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dart / sdk / b3055a148252f1ef73a18e5a45bcf8eb1dd18652 / . / runtime / vm / compiler / backend / il.cc
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// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#if !defined(DART_PRECOMPILED_RUNTIME)
#include "vm/compiler/backend/il.h"
#include "vm/bit_vector.h"
#include "vm/bootstrap.h"
#include "vm/compiler/backend/code_statistics.h"
#include "vm/compiler/backend/constant_propagator.h"
#include "vm/compiler/backend/flow_graph_compiler.h"
#include "vm/compiler/backend/linearscan.h"
#include "vm/compiler/backend/locations.h"
#include "vm/compiler/backend/loops.h"
#include "vm/compiler/backend/range_analysis.h"
#include "vm/compiler/frontend/flow_graph_builder.h"
#include "vm/compiler/jit/compiler.h"
#include "vm/compiler/method_recognizer.h"
#include "vm/cpu.h"
#include "vm/dart_entry.h"
#include "vm/object.h"
#include "vm/object_store.h"
#include "vm/os.h"
#include "vm/regexp_assembler_ir.h"
#include "vm/resolver.h"
#include "vm/scopes.h"
#include "vm/stub_code.h"
#include "vm/symbols.h"
#include "vm/type_testing_stubs.h"
#include "vm/compiler/backend/il_printer.h"
namespace dart {
DEFINE_FLAG(bool,
propagate_ic_data,
true,
"Propagate IC data from unoptimized to optimized IC calls.");
DEFINE_FLAG(bool,
two_args_smi_icd,
true,
"Generate special IC stubs for two args Smi operations");
DEFINE_FLAG(bool,
unbox_numeric_fields,
!USING_DBC,
"Support unboxed double and float32x4 fields.");
class SubclassFinder {
public:
SubclassFinder(Zone* zone,
GrowableArray<intptr_t>* cids,
bool include_abstract)
: array_handles_(zone),
class_handles_(zone),
cids_(cids),
include_abstract_(include_abstract) {}
void ScanSubClasses(const Class& klass) {
if (include_abstract_ || !klass.is_abstract()) {
cids_->Add(klass.id());
}
ScopedHandle<GrowableObjectArray> array(&array_handles_);
ScopedHandle<Class> subclass(&class_handles_);
*array = klass.direct_subclasses();
if (!array->IsNull()) {
for (intptr_t i = 0; i < array->Length(); ++i) {
*subclass ^= array->At(i);
ScanSubClasses(*subclass);
}
}
}
void ScanImplementorClasses(const Class& klass) {
// An implementor of [klass] is
// * the [klass] itself.
// * all implementors of the direct subclasses of [klass].
// * all implementors of the direct implementors of [klass].
if (include_abstract_ || !klass.is_abstract()) {
cids_->Add(klass.id());
}
ScopedHandle<GrowableObjectArray> array(&array_handles_);
ScopedHandle<Class> subclass_or_implementor(&class_handles_);
*array = klass.direct_subclasses();
if (!array->IsNull()) {
for (intptr_t i = 0; i < array->Length(); ++i) {
*subclass_or_implementor ^= (*array).At(i);
ScanImplementorClasses(*subclass_or_implementor);
}
}
*array = klass.direct_implementors();
if (!array->IsNull()) {
for (intptr_t i = 0; i < array->Length(); ++i) {
*subclass_or_implementor ^= (*array).At(i);
ScanImplementorClasses(*subclass_or_implementor);
}
}
}
private:
ReusableHandleStack<GrowableObjectArray> array_handles_;
ReusableHandleStack<Class> class_handles_;
GrowableArray<intptr_t>* cids_;
const bool include_abstract_;
};
const CidRangeVector& HierarchyInfo::SubtypeRangesForClass(
const Class& klass,
bool include_abstract) {
ClassTable* table = thread()->isolate()->class_table();
const intptr_t cid_count = table->NumCids();
CidRangeVector** cid_ranges =
include_abstract ? &cid_subtype_ranges_abstract_ : &cid_subtype_ranges_;
if (*cid_ranges == NULL) {
*cid_ranges = new CidRangeVector[cid_count];
}
CidRangeVector& ranges = (*cid_ranges)[klass.id()];
if (ranges.length() == 0) {
if (!FLAG_precompiled_mode) {
BuildRangesForJIT(table, &ranges, klass, /*use_subtype_test=*/true,
include_abstract);
} else {
BuildRangesFor(table, &ranges, klass, /*use_subtype_test=*/true,
include_abstract);
}
}
return ranges;
}
const CidRangeVector& HierarchyInfo::SubclassRangesForClass(
const Class& klass) {
ClassTable* table = thread()->isolate()->class_table();
const intptr_t cid_count = table->NumCids();
if (cid_subclass_ranges_ == NULL) {
cid_subclass_ranges_ = new CidRangeVector[cid_count];
}
CidRangeVector& ranges = cid_subclass_ranges_[klass.id()];
if (ranges.length() == 0) {
if (!FLAG_precompiled_mode) {
BuildRangesForJIT(table, &ranges, klass, /*use_subtype_test=*/true);
} else {
BuildRangesFor(table, &ranges, klass, /*use_subtype_test=*/false);
}
}
return ranges;
}
void HierarchyInfo::BuildRangesFor(ClassTable* table,
CidRangeVector* ranges,
const Class& klass,
bool use_subtype_test,
bool include_abstract) {
Zone* zone = thread()->zone();
ClassTable* class_table = thread()->isolate()->class_table();
// Only really used if `use_subtype_test == true`.
const Type& dst_type = Type::Handle(zone, Type::RawCast(klass.RareType()));
AbstractType& cls_type = AbstractType::Handle(zone);
Class& cls = Class::Handle(zone);
AbstractType& super_type = AbstractType::Handle(zone);
const intptr_t cid_count = table->NumCids();
intptr_t start = -1;
for (intptr_t cid = kInstanceCid; cid < cid_count; ++cid) {
// Create local zone because deep hierarchies may allocate lots of handles
// within one iteration of this loop.
StackZone stack_zone(thread());
HANDLESCOPE(thread());
if (!table->HasValidClassAt(cid)) continue;
if (cid == kTypeArgumentsCid) continue;
if (cid == kVoidCid) continue;
if (cid == kDynamicCid) continue;
if (cid == kNullCid) continue;
cls = table->At(cid);
if (!include_abstract && cls.is_abstract()) continue;
if (cls.is_patch()) continue;
if (cls.IsTopLevel()) continue;
// We are either interested in [CidRange]es of subclasses or subtypes.
bool test_succeded = false;
if (use_subtype_test) {
cls_type = cls.RareType();
test_succeded = cls_type.IsSubtypeOf(dst_type, NULL, NULL, Heap::kNew);
} else {
while (!cls.IsObjectClass()) {
if (cls.raw() == klass.raw()) {
test_succeded = true;
break;
}
super_type = cls.super_type();
const intptr_t type_class_id = super_type.type_class_id();
cls = class_table->At(type_class_id);
}
}
if (start == -1 && test_succeded) {
start = cid;
} else if (start != -1 && !test_succeded) {
CidRange range(start, cid - 1);
ranges->Add(range);
start = -1;
}
}
if (start != -1) {
CidRange range(start, cid_count - 1);
ranges->Add(range);
}
if (start == -1 && ranges->length() == 0) {
CidRange range;
ASSERT(range.IsIllegalRange());
ranges->Add(range);
}
}
void HierarchyInfo::BuildRangesForJIT(ClassTable* table,
CidRangeVector* ranges,
const Class& dst_klass,
bool use_subtype_test,
bool include_abstract) {
if (dst_klass.InVMHeap()) {
BuildRangesFor(table, ranges, dst_klass, use_subtype_test,
include_abstract);
return;
}
Zone* zone = thread()->zone();
GrowableArray<intptr_t> cids;
SubclassFinder finder(zone, &cids, include_abstract);
if (use_subtype_test) {
finder.ScanImplementorClasses(dst_klass);
} else {
finder.ScanSubClasses(dst_klass);
}
// Sort all collected cids.
intptr_t* cids_array = cids.data();
qsort(cids_array, cids.length(), sizeof(intptr_t),
[](const void* a, const void* b) {
return static_cast<int>(*static_cast<const intptr_t*>(a) -
*static_cast<const intptr_t*>(b));
});
// Build ranges of all the cids.
Class& klass = Class::Handle();
intptr_t left_cid = -1;
intptr_t last_cid = -1;
for (intptr_t i = 0; i < cids.length(); ++i) {
if (left_cid == -1) {
left_cid = last_cid = cids[i];
} else {
const intptr_t current_cid = cids[i];
// Skip duplicates.
if (current_cid == last_cid) continue;
// Consecutive numbers cids are ok.
if (current_cid == (last_cid + 1)) {
last_cid = current_cid;
} else {
// We sorted, after all!
RELEASE_ASSERT(last_cid < current_cid);
intptr_t j = last_cid + 1;
for (; j < current_cid; ++j) {
if (table->HasValidClassAt(j)) {
klass = table->At(j);
if (!klass.is_patch() && !klass.IsTopLevel()) {
// If we care about abstract classes also, we cannot skip over any
// arbitrary abstract class, only those which are subtypes.
if (include_abstract) {
break;
}
// If the class is concrete we cannot skip over it.
if (!klass.is_abstract()) {
break;
}
}
}
}
if (current_cid == j) {
// If there's only abstract cids between [last_cid] and the
// [current_cid] then we connect them.
last_cid = current_cid;
} else {
// Finish the current open cid range and start a new one.
ranges->Add(CidRange{left_cid, last_cid});
left_cid = last_cid = current_cid;
}
}
}
}
// If there is an open cid-range which we haven't finished yet, we'll
// complete it.
if (left_cid != -1) {
ranges->Add(CidRange{left_cid, last_cid});
}
}
bool HierarchyInfo::CanUseSubtypeRangeCheckFor(const AbstractType& type) {
ASSERT(type.IsFinalized() && !type.IsMalformedOrMalbounded());
if (!type.IsInstantiated() || !type.IsType() || type.IsFunctionType() ||
type.IsDartFunctionType()) {
return false;
}
Zone* zone = thread()->zone();
const Class& type_class = Class::Handle(zone, type.type_class());
// The FutureOr<T> type cannot be handled by checking whether the instance is
// a subtype of FutureOr and then checking whether the type argument `T`
// matches.
//
// Instead we would need to perform multiple checks:
//
// instance is Null || instance is T || instance is Future<T>
//
if (type_class.IsFutureOrClass()) {
return false;
}
// We can use class id range checks only if we don't have to test type
// arguments.
//
// This is e.g. true for "String" but also for "List<dynamic>". (A type for
// which the type arguments vector is filled with "dynamic" is known as a rare
// type)
if (type_class.IsGeneric()) {
// TODO(kustermann): We might want to consider extending this when the type
// arguments are not "dynamic" but instantiated-to-bounds.
const Type& rare_type =
Type::Handle(zone, Type::RawCast(type_class.RareType()));
if (!rare_type.Equals(type)) {
return false;
}
}
return true;
}
bool HierarchyInfo::CanUseGenericSubtypeRangeCheckFor(
const AbstractType& type) {
ASSERT(type.IsFinalized() && !type.IsMalformedOrMalbounded());
if (!type.IsType() || type.IsFunctionType() || type.IsDartFunctionType()) {
return false;
}
// NOTE: We do allow non-instantiated types here (in comparison to
// [CanUseSubtypeRangeCheckFor], since we handle type parameters in the type
// expression in some cases (see below).
Zone* zone = thread()->zone();
const Class& type_class = Class::Handle(zone, type.type_class());
const intptr_t num_type_parameters = type_class.NumTypeParameters();
const intptr_t num_type_arguments = type_class.NumTypeArguments();
// The FutureOr<T> type cannot be handled by checking whether the instance is
// a subtype of FutureOr and then checking whether the type argument `T`
// matches.
//
// Instead we would need to perform multiple checks:
//
// instance is Null || instance is T || instance is Future<T>
//
if (type_class.IsFutureOrClass()) {
return false;
}
// This function should only be called for generic classes.
ASSERT(type_class.NumTypeParameters() > 0 &&
type.arguments() != TypeArguments::null());
// If the type class is implemented the different implementations might have
// their type argument vector stored at different offsets and we can therefore
// not perform our optimized [CidRange]-based implementation.
//
// TODO(kustermann): If the class is implemented but all implementations
// store the instantator type argument vector at the same offset we can
// still do it!
if (type_class.is_implemented()) {
return false;
}
const TypeArguments& ta =
TypeArguments::Handle(zone, Type::Cast(type).arguments());
ASSERT(ta.Length() == num_type_arguments);
// The last [num_type_pararameters] entries in the [TypeArguments] vector [ta]
// are the values we have to check against. Ensure we can handle all of them
// via [CidRange]-based checks or that it is a type parameter.
AbstractType& type_arg = AbstractType::Handle(zone);
for (intptr_t i = 0; i < num_type_parameters; ++i) {
type_arg = ta.TypeAt(num_type_arguments - num_type_parameters + i);
if (!CanUseSubtypeRangeCheckFor(type_arg) && !type_arg.IsTypeParameter()) {
return false;
}
}
return true;
}
bool HierarchyInfo::InstanceOfHasClassRange(const AbstractType& type,
intptr_t* lower_limit,
intptr_t* upper_limit) {
if (CanUseSubtypeRangeCheckFor(type)) {
const Class& type_class =
Class::Handle(thread()->zone(), type.type_class());
const CidRangeVector& ranges = SubtypeRangesForClass(type_class);
if (ranges.length() == 1) {
const CidRange& range = ranges[0];
if (!range.IsIllegalRange()) {
*lower_limit = range.cid_start;
*upper_limit = range.cid_end;
return true;
}
}
}
return false;
}
#if defined(DEBUG)
void Instruction::CheckField(const Field& field) const {
ASSERT(field.IsZoneHandle());
ASSERT(!Compiler::IsBackgroundCompilation() || !field.IsOriginal());
}
#endif // DEBUG
Definition::Definition(intptr_t deopt_id)
: Instruction(deopt_id),
range_(NULL),
type_(NULL),
temp_index_(-1),
ssa_temp_index_(-1),
input_use_list_(NULL),
env_use_list_(NULL),
constant_value_(NULL) {}
// A value in the constant propagation lattice.
// - non-constant sentinel
// - a constant (any non-sentinel value)
// - unknown sentinel
Object& Definition::constant_value() {
if (constant_value_ == NULL) {
constant_value_ = &Object::ZoneHandle(ConstantPropagator::Unknown());
}
return *constant_value_;
}
Definition* Definition::OriginalDefinition() {
Definition* defn = this;
while (defn->IsRedefinition() || defn->IsAssertAssignable()) {
if (defn->IsRedefinition()) {
defn = defn->AsRedefinition()->value()->definition();
} else {
defn = defn->AsAssertAssignable()->value()->definition();
}
}
return defn;
}
const ICData* Instruction::GetICData(
const ZoneGrowableArray<const ICData*>& ic_data_array) const {
// The deopt_id can be outside the range of the IC data array for
// computations added in the optimizing compiler.
ASSERT(deopt_id_ != DeoptId::kNone);
if (deopt_id_ < ic_data_array.length()) {
const ICData* result = ic_data_array[deopt_id_];
#if defined(TAG_IC_DATA)
if (result != NULL) {
ICData::Tag ic_data_tag = ICData::Tag::kUnknown;
switch (tag()) {
case kInstanceCall:
ic_data_tag = ICData::Tag::kInstanceCall;
break;
case kStaticCall:
ic_data_tag = ICData::Tag::kStaticCall;
break;
default:
UNREACHABLE();
}
if (result->tag() == ICData::Tag::kUnknown) {
result->set_tag(ic_data_tag);
} else if (result->tag() != ic_data_tag) {
FATAL("ICData tag mismatch");
}
}
#endif
return result;
}
return NULL;
}
intptr_t Instruction::Hashcode() const {
intptr_t result = tag();
for (intptr_t i = 0; i < InputCount(); ++i) {
Value* value = InputAt(i);
intptr_t j = value->definition()->ssa_temp_index();
result = result * 31 + j;
}
return result;
}
bool Instruction::Equals(Instruction* other) const {
if (tag() != other->tag()) return false;
if (InputCount() != other->InputCount()) return false;
for (intptr_t i = 0; i < InputCount(); ++i) {
if (!InputAt(i)->Equals(other->InputAt(i))) return false;
}
return AttributesEqual(other);
}
void Instruction::Unsupported(FlowGraphCompiler* compiler) {
compiler->Bailout(ToCString());
UNREACHABLE();
}
bool Value::Equals(Value* other) const {
return definition() == other->definition();
}
static int OrderById(CidRange* const* a, CidRange* const* b) {
// Negative if 'a' should sort before 'b'.
ASSERT((*a)->IsSingleCid());
ASSERT((*b)->IsSingleCid());
return (*a)->cid_start - (*b)->cid_start;
}
static int OrderByFrequency(CidRange* const* a, CidRange* const* b) {
const TargetInfo* target_info_a = static_cast<const TargetInfo*>(*a);
const TargetInfo* target_info_b = static_cast<const TargetInfo*>(*b);
// Negative if 'a' should sort before 'b'.
return target_info_b->count - target_info_a->count;
}
bool Cids::Equals(const Cids& other) const {
if (length() != other.length()) return false;
for (int i = 0; i < length(); i++) {
if (cid_ranges_[i]->cid_start != other.cid_ranges_[i]->cid_start ||
cid_ranges_[i]->cid_end != other.cid_ranges_[i]->cid_end) {
return false;
}
}
return true;
}
intptr_t Cids::ComputeLowestCid() const {
intptr_t min = kIntptrMax;
for (intptr_t i = 0; i < cid_ranges_.length(); ++i) {
min = Utils::Minimum(min, cid_ranges_[i]->cid_start);
}
return min;
}
intptr_t Cids::ComputeHighestCid() const {
intptr_t max = -1;
for (intptr_t i = 0; i < cid_ranges_.length(); ++i) {
max = Utils::Maximum(max, cid_ranges_[i]->cid_end);
}
return max;
}
bool Cids::HasClassId(intptr_t cid) const {
for (int i = 0; i < length(); i++) {
if (cid_ranges_[i]->Contains(cid)) {
return true;
}
}
return false;
}
Cids* Cids::CreateMonomorphic(Zone* zone, intptr_t cid) {
Cids* cids = new (zone) Cids(zone);
cids->Add(new (zone) CidRange(cid, cid));
return cids;
}
Cids* Cids::Create(Zone* zone, const ICData& ic_data, int argument_number) {
Cids* cids = new (zone) Cids(zone);
cids->CreateHelper(zone, ic_data, argument_number,
/* include_targets = */ false);
cids->Sort(OrderById);
// Merge adjacent class id ranges.
int dest = 0;
for (int src = 1; src < cids->length(); src++) {
if (cids->cid_ranges_[dest]->cid_end + 1 >=
cids->cid_ranges_[src]->cid_start) {
cids->cid_ranges_[dest]->cid_end = cids->cid_ranges_[src]->cid_end;
} else {
dest++;
if (src != dest) cids->cid_ranges_[dest] = cids->cid_ranges_[src];
}
}
cids->SetLength(dest + 1);
return cids;
}
void Cids::CreateHelper(Zone* zone,
const ICData& ic_data,
int argument_number,
bool include_targets) {
ASSERT(argument_number < ic_data.NumArgsTested());
if (ic_data.NumberOfChecks() == 0) return;
Function& dummy = Function::Handle(zone);
bool check_one_arg = ic_data.NumArgsTested() == 1;
int checks = ic_data.NumberOfChecks();
for (int i = 0; i < checks; i++) {
if (ic_data.GetCountAt(i) == 0) continue;
intptr_t id = 0;
if (check_one_arg) {
ic_data.GetOneClassCheckAt(i, &id, &dummy);
} else {
GrowableArray<intptr_t> arg_ids;
ic_data.GetCheckAt(i, &arg_ids, &dummy);
id = arg_ids[argument_number];
}
if (include_targets) {
Function& function = Function::ZoneHandle(zone, ic_data.GetTargetAt(i));
cid_ranges_.Add(new (zone) TargetInfo(
id, id, &function, ic_data.GetCountAt(i), ic_data.GetExactnessAt(i)));
} else {
cid_ranges_.Add(new (zone) CidRange(id, id));
}
}
}
bool Cids::IsMonomorphic() const {
if (length() != 1) return false;
return cid_ranges_[0]->IsSingleCid();
}
intptr_t Cids::MonomorphicReceiverCid() const {
ASSERT(IsMonomorphic());
return cid_ranges_[0]->cid_start;
}
CheckClassInstr::CheckClassInstr(Value* value,
intptr_t deopt_id,
const Cids& cids,
TokenPosition token_pos)
: TemplateInstruction(deopt_id),
cids_(cids),
licm_hoisted_(false),
is_bit_test_(IsCompactCidRange(cids)),
token_pos_(token_pos) {
// Expected useful check data.
const intptr_t number_of_checks = cids.length();
ASSERT(number_of_checks > 0);
SetInputAt(0, value);
// Otherwise use CheckSmiInstr.
ASSERT(number_of_checks != 1 || !cids[0].IsSingleCid() ||
cids[0].cid_start != kSmiCid);
}
bool CheckClassInstr::AttributesEqual(Instruction* other) const {
CheckClassInstr* other_check = other->AsCheckClass();
ASSERT(other_check != NULL);
return cids().Equals(other_check->cids());
}
bool CheckClassInstr::IsDeoptIfNull() const {
if (!cids().IsMonomorphic()) {
return false;
}
CompileType* in_type = value()->Type();
const intptr_t cid = cids().MonomorphicReceiverCid();
// Performance check: use CheckSmiInstr instead.
ASSERT(cid != kSmiCid);
return in_type->is_nullable() && (in_type->ToNullableCid() == cid);
}
// Null object is a singleton of null-class (except for some sentinel,
// transitional temporaries). Instead of checking against the null class only
// we can check against null instance instead.
bool CheckClassInstr::IsDeoptIfNotNull() const {
if (!cids().IsMonomorphic()) {
return false;
}
const intptr_t cid = cids().MonomorphicReceiverCid();
return cid == kNullCid;
}
bool CheckClassInstr::IsCompactCidRange(const Cids& cids) {
const intptr_t number_of_checks = cids.length();
// If there are only two checks, the extra register pressure needed for the
// dense-cid-range code is not justified.
if (number_of_checks <= 2) return false;
// TODO(fschneider): Support smis in dense cid checks.
if (cids.HasClassId(kSmiCid)) return false;
intptr_t min = cids.ComputeLowestCid();
intptr_t max = cids.ComputeHighestCid();
return (max - min) < kBitsPerWord;
}
bool CheckClassInstr::IsBitTest() const {
return is_bit_test_;
}
intptr_t CheckClassInstr::ComputeCidMask() const {
ASSERT(IsBitTest());
intptr_t min = cids_.ComputeLowestCid();
intptr_t mask = 0;
for (intptr_t i = 0; i < cids_.length(); ++i) {
intptr_t run;
uintptr_t range = 1ul + cids_[i].Extent();
if (range >= static_cast<uintptr_t>(kBitsPerWord)) {
run = -1;
} else {
run = (1 << range) - 1;
}
mask |= run << (cids_[i].cid_start - min);
}
return mask;
}
const NativeFieldDesc* NativeFieldDesc::Get(Kind kind) {
static const NativeFieldDesc fields[] = {
#define IMMUTABLE true
#define MUTABLE false
#define DEFINE_NATIVE_FIELD(ClassName, FieldName, cid, mutability) \
NativeFieldDesc(k##ClassName##_##FieldName, ClassName::FieldName##_offset(), \
k##cid##Cid, mutability),
NATIVE_FIELDS_LIST(DEFINE_NATIVE_FIELD)
#undef DEFINE_FIELD
#undef MUTABLE
#undef IMMUTABLE
};
return &fields[kind];
}
const NativeFieldDesc* NativeFieldDesc::GetLengthFieldForArrayCid(
intptr_t array_cid) {
if (RawObject::IsExternalTypedDataClassId(array_cid) ||
RawObject::IsTypedDataClassId(array_cid)) {
return Get(kTypedData_length);
}
switch (array_cid) {
case kGrowableObjectArrayCid:
return Get(kGrowableObjectArray_length);
case kOneByteStringCid:
case kTwoByteStringCid:
case kExternalOneByteStringCid:
case kExternalTwoByteStringCid:
return Get(kString_length);
case kArrayCid:
case kImmutableArrayCid:
return Get(kArray_length);
default:
UNREACHABLE();
return nullptr;
}
}
const NativeFieldDesc* NativeFieldDesc::GetTypeArgumentsField(Zone* zone,
intptr_t offset) {
// TODO(vegorov) consider caching type arguments fields for specific classes
// in some sort of a flow-graph specific cache.
ASSERT(offset != Class::kNoTypeArguments);
return new (zone) NativeFieldDesc(kTypeArguments, offset, kDynamicCid,
/*immutable=*/true);
}
const NativeFieldDesc* NativeFieldDesc::GetTypeArgumentsFieldFor(
Zone* zone,
const Class& cls) {
return GetTypeArgumentsField(zone, cls.type_arguments_field_offset());
}
RawAbstractType* NativeFieldDesc::type() const {
if (cid() == kSmiCid) {
return Type::SmiType();
}
return Type::DynamicType();
}
const char* NativeFieldDesc::name() const {
switch (kind()) {
#define HANDLE_CASE(ClassName, FieldName, cid, mutability) \
case k##ClassName##_##FieldName: \
return #ClassName "." #FieldName;
NATIVE_FIELDS_LIST(HANDLE_CASE)
#undef HANDLE_CASE
case kTypeArguments:
return ":type_arguments";
}
UNREACHABLE();
return nullptr;
}
bool LoadFieldInstr::IsUnboxedLoad() const {
return FLAG_unbox_numeric_fields && (field() != NULL) &&
FlowGraphCompiler::IsUnboxedField(*field());
}
bool LoadFieldInstr::IsPotentialUnboxedLoad() const {
return FLAG_unbox_numeric_fields && (field() != NULL) &&
FlowGraphCompiler::IsPotentialUnboxedField(*field());
}
Representation LoadFieldInstr::representation() const {
if (IsUnboxedLoad()) {
const intptr_t cid = field()->UnboxedFieldCid();
switch (cid) {
case kDoubleCid:
return kUnboxedDouble;
case kFloat32x4Cid:
return kUnboxedFloat32x4;
case kFloat64x2Cid:
return kUnboxedFloat64x2;
default:
UNREACHABLE();
}
}
return kTagged;
}
bool StoreInstanceFieldInstr::IsUnboxedStore() const {
return FLAG_unbox_numeric_fields && !field().IsNull() &&
FlowGraphCompiler::IsUnboxedField(field());
}
bool StoreInstanceFieldInstr::IsPotentialUnboxedStore() const {
return FLAG_unbox_numeric_fields && !field().IsNull() &&
FlowGraphCompiler::IsPotentialUnboxedField(field());
}
Representation StoreInstanceFieldInstr::RequiredInputRepresentation(
intptr_t index) const {
ASSERT((index == 0) || (index == 1));
if ((index == 1) && IsUnboxedStore()) {
const intptr_t cid = field().UnboxedFieldCid();
switch (cid) {
case kDoubleCid:
return kUnboxedDouble;
case kFloat32x4Cid:
return kUnboxedFloat32x4;
case kFloat64x2Cid:
return kUnboxedFloat64x2;
default:
UNREACHABLE();
}
}
return kTagged;
}
bool GuardFieldClassInstr::AttributesEqual(Instruction* other) const {
return field().raw() == other->AsGuardFieldClass()->field().raw();
}
bool GuardFieldLengthInstr::AttributesEqual(Instruction* other) const {
return field().raw() == other->AsGuardFieldLength()->field().raw();
}
bool GuardFieldTypeInstr::AttributesEqual(Instruction* other) const {
return field().raw() == other->AsGuardFieldType()->field().raw();
}
bool AssertAssignableInstr::AttributesEqual(Instruction* other) const {
AssertAssignableInstr* other_assert = other->AsAssertAssignable();
ASSERT(other_assert != NULL);
// This predicate has to be commutative for DominatorBasedCSE to work.
// TODO(fschneider): Eliminate more asserts with subtype relation.
return dst_type().raw() == other_assert->dst_type().raw();
}
Instruction* AssertSubtypeInstr::Canonicalize(FlowGraph* flow_graph) {
// If all values for type parameters are known (i.e. from instantiator and
// function) we can instantiate the sub and super type and remove this
// instruction if the subtype test succeeds.
ConstantInstr* constant_instantiator_type_args =
instantiator_type_arguments()->definition()->AsConstant();
ConstantInstr* constant_function_type_args =
function_type_arguments()->definition()->AsConstant();
if ((constant_instantiator_type_args != NULL) &&
(constant_function_type_args != NULL)) {
ASSERT(constant_instantiator_type_args->value().IsNull() ||
constant_instantiator_type_args->value().IsTypeArguments());
ASSERT(constant_function_type_args->value().IsNull() ||
constant_function_type_args->value().IsTypeArguments());
Zone* Z = Thread::Current()->zone();
const TypeArguments& instantiator_type_args = TypeArguments::Handle(
Z,
TypeArguments::RawCast(constant_instantiator_type_args->value().raw()));
const TypeArguments& function_type_args = TypeArguments::Handle(
Z, TypeArguments::RawCast(constant_function_type_args->value().raw()));
Error& error_bound = Error::Handle(Z);
AbstractType& sub_type = AbstractType::Handle(Z, sub_type_.raw());
AbstractType& super_type = AbstractType::Handle(Z, super_type_.raw());
if (AbstractType::InstantiateAndTestSubtype(
&sub_type, &super_type, &error_bound, instantiator_type_args,
function_type_args)) {
return NULL;
}
}
return this;
}
bool AssertSubtypeInstr::AttributesEqual(Instruction* other) const {
AssertSubtypeInstr* other_assert = other->AsAssertSubtype();
ASSERT(other_assert != NULL);
return super_type().raw() == other_assert->super_type().raw() &&
sub_type().raw() == other_assert->sub_type().raw();
}
bool StrictCompareInstr::AttributesEqual(Instruction* other) const {
StrictCompareInstr* other_op = other->AsStrictCompare();
ASSERT(other_op != NULL);
return ComparisonInstr::AttributesEqual(other) &&
(needs_number_check() == other_op->needs_number_check());
}
bool MathMinMaxInstr::AttributesEqual(Instruction* other) const {
MathMinMaxInstr* other_op = other->AsMathMinMax();
ASSERT(other_op != NULL);
return (op_kind() == other_op->op_kind()) &&
(result_cid() == other_op->result_cid());
}
bool BinaryIntegerOpInstr::AttributesEqual(Instruction* other) const {
ASSERT(other->tag() == tag());
BinaryIntegerOpInstr* other_op = other->AsBinaryIntegerOp();
return (op_kind() == other_op->op_kind()) &&
(can_overflow() == other_op->can_overflow()) &&
(is_truncating() == other_op->is_truncating());
}
bool LoadFieldInstr::AttributesEqual(Instruction* other) const {
LoadFieldInstr* other_load = other->AsLoadField();
ASSERT(other_load != NULL);
if (field() != NULL) {
return (other_load->field() != NULL) &&
(field()->raw() == other_load->field()->raw());
}
return (other_load->field() == NULL) &&
(offset_in_bytes() == other_load->offset_in_bytes());
}
Instruction* InitStaticFieldInstr::Canonicalize(FlowGraph* flow_graph) {
const bool is_initialized =
(field_.StaticValue() != Object::sentinel().raw()) &&
(field_.StaticValue() != Object::transition_sentinel().raw());
// When precompiling, the fact that a field is currently initialized does not
// make it safe to omit code that checks if the field needs initialization
// because the field will be reset so it starts uninitialized in the process
// running the precompiled code. We must be prepared to reinitialize fields.
return is_initialized && !FLAG_fields_may_be_reset ? NULL : this;
}
bool LoadStaticFieldInstr::AttributesEqual(Instruction* other) const {
LoadStaticFieldInstr* other_load = other->AsLoadStaticField();
ASSERT(other_load != NULL);
// Assert that the field is initialized.
ASSERT(StaticField().StaticValue() != Object::sentinel().raw());
ASSERT(StaticField().StaticValue() != Object::transition_sentinel().raw());
return StaticField().raw() == other_load->StaticField().raw();
}
const Field& LoadStaticFieldInstr::StaticField() const {
return Field::Cast(field_value()->BoundConstant());
}
bool LoadStaticFieldInstr::IsFieldInitialized() const {
const Field& field = StaticField();
return (field.StaticValue() != Object::sentinel().raw()) &&
(field.StaticValue() != Object::transition_sentinel().raw());
}
ConstantInstr::ConstantInstr(const Object& value, TokenPosition token_pos)
: value_(value), token_pos_(token_pos) {
// Check that the value is not an incorrect Integer representation.
ASSERT(!value.IsMint() || !Smi::IsValid(Mint::Cast(value).AsInt64Value()));
ASSERT(!value.IsField() || Field::Cast(value).IsOriginal());
ASSERT(value.IsSmi() || value.IsOld());
}
bool ConstantInstr::AttributesEqual(Instruction* other) const {
ConstantInstr* other_constant = other->AsConstant();
ASSERT(other_constant != NULL);
return (value().raw() == other_constant->value().raw());
}
UnboxedConstantInstr::UnboxedConstantInstr(const Object& value,
Representation representation)
: ConstantInstr(value),
representation_(representation),
constant_address_(0) {
if (representation_ == kUnboxedDouble) {
ASSERT(value.IsDouble());
constant_address_ = FindDoubleConstant(Double::Cast(value).value());
}
}
// Returns true if the value represents a constant.
bool Value::BindsToConstant() const {
return definition()->IsConstant();
}
// Returns true if the value represents constant null.
bool Value::BindsToConstantNull() const {
ConstantInstr* constant = definition()->AsConstant();
return (constant != NULL) && constant->value().IsNull();
}
const Object& Value::BoundConstant() const {
ASSERT(BindsToConstant());
ConstantInstr* constant = definition()->AsConstant();
ASSERT(constant != NULL);
return constant->value();
}
GraphEntryInstr::GraphEntryInstr(const ParsedFunction& parsed_function,
intptr_t osr_id)
: BlockEntryWithInitialDefs(0,
kInvalidTryIndex,
CompilerState::Current().GetNextDeoptId()),
parsed_function_(parsed_function),
catch_entries_(),
indirect_entries_(),
osr_id_(osr_id),
entry_count_(0),
spill_slot_count_(0),
fixed_slot_count_(0) {}
ConstantInstr* GraphEntryInstr::constant_null() {
ASSERT(initial_definitions()->length() > 0);
for (intptr_t i = 0; i < initial_definitions()->length(); ++i) {
ConstantInstr* defn = (*initial_definitions())[i]->AsConstant();
if (defn != NULL && defn->value().IsNull()) return defn;
}
UNREACHABLE();
return NULL;
}
CatchBlockEntryInstr* GraphEntryInstr::GetCatchEntry(intptr_t index) {
// TODO(fschneider): Sort the catch entries by catch_try_index to avoid
// searching.
for (intptr_t i = 0; i < catch_entries_.length(); ++i) {
if (catch_entries_[i]->catch_try_index() == index) return catch_entries_[i];
}
return NULL;
}
bool GraphEntryInstr::IsCompiledForOsr() const {
return osr_id_ != Compiler::kNoOSRDeoptId;
}
// ==== Support for visiting flow graphs.
#define DEFINE_ACCEPT(ShortName, Attrs) \
void ShortName##Instr::Accept(FlowGraphVisitor* visitor) { \
visitor->Visit##ShortName(this); \
}
FOR_EACH_INSTRUCTION(DEFINE_ACCEPT)
#undef DEFINE_ACCEPT
void Instruction::SetEnvironment(Environment* deopt_env) {
intptr_t use_index = 0;
for (Environment::DeepIterator it(deopt_env); !it.Done(); it.Advance()) {
Value* use = it.CurrentValue();
use->set_instruction(this);
use->set_use_index(use_index++);
}
env_ = deopt_env;
}
void Instruction::RemoveEnvironment() {
for (Environment::DeepIterator it(env()); !it.Done(); it.Advance()) {
it.CurrentValue()->RemoveFromUseList();
}
env_ = NULL;
}
Instruction* Instruction::RemoveFromGraph(bool return_previous) {
ASSERT(!IsBlockEntry());
ASSERT(!IsBranch());
ASSERT(!IsThrow());
ASSERT(!IsReturn());
ASSERT(!IsReThrow());
ASSERT(!IsGoto());
ASSERT(previous() != NULL);
// We cannot assert that the instruction, if it is a definition, has no
// uses. This function is used to remove instructions from the graph and
// reinsert them elsewhere (e.g., hoisting).
Instruction* prev_instr = previous();
Instruction* next_instr = next();
ASSERT(next_instr != NULL);
ASSERT(!next_instr->IsBlockEntry());
prev_instr->LinkTo(next_instr);
UnuseAllInputs();
// Reset the successor and previous instruction to indicate that the
// instruction is removed from the graph.
set_previous(NULL);
set_next(NULL);
return return_previous ? prev_instr : next_instr;
}
void Instruction::InsertAfter(Instruction* prev) {
ASSERT(previous_ == NULL);
ASSERT(next_ == NULL);
previous_ = prev;
next_ = prev->next_;
next_->previous_ = this;
previous_->next_ = this;
// Update def-use chains whenever instructions are added to the graph
// after initial graph construction.
for (intptr_t i = InputCount() - 1; i >= 0; --i) {
Value* input = InputAt(i);
input->definition()->AddInputUse(input);
}
}
Instruction* Instruction::AppendInstruction(Instruction* tail) {
LinkTo(tail);
// Update def-use chains whenever instructions are added to the graph
// after initial graph construction.
for (intptr_t i = tail->InputCount() - 1; i >= 0; --i) {
Value* input = tail->InputAt(i);
input->definition()->AddInputUse(input);
}
return tail;
}
BlockEntryInstr* Instruction::GetBlock() {
// TODO(fschneider): Implement a faster way to get the block of an
// instruction.
ASSERT(previous() != NULL);
Instruction* result = previous();
while (!result->IsBlockEntry())
result = result->previous();
return result->AsBlockEntry();
}
void ForwardInstructionIterator::RemoveCurrentFromGraph() {
current_ = current_->RemoveFromGraph(true); // Set current_ to previous.
}
void BackwardInstructionIterator::RemoveCurrentFromGraph() {
current_ = current_->RemoveFromGraph(false); // Set current_ to next.
}
// Default implementation of visiting basic blocks. Can be overridden.
void FlowGraphVisitor::VisitBlocks() {
ASSERT(current_iterator_ == NULL);
for (intptr_t i = 0; i < block_order_.length(); ++i) {
BlockEntryInstr* entry = block_order_[i];
entry->Accept(this);
ForwardInstructionIterator it(entry);
current_iterator_ = &it;
for (; !it.Done(); it.Advance()) {
it.Current()->Accept(this);
}
current_iterator_ = NULL;
}
}
bool Value::NeedsWriteBarrier() {
if (Type()->IsNull() || (Type()->ToNullableCid() == kSmiCid) ||
(Type()->ToNullableCid() == kBoolCid)) {
return false;
}
// Strictly speaking, the incremental barrier can only be skipped for
// immediate objects (Smis) or permanent objects (vm-isolate heap or
// image pages). Here we choose to skip the barrier for any constant on
// the assumption it will remain reachable through the object pool.
// TODO(concurrent-marking): Consider ensuring marking is not in progress
// when code is disabled or only omitting the barrier if code collection
// is disabled.
return !BindsToConstant();
}
void JoinEntryInstr::AddPredecessor(BlockEntryInstr* predecessor) {
// Require the predecessors to be sorted by block_id to make managing
// their corresponding phi inputs simpler.
intptr_t pred_id = predecessor->block_id();
intptr_t index = 0;
while ((index < predecessors_.length()) &&
(predecessors_[index]->block_id() < pred_id)) {
++index;
}
#if defined(DEBUG)
for (intptr_t i = index; i < predecessors_.length(); ++i) {
ASSERT(predecessors_[i]->block_id() != pred_id);
}
#endif
predecessors_.InsertAt(index, predecessor);
}
intptr_t JoinEntryInstr::IndexOfPredecessor(BlockEntryInstr* pred) const {
for (intptr_t i = 0; i < predecessors_.length(); ++i) {
if (predecessors_[i] == pred) return i;
}
return -1;
}
void Value::AddToList(Value* value, Value** list) {
ASSERT(value->next_use() == nullptr);
ASSERT(value->previous_use() == nullptr);
Value* next = *list;
ASSERT(value != next);
*list = value;
value->set_next_use(next);
value->set_previous_use(NULL);
if (next != NULL) next->set_previous_use(value);
}
void Value::RemoveFromUseList() {
Definition* def = definition();
Value* next = next_use();
if (this == def->input_use_list()) {
def->set_input_use_list(next);
if (next != NULL) next->set_previous_use(NULL);
} else if (this == def->env_use_list()) {
def->set_env_use_list(next);
if (next != NULL) next->set_previous_use(NULL);
} else {
Value* prev = previous_use();
prev->set_next_use(next);
if (next != NULL) next->set_previous_use(prev);
}
set_previous_use(NULL);
set_next_use(NULL);
}
// True if the definition has a single input use and is used only in
// environments at the same instruction as that input use.
bool Definition::HasOnlyUse(Value* use) const {
if (!HasOnlyInputUse(use)) {
return false;
}
Instruction* target = use->instruction();
for (Value::Iterator it(env_use_list()); !it.Done(); it.Advance()) {
if (it.Current()->instruction() != target) return false;
}
return true;
}
bool Definition::HasOnlyInputUse(Value* use) const {
return (input_use_list() == use) && (use->next_use() == NULL);
}
void Definition::ReplaceUsesWith(Definition* other) {
ASSERT(other != NULL);
ASSERT(this != other);
Value* current = NULL;
Value* next = input_use_list();
if (next != NULL) {
// Change all the definitions.
while (next != NULL) {
current = next;
current->set_definition(other);
next = current->next_use();
}
// Concatenate the lists.
next = other->input_use_list();
current->set_next_use(next);
if (next != NULL) next->set_previous_use(current);
other->set_input_use_list(input_use_list());
set_input_use_list(NULL);
}
// Repeat for environment uses.
current = NULL;
next = env_use_list();
if (next != NULL) {
while (next != NULL) {
current = next;
current->set_definition(other);
next = current->next_use();
}
next = other->env_use_list();
current->set_next_use(next);
if (next != NULL) next->set_previous_use(current);
other->set_env_use_list(env_use_list());
set_env_use_list(NULL);
}
}
void Instruction::UnuseAllInputs() {
for (intptr_t i = InputCount() - 1; i >= 0; --i) {
InputAt(i)->RemoveFromUseList();
}
for (Environment::DeepIterator it(env()); !it.Done(); it.Advance()) {
it.CurrentValue()->RemoveFromUseList();
}
}
void Instruction::InheritDeoptTargetAfter(FlowGraph* flow_graph,
Definition* call,
Definition* result) {
ASSERT(call->env() != NULL);
deopt_id_ = DeoptId::ToDeoptAfter(call->deopt_id_);
call->env()->DeepCopyAfterTo(
flow_graph->zone(), this, call->ArgumentCount(),
flow_graph->constant_dead(),
result != NULL ? result : flow_graph->constant_dead());
env()->set_deopt_id(deopt_id_);
}
void Instruction::InheritDeoptTarget(Zone* zone, Instruction* other) {
ASSERT(other->env() != NULL);
CopyDeoptIdFrom(*other);
other->env()->DeepCopyTo(zone, this);
env()->set_deopt_id(deopt_id_);
}
void BranchInstr::InheritDeoptTarget(Zone* zone, Instruction* other) {
ASSERT(env() == NULL);
Instruction::InheritDeoptTarget(zone, other);
comparison()->SetDeoptId(*this);
}
bool Instruction::IsDominatedBy(Instruction* dom) {
BlockEntryInstr* block = GetBlock();
BlockEntryInstr* dom_block = dom->GetBlock();
if (dom->IsPhi()) {
dom = dom_block;
}
if (block == dom_block) {
if ((block == dom) || (this == block->last_instruction())) {
return true;
}
if (IsPhi()) {
return false;
}
for (Instruction* curr = dom->next(); curr != NULL; curr = curr->next()) {
if (curr == this) return true;
}
return false;
}
return dom_block->Dominates(block);
}
bool Instruction::HasUnmatchedInputRepresentations() const {
for (intptr_t i = 0; i < InputCount(); i++) {
Definition* input = InputAt(i)->definition();
if (RequiredInputRepresentation(i) != input->representation()) {
return true;
}
}
return false;
}
const intptr_t Instruction::kInstructionAttrs[Instruction::kNumInstructions] = {
#define INSTR_ATTRS(type, attrs) InstrAttrs::attrs,
FOR_EACH_INSTRUCTION(INSTR_ATTRS)
#undef INSTR_ATTRS
};
bool Instruction::CanTriggerGC() const {
return (kInstructionAttrs[tag()] & InstrAttrs::kNoGC) == 0;
}
void Definition::ReplaceWith(Definition* other,
ForwardInstructionIterator* iterator) {
// Record other's input uses.
for (intptr_t i = other->InputCount() - 1; i >= 0; --i) {
Value* input = other->InputAt(i);
input->definition()->AddInputUse(input);
}
// Take other's environment from this definition.
ASSERT(other->env() == NULL);
other->SetEnvironment(env());
ClearEnv();
// Replace all uses of this definition with other.
ReplaceUsesWith(other);
// Reuse this instruction's SSA name for other.
ASSERT(!other->HasSSATemp());
if (HasSSATemp()) {
other->set_ssa_temp_index(ssa_temp_index());
}
// Finally insert the other definition in place of this one in the graph.
previous()->LinkTo(other);
if ((iterator != NULL) && (this == iterator->Current())) {
// Remove through the iterator.
other->LinkTo(this);
iterator->RemoveCurrentFromGraph();
} else {
other->LinkTo(next());
// Remove this definition's input uses.
UnuseAllInputs();
}
set_previous(NULL);
set_next(NULL);
}
void BranchInstr::SetComparison(ComparisonInstr* new_comparison) {
for (intptr_t i = new_comparison->InputCount() - 1; i >= 0; --i) {
Value* input = new_comparison->InputAt(i);
input->definition()->AddInputUse(input);
input->set_instruction(this);
}
// There should be no need to copy or unuse an environment.
ASSERT(comparison()->env() == NULL);
ASSERT(new_comparison->env() == NULL);
// Remove the current comparison's input uses.
comparison()->UnuseAllInputs();
ASSERT(!new_comparison->HasUses());
comparison_ = new_comparison;
}
// ==== Postorder graph traversal.
static bool IsMarked(BlockEntryInstr* block,
GrowableArray<BlockEntryInstr*>* preorder) {
// Detect that a block has been visited as part of the current
// DiscoverBlocks (we can call DiscoverBlocks multiple times). The block
// will be 'marked' by (1) having a preorder number in the range of the
// preorder array and (2) being in the preorder array at that index.
intptr_t i = block->preorder_number();
return (i >= 0) && (i < preorder->length()) && ((*preorder)[i] == block);
}
// Base class implementation used for JoinEntry and TargetEntry.
bool BlockEntryInstr::DiscoverBlock(BlockEntryInstr* predecessor,
GrowableArray<BlockEntryInstr*>* preorder,
GrowableArray<intptr_t>* parent) {
// If this block has a predecessor (i.e., is not the graph entry) we can
// assume the preorder array is non-empty.
ASSERT((predecessor == NULL) || !preorder->is_empty());
// Blocks with a single predecessor cannot have been reached before.
ASSERT(IsJoinEntry() || !IsMarked(this, preorder));
// 1. If the block has already been reached, add current_block as a
// basic-block predecessor and we are done.
if (IsMarked(this, preorder)) {
ASSERT(predecessor != NULL);
AddPredecessor(predecessor);
return false;
}
// 2. Otherwise, clear the predecessors which might have been computed on
// some earlier call to DiscoverBlocks and record this predecessor.
ClearPredecessors();
if (predecessor != NULL) AddPredecessor(predecessor);
// 3. The predecessor is the spanning-tree parent. The graph entry has no
// parent, indicated by -1.
intptr_t parent_number =
(predecessor == NULL) ? -1 : predecessor->preorder_number();
parent->Add(parent_number);
// 4. Assign the preorder number and add the block entry to the list.
set_preorder_number(preorder->length());
preorder->Add(this);
// The preorder and parent arrays are indexed by
// preorder block number, so they should stay in lockstep.
ASSERT(preorder->length() == parent->length());
// 5. Iterate straight-line successors to record assigned variables and
// find the last instruction in the block. The graph entry block consists
// of only the entry instruction, so that is the last instruction in the
// block.
Instruction* last = this;
for (ForwardInstructionIterator it(this); !it.Done(); it.Advance()) {
last = it.Current();
}
set_last_instruction(last);
if (last->IsGoto()) last->AsGoto()->set_block(this);
return true;
}
void GraphEntryInstr::RelinkToOsrEntry(Zone* zone, intptr_t max_block_id) {
ASSERT(osr_id_ != Compiler::kNoOSRDeoptId);
BitVector* block_marks = new (zone) BitVector(zone, max_block_id + 1);
bool found = FindOsrEntryAndRelink(this, /*parent=*/NULL, block_marks);
ASSERT(found);
}
bool BlockEntryInstr::FindOsrEntryAndRelink(GraphEntryInstr* graph_entry,
Instruction* parent,
BitVector* block_marks) {
const intptr_t osr_id = graph_entry->osr_id();
// Search for the instruction with the OSR id. Use a depth first search
// because basic blocks have not been discovered yet. Prune unreachable
// blocks by replacing the normal entry with a jump to the block
// containing the OSR entry point.
// Do not visit blocks more than once.
if (block_marks->Contains(block_id())) return false;
block_marks->Add(block_id());
// Search this block for the OSR id.
Instruction* instr = this;
for (ForwardInstructionIterator it(this); !it.Done(); it.Advance()) {
instr = it.Current();
if (instr->GetDeoptId() == osr_id) {
// Sanity check that we found a stack check instruction.
ASSERT(instr->IsCheckStackOverflow());
// Loop stack check checks are always in join blocks so that they can
// be the target of a goto.
ASSERT(IsJoinEntry());
// The instruction should be the first instruction in the block so
// we can simply jump to the beginning of the block.
ASSERT(instr->previous() == this);
auto normal_entry = graph_entry->normal_entry();
auto osr_entry = new OsrEntryInstr(graph_entry, normal_entry->block_id(),
normal_entry->try_index(),
normal_entry->deopt_id());
auto goto_join = new GotoInstr(AsJoinEntry(),
CompilerState::Current().GetNextDeoptId());
goto_join->CopyDeoptIdFrom(*parent);
osr_entry->LinkTo(goto_join);
// Remove normal function entries & add osr entry.
graph_entry->set_normal_entry(nullptr);
graph_entry->set_unchecked_entry(nullptr);
graph_entry->set_osr_entry(osr_entry);
return true;
}
}
// Recursively search the successors.
for (intptr_t i = instr->SuccessorCount() - 1; i >= 0; --i) {
if (instr->SuccessorAt(i)->FindOsrEntryAndRelink(graph_entry, instr,
block_marks)) {
return true;
}
}
return false;
}
bool BlockEntryInstr::Dominates(BlockEntryInstr* other) const {
// TODO(fschneider): Make this faster by e.g. storing dominators for each
// block while computing the dominator tree.
ASSERT(other != NULL);
BlockEntryInstr* current = other;
while (current != NULL && current != this) {
current = current->dominator();
}
return current == this;
}
BlockEntryInstr* BlockEntryInstr::ImmediateDominator() const {
Instruction* last = dominator()->last_instruction();
if ((last->SuccessorCount() == 1) && (last->SuccessorAt(0) == this)) {
return dominator();
}
return NULL;
}
bool BlockEntryInstr::IsLoopHeader() const {
return loop_info_ != nullptr && loop_info_->header() == this;
}
// Helper to mutate the graph during inlining. This block should be
// replaced with new_block as a predecessor of all of this block's
// successors. For each successor, the predecessors will be reordered
// to preserve block-order sorting of the predecessors as well as the
// phis if the successor is a join.
void BlockEntryInstr::ReplaceAsPredecessorWith(BlockEntryInstr* new_block) {
// Set the last instruction of the new block to that of the old block.
Instruction* last = last_instruction();
new_block->set_last_instruction(last);
// For each successor, update the predecessors.
for (intptr_t sidx = 0; sidx < last->SuccessorCount(); ++sidx) {
// If the successor is a target, update its predecessor.
TargetEntryInstr* target = last->SuccessorAt(sidx)->AsTargetEntry();
if (target != NULL) {
target->predecessor_ = new_block;
continue;
}
// If the successor is a join, update each predecessor and the phis.
JoinEntryInstr* join = last->SuccessorAt(sidx)->AsJoinEntry();
ASSERT(join != NULL);
// Find the old predecessor index.
intptr_t old_index = join->IndexOfPredecessor(this);
intptr_t pred_count = join->PredecessorCount();
ASSERT(old_index >= 0);
ASSERT(old_index < pred_count);
// Find the new predecessor index while reordering the predecessors.
intptr_t new_id = new_block->block_id();
intptr_t new_index = old_index;
if (block_id() < new_id) {
// Search upwards, bubbling down intermediate predecessors.
for (; new_index < pred_count - 1; ++new_index) {
if (join->predecessors_[new_index + 1]->block_id() > new_id) break;
join->predecessors_[new_index] = join->predecessors_[new_index + 1];
}
} else {
// Search downwards, bubbling up intermediate predecessors.
for (; new_index > 0; --new_index) {
if (join->predecessors_[new_index - 1]->block_id() < new_id) break;
join->predecessors_[new_index] = join->predecessors_[new_index - 1];
}
}
join->predecessors_[new_index] = new_block;
// If the new and old predecessor index match there is nothing to update.
if ((join->phis() == NULL) || (old_index == new_index)) return;
// Otherwise, reorder the predecessor uses in each phi.
for (PhiIterator it(join); !it.Done(); it.Advance()) {
PhiInstr* phi = it.Current();
ASSERT(phi != NULL);
ASSERT(pred_count == phi->InputCount());
// Save the predecessor use.
Value* pred_use = phi->InputAt(old_index);
// Move uses between old and new.
intptr_t step = (old_index < new_index) ? 1 : -1;
for (intptr_t use_idx = old_index; use_idx != new_index;
use_idx += step) {
phi->SetInputAt(use_idx, phi->InputAt(use_idx + step));
}
// Write the predecessor use.
phi->SetInputAt(new_index, pred_use);
}
}
}
void BlockEntryInstr::ClearAllInstructions() {
JoinEntryInstr* join = this->AsJoinEntry();
if (join != NULL) {
for (PhiIterator it(join); !it.Done(); it.Advance()) {
it.Current()->UnuseAllInputs();
}
}
UnuseAllInputs();
for (ForwardInstructionIterator it(this); !it.Done(); it.Advance()) {
it.Current()->UnuseAllInputs();
}
}
PhiInstr* JoinEntryInstr::InsertPhi(intptr_t var_index, intptr_t var_count) {
// Lazily initialize the array of phis.
// Currently, phis are stored in a sparse array that holds the phi
// for variable with index i at position i.
// TODO(fschneider): Store phis in a more compact way.
if (phis_ == NULL) {
phis_ = new ZoneGrowableArray<PhiInstr*>(var_count);
for (intptr_t i = 0; i < var_count; i++) {
phis_->Add(NULL);
}
}
ASSERT((*phis_)[var_index] == NULL);
return (*phis_)[var_index] = new PhiInstr(this, PredecessorCount());
}
void JoinEntryInstr::InsertPhi(PhiInstr* phi) {
// Lazily initialize the array of phis.
if (phis_ == NULL) {
phis_ = new ZoneGrowableArray<PhiInstr*>(1);
}
phis_->Add(phi);
}
void JoinEntryInstr::RemovePhi(PhiInstr* phi) {
ASSERT(phis_ != NULL);
for (intptr_t index = 0; index < phis_->length(); ++index) {
if (phi == (*phis_)[index]) {
(*phis_)[index] = phis_->Last();
phis_->RemoveLast();
return;
}
}
}
void JoinEntryInstr::RemoveDeadPhis(Definition* replacement) {
if (phis_ == NULL) return;
intptr_t to_index = 0;
for (intptr_t from_index = 0; from_index < phis_->length(); ++from_index) {
PhiInstr* phi = (*phis_)[from_index];
if (phi != NULL) {
if (phi->is_alive()) {
(*phis_)[to_index++] = phi;
for (intptr_t i = phi->InputCount() - 1; i >= 0; --i) {
Value* input = phi->InputAt(i);
input->definition()->AddInputUse(input);
}
} else {
phi->ReplaceUsesWith(replacement);
}
}
}
if (to_index == 0) {
phis_ = NULL;
} else {
phis_->TruncateTo(to_index);
}
}
intptr_t Instruction::SuccessorCount() const {
return 0;
}
BlockEntryInstr* Instruction::SuccessorAt(intptr_t index) const {
// Called only if index is in range. Only control-transfer instructions
// can have non-zero successor counts and they override this function.
UNREACHABLE();
return NULL;
}
intptr_t GraphEntryInstr::SuccessorCount() const {
return (normal_entry() == nullptr ? 0 : 1) +
(unchecked_entry() == nullptr ? 0 : 1) +
(osr_entry() == nullptr ? 0 : 1) + catch_entries_.length();
}
BlockEntryInstr* GraphEntryInstr::SuccessorAt(intptr_t index) const {
if (normal_entry() != nullptr) {
if (index == 0) return normal_entry_;
index--;
}
if (unchecked_entry() != nullptr) {
if (index == 0) return unchecked_entry();
index--;
}
if (osr_entry() != nullptr) {
if (index == 0) return osr_entry();
index--;
}
return catch_entries_[index];
}
intptr_t BranchInstr::SuccessorCount() const {
return 2;
}
BlockEntryInstr* BranchInstr::SuccessorAt(intptr_t index) const {
if (index == 0) return true_successor_;
if (index == 1) return false_successor_;
UNREACHABLE();
return NULL;
}
intptr_t GotoInstr::SuccessorCount() const {
return 1;
}
BlockEntryInstr* GotoInstr::SuccessorAt(intptr_t index) const {
ASSERT(index == 0);
return successor();
}
void Instruction::Goto(JoinEntryInstr* entry) {
LinkTo(new GotoInstr(entry, CompilerState::Current().GetNextDeoptId()));
}
bool UnboxedIntConverterInstr::ComputeCanDeoptimize() const {
return (to() == kUnboxedInt32) && !is_truncating() &&
!RangeUtils::Fits(value()->definition()->range(),
RangeBoundary::kRangeBoundaryInt32);
}
bool UnboxInt32Instr::ComputeCanDeoptimize() const {
if (speculative_mode() == kNotSpeculative) {
return false;
}
const intptr_t value_cid = value()->Type()->ToCid();
if (value_cid == kSmiCid) {
return (kSmiBits > 32) && !is_truncating() &&
!RangeUtils::Fits(value()->definition()->range(),
RangeBoundary::kRangeBoundaryInt32);
} else if (value_cid == kMintCid) {
return !is_truncating() &&
!RangeUtils::Fits(value()->definition()->range(),
RangeBoundary::kRangeBoundaryInt32);
} else if (is_truncating() && value()->definition()->IsBoxInteger()) {
return false;
} else if ((kSmiBits < 32) && value()->Type()->IsInt()) {
return !RangeUtils::Fits(value()->definition()->range(),
RangeBoundary::kRangeBoundaryInt32);
} else {
return true;
}
}
bool UnboxUint32Instr::ComputeCanDeoptimize() const {
ASSERT(is_truncating());
if (speculative_mode() == kNotSpeculative) {
return false;
}
if ((value()->Type()->ToCid() == kSmiCid) ||
(value()->Type()->ToCid() == kMintCid)) {
return false;
}
// Check input value's range.
Range* value_range = value()->definition()->range();
return !RangeUtils::Fits(value_range, RangeBoundary::kRangeBoundaryInt64);
}
bool BinaryInt32OpInstr::ComputeCanDeoptimize() const {
switch (op_kind()) {
case Token::kBIT_AND:
case Token::kBIT_OR:
case Token::kBIT_XOR:
return false;
case Token::kSHR:
return false;
case Token::kSHL:
// Currently only shifts by in range constant are supported, see
// BinaryInt32OpInstr::IsSupported.
return can_overflow();
case Token::kMOD: {
UNREACHABLE();
}
default:
return can_overflow();
}
}
bool BinarySmiOpInstr::ComputeCanDeoptimize() const {
switch (op_kind()) {
case Token::kBIT_AND:
case Token::kBIT_OR:
case Token::kBIT_XOR:
return false;
case Token::kSHR:
return !RangeUtils::IsPositive(right_range());
case Token::kSHL:
return can_overflow() || !RangeUtils::IsPositive(right_range());
case Token::kMOD:
return RangeUtils::CanBeZero(right_range());
default:
return can_overflow();
}
}
bool ShiftIntegerOpInstr::IsShiftCountInRange(int64_t max) const {
return RangeUtils::IsWithin(shift_range(), 0, max);
}
bool BinaryIntegerOpInstr::RightIsPowerOfTwoConstant() const {
if (!right()->definition()->IsConstant()) return false;
const Object& constant = right()->definition()->AsConstant()->value();
if (!constant.IsSmi()) return false;
const intptr_t int_value = Smi::Cast(constant).Value();
ASSERT(int_value != kIntptrMin);
return Utils::IsPowerOfTwo(Utils::Abs(int_value));
}
static intptr_t RepresentationBits(Representation r) {
switch (r) {
case kTagged:
return kBitsPerWord - 1;
case kUnboxedInt32:
case kUnboxedUint32:
return 32;
case kUnboxedInt64:
return 64;
default:
UNREACHABLE();
return 0;
}
}
static int64_t RepresentationMask(Representation r) {
return static_cast<int64_t>(static_cast<uint64_t>(-1) >>
(64 - RepresentationBits(r)));
}
static bool ToIntegerConstant(Value* value, int64_t* result) {
if (!value->BindsToConstant()) {
UnboxInstr* unbox = value->definition()->AsUnbox();
if (unbox != NULL) {
switch (unbox->representation()) {
case kUnboxedDouble:
case kUnboxedInt64:
return ToIntegerConstant(unbox->value(), result);
case kUnboxedUint32:
if (ToIntegerConstant(unbox->value(), result)) {
*result &= RepresentationMask(kUnboxedUint32);
return true;
}
break;
// No need to handle Unbox<Int32>(Constant(C)) because it gets
// canonicalized to UnboxedConstant<Int32>(C).
case kUnboxedInt32:
default:
break;
}
}
return false;
}
const Object& constant = value->BoundConstant();
if (constant.IsDouble()) {
const Double& double_constant = Double::Cast(constant);
*result = Utils::SafeDoubleToInt<int64_t>(double_constant.value());
return (static_cast<double>(*result) == double_constant.value());
} else if (constant.IsSmi()) {
*result = Smi::Cast(constant).Value();
return true;
} else if (constant.IsMint()) {
*result = Mint::Cast(constant).value();
return true;
}
return false;
}
static Definition* CanonicalizeCommutativeDoubleArithmetic(Token::Kind op,
Value* left,
Value* right) {
int64_t left_value;
if (!ToIntegerConstant(left, &left_value)) {
return NULL;
}
// Can't apply 0.0 * x -> 0.0 equivalence to double operation because
// 0.0 * NaN is NaN not 0.0.
// Can't apply 0.0 + x -> x to double because 0.0 + (-0.0) is 0.0 not -0.0.
switch (op) {
case Token::kMUL:
if (left_value == 1) {
if (right->definition()->representation() != kUnboxedDouble) {
// Can't yet apply the equivalence because representation selection
// did not run yet. We need it to guarantee that right value is
// correctly coerced to double. The second canonicalization pass
// will apply this equivalence.
return NULL;
} else {
return right->definition();
}
}
break;
default:
break;
}
return NULL;
}
Definition* DoubleToFloatInstr::Canonicalize(FlowGraph* flow_graph) {
#ifdef DEBUG
// Must only be used in Float32 StoreIndexedInstr or FloatToDoubleInstr or
// Phis introduce by load forwarding.
ASSERT(env_use_list() == NULL);
for (Value* use = input_use_list(); use != NULL; use = use->next_use()) {
ASSERT(use->instruction()->IsPhi() ||
use->instruction()->IsFloatToDouble() ||
(use->instruction()->IsStoreIndexed() &&
(use->instruction()->AsStoreIndexed()->class_id() ==
kTypedDataFloat32ArrayCid)));
}
#endif
if (!HasUses()) return NULL;
if (value()->definition()->IsFloatToDouble()) {
// F2D(D2F(v)) == v.
return value()->definition()->AsFloatToDouble()->value()->definition();
}
return this;
}
Definition* FloatToDoubleInstr::Canonicalize(FlowGraph* flow_graph) {
return HasUses() ? this : NULL;
}
Definition* BinaryDoubleOpInstr::Canonicalize(FlowGraph* flow_graph) {
if (!HasUses()) return NULL;
Definition* result = NULL;
result = CanonicalizeCommutativeDoubleArithmetic(op_kind(), left(), right());
if (result != NULL) {
return result;
}
result = CanonicalizeCommutativeDoubleArithmetic(op_kind(), right(), left());
if (result != NULL) {
return result;
}
if ((op_kind() == Token::kMUL) &&
(left()->definition() == right()->definition())) {
MathUnaryInstr* math_unary = new MathUnaryInstr(
MathUnaryInstr::kDoubleSquare, new Value(left()->definition()),
DeoptimizationTarget());
flow_graph->InsertBefore(this, math_unary, env(), FlowGraph::kValue);
return math_unary;
}
return this;
}
Definition* DoubleTestOpInstr::Canonicalize(FlowGraph* flow_graph) {
return HasUses() ? this : NULL;
}
static bool IsCommutative(Token::Kind op) {
switch (op) {
case Token::kMUL:
case Token::kADD:
case Token::kBIT_AND:
case Token::kBIT_OR:
case Token::kBIT_XOR:
return true;
default:
return false;
}
}
UnaryIntegerOpInstr* UnaryIntegerOpInstr::Make(Representation representation,
Token::Kind op_kind,
Value* value,
intptr_t deopt_id,
Range* range) {
UnaryIntegerOpInstr* op = NULL;
switch (representation) {
case kTagged:
op = new UnarySmiOpInstr(op_kind, value, deopt_id);
break;
case kUnboxedInt32:
return NULL;
case kUnboxedUint32:
op = new UnaryUint32OpInstr(op_kind, value, deopt_id);
break;
case kUnboxedInt64:
op = new UnaryInt64OpInstr(op_kind, value, deopt_id);
break;
default:
UNREACHABLE();
return NULL;
}
if (op == NULL) {
return op;
}
if (!Range::IsUnknown(range)) {
op->set_range(*range);
}
ASSERT(op->representation() == representation);
return op;
}
BinaryIntegerOpInstr* BinaryIntegerOpInstr::Make(
Representation representation,
Token::Kind op_kind,
Value* left,
Value* right,
intptr_t deopt_id,
bool can_overflow,
bool is_truncating,
Range* range,
SpeculativeMode speculative_mode) {
BinaryIntegerOpInstr* op = NULL;
switch (representation) {
case kTagged:
op = new BinarySmiOpInstr(op_kind, left, right, deopt_id);
break;
case kUnboxedInt32:
if (!BinaryInt32OpInstr::IsSupported(op_kind, left, right)) {
return NULL;
}
op = new BinaryInt32OpInstr(op_kind, left, right, deopt_id);
break;
case kUnboxedUint32:
if ((op_kind == Token::kSHR) || (op_kind == Token::kSHL)) {
if (speculative_mode == kNotSpeculative) {
op = new ShiftUint32OpInstr(op_kind, left, right, deopt_id);
} else {
op =
new SpeculativeShiftUint32OpInstr(op_kind, left, right, deopt_id);
}
} else {
op = new BinaryUint32OpInstr(op_kind, left, right, deopt_id);
}
break;
case kUnboxedInt64:
if ((op_kind == Token::kSHR) || (op_kind == Token::kSHL)) {
if (speculative_mode == kNotSpeculative) {
op = new ShiftInt64OpInstr(op_kind, left, right, deopt_id);
} else {
op = new SpeculativeShiftInt64OpInstr(op_kind, left, right, deopt_id);
}
} else {
op = new BinaryInt64OpInstr(op_kind, left, right, deopt_id);
}
break;
default:
UNREACHABLE();
return NULL;
}
if (!Range::IsUnknown(range)) {
op->set_range(*range);
}
op->set_can_overflow(can_overflow);
if (is_truncating) {
op->mark_truncating();
}
ASSERT(op->representation() == representation);
return op;
}
static bool IsRepresentable(const Integer& value, Representation rep) {
switch (rep) {
case kTagged: // Smi case.
return value.IsSmi();
case kUnboxedInt32:
if (value.IsSmi() || value.IsMint()) {
return Utils::IsInt(32, value.AsInt64Value());
}
return false;
case kUnboxedInt64:
return value.IsSmi() || value.IsMint();
case kUnboxedUint32: // Only truncating Uint32 arithmetic is supported.
default:
UNREACHABLE();
}
return false;
}
RawInteger* UnaryIntegerOpInstr::Evaluate(const Integer& value) const {
Thread* thread = Thread::Current();
Zone* zone = thread->zone();
Integer& result = Integer::Handle(zone);
switch (op_kind()) {
case Token::kNEGATE:
result = value.ArithmeticOp(Token::kMUL, Smi::Handle(zone, Smi::New(-1)),
Heap::kOld);
break;
case Token::kBIT_NOT:
if (value.IsSmi()) {
result = Integer::New(~Smi::Cast(value).Value(), Heap::kOld);
} else if (value.IsMint()) {
result = Integer::New(~Mint::Cast(value).value(), Heap::kOld);
}
break;
default:
UNREACHABLE();
}
if (!result.IsNull()) {
if (!IsRepresentable(result, representation())) {
// If this operation is not truncating it would deoptimize on overflow.
// Check that we match this behavior and don't produce a value that is
// larger than something this operation can produce. We could have
// specialized instructions that use this value under this assumption.
return Integer::null();
}
const char* error_str = NULL;
result ^= result.CheckAndCanonicalize(thread, &error_str);
if (error_str != NULL) {
FATAL1("Failed to canonicalize: %s", error_str);
}
}
return result.raw();
}
RawInteger* BinaryIntegerOpInstr::Evaluate(const Integer& left,
const Integer& right) const {
Thread* thread = Thread::Current();
Zone* zone = thread->zone();
Integer& result = Integer::Handle(zone);
switch (op_kind()) {
case Token::kTRUNCDIV:
case Token::kMOD:
// Check right value for zero.
if (right.AsInt64Value() == 0) {
break; // Will throw.
}
// Fall through.
case Token::kADD:
case Token::kSUB:
case Token::kMUL: {
result = left.ArithmeticOp(op_kind(), right, Heap::kOld);
break;
}
case Token::kSHL:
case Token::kSHR:
if (right.AsInt64Value() >= 0) {
result = left.ShiftOp(op_kind(), right, Heap::kOld);
}
break;
case Token::kBIT_AND:
case Token::kBIT_OR:
case Token::kBIT_XOR: {
result = left.BitOp(op_kind(), right, Heap::kOld);
break;
}
case Token::kDIV:
break;
default:
UNREACHABLE();
}
if (!result.IsNull()) {
if (is_truncating()) {
int64_t truncated = result.AsTruncatedInt64Value();
truncated &= RepresentationMask(representation());
result = Integer::New(truncated, Heap::kOld);
ASSERT(IsRepresentable(result, representation()));
} else if (!IsRepresentable(result, representation())) {
// If this operation is not truncating it would deoptimize on overflow.
// Check that we match this behavior and don't produce a value that is
// larger than something this operation can produce. We could have
// specialized instructions that use this value under this assumption.
return Integer::null();
}
const char* error_str = NULL;
result ^= result.CheckAndCanonicalize(thread, &error_str);
if (error_str != NULL) {
FATAL1("Failed to canonicalize: %s", error_str);
}
}
return result.raw();
}
Definition* BinaryIntegerOpInstr::CreateConstantResult(FlowGraph* flow_graph,
const Integer& result) {
Definition* result_defn = flow_graph->GetConstant(result);
if (representation() != kTagged) {
result_defn = UnboxInstr::Create(representation(), new Value(result_defn),
GetDeoptId());
flow_graph->InsertBefore(this, result_defn, env(), FlowGraph::kValue);
}
return result_defn;
}
Definition* CheckedSmiOpInstr::Canonicalize(FlowGraph* flow_graph) {
if ((left()->Type()->ToCid() == kSmiCid) &&
(right()->Type()->ToCid() == kSmiCid)) {
Definition* replacement = NULL;
// Operations that can't deoptimize are specialized here: These include
// bit-wise operators and comparisons. Other arithmetic operations can
// overflow or divide by 0 and can't be specialized unless we have extra
// range information.
switch (op_kind()) {
case Token::kBIT_AND:
case Token::kBIT_OR:
case Token::kBIT_XOR:
replacement = new BinarySmiOpInstr(
op_kind(), new Value(left()->definition()),
new Value(right()->definition()), DeoptId::kNone);
default:
break;
}
if (replacement != NULL) {
flow_graph->InsertBefore(this, replacement, env(), FlowGraph::kValue);
return replacement;
}
}
return this;
}
ComparisonInstr* CheckedSmiComparisonInstr::CopyWithNewOperands(Value* left,
Value* right) {
UNREACHABLE();
return NULL;
}
Definition* CheckedSmiComparisonInstr::Canonicalize(FlowGraph* flow_graph) {
CompileType* left_type = left()->Type();
CompileType* right_type = right()->Type();
intptr_t op_cid = kIllegalCid;
SpeculativeMode speculative_mode = kGuardInputs;
if ((left_type->ToCid() == kSmiCid) && (right_type->ToCid() == kSmiCid)) {
op_cid = kSmiCid;
} else if (Isolate::Current()->can_use_strong_mode_types() &&
FlowGraphCompiler::SupportsUnboxedInt64() &&
// TODO(dartbug.com/30480): handle nullable types here
left_type->IsNullableInt() && !left_type->is_nullable() &&
right_type->IsNullableInt() && !right_type->is_nullable()) {
op_cid = kMintCid;
speculative_mode = kNotSpeculative;
}
if (op_cid != kIllegalCid) {
Definition* replacement = NULL;
if (Token::IsRelationalOperator(kind())) {
replacement = new RelationalOpInstr(
token_pos(), kind(), left()->CopyWithType(), right()->CopyWithType(),
op_cid, DeoptId::kNone, speculative_mode);
} else if (Token::IsEqualityOperator(kind())) {
replacement = new EqualityCompareInstr(
token_pos(), kind(), left()->CopyWithType(), right()->CopyWithType(),
op_cid, DeoptId::kNone, speculative_mode);
}
if (replacement != NULL) {
if (FLAG_trace_strong_mode_types && (op_cid == kMintCid)) {
THR_Print("[Strong mode] Optimization: replacing %s with %s\n",
ToCString(), replacement->ToCString());
}
flow_graph->InsertBefore(this, replacement, env(), FlowGraph::kValue);
return replacement;
}
}
return this;
}
Definition* BinaryIntegerOpInstr::Canonicalize(FlowGraph* flow_graph) {
// If both operands are constants evaluate this expression. Might
// occur due to load forwarding after constant propagation pass
// have already been run.
if (left()->BindsToConstant() && left()->BoundConstant().IsInteger() &&
right()->BindsToConstant() && right()->BoundConstant().IsInteger()) {
const Integer& result =
Integer::Handle(Evaluate(Integer::Cast(left()->BoundConstant()),
Integer::Cast(right()->BoundConstant())));
if (!result.IsNull()) {
return CreateConstantResult(flow_graph, result);
}
}
if (left()->BindsToConstant() && !right()->BindsToConstant() &&
IsCommutative(op_kind())) {
Value* l = left();
Value* r = right();
SetInputAt(0, r);
SetInputAt(1, l);
}
int64_t rhs;
if (!ToIntegerConstant(right(), &rhs)) {
return this;
}
const int64_t range_mask = RepresentationMask(representation());
if (is_truncating()) {
switch (op_kind()) {
case Token::kMUL:
case Token::kSUB:
case Token::kADD:
case Token::kBIT_AND:
case Token::kBIT_OR:
case Token::kBIT_XOR:
rhs = (rhs & range_mask);
break;
default:
break;
}
}
switch (op_kind()) {
case Token::kMUL:
if (rhs == 1) {
return left()->definition();
} else if (rhs == 0) {
return right()->definition();
} else if (rhs == 2) {
ConstantInstr* constant_1 =
flow_graph->GetConstant(Smi::Handle(Smi::New(1)));
BinaryIntegerOpInstr* shift = BinaryIntegerOpInstr::Make(
representation(), Token::kSHL, left()->CopyWithType(),
new Value(constant_1), GetDeoptId(), can_overflow(),
is_truncating(), range(), speculative_mode());
if (shift != NULL) {
flow_graph->InsertBefore(this, shift, env(), FlowGraph::kValue);
return shift;
}
}
break;
case Token::kADD:
if (rhs == 0) {
return left()->definition();
}
break;
case Token::kBIT_AND:
if (rhs == 0) {
return right()->definition();
} else if (rhs == range_mask) {
return left()->definition();
}
break;
case Token::kBIT_OR:
if (rhs == 0) {
return left()->definition();
} else if (rhs == range_mask) {
return right()->definition();
}
break;
case Token::kBIT_XOR:
if (rhs == 0) {
return left()->definition();
} else if (rhs == range_mask) {
UnaryIntegerOpInstr* bit_not = UnaryIntegerOpInstr::Make(
representation(), Token::kBIT_NOT, left()->CopyWithType(),
GetDeoptId(), range());
if (bit_not != NULL) {
flow_graph->InsertBefore(this, bit_not, env(), FlowGraph::kValue);
return bit_not;
}
}
break;
case Token::kSUB:
if (rhs == 0) {
return left()->definition();
}
break;
case Token::kTRUNCDIV:
if (rhs == 1) {
return left()->definition();
} else if (rhs == -1) {
UnaryIntegerOpInstr* negation = UnaryIntegerOpInstr::Make(
representation(), Token::kNEGATE, left()->CopyWithType(),
GetDeoptId(), range());
if (negation != NULL) {
flow_graph->InsertBefore(this, negation, env(), FlowGraph::kValue);
return negation;
}
}
break;
case Token::kSHR:
if (rhs == 0) {
return left()->definition();
} else if (rhs < 0) {
// Instruction will always throw on negative rhs operand.
if (!CanDeoptimize()) {
// For non-speculative operations (no deopt), let
// the code generator deal with throw on slowpath.
break;
}
ASSERT(GetDeoptId() != DeoptId::kNone);
DeoptimizeInstr* deopt =
new DeoptimizeInstr(ICData::kDeoptBinarySmiOp, GetDeoptId());
flow_graph->InsertBefore(this, deopt, env(), FlowGraph::kEffect);
// Replace with zero since it always throws.
return CreateConstantResult(flow_graph, Integer::Handle(Smi::New(0)));
}
break;
case Token::kSHL: {
const intptr_t result_bits = RepresentationBits(representation());
if (rhs == 0) {
return left()->definition();
} else if ((rhs >= kBitsPerInt64) ||
((rhs >= result_bits) && is_truncating())) {
return CreateConstantResult(flow_graph, Integer::Handle(Smi::New(0)));
} else if ((rhs < 0) || ((rhs >= result_bits) && !is_truncating())) {
// Instruction will always throw on negative rhs operand or
// deoptimize on large rhs operand.
if (!CanDeoptimize()) {
// For non-speculative operations (no deopt), let
// the code generator deal with throw on slowpath.
break;
}
ASSERT(GetDeoptId() != DeoptId::kNone);
DeoptimizeInstr* deopt =
new DeoptimizeInstr(ICData::kDeoptBinarySmiOp, GetDeoptId());
flow_graph->InsertBefore(this, deopt, env(), FlowGraph::kEffect);
// Replace with zero since it overshifted or always throws.
return CreateConstantResult(flow_graph, Integer::Handle(Smi::New(0)));
}
break;
}
default:
break;
}
return this;
}
// Optimizations that eliminate or simplify individual instructions.
Instruction* Instruction::Canonicalize(FlowGraph* flow_graph) {
return this;
}
Definition* Definition::Canonicalize(FlowGraph* flow_graph) {
return this;
}
Definition* RedefinitionInstr::Canonicalize(FlowGraph* flow_graph) {
// Must not remove Redifinitions without uses until LICM, even though
// Redefinition might not have any uses itself it can still be dominating
// uses of the value it redefines and must serve as a barrier for those
// uses. RenameUsesDominatedByRedefinitions would normalize the graph and
// route those uses through this redefinition.
if (!HasUses() && !flow_graph->is_licm_allowed()) {
return NULL;
}
if ((constrained_type() != NULL) &&
Type()->IsEqualTo(value()->definition()->Type())) {
return value()->definition();
}
return this;
}
Instruction* CheckStackOverflowInstr::Canonicalize(FlowGraph* flow_graph) {
switch (kind_) {
case kOsrAndPreemption:
return this;
case kOsrOnly:
// Don't need OSR entries in the optimized code.
return NULL;
}
// Switch above exhausts all possibilities but some compilers can't figure
// it out.
UNREACHABLE();
return this;
}
bool LoadFieldInstr::IsImmutableLengthLoad() const {
if (native_field() != nullptr) {
switch (native_field()->kind()) {
case NativeFieldDesc::kArray_length:
case NativeFieldDesc::kTypedData_length:
case NativeFieldDesc::kString_length:
return true;
case NativeFieldDesc::kGrowableObjectArray_length:
return false;
// Not length loads.
case NativeFieldDesc::kLinkedHashMap_index:
case NativeFieldDesc::kLinkedHashMap_data:
case NativeFieldDesc::kLinkedHashMap_hash_mask:
case NativeFieldDesc::kLinkedHashMap_used_data:
case NativeFieldDesc::kLinkedHashMap_deleted_keys:
case NativeFieldDesc::kArgumentsDescriptor_type_args_len:
case NativeFieldDesc::kTypeArguments:
return false;
}
}
return false;
}
bool LoadFieldInstr::IsFixedLengthArrayCid(intptr_t cid) {
if (RawObject::IsTypedDataClassId(cid) ||
RawObject::IsExternalTypedDataClassId(cid)) {
return true;
}
switch (cid) {
case kArrayCid:
case kImmutableArrayCid:
return true;
default:
return false;
}
}
Definition* ConstantInstr::Canonicalize(FlowGraph* flow_graph) {
return HasUses() ? this : NULL;
}
// A math unary instruction has a side effect (exception
// thrown) if the argument is not a number.
// TODO(srdjan): eliminate if has no uses and input is guaranteed to be number.
Definition* MathUnaryInstr::Canonicalize(FlowGraph* flow_graph) {
return this;
}
bool LoadFieldInstr::Evaluate(const Object& instance, Object* result) {
if (native_field() != nullptr) {
switch (native_field()->kind()) {
case NativeFieldDesc::kArgumentsDescriptor_type_args_len:
if (instance.IsArray() && Array::Cast(instance).IsImmutable()) {
ArgumentsDescriptor desc(Array::Cast(instance));
*result = Smi::New(desc.TypeArgsLen());
return true;
}
return false;
default:
break;
}
}
if (field() == nullptr || !field()->is_final() || !instance.IsInstance()) {
return false;
}
// Check that instance really has the field which we
// are trying to load from.
Class& cls = Class::Handle(instance.clazz());
while (cls.raw() != Class::null() && cls.raw() != field()->Owner()) {
cls = cls.SuperClass();
}
if (cls.raw() != field()->Owner()) {
// Failed to find the field in class or its superclasses.
return false;
}
// Object has the field: execute the load.
*result = Instance::Cast(instance).GetField(*field());
return true;
}
Definition* LoadFieldInstr::Canonicalize(FlowGraph* flow_graph) {
if (!HasUses()) return nullptr;
if (IsImmutableLengthLoad()) {
Definition* array = instance()->definition()->OriginalDefinition();
if (StaticCallInstr* call = array->AsStaticCall()) {
// For fixed length arrays if the array is the result of a known
// constructor call we can replace the length load with the length
// argument passed to the constructor.
if (call->is_known_list_constructor() &&
IsFixedLengthArrayCid(call->Type()->ToCid())) {
return call->ArgumentAt(1);
}
} else if (CreateArrayInstr* create_array = array->AsCreateArray()) {
if (native_field() == NativeFieldDesc::Array_length()) {
return create_array->num_elements()->definition();
}
} else if (LoadFieldInstr* load_array = array->AsLoadField()) {
// For arrays with guarded lengths, replace the length load
// with a constant.
if (const Field* field = load_array->field()) {
if (field->guarded_list_length() >= 0) {
return flow_graph->GetConstant(
Smi::Handle(Smi::New(field->guarded_list_length())));
}
}
}
} else if (native_field() != nullptr &&
native_field()->kind() == NativeFieldDesc::kTypeArguments) {
Definition* array = instance()->definition()->OriginalDefinition();
if (StaticCallInstr* call = array->AsStaticCall()) {
if (call->is_known_list_constructor()) {
return call->ArgumentAt(0);
} else if (call->function().recognized_kind() ==
MethodRecognizer::kLinkedHashMap_getData) {
return flow_graph->constant_null();
}
} else if (CreateArrayInstr* create_array = array->AsCreateArray()) {
return create_array->element_type()->definition();
} else if (LoadFieldInstr* load_array = array->AsLoadField()) {
const Field* field = load_array->field();
// For trivially exact fields we know that type arguments match
// static type arguments exactly.
if ((field != nullptr) &&
field->static_type_exactness_state().IsTriviallyExact()) {
return flow_graph->GetConstant(TypeArguments::Handle(
AbstractType::Handle(field->type()).arguments()));
} else if (const NativeFieldDesc* native_field =
load_array->native_field()) {
if (native_field == NativeFieldDesc::LinkedHashMap_data()) {
return flow_graph->constant_null();
}
}
}
}
// Try folding away loads from constant objects.
if (instance()->BindsToConstant()) {
Object& result = Object::Handle();
if (Evaluate(instance()->BoundConstant(), &result)) {
if (result.IsSmi() || result.IsOld()) {
return flow_graph->GetConstant(result);
}
}
}
return this;
}
Definition* AssertBooleanInstr::Canonicalize(FlowGraph* flow_graph) {
if (FLAG_eliminate_type_checks) {
if (value()->Type()->ToCid() == kBoolCid) {
return value()->definition();
}
// In strong mode type is already verified either by static analysis
// or runtime checks, so AssertBoolean just ensures that value is not null.
if (FLAG_strong && !value()->Type()->is_nullable()) {
return value()->definition();
}
}
return this;
}
Definition* AssertAssignableInstr::Canonicalize(FlowGraph* flow_graph) {
if (FLAG_eliminate_type_checks &&
value()->Type()->IsAssignableTo(dst_type())) {
return value()->definition();
}
if (dst_type().IsInstantiated()) {
return this;
}
// For uninstantiated target types: If the instantiator and function
// type arguments are constant, instantiate the target type here.
// Note: these constant type arguments might not necessarily correspond
// to the correct instantiator because AssertAssignable might
// be located in the unreachable part of the graph (e.g.
// it might be dominated by CheckClass that always fails).
// This means that the code below must guard against such possibility.
Zone* Z = Thread::Current()->zone();
const TypeArguments* instantiator_type_args = nullptr;
const TypeArguments* function_type_args = nullptr;
if (instantiator_type_arguments()->BindsToConstant()) {
const Object& val = instantiator_type_arguments()->BoundConstant();
instantiator_type_args = (val.raw() == TypeArguments::null())
? &TypeArguments::null_type_arguments()
: &TypeArguments::Cast(val);
}
if (function_type_arguments()->BindsToConstant()) {
const Object& val = function_type_arguments()->BoundConstant();
function_type_args =
(val.raw() == TypeArguments::null())
? &TypeArguments::null_type_arguments()
: &TypeArguments::Cast(function_type_arguments()->BoundConstant());
}
// If instantiator_type_args are not constant try to match the pattern
// obj.field.:type_arguments where field's static type exactness state