAccess(HValue* object,
int num_untransitionable_maps = 0;
Handle<Map> untransitionable_map;
+ HTransitionElementsKind* transition = NULL;
for (int i = 0; i < maps->length(); ++i) {
Handle<Map> map = maps->at(i);
ASSERT(map->IsMap());
if (!transition_target.at(i).is_null()) {
- AddInstruction(new(zone()) HTransitionElementsKind(
- object, map, transition_target.at(i)));
+ ASSERT(Map::IsValidElementsTransition(
+ map->elements_kind(),
+ transition_target.at(i)->elements_kind()));
+ transition = new(zone()) HTransitionElementsKind(
+ object, map, transition_target.at(i));
+ AddInstruction(transition);
} else {
type_todo[map->elements_kind()] = true;
if (map->elements_kind() >= FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND) {
@@ -5387,7 +5419,7 @@ HValue* HGraphBuilder::HandlePolymorphicElementAccess(HValue* object,
: BuildLoadKeyedGeneric(object, key));
} else {
instr = AddInstruction(BuildMonomorphicElementAccess(
- object, key, val, untransitionable_map, is_store));
+ object, key, val, transition, untransitionable_map, is_store));
}
*has_side_effects |= instr->HasObservableSideEffects();
instr->set_position(position);
@@ -5404,20 +5436,18 @@ HValue* HGraphBuilder::HandlePolymorphicElementAccess(HValue* object,
HLoadExternalArrayPointer* external_elements = NULL;
HInstruction* checked_key = NULL;
- // Generated code assumes that FAST_SMI_ONLY_ELEMENTS, FAST_ELEMENTS,
- // FAST_DOUBLE_ELEMENTS and DICTIONARY_ELEMENTS are handled before external
- // arrays.
- STATIC_ASSERT(FAST_SMI_ONLY_ELEMENTS < FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND);
- STATIC_ASSERT(FAST_ELEMENTS < FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND);
+ // Generated code assumes that FAST_* and DICTIONARY_ELEMENTS ElementsKinds
+ // are handled before external arrays.
+ STATIC_ASSERT(FAST_SMI_ELEMENTS < FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND);
+ STATIC_ASSERT(FAST_HOLEY_ELEMENTS < FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND);
STATIC_ASSERT(FAST_DOUBLE_ELEMENTS < FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND);
STATIC_ASSERT(DICTIONARY_ELEMENTS < FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND);
for (ElementsKind elements_kind = FIRST_ELEMENTS_KIND;
elements_kind <= LAST_ELEMENTS_KIND;
elements_kind = ElementsKind(elements_kind + 1)) {
- // After having handled FAST_ELEMENTS, FAST_SMI_ONLY_ELEMENTS,
- // FAST_DOUBLE_ELEMENTS and DICTIONARY_ELEMENTS, we need to add some code
- // that's executed for all external array cases.
+ // After having handled FAST_* and DICTIONARY_ELEMENTS, we need to add some
+ // code that's executed for all external array cases.
STATIC_ASSERT(LAST_EXTERNAL_ARRAY_ELEMENTS_KIND ==
LAST_ELEMENTS_KIND);
if (elements_kind == FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND
@@ -5439,10 +5469,8 @@ HValue* HGraphBuilder::HandlePolymorphicElementAccess(HValue* object,
set_current_block(if_true);
HInstruction* access;
- if (elements_kind == FAST_SMI_ONLY_ELEMENTS ||
- elements_kind == FAST_ELEMENTS ||
- elements_kind == FAST_DOUBLE_ELEMENTS) {
- if (is_store && elements_kind != FAST_DOUBLE_ELEMENTS) {
+ if (IsFastElementsKind(elements_kind)) {
+ if (is_store && !IsFastDoubleElementsKind(elements_kind)) {
AddInstruction(new(zone()) HCheckMaps(
elements, isolate()->factory()->fixed_array_map(),
elements_kind_branch));
@@ -5529,7 +5557,7 @@ HValue* HGraphBuilder::HandleKeyedElementAccess(HValue* obj,
: BuildLoadKeyedGeneric(obj, key);
} else {
AddInstruction(new(zone()) HCheckNonSmi(obj));
- instr = BuildMonomorphicElementAccess(obj, key, val, map, is_store);
+ instr = BuildMonomorphicElementAccess(obj, key, val, NULL, map, is_store);
}
} else if (expr->GetReceiverTypes() != NULL &&
!expr->GetReceiverTypes()->is_empty()) {
« no previous file with comments | « src/hydrogen.h ('k') | src/hydrogen-instructions.h » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698