Revision: 9712
Author: [email protected]
Date: Thu Oct 20 01:41:38 2011
Log: Handle keyed stores after elements transition monomorphically if
possible
Review URL: http://codereview.chromium.org/8354003
http://code.google.com/p/v8/source/detail?r=9712
Modified:
/branches/bleeding_edge/src/hydrogen.cc
/branches/bleeding_edge/src/hydrogen.h
/branches/bleeding_edge/src/type-info.cc
=======================================
--- /branches/bleeding_edge/src/hydrogen.cc Wed Oct 19 05:10:18 2011
+++ /branches/bleeding_edge/src/hydrogen.cc Thu Oct 20 01:41:38 2011
@@ -4034,11 +4034,8 @@
HInstruction* HGraphBuilder::BuildMonomorphicElementAccess(HValue* object,
HValue* key,
HValue* val,
- Expression*
expr,
+ Handle<Map> map,
bool is_store) {
- ASSERT(expr->IsMonomorphic());
- Handle<Map> map = expr->GetMonomorphicReceiverType();
- AddInstruction(new(zone()) HCheckNonSmi(object));
HInstruction* mapcheck = AddInstruction(new(zone()) HCheckMap(object,
map));
bool fast_smi_only_elements = map->has_fast_smi_only_elements();
bool fast_elements = map->has_fast_elements();
@@ -4088,7 +4085,6 @@
bool*
has_side_effects) {
*has_side_effects = false;
AddInstruction(new(zone()) HCheckNonSmi(object));
- AddInstruction(HCheckInstanceType::NewIsSpecObject(object));
SmallMapList* maps = prop->GetReceiverTypes();
bool todo_external_array = false;
@@ -4120,6 +4116,8 @@
}
}
+ int num_untransitionable_maps = 0;
+ Handle<Map> untransitionable_map;
for (int i = 0; i < maps->length(); ++i) {
Handle<Map> map = maps->at(i);
ASSERT(map->IsMap());
@@ -4132,9 +4130,22 @@
if (map->elements_kind() >= FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND) {
todo_external_array = true;
}
+ num_untransitionable_maps++;
+ untransitionable_map = map;
}
}
+ // If only one map is left after transitioning, handle this case
+ // monomorphically.
+ if (num_untransitionable_maps == 1) {
+ HInstruction* instr = AddInstruction(BuildMonomorphicElementAccess(
+ object, key, val, untransitionable_map, is_store));
+ *has_side_effects |= instr->HasSideEffects();
+ instr->set_position(position);
+ return is_store ? NULL : instr;
+ }
+
+ AddInstruction(HCheckInstanceType::NewIsSpecObject(object));
HBasicBlock* join = graph()->CreateBasicBlock();
HInstruction* elements_kind_instr =
@@ -4266,7 +4277,9 @@
ASSERT(!expr->IsPropertyName());
HInstruction* instr = NULL;
if (expr->IsMonomorphic()) {
- instr = BuildMonomorphicElementAccess(obj, key, val, expr, is_store);
+ Handle<Map> map = expr->GetMonomorphicReceiverType();
+ AddInstruction(new(zone()) HCheckNonSmi(obj));
+ instr = BuildMonomorphicElementAccess(obj, key, val, map, is_store);
} else if (expr->GetReceiverTypes() != NULL &&
!expr->GetReceiverTypes()->is_empty()) {
return HandlePolymorphicElementAccess(
=======================================
--- /branches/bleeding_edge/src/hydrogen.h Wed Oct 19 00:35:30 2011
+++ /branches/bleeding_edge/src/hydrogen.h Thu Oct 20 01:41:38 2011
@@ -950,7 +950,7 @@
HInstruction* BuildMonomorphicElementAccess(HValue* object,
HValue* key,
HValue* val,
- Expression* expr,
+ Handle<Map> map,
bool is_store);
HValue* HandlePolymorphicElementAccess(HValue* object,
HValue* key,
=======================================
--- /branches/bleeding_edge/src/type-info.cc Fri Oct 14 05:26:29 2011
+++ /branches/bleeding_edge/src/type-info.cc Thu Oct 20 01:41:38 2011
@@ -421,6 +421,14 @@
isolate_->stub_cache()->CollectMatchingMaps(types, *name, flags);
}
}
+
+
+static void AddMapIfMissing(Handle<Map> map, SmallMapList* list) {
+ for (int i = 0; i < list->length(); ++i) {
+ if (list->at(i).is_identical_to(map)) return;
+ }
+ list->Add(map);
+}
void TypeFeedbackOracle::CollectKeyedReceiverTypes(unsigned ast_id,
@@ -436,7 +444,7 @@
RelocInfo* info = it.rinfo();
Object* object = info->target_object();
if (object->IsMap()) {
- types->Add(Handle<Map>(Map::cast(object)));
+ AddMapIfMissing(Handle<Map>(Map::cast(object)), types);
}
}
}
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