/*
* 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 "optimizing_compiler.h"
#include <fstream>
#include <stdint.h>
#include "art_method-inl.h"
#include "base/arena_allocator.h"
#include "base/dumpable.h"
#include "base/timing_logger.h"
#include "boolean_simplifier.h"
#include "bounds_check_elimination.h"
#include "builder.h"
#include "code_generator.h"
#include "compiled_method.h"
#include "compiler.h"
#include "constant_folding.h"
#include "dead_code_elimination.h"
#include "dex/quick/dex_file_to_method_inliner_map.h"
#include "dex/verified_method.h"
#include "dex/verification_results.h"
#include "driver/compiler_driver.h"
#include "driver/compiler_options.h"
#include "driver/dex_compilation_unit.h"
#include "elf_writer_quick.h"
#include "graph_visualizer.h"
#include "gvn.h"
#include "inliner.h"
#include "instruction_simplifier.h"
#include "intrinsics.h"
#include "licm.h"
#include "jni/quick/jni_compiler.h"
#include "nodes.h"
#include "prepare_for_register_allocation.h"
#include "reference_type_propagation.h"
#include "register_allocator.h"
#include "side_effects_analysis.h"
#include "ssa_builder.h"
#include "ssa_phi_elimination.h"
#include "ssa_liveness_analysis.h"
#include "utils/assembler.h"
namespace art {
/**
* Used by the code generator, to allocate the code in a vector.
*/
class CodeVectorAllocator FINAL : public CodeAllocator {
public:
CodeVectorAllocator() : size_(0) {}
virtual uint8_t* Allocate(size_t size) {
size_ = size;
memory_.resize(size);
return &memory_[0];
}
size_t GetSize() const { return size_; }
const std::vector<uint8_t>& GetMemory() const { return memory_; }
private:
std::vector<uint8_t> memory_;
size_t size_;
DISALLOW_COPY_AND_ASSIGN(CodeVectorAllocator);
};
/**
* Filter to apply to the visualizer. Methods whose name contain that filter will
* be dumped.
*/
static const char* kStringFilter = "";
class PassInfo;
class PassInfoPrinter : public ValueObject {
public:
PassInfoPrinter(HGraph* graph,
const char* method_name,
const CodeGenerator& codegen,
std::ostream* visualizer_output,
CompilerDriver* compiler_driver)
: method_name_(method_name),
timing_logger_enabled_(compiler_driver->GetDumpPasses()),
timing_logger_(method_name, true, true),
visualizer_enabled_(!compiler_driver->GetDumpCfgFileName().empty()),
visualizer_(visualizer_output, graph, codegen) {
if (strstr(method_name, kStringFilter) == nullptr) {
timing_logger_enabled_ = visualizer_enabled_ = false;
}
if (visualizer_enabled_) {
visualizer_.PrintHeader(method_name_);
}
}
~PassInfoPrinter() {
if (timing_logger_enabled_) {
LOG(INFO) << "TIMINGS " << method_name_;
LOG(INFO) << Dumpable<TimingLogger>(timing_logger_);
}
}
private:
void StartPass(const char* pass_name) {
// Dump graph first, then start timer.
if (visualizer_enabled_) {
visualizer_.DumpGraph(pass_name, /* is_after_pass */ false);
}
if (timing_logger_enabled_) {
timing_logger_.StartTiming(pass_name);
}
}
void EndPass(const char* pass_name) {
// Pause timer first, then dump graph.
if (timing_logger_enabled_) {
timing_logger_.EndTiming();
}
if (visualizer_enabled_) {
visualizer_.DumpGraph(pass_name, /* is_after_pass */ true);
}
}
const char* method_name_;
bool timing_logger_enabled_;
TimingLogger timing_logger_;
bool visualizer_enabled_;
HGraphVisualizer visualizer_;
friend PassInfo;
DISALLOW_COPY_AND_ASSIGN(PassInfoPrinter);
};
class PassInfo : public ValueObject {
public:
PassInfo(const char *pass_name, PassInfoPrinter* pass_info_printer)
: pass_name_(pass_name),
pass_info_printer_(pass_info_printer) {
pass_info_printer_->StartPass(pass_name_);
}
~PassInfo() {
pass_info_printer_->EndPass(pass_name_);
}
private:
const char* const pass_name_;
PassInfoPrinter* const pass_info_printer_;
};
class OptimizingCompiler FINAL : public Compiler {
public:
explicit OptimizingCompiler(CompilerDriver* driver);
~OptimizingCompiler();
bool CanCompileMethod(uint32_t method_idx, const DexFile& dex_file, CompilationUnit* cu) const
OVERRIDE;
CompiledMethod* Compile(const DexFile::CodeItem* code_item,
uint32_t access_flags,
InvokeType invoke_type,
uint16_t class_def_idx,
uint32_t method_idx,
jobject class_loader,
const DexFile& dex_file) const OVERRIDE;
CompiledMethod* TryCompile(const DexFile::CodeItem* code_item,
uint32_t access_flags,
InvokeType invoke_type,
uint16_t class_def_idx,
uint32_t method_idx,
jobject class_loader,
const DexFile& dex_file) const;
CompiledMethod* JniCompile(uint32_t access_flags,
uint32_t method_idx,
const DexFile& dex_file) const OVERRIDE {
return ArtQuickJniCompileMethod(GetCompilerDriver(), access_flags, method_idx, dex_file);
}
uintptr_t GetEntryPointOf(ArtMethod* method) const OVERRIDE
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
return reinterpret_cast<uintptr_t>(method->GetEntryPointFromQuickCompiledCodePtrSize(
InstructionSetPointerSize(GetCompilerDriver()->GetInstructionSet())));
}
void InitCompilationUnit(CompilationUnit& cu) const OVERRIDE;
void Init() OVERRIDE;
void UnInit() const OVERRIDE;
void MaybeRecordStat(MethodCompilationStat compilation_stat) const {
if (compilation_stats_.get() != nullptr) {
compilation_stats_->RecordStat(compilation_stat);
}
}
private:
// Whether we should run any optimization or register allocation. If false, will
// just run the code generation after the graph was built.
const bool run_optimizations_;
// Optimize and compile `graph`.
CompiledMethod* CompileOptimized(HGraph* graph,
CodeGenerator* codegen,
CompilerDriver* driver,
const DexFile& dex_file,
const DexCompilationUnit& dex_compilation_unit,
PassInfoPrinter* pass_info) const;
// Just compile without doing optimizations.
CompiledMethod* CompileBaseline(CodeGenerator* codegen,
CompilerDriver* driver,
const DexCompilationUnit& dex_compilation_unit) const;
std::unique_ptr<OptimizingCompilerStats> compilation_stats_;
std::unique_ptr<std::ostream> visualizer_output_;
// Delegate to Quick in case the optimizing compiler cannot compile a method.
std::unique_ptr<Compiler> delegate_;
DISALLOW_COPY_AND_ASSIGN(OptimizingCompiler);
};
static const int kMaximumCompilationTimeBeforeWarning = 100; /* ms */
OptimizingCompiler::OptimizingCompiler(CompilerDriver* driver)
: Compiler(driver, kMaximumCompilationTimeBeforeWarning),
run_optimizations_(
(driver->GetCompilerOptions().GetCompilerFilter() != CompilerOptions::kTime)
&& !driver->GetCompilerOptions().GetDebuggable()),
delegate_(Create(driver, Compiler::Kind::kQuick)) {}
void OptimizingCompiler::Init() {
delegate_->Init();
// Enable C1visualizer output. Must be done in Init() because the compiler
// driver is not fully initialized when passed to the compiler's constructor.
CompilerDriver* driver = GetCompilerDriver();
const std::string cfg_file_name = driver->GetDumpCfgFileName();
if (!cfg_file_name.empty()) {
CHECK_EQ(driver->GetThreadCount(), 1U)
<< "Graph visualizer requires the compiler to run single-threaded. "
<< "Invoke the compiler with '-j1'.";
visualizer_output_.reset(new std::ofstream(cfg_file_name));
}
if (driver->GetDumpStats()) {
compilation_stats_.reset(new OptimizingCompilerStats());
}
}
void OptimizingCompiler::UnInit() const {
delegate_->UnInit();
}
OptimizingCompiler::~OptimizingCompiler() {
if (compilation_stats_.get() != nullptr) {
compilation_stats_->Log();
}
}
void OptimizingCompiler::InitCompilationUnit(CompilationUnit& cu) const {
delegate_->InitCompilationUnit(cu);
}
bool OptimizingCompiler::CanCompileMethod(uint32_t method_idx ATTRIBUTE_UNUSED,
const DexFile& dex_file ATTRIBUTE_UNUSED,
CompilationUnit* cu ATTRIBUTE_UNUSED) const {
return true;
}
static bool IsInstructionSetSupported(InstructionSet instruction_set) {
return instruction_set == kArm64
|| (instruction_set == kThumb2 && !kArm32QuickCodeUseSoftFloat)
|| instruction_set == kMips64
|| instruction_set == kX86
|| instruction_set == kX86_64;
}
static bool CanOptimize(const DexFile::CodeItem& code_item) {
// TODO: We currently cannot optimize methods with try/catch.
return code_item.tries_size_ == 0;
}
static void RunOptimizations(HOptimization* optimizations[],
size_t length,
PassInfoPrinter* pass_info_printer) {
for (size_t i = 0; i < length; ++i) {
HOptimization* optimization = optimizations[i];
{
PassInfo pass_info(optimization->GetPassName(), pass_info_printer);
optimization->Run();
}
optimization->Check();
}
}
static void RunOptimizations(HGraph* graph,
CompilerDriver* driver,
OptimizingCompilerStats* stats,
const DexFile& dex_file,
const DexCompilationUnit& dex_compilation_unit,
PassInfoPrinter* pass_info_printer,
StackHandleScopeCollection* handles) {
HDeadCodeElimination dce1(graph, stats,
HDeadCodeElimination::kInitialDeadCodeEliminationPassName);
HDeadCodeElimination dce2(graph, stats,
HDeadCodeElimination::kFinalDeadCodeEliminationPassName);
HConstantFolding fold1(graph);
InstructionSimplifier simplify1(graph, stats);
HBooleanSimplifier boolean_simplify(graph);
HInliner inliner(graph, dex_compilation_unit, dex_compilation_unit, driver, stats);
HConstantFolding fold2(graph, "constant_folding_after_inlining");
SideEffectsAnalysis side_effects(graph);
GVNOptimization gvn(graph, side_effects);
LICM licm(graph, side_effects);
BoundsCheckElimination bce(graph);
ReferenceTypePropagation type_propagation(graph, dex_file, dex_compilation_unit, handles);
InstructionSimplifier simplify2(graph, stats, "instruction_simplifier_after_types");
InstructionSimplifier simplify3(graph, stats, "instruction_simplifier_before_codegen");
IntrinsicsRecognizer intrinsics(graph, dex_compilation_unit.GetDexFile(), driver);
HOptimization* optimizations[] = {
&intrinsics,
&fold1,
&simplify1,
&dce1,
&inliner,
// BooleanSimplifier depends on the InstructionSimplifier removing redundant
// suspend checks to recognize empty blocks.
&boolean_simplify,
&fold2,
&side_effects,
&gvn,
&licm,
&bce,
&type_propagation,
&simplify2,
&dce2,
// The codegen has a few assumptions that only the instruction simplifier can
// satisfy. For example, the code generator does not expect to see a
// HTypeConversion from a type to the same type.
&simplify3,
};
RunOptimizations(optimizations, arraysize(optimizations), pass_info_printer);
}
// The stack map we generate must be 4-byte aligned on ARM. Since existing
// maps are generated alongside these stack maps, we must also align them.
static ArrayRef<const uint8_t> AlignVectorSize(std::vector<uint8_t>& vector) {
size_t size = vector.size();
size_t aligned_size = RoundUp(size, 4);
for (; size < aligned_size; ++size) {
vector.push_back(0);
}
return ArrayRef<const uint8_t>(vector);
}
static void AllocateRegisters(HGraph* graph,
CodeGenerator* codegen,
PassInfoPrinter* pass_info_printer) {
PrepareForRegisterAllocation(graph).Run();
SsaLivenessAnalysis liveness(graph, codegen);
{
PassInfo pass_info(SsaLivenessAnalysis::kLivenessPassName, pass_info_printer);
liveness.Analyze();
}
{
PassInfo pass_info(RegisterAllocator::kRegisterAllocatorPassName, pass_info_printer);
RegisterAllocator(graph->GetArena(), codegen, liveness).AllocateRegisters();
}
}
CompiledMethod* OptimizingCompiler::CompileOptimized(HGraph* graph,
CodeGenerator* codegen,
CompilerDriver* compiler_driver,
const DexFile& dex_file,
const DexCompilationUnit& dex_compilation_unit,
PassInfoPrinter* pass_info_printer) const {
StackHandleScopeCollection handles(Thread::Current());
RunOptimizations(graph, compiler_driver, compilation_stats_.get(),
dex_file, dex_compilation_unit, pass_info_printer, &handles);
AllocateRegisters(graph, codegen, pass_info_printer);
CodeVectorAllocator allocator;
codegen->CompileOptimized(&allocator);
DefaultSrcMap src_mapping_table;
if (compiler_driver->GetCompilerOptions().GetGenerateDebugInfo()) {
codegen->BuildSourceMap(&src_mapping_table);
}
std::vector<uint8_t> stack_map;
codegen->BuildStackMaps(&stack_map);
MaybeRecordStat(MethodCompilationStat::kCompiledOptimized);
return CompiledMethod::SwapAllocCompiledMethod(
compiler_driver,
codegen->GetInstructionSet(),
ArrayRef<const uint8_t>(allocator.GetMemory()),
// Follow Quick's behavior and set the frame size to zero if it is
// considered "empty" (see the definition of
// art::CodeGenerator::HasEmptyFrame).
codegen->HasEmptyFrame() ? 0 : codegen->GetFrameSize(),
codegen->GetCoreSpillMask(),
codegen->GetFpuSpillMask(),
&src_mapping_table,
ArrayRef<const uint8_t>(), // mapping_table.
ArrayRef<const uint8_t>(stack_map),
ArrayRef<const uint8_t>(), // native_gc_map.
ArrayRef<const uint8_t>(*codegen->GetAssembler()->cfi().data()),
ArrayRef<const LinkerPatch>());
}
CompiledMethod* OptimizingCompiler::CompileBaseline(
CodeGenerator* codegen,
CompilerDriver* compiler_driver,
const DexCompilationUnit& dex_compilation_unit) const {
CodeVectorAllocator allocator;
codegen->CompileBaseline(&allocator);
std::vector<uint8_t> mapping_table;
codegen->BuildMappingTable(&mapping_table);
DefaultSrcMap src_mapping_table;
if (compiler_driver->GetCompilerOptions().GetGenerateDebugInfo()) {
codegen->BuildSourceMap(&src_mapping_table);
}
std::vector<uint8_t> vmap_table;
codegen->BuildVMapTable(&vmap_table);
std::vector<uint8_t> gc_map;
codegen->BuildNativeGCMap(&gc_map, dex_compilation_unit);
MaybeRecordStat(MethodCompilationStat::kCompiledBaseline);
return CompiledMethod::SwapAllocCompiledMethod(
compiler_driver,
codegen->GetInstructionSet(),
ArrayRef<const uint8_t>(allocator.GetMemory()),
// Follow Quick's behavior and set the frame size to zero if it is
// considered "empty" (see the definition of
// art::CodeGenerator::HasEmptyFrame).
codegen->HasEmptyFrame() ? 0 : codegen->GetFrameSize(),
codegen->GetCoreSpillMask(),
codegen->GetFpuSpillMask(),
&src_mapping_table,
AlignVectorSize(mapping_table),
AlignVectorSize(vmap_table),
AlignVectorSize(gc_map),
ArrayRef<const uint8_t>(*codegen->GetAssembler()->cfi().data()),
ArrayRef<const LinkerPatch>());
}
CompiledMethod* OptimizingCompiler::TryCompile(const DexFile::CodeItem* code_item,
uint32_t access_flags,
InvokeType invoke_type,
uint16_t class_def_idx,
uint32_t method_idx,
jobject class_loader,
const DexFile& dex_file) const {
UNUSED(invoke_type);
std::string method_name = PrettyMethod(method_idx, dex_file);
MaybeRecordStat(MethodCompilationStat::kAttemptCompilation);
CompilerDriver* compiler_driver = GetCompilerDriver();
InstructionSet instruction_set = compiler_driver->GetInstructionSet();
// Always use the thumb2 assembler: some runtime functionality (like implicit stack
// overflow checks) assume thumb2.
if (instruction_set == kArm) {
instruction_set = kThumb2;
}
// `run_optimizations_` is set explicitly (either through a compiler filter
// or the debuggable flag). If it is set, we can run baseline. Otherwise, we
// fall back to Quick.
bool should_use_baseline = !run_optimizations_;
bool can_optimize = CanOptimize(*code_item);
if (!can_optimize && !should_use_baseline) {
// We know we will not compile this method. Bail out before doing any work.
return nullptr;
}
// Do not attempt to compile on architectures we do not support.
if (!IsInstructionSetSupported(instruction_set)) {
MaybeRecordStat(MethodCompilationStat::kNotCompiledUnsupportedIsa);
return nullptr;
}
if (Compiler::IsPathologicalCase(*code_item, method_idx, dex_file)) {
MaybeRecordStat(MethodCompilationStat::kNotCompiledPathological);
return nullptr;
}
// Implementation of the space filter: do not compile a code item whose size in
// code units is bigger than 128.
static constexpr size_t kSpaceFilterOptimizingThreshold = 128;
const CompilerOptions& compiler_options = compiler_driver->GetCompilerOptions();
if ((compiler_options.GetCompilerFilter() == CompilerOptions::kSpace)
&& (code_item->insns_size_in_code_units_ > kSpaceFilterOptimizingThreshold)) {
MaybeRecordStat(MethodCompilationStat::kNotCompiledSpaceFilter);
return nullptr;
}
DexCompilationUnit dex_compilation_unit(
nullptr, class_loader, art::Runtime::Current()->GetClassLinker(), dex_file, code_item,
class_def_idx, method_idx, access_flags,
compiler_driver->GetVerifiedMethod(&dex_file, method_idx));
ArenaAllocator arena(Runtime::Current()->GetArenaPool());
HGraph* graph = new (&arena) HGraph(
&arena, dex_file, method_idx, compiler_driver->GetInstructionSet(),
compiler_driver->GetCompilerOptions().GetDebuggable());
// For testing purposes, we put a special marker on method names that should be compiled
// with this compiler. This makes sure we're not regressing.
bool shouldCompile = method_name.find("$opt$") != std::string::npos;
bool shouldOptimize = method_name.find("$opt$reg$") != std::string::npos && run_optimizations_;
std::unique_ptr<CodeGenerator> codegen(
CodeGenerator::Create(graph,
instruction_set,
*compiler_driver->GetInstructionSetFeatures(),
compiler_driver->GetCompilerOptions()));
if (codegen.get() == nullptr) {
CHECK(!shouldCompile) << "Could not find code generator for optimizing compiler";
MaybeRecordStat(MethodCompilationStat::kNotCompiledNoCodegen);
return nullptr;
}
codegen->GetAssembler()->cfi().SetEnabled(
compiler_driver->GetCompilerOptions().GetGenerateDebugInfo());
PassInfoPrinter pass_info_printer(graph,
method_name.c_str(),
*codegen.get(),
visualizer_output_.get(),
compiler_driver);
HGraphBuilder builder(graph,
&dex_compilation_unit,
&dex_compilation_unit,
&dex_file,
compiler_driver,
compilation_stats_.get());
VLOG(compiler) << "Building " << method_name;
{
PassInfo pass_info(HGraphBuilder::kBuilderPassName, &pass_info_printer);
if (!builder.BuildGraph(*code_item)) {
DCHECK(!(IsCompilingWithCoreImage() && shouldCompile))
<< "Could not build graph in optimizing compiler";
return nullptr;
}
}
bool can_allocate_registers = RegisterAllocator::CanAllocateRegistersFor(*graph, instruction_set);
if (run_optimizations_ && can_optimize && can_allocate_registers) {
VLOG(compiler) << "Optimizing " << method_name;
{
PassInfo pass_info(SsaBuilder::kSsaBuilderPassName, &pass_info_printer);
if (!graph->TryBuildingSsa()) {
// We could not transform the graph to SSA, bailout.
LOG(INFO) << "Skipping compilation of " << method_name << ": it contains a non natural loop";
MaybeRecordStat(MethodCompilationStat::kNotCompiledCannotBuildSSA);
return nullptr;
}
}
return CompileOptimized(graph,
codegen.get(),
compiler_driver,
dex_file,
dex_compilation_unit,
&pass_info_printer);
} else if (shouldOptimize && can_allocate_registers) {
LOG(FATAL) << "Could not allocate registers in optimizing compiler";
UNREACHABLE();
} else if (should_use_baseline) {
VLOG(compiler) << "Compile baseline " << method_name;
if (!run_optimizations_) {
MaybeRecordStat(MethodCompilationStat::kNotOptimizedDisabled);
} else if (!can_optimize) {
MaybeRecordStat(MethodCompilationStat::kNotOptimizedTryCatch);
} else if (!can_allocate_registers) {
MaybeRecordStat(MethodCompilationStat::kNotOptimizedRegisterAllocator);
}
return CompileBaseline(codegen.get(), compiler_driver, dex_compilation_unit);
} else {
return nullptr;
}
}
CompiledMethod* OptimizingCompiler::Compile(const DexFile::CodeItem* code_item,
uint32_t access_flags,
InvokeType invoke_type,
uint16_t class_def_idx,
uint32_t method_idx,
jobject jclass_loader,
const DexFile& dex_file) const {
CompilerDriver* compiler_driver = GetCompilerDriver();
CompiledMethod* method = nullptr;
if (compiler_driver->IsMethodVerifiedWithoutFailures(method_idx, class_def_idx, dex_file) &&
!compiler_driver->GetVerifiedMethod(&dex_file, method_idx)->HasRuntimeThrow()) {
method = TryCompile(code_item, access_flags, invoke_type, class_def_idx,
method_idx, jclass_loader, dex_file);
} else {
if (compiler_driver->GetCompilerOptions().VerifyAtRuntime()) {
MaybeRecordStat(MethodCompilationStat::kNotCompiledVerifyAtRuntime);
} else {
MaybeRecordStat(MethodCompilationStat::kNotCompiledClassNotVerified);
}
}
if (method != nullptr) {
return method;
}
method = delegate_->Compile(code_item, access_flags, invoke_type, class_def_idx, method_idx,
jclass_loader, dex_file);
if (method != nullptr) {
MaybeRecordStat(MethodCompilationStat::kCompiledQuick);
}
return method;
}
Compiler* CreateOptimizingCompiler(CompilerDriver* driver) {
return new OptimizingCompiler(driver);
}
bool IsCompilingWithCoreImage() {
const std::string& image = Runtime::Current()->GetImageLocation();
return EndsWith(image, "core.art") || EndsWith(image, "core-optimizing.art");
}
} // namespace art