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X87: Use Cells to check prototype chain validity (disabled by default).

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port 0179ec5797 (r27846).

original commit message:

 The cells are stored on prototypes (in their map's PrototypeInfo). When a
 prototype object changes its map, then both its own validity cell and those
 of all "downsstream" prototypes are invalidated; handlers for a given receiver
 embed the currently valid cell for that receiver's prototype during their
 compilation and check it on execution.

BUG=

Review URL: https://codereview.chromium.org/1090803002

Cr-Commit-Position: refs/heads/master@{#27877}
This commit is contained in:
chunyang.dai 2015-04-16 03:40:54 -07:00 committed by Commit bot
parent a3f5e04c99
commit 758c5e123b
1 changed files with 52 additions and 13 deletions
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65
src/ic/x87/handler-compiler-x87.cc
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@ -414,8 +414,8 @@ void NamedStoreHandlerCompiler::GenerateFieldTypeChecks(HeapType* field_type,
Register PropertyHandlerCompiler::CheckPrototypes(
Register object_reg, Register holder_reg, Register scratch1,
Register scratch2, Handle<Name> name, Label* miss,
PrototypeCheckType check) {
Register scratch2, Handle<Name> name, Label* miss, PrototypeCheckType check,
ReturnHolder return_what) {
Handle<Map> receiver_map = map();
// Make sure there's no overlap between holder and object registers.
@ -423,6 +423,30 @@ Register PropertyHandlerCompiler::CheckPrototypes(
DCHECK(!scratch2.is(object_reg) && !scratch2.is(holder_reg) &&
!scratch2.is(scratch1));
if (FLAG_eliminate_prototype_chain_checks) {
Handle<Cell> validity_cell =
Map::GetOrCreatePrototypeChainValidityCell(receiver_map, isolate());
if (!validity_cell.is_null()) {
DCHECK_EQ(Smi::FromInt(Map::kPrototypeChainValid),
validity_cell->value());
// Operand::ForCell(...) points to the cell's payload!
__ cmp(Operand::ForCell(validity_cell),
Immediate(Smi::FromInt(Map::kPrototypeChainValid)));
__ j(not_equal, miss);
}
// The prototype chain of primitives (and their JSValue wrappers) depends
// on the native context, which can't be guarded by validity cells.
// |object_reg| holds the native context specific prototype in this case;
// we need to check its map.
if (check == CHECK_ALL_MAPS) {
__ mov(scratch1, FieldOperand(object_reg, HeapObject::kMapOffset));
Handle<WeakCell> cell = Map::WeakCellForMap(receiver_map);
__ CmpWeakValue(scratch1, cell, scratch2);
__ j(not_equal, miss);
}
}
// Keep track of the current object in register reg.
Register reg = object_reg;
int depth = 0;
@ -467,28 +491,37 @@ Register PropertyHandlerCompiler::CheckPrototypes(
current->property_dictionary()->FindEntry(name) ==
NameDictionary::kNotFound);
if (FLAG_eliminate_prototype_chain_checks && depth > 1) {
// TODO(jkummerow): Cache and re-use weak cell.
__ LoadWeakValue(reg, isolate()->factory()->NewWeakCell(current), miss);
}
GenerateDictionaryNegativeLookup(masm(), miss, reg, name, scratch1,
scratch2);
__ mov(scratch1, FieldOperand(reg, HeapObject::kMapOffset));
reg = holder_reg; // From now on the object will be in holder_reg.
__ mov(reg, FieldOperand(scratch1, Map::kPrototypeOffset));
if (!FLAG_eliminate_prototype_chain_checks) {
__ mov(scratch1, FieldOperand(reg, HeapObject::kMapOffset));
__ mov(holder_reg, FieldOperand(scratch1, Map::kPrototypeOffset));
}
} else {
Register map_reg = scratch1;
__ mov(map_reg, FieldOperand(reg, HeapObject::kMapOffset));
if (!FLAG_eliminate_prototype_chain_checks) {
__ mov(map_reg, FieldOperand(reg, HeapObject::kMapOffset));
}
if (current_map->IsJSGlobalObjectMap()) {
GenerateCheckPropertyCell(masm(), Handle<JSGlobalObject>::cast(current),
name, scratch2, miss);
} else if (depth != 1 || check == CHECK_ALL_MAPS) {
} else if (!FLAG_eliminate_prototype_chain_checks &&
(depth != 1 || check == CHECK_ALL_MAPS)) {
Handle<WeakCell> cell = Map::WeakCellForMap(current_map);
__ CmpWeakValue(map_reg, cell, scratch2);
__ j(not_equal, miss);
}
reg = holder_reg; // From now on the object will be in holder_reg.
__ mov(reg, FieldOperand(map_reg, Map::kPrototypeOffset));
if (!FLAG_eliminate_prototype_chain_checks) {
__ mov(holder_reg, FieldOperand(map_reg, Map::kPrototypeOffset));
}
}
reg = holder_reg; // From now on the object will be in holder_reg.
// Go to the next object in the prototype chain.
current = prototype;
current_map = handle(current->map());
@ -499,7 +532,8 @@ Register PropertyHandlerCompiler::CheckPrototypes(
// Log the check depth.
LOG(isolate(), IntEvent("check-maps-depth", depth + 1));
if (depth != 0 || check == CHECK_ALL_MAPS) {
if (!FLAG_eliminate_prototype_chain_checks &&
(depth != 0 || check == CHECK_ALL_MAPS)) {
// Check the holder map.
__ mov(scratch1, FieldOperand(reg, HeapObject::kMapOffset));
Handle<WeakCell> cell = Map::WeakCellForMap(current_map);
@ -507,8 +541,13 @@ Register PropertyHandlerCompiler::CheckPrototypes(
__ j(not_equal, miss);
}
bool return_holder = return_what == RETURN_HOLDER;
if (FLAG_eliminate_prototype_chain_checks && return_holder && depth != 0) {
__ LoadWeakValue(reg, isolate()->factory()->NewWeakCell(current), miss);
}
// Return the register containing the holder.
return reg;
return return_holder ? reg : no_reg;
}
@ -738,7 +777,7 @@ Handle<Code> NamedLoadHandlerCompiler::CompileLoadGlobal(
if (IC::ICUseVector(kind())) {
PushVectorAndSlot();
}
FrontendHeader(receiver(), name, &miss);
FrontendHeader(receiver(), name, &miss, DONT_RETURN_ANYTHING);
// Get the value from the cell.
Register result = StoreDescriptor::ValueRegister();
Handle<WeakCell> weak_cell = factory()->NewWeakCell(cell);