/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "inliner.h"
#include "art_method-inl.h"
#include "base/enums.h"
#include "base/logging.h"
#include "builder.h"
#include "class_linker.h"
#include "class_root-inl.h"
#include "constant_folding.h"
#include "data_type-inl.h"
#include "dead_code_elimination.h"
#include "dex/inline_method_analyser.h"
#include "driver/compiler_options.h"
#include "driver/dex_compilation_unit.h"
#include "instruction_simplifier.h"
#include "intrinsics.h"
#include "jit/jit.h"
#include "jit/jit_code_cache.h"
#include "mirror/class_loader.h"
#include "mirror/dex_cache.h"
#include "mirror/object_array-alloc-inl.h"
#include "mirror/object_array-inl.h"
#include "nodes.h"
#include "reference_type_propagation.h"
#include "register_allocator_linear_scan.h"
#include "scoped_thread_state_change-inl.h"
#include "sharpening.h"
#include "ssa_builder.h"
#include "ssa_phi_elimination.h"
#include "thread.h"
#include "verifier/verifier_compiler_binding.h"
namespace art {
// Instruction limit to control memory.
static constexpr size_t kMaximumNumberOfTotalInstructions = 1024;
// Maximum number of instructions for considering a method small,
// which we will always try to inline if the other non-instruction limits
// are not reached.
static constexpr size_t kMaximumNumberOfInstructionsForSmallMethod = 3;
// Limit the number of dex registers that we accumulate while inlining
// to avoid creating large amount of nested environments.
static constexpr size_t kMaximumNumberOfCumulatedDexRegisters = 32;
// Limit recursive call inlining, which do not benefit from too
// much inlining compared to code locality.
static constexpr size_t kMaximumNumberOfRecursiveCalls = 4;
// Limit recursive polymorphic call inlining to prevent code bloat, since it can quickly get out of
// hand in the presence of multiple Wrapper classes. We set this to 0 to disallow polymorphic
// recursive calls at all.
static constexpr size_t kMaximumNumberOfPolymorphicRecursiveCalls = 0;
// Controls the use of inline caches in AOT mode.
static constexpr bool kUseAOTInlineCaches = true;
// We check for line numbers to make sure the DepthString implementation
// aligns the output nicely.
#define LOG_INTERNAL(msg) \
static_assert(__LINE__ > 10, "Unhandled line number"); \
static_assert(__LINE__ < 10000, "Unhandled line number"); \
VLOG(compiler) << DepthString(__LINE__) << msg
#define LOG_TRY() LOG_INTERNAL("Try inlinining call: ")
#define LOG_NOTE() LOG_INTERNAL("Note: ")
#define LOG_SUCCESS() LOG_INTERNAL("Success: ")
#define LOG_FAIL(stats_ptr, stat) MaybeRecordStat(stats_ptr, stat); LOG_INTERNAL("Fail: ")
#define LOG_FAIL_NO_STAT() LOG_INTERNAL("Fail: ")
std::string HInliner::DepthString(int line) const {
std::string value;
// Indent according to the inlining depth.
size_t count = depth_;
// Line numbers get printed in the log, so add a space if the log's line is less
// than 1000, and two if less than 100. 10 cannot be reached as it's the copyright.
if (!kIsTargetBuild) {
if (line < 100) {
value += " ";
}
if (line < 1000) {
value += " ";
}
// Safeguard if this file reaches more than 10000 lines.
DCHECK_LT(line, 10000);
}
for (size_t i = 0; i < count; ++i) {
value += " ";
}
return value;
}
static size_t CountNumberOfInstructions(HGraph* graph) {
size_t number_of_instructions = 0;
for (HBasicBlock* block : graph->GetReversePostOrderSkipEntryBlock()) {
for (HInstructionIterator instr_it(block->GetInstructions());
!instr_it.Done();
instr_it.Advance()) {
++number_of_instructions;
}
}
return number_of_instructions;
}
void HInliner::UpdateInliningBudget() {
if (total_number_of_instructions_ >= kMaximumNumberOfTotalInstructions) {
// Always try to inline small methods.
inlining_budget_ = kMaximumNumberOfInstructionsForSmallMethod;
} else {
inlining_budget_ = std::max(
kMaximumNumberOfInstructionsForSmallMethod,
kMaximumNumberOfTotalInstructions - total_number_of_instructions_);
}
}
bool HInliner::Run() {
if (codegen_->GetCompilerOptions().GetInlineMaxCodeUnits() == 0) {
// Inlining effectively disabled.
return false;
} else if (graph_->IsDebuggable()) {
// For simplicity, we currently never inline when the graph is debuggable. This avoids
// doing some logic in the runtime to discover if a method could have been inlined.
return false;
}
bool did_inline = false;
bool did_set_always_throws = false;
// Initialize the number of instructions for the method being compiled. Recursive calls
// to HInliner::Run have already updated the instruction count.
if (outermost_graph_ == graph_) {
total_number_of_instructions_ = CountNumberOfInstructions(graph_);
}
UpdateInliningBudget();
DCHECK_NE(total_number_of_instructions_, 0u);
DCHECK_NE(inlining_budget_, 0u);
// If we're compiling tests, honor inlining directives in method names:
// - if a method's name contains the substring "$noinline$", do not
// inline that method;
// - if a method's name contains the substring "$inline$", ensure
// that this method is actually inlined.
// We limit the latter to AOT compilation, as the JIT may or may not inline
// depending on the state of classes at runtime.
const bool honor_noinline_directives = codegen_->GetCompilerOptions().CompileArtTest();
const bool honor_inline_directives =
honor_noinline_directives && Runtime::Current()->IsAotCompiler();
// Keep a copy of all blocks when starting the visit.
ArenaVector<HBasicBlock*> blocks = graph_->GetReversePostOrder();
DCHECK(!blocks.empty());
// Because we are changing the graph when inlining,
// we just iterate over the blocks of the outer method.
// This avoids doing the inlining work again on the inlined blocks.
for (HBasicBlock* block : blocks) {
for (HInstruction* instruction = block->GetFirstInstruction(); instruction != nullptr;) {
HInstruction* next = instruction->GetNext();
HInvoke* call = instruction->AsInvoke();
// As long as the call is not intrinsified, it is worth trying to inline.
if (call != nullptr && call->GetIntrinsic() == Intrinsics::kNone) {
if (honor_noinline_directives) {
// Debugging case: directives in method names control or assert on inlining.
std::string callee_name =
call->GetMethodReference().PrettyMethod(/* with_signature= */ false);
// Tests prevent inlining by having $noinline$ in their method names.
if (callee_name.find("$noinline$") == std::string::npos) {
if (TryInline(call, &did_set_always_throws)) {
did_inline = true;
} else if (honor_inline_directives) {
bool should_have_inlined = (callee_name.find("$inline$") != std::string::npos);
CHECK(!should_have_inlined) << "Could not inline " << callee_name;
}
}
} else {
DCHECK(!honor_inline_directives);
// Normal case: try to inline.
if (TryInline(call, &did_set_always_throws)) {
did_inline = true;
}
}
}
instruction = next;
}
}
return did_inline || did_set_always_throws;
}
static bool IsMethodOrDeclaringClassFinal(ArtMethod* method)
REQUIRES_SHARED(Locks::mutator_lock_) {
return method->IsFinal() || method->GetDeclaringClass()->IsFinal();
}
/**
* Given the `resolved_method` looked up in the dex cache, try to find
* the actual runtime target of an interface or virtual call.
* Return nullptr if the runtime target cannot be proven.
*/
static ArtMethod* FindVirtualOrInterfaceTarget(HInvoke* invoke)
REQUIRES_SHARED(Locks::mutator_lock_) {
ArtMethod* resolved_method = invoke->GetResolvedMethod();
if (IsMethodOrDeclaringClassFinal(resolved_method)) {
// No need to lookup further, the resolved method will be the target.
return resolved_method;
}
HInstruction* receiver = invoke->InputAt(0);
if (receiver->IsNullCheck()) {
// Due to multiple levels of inlining within the same pass, it might be that
// null check does not have the reference type of the actual receiver.
receiver = receiver->InputAt(0);
}
ReferenceTypeInfo info = receiver->GetReferenceTypeInfo();
DCHECK(info.IsValid()) << "Invalid RTI for " << receiver->DebugName();
if (!info.IsExact()) {
// We currently only support inlining with known receivers.
// TODO: Remove this check, we should be able to inline final methods
// on unknown receivers.
return nullptr;
} else if (info.GetTypeHandle()->IsInterface()) {
// Statically knowing that the receiver has an interface type cannot
// help us find what is the target method.
return nullptr;
} else if (!resolved_method->GetDeclaringClass()->IsAssignableFrom(info.GetTypeHandle().Get())) {
// The method that we're trying to call is not in the receiver's class or super classes.
return nullptr;
} else if (info.GetTypeHandle()->IsErroneous()) {
// If the type is erroneous, do not go further, as we are going to query the vtable or
// imt table, that we can only safely do on non-erroneous classes.
return nullptr;
}
ClassLinker* cl = Runtime::Current()->GetClassLinker();
PointerSize pointer_size = cl->GetImagePointerSize();
if (invoke->IsInvokeInterface()) {
resolved_method = info.GetTypeHandle()->FindVirtualMethodForInterface(
resolved_method, pointer_size);
} else {
DCHECK(invoke->IsInvokeVirtual());
resolved_method = info.GetTypeHandle()->FindVirtualMethodForVirtual(
resolved_method, pointer_size);
}
if (resolved_method == nullptr) {
// The information we had on the receiver was not enough to find
// the target method. Since we check above the exact type of the receiver,
// the only reason this can happen is an IncompatibleClassChangeError.
return nullptr;
} else if (!resolved_method->IsInvokable()) {
// The information we had on the receiver was not enough to find
// the target method. Since we check above the exact type of the receiver,
// the only reason this can happen is an IncompatibleClassChangeError.
return nullptr;
} else if (IsMethodOrDeclaringClassFinal(resolved_method)) {
// A final method has to be the target method.
return resolved_method;
} else if (info.IsExact()) {
// If we found a method and the receiver's concrete type is statically
// known, we know for sure the target.
return resolved_method;
} else {
// Even if we did find a method, the receiver type was not enough to
// statically find the runtime target.
return nullptr;
}
}
static uint32_t FindMethodIndexIn(ArtMethod* method,
const DexFile& dex_file,
uint32_t name_and_signature_index)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (IsSameDexFile(*method->GetDexFile(), dex_file)) {
return method->GetDexMethodIndex();
} else {
return method->FindDexMethodIndexInOtherDexFile(dex_file, name_and_signature_index);
}
}
static dex::TypeIndex FindClassIndexIn(ObjPtr<mirror::Class> cls,
const DexCompilationUnit& compilation_unit)
REQUIRES_SHARED(Locks::mutator_lock_) {
const DexFile& dex_file = *compilation_unit.GetDexFile();
dex::TypeIndex index;
if (cls->GetDexCache() == nullptr) {
DCHECK(cls->IsArrayClass()) << cls->PrettyClass();
index = cls->FindTypeIndexInOtherDexFile(dex_file);
} else if (!cls->GetDexTypeIndex().IsValid()) {
DCHECK(cls->IsProxyClass()) << cls->PrettyClass();
// TODO: deal with proxy classes.
} else if (IsSameDexFile(cls->GetDexFile(), dex_file)) {
DCHECK_EQ(cls->GetDexCache(), compilation_unit.GetDexCache().Get());
index = cls->GetDexTypeIndex();
} else {
index = cls->FindTypeIndexInOtherDexFile(dex_file);
// We cannot guarantee the entry will resolve to the same class,
// as there may be different class loaders. So only return the index if it's
// the right class already resolved with the class loader.
if (index.IsValid()) {
ObjPtr<mirror::Class> resolved = compilation_unit.GetClassLinker()->LookupResolvedType(
index, compilation_unit.GetDexCache().Get(), compilation_unit.GetClassLoader().Get());
if (resolved != cls) {
index = dex::TypeIndex::Invalid();
}
}
}
return index;
}
HInliner::InlineCacheType HInliner::GetInlineCacheType(
const StackHandleScope<InlineCache::kIndividualCacheSize>& classes) {
DCHECK_EQ(classes.NumberOfReferences(), InlineCache::kIndividualCacheSize);
uint8_t number_of_types = InlineCache::kIndividualCacheSize - classes.RemainingSlots();
if (number_of_types == 0) {
return kInlineCacheUninitialized;
} else if (number_of_types == 1) {
return kInlineCacheMonomorphic;
} else if (number_of_types == InlineCache::kIndividualCacheSize) {
return kInlineCacheMegamorphic;
} else {
return kInlineCachePolymorphic;
}
}
static inline ObjPtr<mirror::Class> GetMonomorphicType(
const StackHandleScope<InlineCache::kIndividualCacheSize>& classes)
REQUIRES_SHARED(Locks::mutator_lock_) {
DCHECK(classes.GetReference(0) != nullptr);
return classes.GetReference(0)->AsClass();
}
ArtMethod* HInliner::FindMethodFromCHA(ArtMethod* resolved_method) {
if (!resolved_method->HasSingleImplementation()) {
return nullptr;
}
if (Runtime::Current()->IsAotCompiler()) {
// No CHA-based devirtulization for AOT compiler (yet).
return nullptr;
}
if (Runtime::Current()->IsZygote()) {
// No CHA-based devirtulization for Zygote, as it compiles with
// offline information.
return nullptr;
}
if (outermost_graph_->IsCompilingOsr()) {
// We do not support HDeoptimize in OSR methods.
return nullptr;
}
PointerSize pointer_size = caller_compilation_unit_.GetClassLinker()->GetImagePointerSize();
ArtMethod* single_impl = resolved_method->GetSingleImplementation(pointer_size);
if (single_impl == nullptr) {
return nullptr;
}
if (single_impl->IsProxyMethod()) {
// Proxy method is a generic invoker that's not worth
// devirtualizing/inlining. It also causes issues when the proxy
// method is in another dex file if we try to rewrite invoke-interface to
// invoke-virtual because a proxy method doesn't have a real dex file.
return nullptr;
}
if (!single_impl->GetDeclaringClass()->IsResolved()) {
// There's a race with the class loading, which updates the CHA info
// before setting the class to resolved. So we just bail for this
// rare occurence.
return nullptr;
}
return single_impl;
}
static bool IsMethodVerified(ArtMethod* method)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (method->GetDeclaringClass()->IsVerified()) {
return true;
}
// For AOT, we check if the class has a verification status that allows us to
// inline / analyze.
// At runtime, we know this is cold code if the class is not verified, so don't
// bother analyzing.
if (Runtime::Current()->IsAotCompiler()) {
if (method->GetDeclaringClass()->IsVerifiedNeedsAccessChecks() ||
method->GetDeclaringClass()->ShouldVerifyAtRuntime()) {
return true;
}
}
return false;
}
static bool AlwaysThrows(ArtMethod* method)
REQUIRES_SHARED(Locks::mutator_lock_) {
DCHECK(method != nullptr);
// Skip non-compilable and unverified methods.
if (!method->IsCompilable() || !IsMethodVerified(method)) {
return false;
}
// Skip native methods, methods with try blocks, and methods that are too large.
CodeItemDataAccessor accessor(method->DexInstructionData());
if (!accessor.HasCodeItem() ||
accessor.TriesSize() != 0 ||
accessor.InsnsSizeInCodeUnits() > kMaximumNumberOfTotalInstructions) {
return false;
}
// Scan for exits.
bool throw_seen = false;
for (const DexInstructionPcPair& pair : accessor) {
switch (pair.Inst().Opcode()) {
case Instruction::RETURN:
case Instruction::RETURN_VOID:
case Instruction::RETURN_WIDE:
case Instruction::RETURN_OBJECT:
return false; // found regular control flow back
case Instruction::THROW:
throw_seen = true;
break;
default:
break;
}
}
return throw_seen;
}
bool HInliner::TryInline(HInvoke* invoke_instruction, /*inout*/ bool* did_set_always_throws) {
MaybeRecordStat(stats_, MethodCompilationStat::kTryInline);
// Don't bother to move further if we know the method is unresolved or the invocation is
// polymorphic (invoke-{polymorphic,custom}).
if (invoke_instruction->IsInvokeUnresolved()) {
MaybeRecordStat(stats_, MethodCompilationStat::kNotInlinedUnresolved);
return false;
} else if (invoke_instruction->IsInvokePolymorphic()) {
MaybeRecordStat(stats_, MethodCompilationStat::kNotInlinedPolymorphic);
return false;
} else if (invoke_instruction->IsInvokeCustom()) {
MaybeRecordStat(stats_, MethodCompilationStat::kNotInlinedCustom);
return false;
}
ScopedObjectAccess soa(Thread::Current());
LOG_TRY() << invoke_instruction->GetMethodReference().PrettyMethod();
ArtMethod* resolved_method = invoke_instruction->GetResolvedMethod();
if (resolved_method == nullptr) {
DCHECK(invoke_instruction->IsInvokeStaticOrDirect());
DCHECK(invoke_instruction->AsInvokeStaticOrDirect()->IsStringInit());
LOG_FAIL_NO_STAT() << "Not inlining a String.<init> method";
return false;
}
ArtMethod* actual_method = invoke_instruction->IsInvokeStaticOrDirect()
? invoke_instruction->GetResolvedMethod()
: FindVirtualOrInterfaceTarget(invoke_instruction);
if (actual_method != nullptr) {
// Single target.
bool result = TryInlineAndReplace(invoke_instruction,
actual_method,
ReferenceTypeInfo::CreateInvalid(),
/* do_rtp= */ true);
if (result) {
MaybeRecordStat(stats_, MethodCompilationStat::kInlinedInvokeVirtualOrInterface);
if (outermost_graph_ == graph_) {
MaybeRecordStat(stats_, MethodCompilationStat::kInlinedLastInvokeVirtualOrInterface);
}
} else {
HInvoke* invoke_to_analyze = nullptr;
if (TryDevirtualize(invoke_instruction, actual_method, &invoke_to_analyze)) {
// Consider devirtualization as inlining.
result = true;
MaybeRecordStat(stats_, MethodCompilationStat::kDevirtualized);
} else {
invoke_to_analyze = invoke_instruction;
}
// Set always throws property for non-inlined method call with single
// target.
if (AlwaysThrows(actual_method)) {
invoke_to_analyze->SetAlwaysThrows(true);
*did_set_always_throws = true;
}
}
return result;
}
DCHECK(!invoke_instruction->IsInvokeStaticOrDirect());
if (TryInlineFromCHA(invoke_instruction)) {
return true;
}
return TryInlineFromInlineCache(invoke_instruction);
}
bool HInliner::TryInlineFromCHA(HInvoke* invoke_instruction) {
ArtMethod* method = FindMethodFromCHA(invoke_instruction->GetResolvedMethod());
if (method == nullptr) {
return false;
}
LOG_NOTE() << "Try CHA-based inlining of " << method->PrettyMethod();
uint32_t dex_pc = invoke_instruction->GetDexPc();
HInstruction* cursor = invoke_instruction->GetPrevious();
HBasicBlock* bb_cursor = invoke_instruction->GetBlock();
if (!TryInlineAndReplace(invoke_instruction,
method,
ReferenceTypeInfo::CreateInvalid(),
/* do_rtp= */ true)) {
return false;
}
AddCHAGuard(invoke_instruction, dex_pc, cursor, bb_cursor);
// Add dependency due to devirtualization: we are assuming the resolved method
// has a single implementation.
outermost_graph_->AddCHASingleImplementationDependency(invoke_instruction->GetResolvedMethod());
MaybeRecordStat(stats_, MethodCompilationStat::kCHAInline);
return true;
}
bool HInliner::UseOnlyPolymorphicInliningWithNoDeopt() {
// If we are compiling AOT or OSR, pretend the call using inline caches is polymorphic and
// do not generate a deopt.
//
// For AOT:
// Generating a deopt does not ensure that we will actually capture the new types;
// and the danger is that we could be stuck in a loop with "forever" deoptimizations.
// Take for example the following scenario:
// - we capture the inline cache in one run
// - the next run, we deoptimize because we miss a type check, but the method
// never becomes hot again
// In this case, the inline cache will not be updated in the profile and the AOT code
// will keep deoptimizing.
// Another scenario is if we use profile compilation for a process which is not allowed
// to JIT (e.g. system server). If we deoptimize we will run interpreted code for the
// rest of the lifetime.
// TODO(calin):
// This is a compromise because we will most likely never update the inline cache
// in the profile (unless there's another reason to deopt). So we might be stuck with
// a sub-optimal inline cache.
// We could be smarter when capturing inline caches to mitigate this.
// (e.g. by having different thresholds for new and old methods).
//
// For OSR:
// We may come from the interpreter and it may have seen different receiver types.
return Runtime::Current()->IsAotCompiler() || outermost_graph_->IsCompilingOsr();
}
bool HInliner::TryInlineFromInlineCache(HInvoke* invoke_instruction)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (Runtime::Current()->IsAotCompiler() && !kUseAOTInlineCaches) {
return false;
}
StackHandleScope<InlineCache::kIndividualCacheSize> classes(Thread::Current());
// The Zygote JIT compiles based on a profile, so we shouldn't use runtime inline caches
// for it.
InlineCacheType inline_cache_type =
(Runtime::Current()->IsAotCompiler() || Runtime::Current()->IsZygote())
? GetInlineCacheAOT(invoke_instruction, &classes)
: GetInlineCacheJIT(invoke_instruction, &classes);
switch (inline_cache_type) {
case kInlineCacheNoData: {
LOG_FAIL_NO_STAT()
<< "No inline cache information for call to "
<< invoke_instruction->GetMethodReference().PrettyMethod();
return false;
}
case kInlineCacheUninitialized: {
LOG_FAIL_NO_STAT()
<< "Interface or virtual call to "
<< invoke_instruction->GetMethodReference().PrettyMethod()
<< " is not hit and not inlined";
return false;
}
case kInlineCacheMonomorphic: {
MaybeRecordStat(stats_, MethodCompilationStat::kMonomorphicCall);
if (UseOnlyPolymorphicInliningWithNoDeopt()) {
return TryInlinePolymorphicCall(invoke_instruction, classes);
} else {
return TryInlineMonomorphicCall(invoke_instruction, classes);
}
}
case kInlineCachePolymorphic: {
MaybeRecordStat(stats_, MethodCompilationStat::kPolymorphicCall);
return TryInlinePolymorphicCall(invoke_instruction, classes);
}
case kInlineCacheMegamorphic: {
LOG_FAIL_NO_STAT()
<< "Interface or virtual call to "
<< invoke_instruction->GetMethodReference().PrettyMethod()
<< " is megamorphic and not inlined";
MaybeRecordStat(stats_, MethodCompilationStat::kMegamorphicCall);
return false;
}
case kInlineCacheMissingTypes: {
LOG_FAIL_NO_STAT()
<< "Interface or virtual call to "
<< invoke_instruction->GetMethodReference().PrettyMethod()
<< " is missing types and not inlined";
return false;
}
}
UNREACHABLE();
}
HInliner::InlineCacheType HInliner::GetInlineCacheJIT(
HInvoke* invoke_instruction,
/*out*/StackHandleScope<InlineCache::kIndividualCacheSize>* classes) {
DCHECK(codegen_->GetCompilerOptions().IsJitCompiler());
ArtMethod* caller = graph_->GetArtMethod();
// Under JIT, we should always know the caller.
DCHECK(caller != nullptr);
ProfilingInfo* profiling_info = graph_->GetProfilingInfo();
if (profiling_info == nullptr) {
return kInlineCacheNoData;
}
Runtime::Current()->GetJit()->GetCodeCache()->CopyInlineCacheInto(
*profiling_info->GetInlineCache(invoke_instruction->GetDexPc()),
classes);
return GetInlineCacheType(*classes);
}
HInliner::InlineCacheType HInliner::GetInlineCacheAOT(
HInvoke* invoke_instruction,
/*out*/StackHandleScope<InlineCache::kIndividualCacheSize>* classes) {
DCHECK_EQ(classes->NumberOfReferences(), InlineCache::kIndividualCacheSize);
DCHECK_EQ(classes->RemainingSlots(), InlineCache::kIndividualCacheSize);
const ProfileCompilationInfo* pci = codegen_->GetCompilerOptions().GetProfileCompilationInfo();
if (pci == nullptr) {
return kInlineCacheNoData;
}
ProfileCompilationInfo::MethodHotness hotness = pci->GetMethodHotness(MethodReference(
caller_compilation_unit_.GetDexFile(), caller_compilation_unit_.GetDexMethodIndex()));
if (!hotness.IsHot()) {
return kInlineCacheNoData; // no profile information for this invocation.
}
const ProfileCompilationInfo::InlineCacheMap* inline_caches = hotness.GetInlineCacheMap();
DCHECK(inline_caches != nullptr);
const auto it = inline_caches->find(invoke_instruction->GetDexPc());
if (it == inline_caches->end()) {
return kInlineCacheUninitialized;
}
const ProfileCompilationInfo::DexPcData& dex_pc_data = it->second;
if (dex_pc_data.is_missing_types) {
return kInlineCacheMissingTypes;
}
if (dex_pc_data.is_megamorphic) {
return kInlineCacheMegamorphic;
}
DCHECK_LE(dex_pc_data.classes.size(), InlineCache::kIndividualCacheSize);
// Walk over the class descriptors and look up the actual classes.
// If we cannot find a type we return kInlineCacheMissingTypes.
ClassLinker* class_linker = caller_compilation_unit_.GetClassLinker();
for (const dex::TypeIndex& type_index : dex_pc_data.classes) {
const DexFile* dex_file = caller_compilation_unit_.GetDexFile();
const char* descriptor = pci->GetTypeDescriptor(dex_file, type_index);
ObjPtr<mirror::ClassLoader> class_loader = caller_compilation_unit_.GetClassLoader().Get();
ObjPtr<mirror::Class> clazz = class_linker->LookupResolvedType(descriptor, class_loader);
if (clazz == nullptr) {
VLOG(compiler) << "Could not find class from inline cache in AOT mode "
<< invoke_instruction->GetMethodReference().PrettyMethod()
<< " : "
<< descriptor;
return kInlineCacheMissingTypes;
}
DCHECK_NE(classes->RemainingSlots(), 0u);
classes->NewHandle(clazz);
}
return GetInlineCacheType(*classes);
}
HInstanceFieldGet* HInliner::BuildGetReceiverClass(ClassLinker* class_linker,
HInstruction* receiver,
uint32_t dex_pc) const {
ArtField* field = GetClassRoot<mirror::Object>(class_linker)->GetInstanceField(0);
DCHECK_EQ(std::string(field->GetName()), "shadow$_klass_");
HInstanceFieldGet* result = new (graph_->GetAllocator()) HInstanceFieldGet(
receiver,
field,
DataType::Type::kReference,
field->GetOffset(),
field->IsVolatile(),
field->GetDexFieldIndex(),
field->GetDeclaringClass()->GetDexClassDefIndex(),
*field->GetDexFile(),
dex_pc);
// The class of a field is effectively final, and does not have any memory dependencies.
result->SetSideEffects(SideEffects::None());
return result;
}
static ArtMethod* ResolveMethodFromInlineCache(Handle<mirror::Class> klass,
HInvoke* invoke_instruction,
PointerSize pointer_size)
REQUIRES_SHARED(Locks::mutator_lock_) {
ArtMethod* resolved_method = invoke_instruction->GetResolvedMethod();
if (Runtime::Current()->IsAotCompiler()) {
// We can get unrelated types when working with profiles (corruption,
// systme updates, or anyone can write to it). So first check if the class
// actually implements the declaring class of the method that is being
// called in bytecode.
// Note: the lookup methods used below require to have assignable types.
if (!resolved_method->GetDeclaringClass()->IsAssignableFrom(klass.Get())) {
return nullptr;
}
// Also check whether the type in the inline cache is an interface or an
// abstract class. We only expect concrete classes in inline caches, so this
// means the class was changed.
if (klass->IsAbstract() || klass->IsInterface()) {
return nullptr;
}
}
if (invoke_instruction->IsInvokeInterface()) {
resolved_method = klass->FindVirtualMethodForInterface(resolved_method, pointer_size);
} else {
DCHECK(invoke_instruction->IsInvokeVirtual());
resolved_method = klass->FindVirtualMethodForVirtual(resolved_method, pointer_size);
}
// Even if the class exists we can still not have the function the
// inline-cache targets if the profile is from far enough in the past/future.
// We need to allow this since we don't update boot-profiles very often. This
// can occur in boot-profiles with inline-caches.
DCHECK(Runtime::Current()->IsAotCompiler() || resolved_method != nullptr);
return resolved_method;
}
bool HInliner::TryInlineMonomorphicCall(
HInvoke* invoke_instruction,
const StackHandleScope<InlineCache::kIndividualCacheSize>& classes) {
DCHECK(invoke_instruction->IsInvokeVirtual() || invoke_instruction->IsInvokeInterface())
<< invoke_instruction->DebugName();
dex::TypeIndex class_index = FindClassIndexIn(
GetMonomorphicType(classes), caller_compilation_unit_);
if (!class_index.IsValid()) {
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedDexCacheInaccessibleToCaller)
<< "Call to " << ArtMethod::PrettyMethod(invoke_instruction->GetResolvedMethod())
<< " from inline cache is not inlined because its class is not"
<< " accessible to the caller";
return false;
}
ClassLinker* class_linker = caller_compilation_unit_.GetClassLinker();
PointerSize pointer_size = class_linker->GetImagePointerSize();
Handle<mirror::Class> monomorphic_type =
graph_->GetHandleCache()->NewHandle(GetMonomorphicType(classes));
ArtMethod* resolved_method = ResolveMethodFromInlineCache(
monomorphic_type, invoke_instruction, pointer_size);
if (resolved_method == nullptr) {
// Bogus AOT profile, bail.
DCHECK(Runtime::Current()->IsAotCompiler());
return false;
}
LOG_NOTE() << "Try inline monomorphic call to " << resolved_method->PrettyMethod();
HInstruction* receiver = invoke_instruction->InputAt(0);
HInstruction* cursor = invoke_instruction->GetPrevious();
HBasicBlock* bb_cursor = invoke_instruction->GetBlock();
if (!TryInlineAndReplace(invoke_instruction,
resolved_method,
ReferenceTypeInfo::Create(monomorphic_type, /* is_exact= */ true),
/* do_rtp= */ false)) {
return false;
}
// We successfully inlined, now add a guard.
AddTypeGuard(receiver,
cursor,
bb_cursor,
class_index,
monomorphic_type,
invoke_instruction,
/* with_deoptimization= */ true);
// Run type propagation to get the guard typed, and eventually propagate the
// type of the receiver.
ReferenceTypePropagation rtp_fixup(graph_,
outer_compilation_unit_.GetClassLoader(),
outer_compilation_unit_.GetDexCache(),
/* is_first_run= */ false);
rtp_fixup.Run();
MaybeRecordStat(stats_, MethodCompilationStat::kInlinedMonomorphicCall);
return true;
}
void HInliner::AddCHAGuard(HInstruction* invoke_instruction,
uint32_t dex_pc,
HInstruction* cursor,
HBasicBlock* bb_cursor) {
HShouldDeoptimizeFlag* deopt_flag = new (graph_->GetAllocator())
HShouldDeoptimizeFlag(graph_->GetAllocator(), dex_pc);
// ShouldDeoptimizeFlag is used to perform a deoptimization because of a CHA
// invalidation or for debugging reasons. It is OK to just check for non-zero
// value here instead of the specific CHA value. When a debugging deopt is
// requested we deoptimize before we execute any code and hence we shouldn't
// see that case here.
HInstruction* compare = new (graph_->GetAllocator()) HNotEqual(
deopt_flag, graph_->GetIntConstant(0, dex_pc));
HInstruction* deopt = new (graph_->GetAllocator()) HDeoptimize(
graph_->GetAllocator(), compare, DeoptimizationKind::kCHA, dex_pc);
if (cursor != nullptr) {
bb_cursor->InsertInstructionAfter(deopt_flag, cursor);
} else {
bb_cursor->InsertInstructionBefore(deopt_flag, bb_cursor->GetFirstInstruction());
}
bb_cursor->InsertInstructionAfter(compare, deopt_flag);
bb_cursor->InsertInstructionAfter(deopt, compare);
// Add receiver as input to aid CHA guard optimization later.
deopt_flag->AddInput(invoke_instruction->InputAt(0));
DCHECK_EQ(deopt_flag->InputCount(), 1u);
deopt->CopyEnvironmentFrom(invoke_instruction->GetEnvironment());
outermost_graph_->IncrementNumberOfCHAGuards();
}
HInstruction* HInliner::AddTypeGuard(HInstruction* receiver,
HInstruction* cursor,
HBasicBlock* bb_cursor,
dex::TypeIndex class_index,
Handle<mirror::Class> klass,
HInstruction* invoke_instruction,
bool with_deoptimization) {
ClassLinker* class_linker = caller_compilation_unit_.GetClassLinker();
HInstanceFieldGet* receiver_class = BuildGetReceiverClass(
class_linker, receiver, invoke_instruction->GetDexPc());
if (cursor != nullptr) {
bb_cursor->InsertInstructionAfter(receiver_class, cursor);
} else {
bb_cursor->InsertInstructionBefore(receiver_class, bb_cursor->GetFirstInstruction());
}
const DexFile& caller_dex_file = *caller_compilation_unit_.GetDexFile();
bool is_referrer;
ArtMethod* outermost_art_method = outermost_graph_->GetArtMethod();
if (outermost_art_method == nullptr) {
DCHECK(Runtime::Current()->IsAotCompiler());
// We are in AOT mode and we don't have an ART method to determine
// if the inlined method belongs to the referrer. Assume it doesn't.
is_referrer = false;
} else {
is_referrer = klass.Get() == outermost_art_method->GetDeclaringClass();
}
// Note that we will just compare the classes, so we don't need Java semantics access checks.
// Note that the type index and the dex file are relative to the method this type guard is
// inlined into.
HLoadClass* load_class = new (graph_->GetAllocator()) HLoadClass(graph_->GetCurrentMethod(),
class_index,
caller_dex_file,
klass,
is_referrer,
invoke_instruction->GetDexPc(),
/* needs_access_check= */ false);
HLoadClass::LoadKind kind = HSharpening::ComputeLoadClassKind(
load_class, codegen_, caller_compilation_unit_);
DCHECK(kind != HLoadClass::LoadKind::kInvalid)
<< "We should always be able to reference a class for inline caches";
// Load kind must be set before inserting the instruction into the graph.
load_class->SetLoadKind(kind);
bb_cursor->InsertInstructionAfter(load_class, receiver_class);
// In AOT mode, we will most likely load the class from BSS, which will involve a call
// to the runtime. In this case, the load instruction will need an environment so copy
// it from the invoke instruction.
if (load_class->NeedsEnvironment()) {
DCHECK(Runtime::Current()->IsAotCompiler());
load_class->CopyEnvironmentFrom(invoke_instruction->GetEnvironment());
}
HNotEqual* compare = new (graph_->GetAllocator()) HNotEqual(load_class, receiver_class);
bb_cursor->InsertInstructionAfter(compare, load_class);
if (with_deoptimization) {
HDeoptimize* deoptimize = new (graph_->GetAllocator()) HDeoptimize(
graph_->GetAllocator(),
compare,
receiver,
Runtime::Current()->IsAotCompiler()
? DeoptimizationKind::kAotInlineCache
: DeoptimizationKind::kJitInlineCache,
invoke_instruction->GetDexPc());
bb_cursor->InsertInstructionAfter(deoptimize, compare);
deoptimize->CopyEnvironmentFrom(invoke_instruction->GetEnvironment());
DCHECK_EQ(invoke_instruction->InputAt(0), receiver);
receiver->ReplaceUsesDominatedBy(deoptimize, deoptimize);
deoptimize->SetReferenceTypeInfo(receiver->GetReferenceTypeInfo());
}
return compare;
}
static void MaybeReplaceAndRemove(HInstruction* new_instruction, HInstruction* old_instruction) {
DCHECK(new_instruction != old_instruction);
if (new_instruction != nullptr) {
old_instruction->ReplaceWith(new_instruction);
}
old_instruction->GetBlock()->RemoveInstruction(old_instruction);
}
bool HInliner::TryInlinePolymorphicCall(
HInvoke* invoke_instruction,
const StackHandleScope<InlineCache::kIndividualCacheSize>& classes) {
DCHECK(invoke_instruction->IsInvokeVirtual() || invoke_instruction->IsInvokeInterface())
<< invoke_instruction->DebugName();
if (TryInlinePolymorphicCallToSameTarget(invoke_instruction, classes)) {
return true;
}
ClassLinker* class_linker = caller_compilation_unit_.GetClassLinker();
PointerSize pointer_size = class_linker->GetImagePointerSize();
bool all_targets_inlined = true;
bool one_target_inlined = false;
DCHECK_EQ(classes.NumberOfReferences(), InlineCache::kIndividualCacheSize);
uint8_t number_of_types = InlineCache::kIndividualCacheSize - classes.RemainingSlots();
for (size_t i = 0; i != number_of_types; ++i) {
DCHECK(classes.GetReference(i) != nullptr);
Handle<mirror::Class> handle =
graph_->GetHandleCache()->NewHandle(classes.GetReference(i)->AsClass());
ArtMethod* method = ResolveMethodFromInlineCache(handle, invoke_instruction, pointer_size);
if (method == nullptr) {
DCHECK(Runtime::Current()->IsAotCompiler());
// AOT profile is bogus. This loop expects to iterate over all entries,
// so just just continue.
all_targets_inlined = false;
continue;
}
HInstruction* receiver = invoke_instruction->InputAt(0);
HInstruction* cursor = invoke_instruction->GetPrevious();
HBasicBlock* bb_cursor = invoke_instruction->GetBlock();
dex::TypeIndex class_index = FindClassIndexIn(handle.Get(), caller_compilation_unit_);
HInstruction* return_replacement = nullptr;
// In monomorphic cases when UseOnlyPolymorphicInliningWithNoDeopt() is true, we call
// `TryInlinePolymorphicCall` even though we are monomorphic.
const bool actually_monomorphic = number_of_types == 1;
DCHECK_IMPLIES(actually_monomorphic, UseOnlyPolymorphicInliningWithNoDeopt());
// We only want to limit recursive polymorphic cases, not monomorphic ones.
const bool too_many_polymorphic_recursive_calls =
!actually_monomorphic &&
CountRecursiveCallsOf(method) > kMaximumNumberOfPolymorphicRecursiveCalls;
if (too_many_polymorphic_recursive_calls) {
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedPolymorphicRecursiveBudget)
<< "Method " << method->PrettyMethod()
<< " is not inlined because it has reached its polymorphic recursive call budget.";
} else if (class_index.IsValid()) {
LOG_NOTE() << "Try inline polymorphic call to " << method->PrettyMethod();
}
if (too_many_polymorphic_recursive_calls ||
!class_index.IsValid() ||
!TryBuildAndInline(invoke_instruction,
method,
ReferenceTypeInfo::Create(handle, /* is_exact= */ true),
&return_replacement)) {
all_targets_inlined = false;
} else {
one_target_inlined = true;
LOG_SUCCESS() << "Polymorphic call to "
<< invoke_instruction->GetMethodReference().PrettyMethod()
<< " has inlined " << ArtMethod::PrettyMethod(method);
// If we have inlined all targets before, and this receiver is the last seen,
// we deoptimize instead of keeping the original invoke instruction.
bool deoptimize = !UseOnlyPolymorphicInliningWithNoDeopt() &&
all_targets_inlined &&
(i + 1 == number_of_types);
HInstruction* compare = AddTypeGuard(receiver,
cursor,
bb_cursor,
class_index,
handle,
invoke_instruction,
deoptimize);
if (deoptimize) {
MaybeReplaceAndRemove(return_replacement, invoke_instruction);
} else {
CreateDiamondPatternForPolymorphicInline(compare, return_replacement, invoke_instruction);
}
}
}
if (!one_target_inlined) {
LOG_FAIL_NO_STAT()
<< "Call to " << invoke_instruction->GetMethodReference().PrettyMethod()
<< " from inline cache is not inlined because none"
<< " of its targets could be inlined";
return false;
}
MaybeRecordStat(stats_, MethodCompilationStat::kInlinedPolymorphicCall);
// Run type propagation to get the guards typed.
ReferenceTypePropagation rtp_fixup(graph_,
outer_compilation_unit_.GetClassLoader(),
outer_compilation_unit_.GetDexCache(),
/* is_first_run= */ false);
rtp_fixup.Run();
return true;
}
void HInliner::CreateDiamondPatternForPolymorphicInline(HInstruction* compare,
HInstruction* return_replacement,
HInstruction* invoke_instruction) {
uint32_t dex_pc = invoke_instruction->GetDexPc();
HBasicBlock* cursor_block = compare->GetBlock();
HBasicBlock* original_invoke_block = invoke_instruction->GetBlock();
ArenaAllocator* allocator = graph_->GetAllocator();
// Spit the block after the compare: `cursor_block` will now be the start of the diamond,
// and the returned block is the start of the then branch (that could contain multiple blocks).
HBasicBlock* then = cursor_block->SplitAfterForInlining(compare);
// Split the block containing the invoke before and after the invoke. The returned block
// of the split before will contain the invoke and will be the otherwise branch of
// the diamond. The returned block of the split after will be the merge block
// of the diamond.
HBasicBlock* end_then = invoke_instruction->GetBlock();
HBasicBlock* otherwise = end_then->SplitBeforeForInlining(invoke_instruction);
HBasicBlock* merge = otherwise->SplitAfterForInlining(invoke_instruction);
// If the methods we are inlining return a value, we create a phi in the merge block
// that will have the `invoke_instruction and the `return_replacement` as inputs.
if (return_replacement != nullptr) {
HPhi* phi = new (allocator) HPhi(
allocator, kNoRegNumber, 0, HPhi::ToPhiType(invoke_instruction->GetType()), dex_pc);
merge->AddPhi(phi);
invoke_instruction->ReplaceWith(phi);
phi->AddInput(return_replacement);
phi->AddInput(invoke_instruction);
}
// Add the control flow instructions.
otherwise->AddInstruction(new (allocator) HGoto(dex_pc));
end_then->AddInstruction(new (allocator) HGoto(dex_pc));
cursor_block->AddInstruction(new (allocator) HIf(compare, dex_pc));
// Add the newly created blocks to the graph.
graph_->AddBlock(then);
graph_->AddBlock(otherwise);
graph_->AddBlock(merge);
// Set up successor (and implictly predecessor) relations.
cursor_block->AddSuccessor(otherwise);
cursor_block->AddSuccessor(then);
end_then->AddSuccessor(merge);
otherwise->AddSuccessor(merge);
// Set up dominance information.
then->SetDominator(cursor_block);
cursor_block->AddDominatedBlock(then);
otherwise->SetDominator(cursor_block);
cursor_block->AddDominatedBlock(otherwise);
merge->SetDominator(cursor_block);
cursor_block->AddDominatedBlock(merge);
// Update the revert post order.
size_t index = IndexOfElement(graph_->reverse_post_order_, cursor_block);
MakeRoomFor(&graph_->reverse_post_order_, 1, index);
graph_->reverse_post_order_[++index] = then;
index = IndexOfElement(graph_->reverse_post_order_, end_then);
MakeRoomFor(&graph_->reverse_post_order_, 2, index);
graph_->reverse_post_order_[++index] = otherwise;
graph_->reverse_post_order_[++index] = merge;
graph_->UpdateLoopAndTryInformationOfNewBlock(
then, original_invoke_block, /* replace_if_back_edge= */ false);
graph_->UpdateLoopAndTryInformationOfNewBlock(
otherwise, original_invoke_block, /* replace_if_back_edge= */ false);
// In case the original invoke location was a back edge, we need to update
// the loop to now have the merge block as a back edge.
graph_->UpdateLoopAndTryInformationOfNewBlock(
merge, original_invoke_block, /* replace_if_back_edge= */ true);
}
bool HInliner::TryInlinePolymorphicCallToSameTarget(
HInvoke* invoke_instruction,
const StackHandleScope<InlineCache::kIndividualCacheSize>& classes) {
// This optimization only works under JIT for now.
if (!codegen_->GetCompilerOptions().IsJitCompiler()) {
return false;
}
ClassLinker* class_linker = caller_compilation_unit_.GetClassLinker();
PointerSize pointer_size = class_linker->GetImagePointerSize();
ArtMethod* actual_method = nullptr;
size_t method_index = invoke_instruction->IsInvokeVirtual()
? invoke_instruction->AsInvokeVirtual()->GetVTableIndex()
: invoke_instruction->AsInvokeInterface()->GetImtIndex();
// Check whether we are actually calling the same method among
// the different types seen.
DCHECK_EQ(classes.NumberOfReferences(), InlineCache::kIndividualCacheSize);
uint8_t number_of_types = InlineCache::kIndividualCacheSize - classes.RemainingSlots();
for (size_t i = 0; i != number_of_types; ++i) {
DCHECK(classes.GetReference(i) != nullptr);
ArtMethod* new_method = nullptr;
if (invoke_instruction->IsInvokeInterface()) {
new_method = classes.GetReference(i)->AsClass()->GetImt(pointer_size)->Get(
method_index, pointer_size);
if (new_method->IsRuntimeMethod()) {
// Bail out as soon as we see a conflict trampoline in one of the target's
// interface table.
return false;
}
} else {
DCHECK(invoke_instruction->IsInvokeVirtual());
new_method =
classes.GetReference(i)->AsClass()->GetEmbeddedVTableEntry(method_index, pointer_size);
}
DCHECK(new_method != nullptr);
if (actual_method == nullptr) {
actual_method = new_method;
} else if (actual_method != new_method) {
// Different methods, bailout.
return false;
}
}
HInstruction* receiver = invoke_instruction->InputAt(0);
HInstruction* cursor = invoke_instruction->GetPrevious();
HBasicBlock* bb_cursor = invoke_instruction->GetBlock();
HInstruction* return_replacement = nullptr;
if (!TryBuildAndInline(invoke_instruction,
actual_method,
ReferenceTypeInfo::CreateInvalid(),
&return_replacement)) {
return false;
}
// We successfully inlined, now add a guard.
HInstanceFieldGet* receiver_class = BuildGetReceiverClass(
class_linker, receiver, invoke_instruction->GetDexPc());
DataType::Type type = Is64BitInstructionSet(graph_->GetInstructionSet())
? DataType::Type::kInt64
: DataType::Type::kInt32;
HClassTableGet* class_table_get = new (graph_->GetAllocator()) HClassTableGet(
receiver_class,
type,
invoke_instruction->IsInvokeVirtual() ? HClassTableGet::TableKind::kVTable
: HClassTableGet::TableKind::kIMTable,
method_index,
invoke_instruction->GetDexPc());
HConstant* constant;
if (type == DataType::Type::kInt64) {
constant = graph_->GetLongConstant(
reinterpret_cast<intptr_t>(actual_method), invoke_instruction->GetDexPc());
} else {
constant = graph_->GetIntConstant(
reinterpret_cast<intptr_t>(actual_method), invoke_instruction->GetDexPc());
}
HNotEqual* compare = new (graph_->GetAllocator()) HNotEqual(class_table_get, constant);
if (cursor != nullptr) {
bb_cursor->InsertInstructionAfter(receiver_class, cursor);
} else {
bb_cursor->InsertInstructionBefore(receiver_class, bb_cursor->GetFirstInstruction());
}
bb_cursor->InsertInstructionAfter(class_table_get, receiver_class);
bb_cursor->InsertInstructionAfter(compare, class_table_get);
if (outermost_graph_->IsCompilingOsr()) {
CreateDiamondPatternForPolymorphicInline(compare, return_replacement, invoke_instruction);
} else {
HDeoptimize* deoptimize = new (graph_->GetAllocator()) HDeoptimize(
graph_->GetAllocator(),
compare,
receiver,
DeoptimizationKind::kJitSameTarget,
invoke_instruction->GetDexPc());
bb_cursor->InsertInstructionAfter(deoptimize, compare);
deoptimize->CopyEnvironmentFrom(invoke_instruction->GetEnvironment());
MaybeReplaceAndRemove(return_replacement, invoke_instruction);
receiver->ReplaceUsesDominatedBy(deoptimize, deoptimize);
deoptimize->SetReferenceTypeInfo(receiver->GetReferenceTypeInfo());
}
// Run type propagation to get the guard typed.
ReferenceTypePropagation rtp_fixup(graph_,
outer_compilation_unit_.GetClassLoader(),
outer_compilation_unit_.GetDexCache(),
/* is_first_run= */ false);
rtp_fixup.Run();
MaybeRecordStat(stats_, MethodCompilationStat::kInlinedPolymorphicCall);
LOG_SUCCESS() << "Inlined same polymorphic target " << actual_method->PrettyMethod();
return true;
}
void HInliner::MaybeRunReferenceTypePropagation(HInstruction* replacement,
HInvoke* invoke_instruction) {
if (ReturnTypeMoreSpecific(replacement, invoke_instruction)) {
// Actual return value has a more specific type than the method's declared
// return type. Run RTP again on the outer graph to propagate it.
ReferenceTypePropagation(graph_,
outer_compilation_unit_.GetClassLoader(),
outer_compilation_unit_.GetDexCache(),
/* is_first_run= */ false).Run();
}
}
bool HInliner::TryDevirtualize(HInvoke* invoke_instruction,
ArtMethod* method,
HInvoke** replacement) {
DCHECK(invoke_instruction != *replacement);
if (!invoke_instruction->IsInvokeInterface() && !invoke_instruction->IsInvokeVirtual()) {
return false;
}
// Don't bother trying to call directly a default conflict method. It
// doesn't have a proper MethodReference, but also `GetCanonicalMethod`
// will return an actual default implementation.
if (method->IsDefaultConflicting()) {
return false;
}
DCHECK(!method->IsProxyMethod());
ClassLinker* cl = Runtime::Current()->GetClassLinker();
PointerSize pointer_size = cl->GetImagePointerSize();
// The sharpening logic assumes the caller isn't passing a copied method.
method = method->GetCanonicalMethod(pointer_size);
uint32_t dex_method_index = FindMethodIndexIn(
method,
*invoke_instruction->GetMethodReference().dex_file,
invoke_instruction->GetMethodReference().index);
if (dex_method_index == dex::kDexNoIndex) {
return false;
}
HInvokeStaticOrDirect::DispatchInfo dispatch_info =
HSharpening::SharpenLoadMethod(method,
/* has_method_id= */ true,
/* for_interface_call= */ false,
codegen_);
DCHECK_NE(dispatch_info.code_ptr_location, CodePtrLocation::kCallCriticalNative);
if (dispatch_info.method_load_kind == MethodLoadKind::kRuntimeCall) {
// If sharpening returns that we need to load the method at runtime, keep
// the virtual/interface call which will be faster.
// Also, the entrypoints for runtime calls do not handle devirtualized
// calls.
return false;
}
HInvokeStaticOrDirect* new_invoke = new (graph_->GetAllocator()) HInvokeStaticOrDirect(
graph_->GetAllocator(),
invoke_instruction->GetNumberOfArguments(),
invoke_instruction->GetType(),
invoke_instruction->GetDexPc(),
MethodReference(invoke_instruction->GetMethodReference().dex_file, dex_method_index),
method,
dispatch_info,
kDirect,
MethodReference(method->GetDexFile(), method->GetDexMethodIndex()),
HInvokeStaticOrDirect::ClinitCheckRequirement::kNone);
HInputsRef inputs = invoke_instruction->GetInputs();
DCHECK_EQ(inputs.size(), invoke_instruction->GetNumberOfArguments());
for (size_t index = 0; index != inputs.size(); ++index) {
new_invoke->SetArgumentAt(index, inputs[index]);
}
if (HInvokeStaticOrDirect::NeedsCurrentMethodInput(dispatch_info)) {
new_invoke->SetRawInputAt(new_invoke->GetCurrentMethodIndexUnchecked(),
graph_->GetCurrentMethod());
}
invoke_instruction->GetBlock()->InsertInstructionBefore(new_invoke, invoke_instruction);
new_invoke->CopyEnvironmentFrom(invoke_instruction->GetEnvironment());
if (invoke_instruction->GetType() == DataType::Type::kReference) {
new_invoke->SetReferenceTypeInfo(invoke_instruction->GetReferenceTypeInfo());
}
*replacement = new_invoke;
MaybeReplaceAndRemove(*replacement, invoke_instruction);
// No need to call MaybeRunReferenceTypePropagation, as we know the return type
// cannot be more specific.
DCHECK(!ReturnTypeMoreSpecific(*replacement, invoke_instruction));
return true;
}
bool HInliner::TryInlineAndReplace(HInvoke* invoke_instruction,
ArtMethod* method,
ReferenceTypeInfo receiver_type,
bool do_rtp) {
DCHECK(!invoke_instruction->IsIntrinsic());
HInstruction* return_replacement = nullptr;
if (!TryBuildAndInline(invoke_instruction, method, receiver_type, &return_replacement)) {
return false;
}
MaybeReplaceAndRemove(return_replacement, invoke_instruction);
FixUpReturnReferenceType(method, return_replacement);
if (do_rtp) {
MaybeRunReferenceTypePropagation(return_replacement, invoke_instruction);
}
return true;
}
size_t HInliner::CountRecursiveCallsOf(ArtMethod* method) const {
const HInliner* current = this;
size_t count = 0;
do {
if (current->graph_->GetArtMethod() == method) {
++count;
}
current = current->parent_;
} while (current != nullptr);
return count;
}
static inline bool MayInline(const CompilerOptions& compiler_options,
const DexFile& inlined_from,
const DexFile& inlined_into) {
// We're not allowed to inline across dex files if we're the no-inline-from dex file.
if (!IsSameDexFile(inlined_from, inlined_into) &&
ContainsElement(compiler_options.GetNoInlineFromDexFile(), &inlined_from)) {
return false;
}
return true;
}
// Returns whether inlining is allowed based on ART semantics.
bool HInliner::IsInliningAllowed(ArtMethod* method, const CodeItemDataAccessor& accessor) const {
if (!accessor.HasCodeItem()) {
LOG_FAIL_NO_STAT()
<< "Method " << method->PrettyMethod() << " is not inlined because it is native";
return false;
}
if (!method->IsCompilable()) {
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedNotCompilable)
<< "Method " << method->PrettyMethod()
<< " has soft failures un-handled by the compiler, so it cannot be inlined";
return false;
}
if (!IsMethodVerified(method)) {
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedNotVerified)
<< "Method " << method->PrettyMethod()
<< " couldn't be verified, so it cannot be inlined";
return false;
}
return true;
}
// Returns whether ART supports inlining this method.
//
// Some methods are not supported because they have features for which inlining
// is not implemented. For example, we do not currently support inlining throw
// instructions into a try block.
bool HInliner::IsInliningSupported(const HInvoke* invoke_instruction,
ArtMethod* method,
const CodeItemDataAccessor& accessor) const {
if (method->IsProxyMethod()) {
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedProxy)
<< "Method " << method->PrettyMethod()
<< " is not inlined because of unimplemented inline support for proxy methods.";
return false;
}
if (accessor.TriesSize() != 0) {
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedTryCatchCallee)
<< "Method " << method->PrettyMethod() << " is not inlined because of try block";
return false;
}
if (invoke_instruction->IsInvokeStaticOrDirect() &&
invoke_instruction->AsInvokeStaticOrDirect()->IsStaticWithImplicitClinitCheck()) {
// Case of a static method that cannot be inlined because it implicitly
// requires an initialization check of its declaring class.
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedDexCacheClinitCheck)
<< "Method " << method->PrettyMethod()
<< " is not inlined because it is static and requires a clinit"
<< " check that cannot be emitted due to Dex cache limitations";
return false;
}
return true;
}
// Returns whether our resource limits allow inlining this method.
bool HInliner::IsInliningBudgetAvailable(ArtMethod* method,
const CodeItemDataAccessor& accessor) const {
if (CountRecursiveCallsOf(method) > kMaximumNumberOfRecursiveCalls) {
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedRecursiveBudget)
<< "Method "
<< method->PrettyMethod()
<< " is not inlined because it has reached its recursive call budget.";
return false;
}
size_t inline_max_code_units = codegen_->GetCompilerOptions().GetInlineMaxCodeUnits();
if (accessor.InsnsSizeInCodeUnits() > inline_max_code_units) {
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedCodeItem)
<< "Method " << method->PrettyMethod()
<< " is not inlined because its code item is too big: "
<< accessor.InsnsSizeInCodeUnits()
<< " > "
<< inline_max_code_units;
return false;
}
return true;
}
bool HInliner::TryBuildAndInline(HInvoke* invoke_instruction,
ArtMethod* method,
ReferenceTypeInfo receiver_type,
HInstruction** return_replacement) {
// If invoke_instruction is devirtualized to a different method, give intrinsics
// another chance before we try to inline it.
if (invoke_instruction->GetResolvedMethod() != method && method->IsIntrinsic()) {
MaybeRecordStat(stats_, MethodCompilationStat::kIntrinsicRecognized);
// For simplicity, always create a new instruction to replace the existing
// invoke.
HInvokeVirtual* new_invoke = new (graph_->GetAllocator()) HInvokeVirtual(
graph_->GetAllocator(),
invoke_instruction->GetNumberOfArguments(),
invoke_instruction->GetType(),
invoke_instruction->GetDexPc(),
invoke_instruction->GetMethodReference(), // Use existing invoke's method's reference.
method,
MethodReference(method->GetDexFile(), method->GetDexMethodIndex()),
method->GetMethodIndex());
DCHECK_NE(new_invoke->GetIntrinsic(), Intrinsics::kNone);
HInputsRef inputs = invoke_instruction->GetInputs();
for (size_t index = 0; index != inputs.size(); ++index) {
new_invoke->SetArgumentAt(index, inputs[index]);
}
invoke_instruction->GetBlock()->InsertInstructionBefore(new_invoke, invoke_instruction);
new_invoke->CopyEnvironmentFrom(invoke_instruction->GetEnvironment());
if (invoke_instruction->GetType() == DataType::Type::kReference) {
new_invoke->SetReferenceTypeInfo(invoke_instruction->GetReferenceTypeInfo());
}
*return_replacement = new_invoke;
return true;
}
// Check whether we're allowed to inline. The outermost compilation unit is the relevant
// dex file here (though the transitivity of an inline chain would allow checking the caller).
if (!MayInline(codegen_->GetCompilerOptions(),
*method->GetDexFile(),
*outer_compilation_unit_.GetDexFile())) {
if (TryPatternSubstitution(invoke_instruction, method, return_replacement)) {
LOG_SUCCESS() << "Successfully replaced pattern of invoke "
<< method->PrettyMethod();
MaybeRecordStat(stats_, MethodCompilationStat::kReplacedInvokeWithSimplePattern);
return true;
}
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedWont)
<< "Won't inline " << method->PrettyMethod() << " in "
<< outer_compilation_unit_.GetDexFile()->GetLocation() << " ("
<< caller_compilation_unit_.GetDexFile()->GetLocation() << ") from "
<< method->GetDexFile()->GetLocation();
return false;
}
CodeItemDataAccessor accessor(method->DexInstructionData());
if (!IsInliningAllowed(method, accessor)) {
return false;
}
if (!IsInliningSupported(invoke_instruction, method, accessor)) {
return false;
}
if (!IsInliningBudgetAvailable(method, accessor)) {
return false;
}
if (!TryBuildAndInlineHelper(
invoke_instruction, method, receiver_type, return_replacement)) {
return false;
}
LOG_SUCCESS() << method->PrettyMethod();
MaybeRecordStat(stats_, MethodCompilationStat::kInlinedInvoke);
if (outermost_graph_ == graph_) {
MaybeRecordStat(stats_, MethodCompilationStat::kInlinedLastInvoke);
}
return true;
}
static HInstruction* GetInvokeInputForArgVRegIndex(HInvoke* invoke_instruction,
size_t arg_vreg_index)
REQUIRES_SHARED(Locks::mutator_lock_) {
size_t input_index = 0;
for (size_t i = 0; i < arg_vreg_index; ++i, ++input_index) {
DCHECK_LT(input_index, invoke_instruction->GetNumberOfArguments());
if (DataType::Is64BitType(invoke_instruction->InputAt(input_index)->GetType())) {
++i;
DCHECK_NE(i, arg_vreg_index);
}
}
DCHECK_LT(input_index, invoke_instruction->GetNumberOfArguments());
return invoke_instruction->InputAt(input_index);
}
// Try to recognize known simple patterns and replace invoke call with appropriate instructions.
bool HInliner::TryPatternSubstitution(HInvoke* invoke_instruction,
ArtMethod* method,
HInstruction** return_replacement) {
InlineMethod inline_method;
if (!InlineMethodAnalyser::AnalyseMethodCode(method, &inline_method)) {
return false;
}
switch (inline_method.opcode) {
case kInlineOpNop:
DCHECK_EQ(invoke_instruction->GetType(), DataType::Type::kVoid);
*return_replacement = nullptr;
break;
case kInlineOpReturnArg:
*return_replacement = GetInvokeInputForArgVRegIndex(invoke_instruction,
inline_method.d.return_data.arg);
break;
case kInlineOpNonWideConst: {
char shorty0 = method->GetShorty()[0];
if (shorty0 == 'L') {
DCHECK_EQ(inline_method.d.data, 0u);
*return_replacement = graph_->GetNullConstant();
} else if (shorty0 == 'F') {
*return_replacement = graph_->GetFloatConstant(
bit_cast<float, int32_t>(static_cast<int32_t>(inline_method.d.data)));
} else {
*return_replacement = graph_->GetIntConstant(static_cast<int32_t>(inline_method.d.data));
}
break;
}
case kInlineOpIGet: {
const InlineIGetIPutData& data = inline_method.d.ifield_data;
if (data.method_is_static || data.object_arg != 0u) {
// TODO: Needs null check.
return false;
}
HInstruction* obj = GetInvokeInputForArgVRegIndex(invoke_instruction, data.object_arg);
HInstanceFieldGet* iget = CreateInstanceFieldGet(data.field_idx, method, obj);
DCHECK_EQ(iget->GetFieldOffset().Uint32Value(), data.field_offset);
DCHECK_EQ(iget->IsVolatile() ? 1u : 0u, data.is_volatile);
invoke_instruction->GetBlock()->InsertInstructionBefore(iget, invoke_instruction);
*return_replacement = iget;
break;
}
case kInlineOpIPut: {
const InlineIGetIPutData& data = inline_method.d.ifield_data;
if (data.method_is_static || data.object_arg != 0u) {
// TODO: Needs null check.
return false;
}
HInstruction* obj = GetInvokeInputForArgVRegIndex(invoke_instruction, data.object_arg);
HInstruction* value = GetInvokeInputForArgVRegIndex(invoke_instruction, data.src_arg);
HInstanceFieldSet* iput = CreateInstanceFieldSet(data.field_idx, method, obj, value);
DCHECK_EQ(iput->GetFieldOffset().Uint32Value(), data.field_offset);
DCHECK_EQ(iput->IsVolatile() ? 1u : 0u, data.is_volatile);
invoke_instruction->GetBlock()->InsertInstructionBefore(iput, invoke_instruction);
if (data.return_arg_plus1 != 0u) {
size_t return_arg = data.return_arg_plus1 - 1u;
*return_replacement = GetInvokeInputForArgVRegIndex(invoke_instruction, return_arg);
}
break;
}
case kInlineOpConstructor: {
const InlineConstructorData& data = inline_method.d.constructor_data;
// Get the indexes to arrays for easier processing.
uint16_t iput_field_indexes[] = {
data.iput0_field_index, data.iput1_field_index, data.iput2_field_index
};
uint16_t iput_args[] = { data.iput0_arg, data.iput1_arg, data.iput2_arg };
static_assert(arraysize(iput_args) == arraysize(iput_field_indexes), "Size mismatch");
// Count valid field indexes.
size_t number_of_iputs = 0u;
while (number_of_iputs != arraysize(iput_field_indexes) &&
iput_field_indexes[number_of_iputs] != DexFile::kDexNoIndex16) {
// Check that there are no duplicate valid field indexes.
DCHECK_EQ(0, std::count(iput_field_indexes + number_of_iputs + 1,
iput_field_indexes + arraysize(iput_field_indexes),
iput_field_indexes[number_of_iputs]));
++number_of_iputs;
}
// Check that there are no valid field indexes in the rest of the array.
DCHECK_EQ(0, std::count_if(iput_field_indexes + number_of_iputs,
iput_field_indexes + arraysize(iput_field_indexes),
[](uint16_t index) { return index != DexFile::kDexNoIndex16; }));
// Create HInstanceFieldSet for each IPUT that stores non-zero data.
HInstruction* obj = GetInvokeInputForArgVRegIndex(invoke_instruction,
/* arg_vreg_index= */ 0u);
bool needs_constructor_barrier = false;
for (size_t i = 0; i != number_of_iputs; ++i) {
HInstruction* value = GetInvokeInputForArgVRegIndex(invoke_instruction, iput_args[i]);
if (!value->IsConstant() || !value->AsConstant()->IsZeroBitPattern()) {
uint16_t field_index = iput_field_indexes[i];
bool is_final;
HInstanceFieldSet* iput =
CreateInstanceFieldSet(field_index, method, obj, value, &is_final);
invoke_instruction->GetBlock()->InsertInstructionBefore(iput, invoke_instruction);
// Check whether the field is final. If it is, we need to add a barrier.
if (is_final) {
needs_constructor_barrier = true;
}
}
}
if (needs_constructor_barrier) {
// See DexCompilationUnit::RequiresConstructorBarrier for more details.
DCHECK(obj != nullptr) << "only non-static methods can have a constructor fence";
HConstructorFence* constructor_fence =
new (graph_->GetAllocator()) HConstructorFence(obj, kNoDexPc, graph_->GetAllocator());
invoke_instruction->GetBlock()->InsertInstructionBefore(constructor_fence,
invoke_instruction);
}
*return_replacement = nullptr;
break;
}
default:
LOG(FATAL) << "UNREACHABLE";
UNREACHABLE();
}
return true;
}
HInstanceFieldGet* HInliner::CreateInstanceFieldGet(uint32_t field_index,
ArtMethod* referrer,
HInstruction* obj)
REQUIRES_SHARED(Locks::mutator_lock_) {
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
ArtField* resolved_field =
class_linker->LookupResolvedField(field_index, referrer, /* is_static= */ false);
DCHECK(resolved_field != nullptr);
HInstanceFieldGet* iget = new (graph_->GetAllocator()) HInstanceFieldGet(
obj,
resolved_field,
DataType::FromShorty(resolved_field->GetTypeDescriptor()[0]),
resolved_field->GetOffset(),
resolved_field->IsVolatile(),
field_index,
resolved_field->GetDeclaringClass()->GetDexClassDefIndex(),
*referrer->GetDexFile(),
// Read barrier generates a runtime call in slow path and we need a valid
// dex pc for the associated stack map. 0 is bogus but valid. Bug: 26854537.
/* dex_pc= */ 0);
if (iget->GetType() == DataType::Type::kReference) {
// Use the same dex_cache that we used for field lookup as the hint_dex_cache.
Handle<mirror::DexCache> dex_cache =
graph_->GetHandleCache()->NewHandle(referrer->GetDexCache());
ReferenceTypePropagation rtp(graph_,
outer_compilation_unit_.GetClassLoader(),
dex_cache,
/* is_first_run= */ false);
rtp.Visit(iget);
}
return iget;
}
HInstanceFieldSet* HInliner::CreateInstanceFieldSet(uint32_t field_index,
ArtMethod* referrer,
HInstruction* obj,
HInstruction* value,
bool* is_final)
REQUIRES_SHARED(Locks::mutator_lock_) {
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
ArtField* resolved_field =
class_linker->LookupResolvedField(field_index, referrer, /* is_static= */ false);
DCHECK(resolved_field != nullptr);
if (is_final != nullptr) {
// This information is needed only for constructors.
DCHECK(referrer->IsConstructor());
*is_final = resolved_field->IsFinal();
}
HInstanceFieldSet* iput = new (graph_->GetAllocator()) HInstanceFieldSet(
obj,
value,
resolved_field,
DataType::FromShorty(resolved_field->GetTypeDescriptor()[0]),
resolved_field->GetOffset(),
resolved_field->IsVolatile(),
field_index,
resolved_field->GetDeclaringClass()->GetDexClassDefIndex(),
*referrer->GetDexFile(),
// Read barrier generates a runtime call in slow path and we need a valid
// dex pc for the associated stack map. 0 is bogus but valid. Bug: 26854537.
/* dex_pc= */ 0);
return iput;
}
template <typename T>
static inline Handle<T> NewHandleIfDifferent(ObjPtr<T> object, Handle<T> hint, HGraph* graph)
REQUIRES_SHARED(Locks::mutator_lock_) {
return (object != hint.Get()) ? graph->GetHandleCache()->NewHandle(object) : hint;
}
static bool CanEncodeInlinedMethodInStackMap(const DexFile& outer_dex_file,
ArtMethod* callee,
const CodeGenerator* codegen,
bool* out_needs_bss_check)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (!Runtime::Current()->IsAotCompiler()) {
// JIT can always encode methods in stack maps.
return true;
}
const DexFile* dex_file = callee->GetDexFile();
if (IsSameDexFile(outer_dex_file, *dex_file)) {
return true;
}
// Inline across dexfiles if the callee's DexFile is:
// 1) in the bootclasspath, or
if (callee->GetDeclaringClass()->IsBootStrapClassLoaded()) {
// In multi-image, each BCP DexFile has their own OatWriter. Since they don't cooperate with
// each other, we request the BSS check for them.
// TODO(solanes, 154012332): Add .bss support for BCP multi-image.
*out_needs_bss_check = codegen->GetCompilerOptions().IsMultiImage();
return true;
}
// 2) is a non-BCP dexfile with the OatFile we are compiling.
if (codegen->GetCompilerOptions().WithinOatFile(dex_file)) {
return true;
}
// TODO(solanes): Support more AOT cases for inlining:
// - methods in class loader context's DexFiles
return false;
}
// Substitutes parameters in the callee graph with their values from the caller.
void HInliner::SubstituteArguments(HGraph* callee_graph,
HInvoke* invoke_instruction,
ReferenceTypeInfo receiver_type,
const DexCompilationUnit& dex_compilation_unit) {
ArtMethod* const resolved_method = callee_graph->GetArtMethod();
size_t parameter_index = 0;
bool run_rtp = false;
for (HInstructionIterator instructions(callee_graph->GetEntryBlock()->GetInstructions());
!instructions.Done();
instructions.Advance()) {
HInstruction* current = instructions.Current();
if (current->IsParameterValue()) {
HInstruction* argument = invoke_instruction->InputAt(parameter_index);
if (argument->IsNullConstant()) {
current->ReplaceWith(callee_graph->GetNullConstant());
} else if (argument->IsIntConstant()) {
current->ReplaceWith(callee_graph->GetIntConstant(argument->AsIntConstant()->GetValue()));
} else if (argument->IsLongConstant()) {
current->ReplaceWith(callee_graph->GetLongConstant(argument->AsLongConstant()->GetValue()));
} else if (argument->IsFloatConstant()) {
current->ReplaceWith(
callee_graph->GetFloatConstant(argument->AsFloatConstant()->GetValue()));
} else if (argument->IsDoubleConstant()) {
current->ReplaceWith(
callee_graph->GetDoubleConstant(argument->AsDoubleConstant()->GetValue()));
} else if (argument->GetType() == DataType::Type::kReference) {
if (!resolved_method->IsStatic() && parameter_index == 0 && receiver_type.IsValid()) {
run_rtp = true;
current->SetReferenceTypeInfo(receiver_type);
} else {
current->SetReferenceTypeInfo(argument->GetReferenceTypeInfo());
}
current->AsParameterValue()->SetCanBeNull(argument->CanBeNull());
}
++parameter_index;
}
}
// We have replaced formal arguments with actual arguments. If actual types
// are more specific than the declared ones, run RTP again on the inner graph.
if (run_rtp || ArgumentTypesMoreSpecific(invoke_instruction, resolved_method)) {
ReferenceTypePropagation(callee_graph,
outer_compilation_unit_.GetClassLoader(),
dex_compilation_unit.GetDexCache(),
/* is_first_run= */ false).Run();
}
}
// Returns whether we can inline the callee_graph into the target_block.
//
// This performs a combination of semantics checks, compiler support checks, and
// resource limit checks.
//
// If this function returns true, it will also set out_number_of_instructions to
// the number of instructions in the inlined body.
bool HInliner::CanInlineBody(const HGraph* callee_graph,
const HBasicBlock* target_block,
size_t* out_number_of_instructions) const {
ArtMethod* const resolved_method = callee_graph->GetArtMethod();
HBasicBlock* exit_block = callee_graph->GetExitBlock();
if (exit_block == nullptr) {
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedInfiniteLoop)
<< "Method " << resolved_method->PrettyMethod()
<< " could not be inlined because it has an infinite loop";
return false;
}
bool has_one_return = false;
for (HBasicBlock* predecessor : exit_block->GetPredecessors()) {
if (predecessor->GetLastInstruction()->IsThrow()) {
if (target_block->IsTryBlock()) {
// TODO(ngeoffray): Support adding HTryBoundary in Hgraph::InlineInto.
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedTryCatchCaller)
<< "Method " << resolved_method->PrettyMethod()
<< " could not be inlined because one branch always throws and"
<< " caller is in a try/catch block";
return false;
} else if (graph_->GetExitBlock() == nullptr) {
// TODO(ngeoffray): Support adding HExit in the caller graph.
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedInfiniteLoop)
<< "Method " << resolved_method->PrettyMethod()
<< " could not be inlined because one branch always throws and"
<< " caller does not have an exit block";
return false;
} else if (graph_->HasIrreducibleLoops()) {
// TODO(ngeoffray): Support re-computing loop information to graphs with
// irreducible loops?
VLOG(compiler) << "Method " << resolved_method->PrettyMethod()
<< " could not be inlined because one branch always throws and"
<< " caller has irreducible loops";
return false;
}
} else {
has_one_return = true;
}
}
if (!has_one_return) {
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedAlwaysThrows)
<< "Method " << resolved_method->PrettyMethod()
<< " could not be inlined because it always throws";
return false;
}
const bool too_many_registers =
total_number_of_dex_registers_ > kMaximumNumberOfCumulatedDexRegisters;
bool needs_bss_check = false;
const bool can_encode_in_stack_map = CanEncodeInlinedMethodInStackMap(
*outer_compilation_unit_.GetDexFile(), resolved_method, codegen_, &needs_bss_check);
size_t number_of_instructions = 0;
// Skip the entry block, it does not contain instructions that prevent inlining.
for (HBasicBlock* block : callee_graph->GetReversePostOrderSkipEntryBlock()) {
if (block->IsLoopHeader()) {
if (block->GetLoopInformation()->IsIrreducible()) {
// Don't inline methods with irreducible loops, they could prevent some
// optimizations to run.
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedIrreducibleLoop)
<< "Method " << resolved_method->PrettyMethod()
<< " could not be inlined because it contains an irreducible loop";
return false;
}
if (!block->GetLoopInformation()->HasExitEdge()) {
// Don't inline methods with loops without exit, since they cause the
// loop information to be computed incorrectly when updating after
// inlining.
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedLoopWithoutExit)
<< "Method " << resolved_method->PrettyMethod()
<< " could not be inlined because it contains a loop with no exit";
return false;
}
}
for (HInstructionIterator instr_it(block->GetInstructions());
!instr_it.Done();
instr_it.Advance()) {
if (++number_of_instructions > inlining_budget_) {
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedInstructionBudget)
<< "Method " << resolved_method->PrettyMethod()
<< " is not inlined because the outer method has reached"
<< " its instruction budget limit.";
return false;
}
HInstruction* current = instr_it.Current();
if (current->NeedsEnvironment()) {
if (too_many_registers) {
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedEnvironmentBudget)
<< "Method " << resolved_method->PrettyMethod()
<< " is not inlined because its caller has reached"
<< " its environment budget limit.";
return false;
}
if (!can_encode_in_stack_map) {
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedStackMaps)
<< "Method " << resolved_method->PrettyMethod() << " could not be inlined because "
<< current->DebugName() << " needs an environment, is in a different dex file"
<< ", and cannot be encoded in the stack maps.";
return false;
}
}
if (current->IsUnresolvedStaticFieldGet() ||
current->IsUnresolvedInstanceFieldGet() ||
current->IsUnresolvedStaticFieldSet() ||
current->IsUnresolvedInstanceFieldSet()) {
// Entrypoint for unresolved fields does not handle inlined frames.
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedUnresolvedEntrypoint)
<< "Method " << resolved_method->PrettyMethod()
<< " could not be inlined because it is using an unresolved"
<< " entrypoint";
return false;
}
// We currently don't have support for inlining across dex files if we are:
// 1) In AoT,
// 2) cross-dex inlining,
// 3) the callee is a BCP DexFile,
// 4) we are compiling multi image, and
// 5) have an instruction that needs a bss entry, which will always be
// 5)b) an instruction that needs an environment.
// 1) - 4) are encoded in `needs_bss_check` (see CanEncodeInlinedMethodInStackMap).
if (needs_bss_check && current->NeedsBss()) {
DCHECK(current->NeedsEnvironment());
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedBss)
<< "Method " << resolved_method->PrettyMethod()
<< " could not be inlined because it needs a BSS check";
return false;
}
}
}
*out_number_of_instructions = number_of_instructions;
return true;
}
bool HInliner::TryBuildAndInlineHelper(HInvoke* invoke_instruction,
ArtMethod* resolved_method,
ReferenceTypeInfo receiver_type,
HInstruction** return_replacement) {
DCHECK(!(resolved_method->IsStatic() && receiver_type.IsValid()));
const dex::CodeItem* code_item = resolved_method->GetCodeItem();
const DexFile& callee_dex_file = *resolved_method->GetDexFile();
uint32_t method_index = resolved_method->GetDexMethodIndex();
CodeItemDebugInfoAccessor code_item_accessor(resolved_method->DexInstructionDebugInfo());
ClassLinker* class_linker = caller_compilation_unit_.GetClassLinker();
Handle<mirror::DexCache> dex_cache = NewHandleIfDifferent(resolved_method->GetDexCache(),
caller_compilation_unit_.GetDexCache(),
graph_);
Handle<mirror::ClassLoader> class_loader =
NewHandleIfDifferent(resolved_method->GetDeclaringClass()->GetClassLoader(),
caller_compilation_unit_.GetClassLoader(),
graph_);
Handle<mirror::Class> compiling_class =
graph_->GetHandleCache()->NewHandle(resolved_method->GetDeclaringClass());
DexCompilationUnit dex_compilation_unit(
class_loader,
class_linker,
callee_dex_file,
code_item,
resolved_method->GetDeclaringClass()->GetDexClassDefIndex(),
method_index,
resolved_method->GetAccessFlags(),
/* verified_method= */ nullptr,
dex_cache,
compiling_class);
InvokeType invoke_type = invoke_instruction->GetInvokeType();
if (invoke_type == kInterface) {
// We have statically resolved the dispatch. To please the class linker
// at runtime, we change this call as if it was a virtual call.
invoke_type = kVirtual;
}
bool caller_dead_reference_safe = graph_->IsDeadReferenceSafe();
const dex::ClassDef& callee_class = resolved_method->GetClassDef();
// MethodContainsRSensitiveAccess is currently slow, but HasDeadReferenceSafeAnnotation()
// is currently rarely true.
bool callee_dead_reference_safe =
annotations::HasDeadReferenceSafeAnnotation(callee_dex_file, callee_class)
&& !annotations::MethodContainsRSensitiveAccess(callee_dex_file, callee_class, method_index);
const int32_t caller_instruction_counter = graph_->GetCurrentInstructionId();
HGraph* callee_graph = new (graph_->GetAllocator()) HGraph(
graph_->GetAllocator(),
graph_->GetArenaStack(),
graph_->GetHandleCache()->GetHandles(),
callee_dex_file,
method_index,
codegen_->GetCompilerOptions().GetInstructionSet(),
invoke_type,
callee_dead_reference_safe,
graph_->IsDebuggable(),
graph_->GetCompilationKind(),
/* start_instruction_id= */ caller_instruction_counter);
callee_graph->SetArtMethod(resolved_method);
ScopedProfilingInfoUse spiu(Runtime::Current()->GetJit(), resolved_method, Thread::Current());
if (Runtime::Current()->GetJit() != nullptr) {
callee_graph->SetProfilingInfo(spiu.GetProfilingInfo());
}
// When they are needed, allocate `inline_stats_` on the Arena instead
// of on the stack, as Clang might produce a stack frame too large
// for this function, that would not fit the requirements of the
// `-Wframe-larger-than` option.
if (stats_ != nullptr) {
// Reuse one object for all inline attempts from this caller to keep Arena memory usage low.
if (inline_stats_ == nullptr) {
void* storage = graph_->GetAllocator()->Alloc<OptimizingCompilerStats>(kArenaAllocMisc);
inline_stats_ = new (storage) OptimizingCompilerStats;
} else {
inline_stats_->Reset();
}
}
HGraphBuilder builder(callee_graph,
code_item_accessor,
&dex_compilation_unit,
&outer_compilation_unit_,
codegen_,
inline_stats_);
if (builder.BuildGraph() != kAnalysisSuccess) {
LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedCannotBuild)
<< "Method " << callee_dex_file.PrettyMethod(method_index)
<< " could not be built, so cannot be inlined";
return false;
}
SubstituteArguments(callee_graph, invoke_instruction, receiver_type, dex_compilation_unit);
RunOptimizations(callee_graph, code_item, dex_compilation_unit);
size_t number_of_instructions = 0;
if (!CanInlineBody(callee_graph, invoke_instruction->GetBlock(), &number_of_instructions)) {
return false;
}
DCHECK_EQ(caller_instruction_counter, graph_->GetCurrentInstructionId())
<< "No instructions can be added to the outer graph while inner graph is being built";
// Inline the callee graph inside the caller graph.
const int32_t callee_instruction_counter = callee_graph->GetCurrentInstructionId();
graph_->SetCurrentInstructionId(callee_instruction_counter);
*return_replacement = callee_graph->InlineInto(graph_, invoke_instruction);
// Update our budget for other inlining attempts in `caller_graph`.
total_number_of_instructions_ += number_of_instructions;
UpdateInliningBudget();
DCHECK_EQ(callee_instruction_counter, callee_graph->GetCurrentInstructionId())
<< "No instructions can be added to the inner graph during inlining into the outer graph";
if (stats_ != nullptr) {
DCHECK(inline_stats_ != nullptr);
inline_stats_->AddTo(stats_);
}
if (caller_dead_reference_safe && !callee_dead_reference_safe) {
// Caller was dead reference safe, but is not anymore, since we inlined dead
// reference unsafe code. Prior transformations remain valid, since they did not
// affect the inlined code.
graph_->MarkDeadReferenceUnsafe();
}
return true;
}
void HInliner::RunOptimizations(HGraph* callee_graph,
const dex::CodeItem* code_item,
const DexCompilationUnit& dex_compilation_unit) {
// Note: if the outermost_graph_ is being compiled OSR, we should not run any
// optimization that could lead to a HDeoptimize. The following optimizations do not.
HDeadCodeElimination dce(callee_graph, inline_stats_, "dead_code_elimination$inliner");
HConstantFolding fold(callee_graph, "constant_folding$inliner");
InstructionSimplifier simplify(callee_graph, codegen_, inline_stats_);
HOptimization* optimizations[] = {
&simplify,
&fold,
&dce,
};
for (size_t i = 0; i < arraysize(optimizations); ++i) {
HOptimization* optimization = optimizations[i];
optimization->Run();
}
// Bail early for pathological cases on the environment (for example recursive calls,
// or too large environment).
if (total_number_of_dex_registers_ > kMaximumNumberOfCumulatedDexRegisters) {
LOG_NOTE() << "Calls in " << callee_graph->GetArtMethod()->PrettyMethod()
<< " will not be inlined because the outer method has reached"
<< " its environment budget limit.";
return;
}
// Bail early if we know we already are over the limit.
size_t number_of_instructions = CountNumberOfInstructions(callee_graph);
if (number_of_instructions > inlining_budget_) {
LOG_NOTE() << "Calls in " << callee_graph->GetArtMethod()->PrettyMethod()
<< " will not be inlined because the outer method has reached"
<< " its instruction budget limit. " << number_of_instructions;
return;
}
CodeItemDataAccessor accessor(callee_graph->GetDexFile(), code_item);
HInliner inliner(callee_graph,
outermost_graph_,
codegen_,
outer_compilation_unit_,
dex_compilation_unit,
inline_stats_,
total_number_of_dex_registers_ + accessor.RegistersSize(),
total_number_of_instructions_ + number_of_instructions,
this,
depth_ + 1);
inliner.Run();
}
static bool IsReferenceTypeRefinement(ObjPtr<mirror::Class> declared_class,
bool declared_is_exact,
bool declared_can_be_null,
HInstruction* actual_obj)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (declared_can_be_null && !actual_obj->CanBeNull()) {
return true;
}
ReferenceTypeInfo actual_rti = actual_obj->GetReferenceTypeInfo();
ObjPtr<mirror::Class> actual_class = actual_rti.GetTypeHandle().Get();
return (actual_rti.IsExact() && !declared_is_exact) ||
(declared_class != actual_class && declared_class->IsAssignableFrom(actual_class));
}
static bool IsReferenceTypeRefinement(ObjPtr<mirror::Class> declared_class,
bool declared_can_be_null,
HInstruction* actual_obj)
REQUIRES_SHARED(Locks::mutator_lock_) {
bool admissible = ReferenceTypePropagation::IsAdmissible(declared_class);
return IsReferenceTypeRefinement(
admissible ? declared_class : GetClassRoot<mirror::Class>(),
/*declared_is_exact=*/ admissible && declared_class->CannotBeAssignedFromOtherTypes(),
declared_can_be_null,
actual_obj);
}
bool HInliner::ArgumentTypesMoreSpecific(HInvoke* invoke_instruction, ArtMethod* resolved_method) {
// If this is an instance call, test whether the type of the `this` argument
// is more specific than the class which declares the method.
if (!resolved_method->IsStatic()) {
if (IsReferenceTypeRefinement(resolved_method->GetDeclaringClass(),
/*declared_can_be_null=*/ false,
invoke_instruction->InputAt(0u))) {
return true;
}
}
// Iterate over the list of parameter types and test whether any of the
// actual inputs has a more specific reference type than the type declared in
// the signature.
const dex::TypeList* param_list = resolved_method->GetParameterTypeList();
for (size_t param_idx = 0,
input_idx = resolved_method->IsStatic() ? 0 : 1,
e = (param_list == nullptr ? 0 : param_list->Size());
param_idx < e;
++param_idx, ++input_idx) {
HInstruction* input = invoke_instruction->InputAt(input_idx);
if (input->GetType() == DataType::Type::kReference) {
ObjPtr<mirror::Class> param_cls = resolved_method->LookupResolvedClassFromTypeIndex(
param_list->GetTypeItem(param_idx).type_idx_);
if (IsReferenceTypeRefinement(param_cls, /*declared_can_be_null=*/ true, input)) {
return true;
}
}
}
return false;
}
bool HInliner::ReturnTypeMoreSpecific(HInstruction* return_replacement,
HInvoke* invoke_instruction) {
// Check the integrity of reference types and run another type propagation if needed.
if (return_replacement != nullptr) {
if (return_replacement->GetType() == DataType::Type::kReference) {
// Test if the return type is a refinement of the declared return type.
ReferenceTypeInfo invoke_rti = invoke_instruction->GetReferenceTypeInfo();
if (IsReferenceTypeRefinement(invoke_rti.GetTypeHandle().Get(),
invoke_rti.IsExact(),
/*declared_can_be_null=*/ true,
return_replacement)) {
return true;
} else if (return_replacement->IsInstanceFieldGet()) {
HInstanceFieldGet* field_get = return_replacement->AsInstanceFieldGet();
if (field_get->GetFieldInfo().GetField() ==
GetClassRoot<mirror::Object>()->GetInstanceField(0)) {
return true;
}
}
} else if (return_replacement->IsInstanceOf()) {
// Inlining InstanceOf into an If may put a tighter bound on reference types.
return true;
}
}
return false;
}
void HInliner::FixUpReturnReferenceType(ArtMethod* resolved_method,
HInstruction* return_replacement) {
if (return_replacement != nullptr) {
if (return_replacement->GetType() == DataType::Type::kReference) {
if (!return_replacement->GetReferenceTypeInfo().IsValid()) {
// Make sure that we have a valid type for the return. We may get an invalid one when
// we inline invokes with multiple branches and create a Phi for the result.
// TODO: we could be more precise by merging the phi inputs but that requires
// some functionality from the reference type propagation.
DCHECK(return_replacement->IsPhi());
ObjPtr<mirror::Class> cls = resolved_method->LookupResolvedReturnType();
ReferenceTypeInfo rti = ReferenceTypePropagation::IsAdmissible(cls)
? ReferenceTypeInfo::Create(graph_->GetHandleCache()->NewHandle(cls))
: graph_->GetInexactObjectRti();
return_replacement->SetReferenceTypeInfo(rti);
}
}
}
}
} // namespace art