/*
* 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 "code_generator.h"
#include "code_generator_arm.h"
#include "code_generator_arm64.h"
#include "code_generator_x86.h"
#include "code_generator_x86_64.h"
#include "code_generator_mips64.h"
#include "compiled_method.h"
#include "dex/verified_method.h"
#include "driver/dex_compilation_unit.h"
#include "gc_map_builder.h"
#include "leb128.h"
#include "mapping_table.h"
#include "mirror/array-inl.h"
#include "mirror/object_array-inl.h"
#include "mirror/object_reference.h"
#include "ssa_liveness_analysis.h"
#include "utils/assembler.h"
#include "verifier/dex_gc_map.h"
#include "vmap_table.h"
namespace art {
// Return whether a location is consistent with a type.
static bool CheckType(Primitive::Type type, Location location) {
if (location.IsFpuRegister()
|| (location.IsUnallocated() && (location.GetPolicy() == Location::kRequiresFpuRegister))) {
return (type == Primitive::kPrimFloat) || (type == Primitive::kPrimDouble);
} else if (location.IsRegister() ||
(location.IsUnallocated() && (location.GetPolicy() == Location::kRequiresRegister))) {
return Primitive::IsIntegralType(type) || (type == Primitive::kPrimNot);
} else if (location.IsRegisterPair()) {
return type == Primitive::kPrimLong;
} else if (location.IsFpuRegisterPair()) {
return type == Primitive::kPrimDouble;
} else if (location.IsStackSlot()) {
return (Primitive::IsIntegralType(type) && type != Primitive::kPrimLong)
|| (type == Primitive::kPrimFloat)
|| (type == Primitive::kPrimNot);
} else if (location.IsDoubleStackSlot()) {
return (type == Primitive::kPrimLong) || (type == Primitive::kPrimDouble);
} else if (location.IsConstant()) {
if (location.GetConstant()->IsIntConstant()) {
return Primitive::IsIntegralType(type) && (type != Primitive::kPrimLong);
} else if (location.GetConstant()->IsNullConstant()) {
return type == Primitive::kPrimNot;
} else if (location.GetConstant()->IsLongConstant()) {
return type == Primitive::kPrimLong;
} else if (location.GetConstant()->IsFloatConstant()) {
return type == Primitive::kPrimFloat;
} else {
return location.GetConstant()->IsDoubleConstant()
&& (type == Primitive::kPrimDouble);
}
} else {
return location.IsInvalid() || (location.GetPolicy() == Location::kAny);
}
}
// Check that a location summary is consistent with an instruction.
static bool CheckTypeConsistency(HInstruction* instruction) {
LocationSummary* locations = instruction->GetLocations();
if (locations == nullptr) {
return true;
}
if (locations->Out().IsUnallocated()
&& (locations->Out().GetPolicy() == Location::kSameAsFirstInput)) {
DCHECK(CheckType(instruction->GetType(), locations->InAt(0)))
<< instruction->GetType()
<< " " << locations->InAt(0);
} else {
DCHECK(CheckType(instruction->GetType(), locations->Out()))
<< instruction->GetType()
<< " " << locations->Out();
}
for (size_t i = 0, e = instruction->InputCount(); i < e; ++i) {
DCHECK(CheckType(instruction->InputAt(i)->GetType(), locations->InAt(i)))
<< instruction->InputAt(i)->GetType()
<< " " << locations->InAt(i);
}
HEnvironment* environment = instruction->GetEnvironment();
for (size_t i = 0; i < instruction->EnvironmentSize(); ++i) {
if (environment->GetInstructionAt(i) != nullptr) {
Primitive::Type type = environment->GetInstructionAt(i)->GetType();
DCHECK(CheckType(type, environment->GetLocationAt(i)))
<< type << " " << environment->GetLocationAt(i);
} else {
DCHECK(environment->GetLocationAt(i).IsInvalid())
<< environment->GetLocationAt(i);
}
}
return true;
}
size_t CodeGenerator::GetCacheOffset(uint32_t index) {
return mirror::ObjectArray<mirror::Object>::OffsetOfElement(index).SizeValue();
}
size_t CodeGenerator::GetCachePointerOffset(uint32_t index) {
auto pointer_size = InstructionSetPointerSize(GetInstructionSet());
return mirror::Array::DataOffset(pointer_size).Uint32Value() + pointer_size * index;
}
void CodeGenerator::CompileBaseline(CodeAllocator* allocator, bool is_leaf) {
Initialize();
if (!is_leaf) {
MarkNotLeaf();
}
const bool is_64_bit = Is64BitInstructionSet(GetInstructionSet());
InitializeCodeGeneration(GetGraph()->GetNumberOfLocalVRegs()
+ GetGraph()->GetTemporariesVRegSlots()
+ 1 /* filler */,
0, /* the baseline compiler does not have live registers at slow path */
0, /* the baseline compiler does not have live registers at slow path */
GetGraph()->GetMaximumNumberOfOutVRegs()
+ (is_64_bit ? 2 : 1) /* current method */,
GetGraph()->GetBlocks());
CompileInternal(allocator, /* is_baseline */ true);
}
bool CodeGenerator::GoesToNextBlock(HBasicBlock* current, HBasicBlock* next) const {
DCHECK_EQ(block_order_->Get(current_block_index_), current);
return GetNextBlockToEmit() == FirstNonEmptyBlock(next);
}
HBasicBlock* CodeGenerator::GetNextBlockToEmit() const {
for (size_t i = current_block_index_ + 1; i < block_order_->Size(); ++i) {
HBasicBlock* block = block_order_->Get(i);
if (!block->IsSingleGoto()) {
return block;
}
}
return nullptr;
}
HBasicBlock* CodeGenerator::FirstNonEmptyBlock(HBasicBlock* block) const {
while (block->IsSingleGoto()) {
block = block->GetSuccessors().Get(0);
}
return block;
}
void CodeGenerator::CompileInternal(CodeAllocator* allocator, bool is_baseline) {
is_baseline_ = is_baseline;
HGraphVisitor* instruction_visitor = GetInstructionVisitor();
DCHECK_EQ(current_block_index_, 0u);
GenerateFrameEntry();
DCHECK_EQ(GetAssembler()->cfi().GetCurrentCFAOffset(), static_cast<int>(frame_size_));
for (size_t e = block_order_->Size(); current_block_index_ < e; ++current_block_index_) {
HBasicBlock* block = block_order_->Get(current_block_index_);
// Don't generate code for an empty block. Its predecessors will branch to its successor
// directly. Also, the label of that block will not be emitted, so this helps catch
// errors where we reference that label.
if (block->IsSingleGoto()) continue;
Bind(block);
for (HInstructionIterator it(block->GetInstructions()); !it.Done(); it.Advance()) {
HInstruction* current = it.Current();
if (is_baseline) {
InitLocationsBaseline(current);
}
DCHECK(CheckTypeConsistency(current));
current->Accept(instruction_visitor);
}
}
// Generate the slow paths.
for (size_t i = 0, e = slow_paths_.Size(); i < e; ++i) {
slow_paths_.Get(i)->EmitNativeCode(this);
}
// Finalize instructions in assember;
Finalize(allocator);
}
void CodeGenerator::CompileOptimized(CodeAllocator* allocator) {
// The register allocator already called `InitializeCodeGeneration`,
// where the frame size has been computed.
DCHECK(block_order_ != nullptr);
Initialize();
CompileInternal(allocator, /* is_baseline */ false);
}
void CodeGenerator::Finalize(CodeAllocator* allocator) {
size_t code_size = GetAssembler()->CodeSize();
uint8_t* buffer = allocator->Allocate(code_size);
MemoryRegion code(buffer, code_size);
GetAssembler()->FinalizeInstructions(code);
}
size_t CodeGenerator::FindFreeEntry(bool* array, size_t length) {
for (size_t i = 0; i < length; ++i) {
if (!array[i]) {
array[i] = true;
return i;
}
}
LOG(FATAL) << "Could not find a register in baseline register allocator";
UNREACHABLE();
}
size_t CodeGenerator::FindTwoFreeConsecutiveAlignedEntries(bool* array, size_t length) {
for (size_t i = 0; i < length - 1; i += 2) {
if (!array[i] && !array[i + 1]) {
array[i] = true;
array[i + 1] = true;
return i;
}
}
LOG(FATAL) << "Could not find a register in baseline register allocator";
UNREACHABLE();
}
void CodeGenerator::InitializeCodeGeneration(size_t number_of_spill_slots,
size_t maximum_number_of_live_core_registers,
size_t maximum_number_of_live_fp_registers,
size_t number_of_out_slots,
const GrowableArray<HBasicBlock*>& block_order) {
block_order_ = &block_order;
DCHECK(block_order_->Get(0) == GetGraph()->GetEntryBlock());
ComputeSpillMask();
first_register_slot_in_slow_path_ = (number_of_out_slots + number_of_spill_slots) * kVRegSize;
if (number_of_spill_slots == 0
&& !HasAllocatedCalleeSaveRegisters()
&& IsLeafMethod()
&& !RequiresCurrentMethod()) {
DCHECK_EQ(maximum_number_of_live_core_registers, 0u);
DCHECK_EQ(maximum_number_of_live_fp_registers, 0u);
SetFrameSize(CallPushesPC() ? GetWordSize() : 0);
} else {
SetFrameSize(RoundUp(
number_of_spill_slots * kVRegSize
+ number_of_out_slots * kVRegSize
+ maximum_number_of_live_core_registers * GetWordSize()
+ maximum_number_of_live_fp_registers * GetFloatingPointSpillSlotSize()
+ FrameEntrySpillSize(),
kStackAlignment));
}
}
Location CodeGenerator::GetTemporaryLocation(HTemporary* temp) const {
uint16_t number_of_locals = GetGraph()->GetNumberOfLocalVRegs();
// The type of the previous instruction tells us if we need a single or double stack slot.
Primitive::Type type = temp->GetType();
int32_t temp_size = (type == Primitive::kPrimLong) || (type == Primitive::kPrimDouble) ? 2 : 1;
// Use the temporary region (right below the dex registers).
int32_t slot = GetFrameSize() - FrameEntrySpillSize()
- kVRegSize // filler
- (number_of_locals * kVRegSize)
- ((temp_size + temp->GetIndex()) * kVRegSize);
return temp_size == 2 ? Location::DoubleStackSlot(slot) : Location::StackSlot(slot);
}
int32_t CodeGenerator::GetStackSlot(HLocal* local) const {
uint16_t reg_number = local->GetRegNumber();
uint16_t number_of_locals = GetGraph()->GetNumberOfLocalVRegs();
if (reg_number >= number_of_locals) {
// Local is a parameter of the method. It is stored in the caller's frame.
// TODO: Share this logic with StackVisitor::GetVRegOffsetFromQuickCode.
return GetFrameSize() + InstructionSetPointerSize(GetInstructionSet()) // ART method
+ (reg_number - number_of_locals) * kVRegSize;
} else {
// Local is a temporary in this method. It is stored in this method's frame.
return GetFrameSize() - FrameEntrySpillSize()
- kVRegSize // filler.
- (number_of_locals * kVRegSize)
+ (reg_number * kVRegSize);
}
}
void CodeGenerator::BlockIfInRegister(Location location, bool is_out) const {
// The DCHECKS below check that a register is not specified twice in
// the summary. The out location can overlap with an input, so we need
// to special case it.
if (location.IsRegister()) {
DCHECK(is_out || !blocked_core_registers_[location.reg()]);
blocked_core_registers_[location.reg()] = true;
} else if (location.IsFpuRegister()) {
DCHECK(is_out || !blocked_fpu_registers_[location.reg()]);
blocked_fpu_registers_[location.reg()] = true;
} else if (location.IsFpuRegisterPair()) {
DCHECK(is_out || !blocked_fpu_registers_[location.AsFpuRegisterPairLow<int>()]);
blocked_fpu_registers_[location.AsFpuRegisterPairLow<int>()] = true;
DCHECK(is_out || !blocked_fpu_registers_[location.AsFpuRegisterPairHigh<int>()]);
blocked_fpu_registers_[location.AsFpuRegisterPairHigh<int>()] = true;
} else if (location.IsRegisterPair()) {
DCHECK(is_out || !blocked_core_registers_[location.AsRegisterPairLow<int>()]);
blocked_core_registers_[location.AsRegisterPairLow<int>()] = true;
DCHECK(is_out || !blocked_core_registers_[location.AsRegisterPairHigh<int>()]);
blocked_core_registers_[location.AsRegisterPairHigh<int>()] = true;
}
}
void CodeGenerator::AllocateRegistersLocally(HInstruction* instruction) const {
LocationSummary* locations = instruction->GetLocations();
if (locations == nullptr) return;
for (size_t i = 0, e = GetNumberOfCoreRegisters(); i < e; ++i) {
blocked_core_registers_[i] = false;
}
for (size_t i = 0, e = GetNumberOfFloatingPointRegisters(); i < e; ++i) {
blocked_fpu_registers_[i] = false;
}
for (size_t i = 0, e = number_of_register_pairs_; i < e; ++i) {
blocked_register_pairs_[i] = false;
}
// Mark all fixed input, temp and output registers as used.
for (size_t i = 0, e = locations->GetInputCount(); i < e; ++i) {
BlockIfInRegister(locations->InAt(i));
}
for (size_t i = 0, e = locations->GetTempCount(); i < e; ++i) {
Location loc = locations->GetTemp(i);
BlockIfInRegister(loc);
}
Location result_location = locations->Out();
if (locations->OutputCanOverlapWithInputs()) {
BlockIfInRegister(result_location, /* is_out */ true);
}
SetupBlockedRegisters(/* is_baseline */ true);
// Allocate all unallocated input locations.
for (size_t i = 0, e = locations->GetInputCount(); i < e; ++i) {
Location loc = locations->InAt(i);
HInstruction* input = instruction->InputAt(i);
if (loc.IsUnallocated()) {
if ((loc.GetPolicy() == Location::kRequiresRegister)
|| (loc.GetPolicy() == Location::kRequiresFpuRegister)) {
loc = AllocateFreeRegister(input->GetType());
} else {
DCHECK_EQ(loc.GetPolicy(), Location::kAny);
HLoadLocal* load = input->AsLoadLocal();
if (load != nullptr) {
loc = GetStackLocation(load);
} else {
loc = AllocateFreeRegister(input->GetType());
}
}
locations->SetInAt(i, loc);
}
}
// Allocate all unallocated temp locations.
for (size_t i = 0, e = locations->GetTempCount(); i < e; ++i) {
Location loc = locations->GetTemp(i);
if (loc.IsUnallocated()) {
switch (loc.GetPolicy()) {
case Location::kRequiresRegister:
// Allocate a core register (large enough to fit a 32-bit integer).
loc = AllocateFreeRegister(Primitive::kPrimInt);
break;
case Location::kRequiresFpuRegister:
// Allocate a core register (large enough to fit a 64-bit double).
loc = AllocateFreeRegister(Primitive::kPrimDouble);
break;
default:
LOG(FATAL) << "Unexpected policy for temporary location "
<< loc.GetPolicy();
}
locations->SetTempAt(i, loc);
}
}
if (result_location.IsUnallocated()) {
switch (result_location.GetPolicy()) {
case Location::kAny:
case Location::kRequiresRegister:
case Location::kRequiresFpuRegister:
result_location = AllocateFreeRegister(instruction->GetType());
break;
case Location::kSameAsFirstInput:
result_location = locations->InAt(0);
break;
}
locations->UpdateOut(result_location);
}
}
void CodeGenerator::InitLocationsBaseline(HInstruction* instruction) {
AllocateLocations(instruction);
if (instruction->GetLocations() == nullptr) {
if (instruction->IsTemporary()) {
HInstruction* previous = instruction->GetPrevious();
Location temp_location = GetTemporaryLocation(instruction->AsTemporary());
Move(previous, temp_location, instruction);
}
return;
}
AllocateRegistersLocally(instruction);
for (size_t i = 0, e = instruction->InputCount(); i < e; ++i) {
Location location = instruction->GetLocations()->InAt(i);
HInstruction* input = instruction->InputAt(i);
if (location.IsValid()) {
// Move the input to the desired location.
if (input->GetNext()->IsTemporary()) {
// If the input was stored in a temporary, use that temporary to
// perform the move.
Move(input->GetNext(), location, instruction);
} else {
Move(input, location, instruction);
}
}
}
}
void CodeGenerator::AllocateLocations(HInstruction* instruction) {
instruction->Accept(GetLocationBuilder());
DCHECK(CheckTypeConsistency(instruction));
LocationSummary* locations = instruction->GetLocations();
if (!instruction->IsSuspendCheckEntry()) {
if (locations != nullptr && locations->CanCall()) {
MarkNotLeaf();
}
if (instruction->NeedsCurrentMethod()) {
SetRequiresCurrentMethod();
}
}
}
CodeGenerator* CodeGenerator::Create(HGraph* graph,
InstructionSet instruction_set,
const InstructionSetFeatures& isa_features,
const CompilerOptions& compiler_options) {
switch (instruction_set) {
case kArm:
case kThumb2: {
return new arm::CodeGeneratorARM(graph,
*isa_features.AsArmInstructionSetFeatures(),
compiler_options);
}
case kArm64: {
return new arm64::CodeGeneratorARM64(graph,
*isa_features.AsArm64InstructionSetFeatures(),
compiler_options);
}
case kMips:
return nullptr;
case kMips64: {
return new mips64::CodeGeneratorMIPS64(graph,
*isa_features.AsMips64InstructionSetFeatures(),
compiler_options);
}
case kX86: {
return new x86::CodeGeneratorX86(graph,
*isa_features.AsX86InstructionSetFeatures(),
compiler_options);
}
case kX86_64: {
return new x86_64::CodeGeneratorX86_64(graph,
*isa_features.AsX86_64InstructionSetFeatures(),
compiler_options);
}
default:
return nullptr;
}
}
void CodeGenerator::BuildNativeGCMap(
std::vector<uint8_t>* data, const DexCompilationUnit& dex_compilation_unit) const {
const std::vector<uint8_t>& gc_map_raw =
dex_compilation_unit.GetVerifiedMethod()->GetDexGcMap();
verifier::DexPcToReferenceMap dex_gc_map(&(gc_map_raw)[0]);
uint32_t max_native_offset = 0;
for (size_t i = 0; i < pc_infos_.Size(); i++) {
uint32_t native_offset = pc_infos_.Get(i).native_pc;
if (native_offset > max_native_offset) {
max_native_offset = native_offset;
}
}
GcMapBuilder builder(data, pc_infos_.Size(), max_native_offset, dex_gc_map.RegWidth());
for (size_t i = 0; i < pc_infos_.Size(); i++) {
struct PcInfo pc_info = pc_infos_.Get(i);
uint32_t native_offset = pc_info.native_pc;
uint32_t dex_pc = pc_info.dex_pc;
const uint8_t* references = dex_gc_map.FindBitMap(dex_pc, false);
CHECK(references != nullptr) << "Missing ref for dex pc 0x" << std::hex << dex_pc;
builder.AddEntry(native_offset, references);
}
}
void CodeGenerator::BuildSourceMap(DefaultSrcMap* src_map) const {
for (size_t i = 0; i < pc_infos_.Size(); i++) {
struct PcInfo pc_info = pc_infos_.Get(i);
uint32_t pc2dex_offset = pc_info.native_pc;
int32_t pc2dex_dalvik_offset = pc_info.dex_pc;
src_map->push_back(SrcMapElem({pc2dex_offset, pc2dex_dalvik_offset}));
}
}
void CodeGenerator::BuildMappingTable(std::vector<uint8_t>* data) const {
uint32_t pc2dex_data_size = 0u;
uint32_t pc2dex_entries = pc_infos_.Size();
uint32_t pc2dex_offset = 0u;
int32_t pc2dex_dalvik_offset = 0;
uint32_t dex2pc_data_size = 0u;
uint32_t dex2pc_entries = 0u;
uint32_t dex2pc_offset = 0u;
int32_t dex2pc_dalvik_offset = 0;
for (size_t i = 0; i < pc2dex_entries; i++) {
struct PcInfo pc_info = pc_infos_.Get(i);
pc2dex_data_size += UnsignedLeb128Size(pc_info.native_pc - pc2dex_offset);
pc2dex_data_size += SignedLeb128Size(pc_info.dex_pc - pc2dex_dalvik_offset);
pc2dex_offset = pc_info.native_pc;
pc2dex_dalvik_offset = pc_info.dex_pc;
}
// Walk over the blocks and find which ones correspond to catch block entries.
for (size_t i = 0; i < graph_->GetBlocks().Size(); ++i) {
HBasicBlock* block = graph_->GetBlocks().Get(i);
if (block->IsCatchBlock()) {
intptr_t native_pc = GetAddressOf(block);
++dex2pc_entries;
dex2pc_data_size += UnsignedLeb128Size(native_pc - dex2pc_offset);
dex2pc_data_size += SignedLeb128Size(block->GetDexPc() - dex2pc_dalvik_offset);
dex2pc_offset = native_pc;
dex2pc_dalvik_offset = block->GetDexPc();
}
}
uint32_t total_entries = pc2dex_entries + dex2pc_entries;
uint32_t hdr_data_size = UnsignedLeb128Size(total_entries) + UnsignedLeb128Size(pc2dex_entries);
uint32_t data_size = hdr_data_size + pc2dex_data_size + dex2pc_data_size;
data->resize(data_size);
uint8_t* data_ptr = &(*data)[0];
uint8_t* write_pos = data_ptr;
write_pos = EncodeUnsignedLeb128(write_pos, total_entries);
write_pos = EncodeUnsignedLeb128(write_pos, pc2dex_entries);
DCHECK_EQ(static_cast<size_t>(write_pos - data_ptr), hdr_data_size);
uint8_t* write_pos2 = write_pos + pc2dex_data_size;
pc2dex_offset = 0u;
pc2dex_dalvik_offset = 0u;
dex2pc_offset = 0u;
dex2pc_dalvik_offset = 0u;
for (size_t i = 0; i < pc2dex_entries; i++) {
struct PcInfo pc_info = pc_infos_.Get(i);
DCHECK(pc2dex_offset <= pc_info.native_pc);
write_pos = EncodeUnsignedLeb128(write_pos, pc_info.native_pc - pc2dex_offset);
write_pos = EncodeSignedLeb128(write_pos, pc_info.dex_pc - pc2dex_dalvik_offset);
pc2dex_offset = pc_info.native_pc;
pc2dex_dalvik_offset = pc_info.dex_pc;
}
for (size_t i = 0; i < graph_->GetBlocks().Size(); ++i) {
HBasicBlock* block = graph_->GetBlocks().Get(i);
if (block->IsCatchBlock()) {
intptr_t native_pc = GetAddressOf(block);
write_pos2 = EncodeUnsignedLeb128(write_pos2, native_pc - dex2pc_offset);
write_pos2 = EncodeSignedLeb128(write_pos2, block->GetDexPc() - dex2pc_dalvik_offset);
dex2pc_offset = native_pc;
dex2pc_dalvik_offset = block->GetDexPc();
}
}
DCHECK_EQ(static_cast<size_t>(write_pos - data_ptr), hdr_data_size + pc2dex_data_size);
DCHECK_EQ(static_cast<size_t>(write_pos2 - data_ptr), data_size);
if (kIsDebugBuild) {
// Verify the encoded table holds the expected data.
MappingTable table(data_ptr);
CHECK_EQ(table.TotalSize(), total_entries);
CHECK_EQ(table.PcToDexSize(), pc2dex_entries);
auto it = table.PcToDexBegin();
auto it2 = table.DexToPcBegin();
for (size_t i = 0; i < pc2dex_entries; i++) {
struct PcInfo pc_info = pc_infos_.Get(i);
CHECK_EQ(pc_info.native_pc, it.NativePcOffset());
CHECK_EQ(pc_info.dex_pc, it.DexPc());
++it;
}
for (size_t i = 0; i < graph_->GetBlocks().Size(); ++i) {
HBasicBlock* block = graph_->GetBlocks().Get(i);
if (block->IsCatchBlock()) {
CHECK_EQ(GetAddressOf(block), it2.NativePcOffset());
CHECK_EQ(block->GetDexPc(), it2.DexPc());
++it2;
}
}
CHECK(it == table.PcToDexEnd());
CHECK(it2 == table.DexToPcEnd());
}
}
void CodeGenerator::BuildVMapTable(std::vector<uint8_t>* data) const {
Leb128EncodingVector vmap_encoder;
// We currently don't use callee-saved registers.
size_t size = 0 + 1 /* marker */ + 0;
vmap_encoder.Reserve(size + 1u); // All values are likely to be one byte in ULEB128 (<128).
vmap_encoder.PushBackUnsigned(size);
vmap_encoder.PushBackUnsigned(VmapTable::kAdjustedFpMarker);
*data = vmap_encoder.GetData();
}
void CodeGenerator::BuildStackMaps(std::vector<uint8_t>* data) {
uint32_t size = stack_map_stream_.PrepareForFillIn();
data->resize(size);
MemoryRegion region(data->data(), size);
stack_map_stream_.FillIn(region);
}
void CodeGenerator::RecordPcInfo(HInstruction* instruction,
uint32_t dex_pc,
SlowPathCode* slow_path) {
if (instruction != nullptr) {
// The code generated for some type conversions and comparisons
// may call the runtime, thus normally requiring a subsequent
// call to this method. However, the method verifier does not
// produce PC information for certain instructions, which are
// considered "atomic" (they cannot join a GC).
// Therefore we do not currently record PC information for such
// instructions. As this may change later, we added this special
// case so that code generators may nevertheless call
// CodeGenerator::RecordPcInfo without triggering an error in
// CodeGenerator::BuildNativeGCMap ("Missing ref for dex pc 0x")
// thereafter.
if (instruction->IsTypeConversion() || instruction->IsCompare()) {
return;
}
if (instruction->IsRem()) {
Primitive::Type type = instruction->AsRem()->GetResultType();
if ((type == Primitive::kPrimFloat) || (type == Primitive::kPrimDouble)) {
return;
}
}
}
// Collect PC infos for the mapping table.
struct PcInfo pc_info;
pc_info.dex_pc = dex_pc;
pc_info.native_pc = GetAssembler()->CodeSize();
pc_infos_.Add(pc_info);
uint32_t inlining_depth = 0;
if (instruction == nullptr) {
// For stack overflow checks.
stack_map_stream_.BeginStackMapEntry(dex_pc, pc_info.native_pc, 0, 0, 0, inlining_depth);
stack_map_stream_.EndStackMapEntry();
return;
}
LocationSummary* locations = instruction->GetLocations();
HEnvironment* environment = instruction->GetEnvironment();
size_t environment_size = instruction->EnvironmentSize();
uint32_t register_mask = locations->GetRegisterMask();
if (locations->OnlyCallsOnSlowPath()) {
// In case of slow path, we currently set the location of caller-save registers
// to register (instead of their stack location when pushed before the slow-path
// call). Therefore register_mask contains both callee-save and caller-save
// registers that hold objects. We must remove the caller-save from the mask, since
// they will be overwritten by the callee.
register_mask &= core_callee_save_mask_;
}
// The register mask must be a subset of callee-save registers.
DCHECK_EQ(register_mask & core_callee_save_mask_, register_mask);
stack_map_stream_.BeginStackMapEntry(dex_pc,
pc_info.native_pc,
register_mask,
locations->GetStackMask(),
environment_size,
inlining_depth);
if (environment != nullptr) {
// TODO: Handle parent environment.
DCHECK(environment->GetParent() == nullptr);
DCHECK_EQ(environment->GetDexPc(), dex_pc);
}
// Walk over the environment, and record the location of dex registers.
for (size_t i = 0; i < environment_size; ++i) {
HInstruction* current = environment->GetInstructionAt(i);
if (current == nullptr) {
stack_map_stream_.AddDexRegisterEntry(i, DexRegisterLocation::Kind::kNone, 0);
continue;
}
Location location = environment->GetLocationAt(i);
switch (location.GetKind()) {
case Location::kConstant: {
DCHECK_EQ(current, location.GetConstant());
if (current->IsLongConstant()) {
int64_t value = current->AsLongConstant()->GetValue();
stack_map_stream_.AddDexRegisterEntry(
i, DexRegisterLocation::Kind::kConstant, Low32Bits(value));
stack_map_stream_.AddDexRegisterEntry(
++i, DexRegisterLocation::Kind::kConstant, High32Bits(value));
DCHECK_LT(i, environment_size);
} else if (current->IsDoubleConstant()) {
int64_t value = bit_cast<int64_t, double>(current->AsDoubleConstant()->GetValue());
stack_map_stream_.AddDexRegisterEntry(
i, DexRegisterLocation::Kind::kConstant, Low32Bits(value));
stack_map_stream_.AddDexRegisterEntry(
++i, DexRegisterLocation::Kind::kConstant, High32Bits(value));
DCHECK_LT(i, environment_size);
} else if (current->IsIntConstant()) {
int32_t value = current->AsIntConstant()->GetValue();
stack_map_stream_.AddDexRegisterEntry(i, DexRegisterLocation::Kind::kConstant, value);
} else if (current->IsNullConstant()) {
stack_map_stream_.AddDexRegisterEntry(i, DexRegisterLocation::Kind::kConstant, 0);
} else {
DCHECK(current->IsFloatConstant()) << current->DebugName();
int32_t value = bit_cast<int32_t, float>(current->AsFloatConstant()->GetValue());
stack_map_stream_.AddDexRegisterEntry(i, DexRegisterLocation::Kind::kConstant, value);
}
break;
}
case Location::kStackSlot: {
stack_map_stream_.AddDexRegisterEntry(
i, DexRegisterLocation::Kind::kInStack, location.GetStackIndex());
break;
}
case Location::kDoubleStackSlot: {
stack_map_stream_.AddDexRegisterEntry(
i, DexRegisterLocation::Kind::kInStack, location.GetStackIndex());
stack_map_stream_.AddDexRegisterEntry(
++i, DexRegisterLocation::Kind::kInStack, location.GetHighStackIndex(kVRegSize));
DCHECK_LT(i, environment_size);
break;
}
case Location::kRegister : {
int id = location.reg();
if (slow_path != nullptr && slow_path->IsCoreRegisterSaved(id)) {
uint32_t offset = slow_path->GetStackOffsetOfCoreRegister(id);
stack_map_stream_.AddDexRegisterEntry(i, DexRegisterLocation::Kind::kInStack, offset);
if (current->GetType() == Primitive::kPrimLong) {
stack_map_stream_.AddDexRegisterEntry(
++i, DexRegisterLocation::Kind::kInStack, offset + kVRegSize);
DCHECK_LT(i, environment_size);
}
} else {
stack_map_stream_.AddDexRegisterEntry(i, DexRegisterLocation::Kind::kInRegister, id);
if (current->GetType() == Primitive::kPrimLong) {
stack_map_stream_.AddDexRegisterEntry(++i, DexRegisterLocation::Kind::kInRegister, id);
DCHECK_LT(i, environment_size);
}
}
break;
}
case Location::kFpuRegister : {
int id = location.reg();
if (slow_path != nullptr && slow_path->IsFpuRegisterSaved(id)) {
uint32_t offset = slow_path->GetStackOffsetOfFpuRegister(id);
stack_map_stream_.AddDexRegisterEntry(i, DexRegisterLocation::Kind::kInStack, offset);
if (current->GetType() == Primitive::kPrimDouble) {
stack_map_stream_.AddDexRegisterEntry(
++i, DexRegisterLocation::Kind::kInStack, offset + kVRegSize);
DCHECK_LT(i, environment_size);
}
} else {
stack_map_stream_.AddDexRegisterEntry(i, DexRegisterLocation::Kind::kInFpuRegister, id);
if (current->GetType() == Primitive::kPrimDouble) {
stack_map_stream_.AddDexRegisterEntry(
++i, DexRegisterLocation::Kind::kInFpuRegister, id);
DCHECK_LT(i, environment_size);
}
}
break;
}
case Location::kFpuRegisterPair : {
int low = location.low();
int high = location.high();
if (slow_path != nullptr && slow_path->IsFpuRegisterSaved(low)) {
uint32_t offset = slow_path->GetStackOffsetOfFpuRegister(low);
stack_map_stream_.AddDexRegisterEntry(i, DexRegisterLocation::Kind::kInStack, offset);
} else {
stack_map_stream_.AddDexRegisterEntry(i, DexRegisterLocation::Kind::kInFpuRegister, low);
}
if (slow_path != nullptr && slow_path->IsFpuRegisterSaved(high)) {
uint32_t offset = slow_path->GetStackOffsetOfFpuRegister(high);
stack_map_stream_.AddDexRegisterEntry(++i, DexRegisterLocation::Kind::kInStack, offset);
} else {
stack_map_stream_.AddDexRegisterEntry(
++i, DexRegisterLocation::Kind::kInFpuRegister, high);
}
DCHECK_LT(i, environment_size);
break;
}
case Location::kRegisterPair : {
int low = location.low();
int high = location.high();
if (slow_path != nullptr && slow_path->IsCoreRegisterSaved(low)) {
uint32_t offset = slow_path->GetStackOffsetOfCoreRegister(low);
stack_map_stream_.AddDexRegisterEntry(i, DexRegisterLocation::Kind::kInStack, offset);
} else {
stack_map_stream_.AddDexRegisterEntry(i, DexRegisterLocation::Kind::kInRegister, low);
}
if (slow_path != nullptr && slow_path->IsCoreRegisterSaved(high)) {
uint32_t offset = slow_path->GetStackOffsetOfCoreRegister(high);
stack_map_stream_.AddDexRegisterEntry(++i, DexRegisterLocation::Kind::kInStack, offset);
} else {
stack_map_stream_.AddDexRegisterEntry(
++i, DexRegisterLocation::Kind::kInRegister, high);
}
DCHECK_LT(i, environment_size);
break;
}
case Location::kInvalid: {
stack_map_stream_.AddDexRegisterEntry(i, DexRegisterLocation::Kind::kNone, 0);
break;
}
default:
LOG(FATAL) << "Unexpected kind " << location.GetKind();
}
}
stack_map_stream_.EndStackMapEntry();
}
bool CodeGenerator::CanMoveNullCheckToUser(HNullCheck* null_check) {
HInstruction* first_next_not_move = null_check->GetNextDisregardingMoves();
return (first_next_not_move != nullptr)
&& first_next_not_move->CanDoImplicitNullCheckOn(null_check->InputAt(0));
}
void CodeGenerator::MaybeRecordImplicitNullCheck(HInstruction* instr) {
// If we are from a static path don't record the pc as we can't throw NPE.
// NB: having the checks here makes the code much less verbose in the arch
// specific code generators.
if (instr->IsStaticFieldSet() || instr->IsStaticFieldGet()) {
return;
}
if (!compiler_options_.GetImplicitNullChecks()) {
return;
}
if (!instr->CanDoImplicitNullCheckOn(instr->InputAt(0))) {
return;
}
// Find the first previous instruction which is not a move.
HInstruction* first_prev_not_move = instr->GetPreviousDisregardingMoves();
// If the instruction is a null check it means that `instr` is the first user
// and needs to record the pc.
if (first_prev_not_move != nullptr && first_prev_not_move->IsNullCheck()) {
HNullCheck* null_check = first_prev_not_move->AsNullCheck();
// TODO: The parallel moves modify the environment. Their changes need to be reverted
// otherwise the stack maps at the throw point will not be correct.
RecordPcInfo(null_check, null_check->GetDexPc());
}
}
void CodeGenerator::ClearSpillSlotsFromLoopPhisInStackMap(HSuspendCheck* suspend_check) const {
LocationSummary* locations = suspend_check->GetLocations();
HBasicBlock* block = suspend_check->GetBlock();
DCHECK(block->GetLoopInformation()->GetSuspendCheck() == suspend_check);
DCHECK(block->IsLoopHeader());
for (HInstructionIterator it(block->GetPhis()); !it.Done(); it.Advance()) {
HInstruction* current = it.Current();
LiveInterval* interval = current->GetLiveInterval();
// We only need to clear bits of loop phis containing objects and allocated in register.
// Loop phis allocated on stack already have the object in the stack.
if (current->GetType() == Primitive::kPrimNot
&& interval->HasRegister()
&& interval->HasSpillSlot()) {
locations->ClearStackBit(interval->GetSpillSlot() / kVRegSize);
}
}
}
void CodeGenerator::EmitParallelMoves(Location from1,
Location to1,
Primitive::Type type1,
Location from2,
Location to2,
Primitive::Type type2) {
HParallelMove parallel_move(GetGraph()->GetArena());
parallel_move.AddMove(from1, to1, type1, nullptr);
parallel_move.AddMove(from2, to2, type2, nullptr);
GetMoveResolver()->EmitNativeCode(¶llel_move);
}
void SlowPathCode::RecordPcInfo(CodeGenerator* codegen, HInstruction* instruction, uint32_t dex_pc) {
codegen->RecordPcInfo(instruction, dex_pc, this);
}
void SlowPathCode::SaveLiveRegisters(CodeGenerator* codegen, LocationSummary* locations) {
RegisterSet* register_set = locations->GetLiveRegisters();
size_t stack_offset = codegen->GetFirstRegisterSlotInSlowPath();
for (size_t i = 0, e = codegen->GetNumberOfCoreRegisters(); i < e; ++i) {
if (!codegen->IsCoreCalleeSaveRegister(i)) {
if (register_set->ContainsCoreRegister(i)) {
// If the register holds an object, update the stack mask.
if (locations->RegisterContainsObject(i)) {
locations->SetStackBit(stack_offset / kVRegSize);
}
DCHECK_LT(stack_offset, codegen->GetFrameSize() - codegen->FrameEntrySpillSize());
DCHECK_LT(i, kMaximumNumberOfExpectedRegisters);
saved_core_stack_offsets_[i] = stack_offset;
stack_offset += codegen->SaveCoreRegister(stack_offset, i);
}
}
}
for (size_t i = 0, e = codegen->GetNumberOfFloatingPointRegisters(); i < e; ++i) {
if (!codegen->IsFloatingPointCalleeSaveRegister(i)) {
if (register_set->ContainsFloatingPointRegister(i)) {
DCHECK_LT(stack_offset, codegen->GetFrameSize() - codegen->FrameEntrySpillSize());
DCHECK_LT(i, kMaximumNumberOfExpectedRegisters);
saved_fpu_stack_offsets_[i] = stack_offset;
stack_offset += codegen->SaveFloatingPointRegister(stack_offset, i);
}
}
}
}
void SlowPathCode::RestoreLiveRegisters(CodeGenerator* codegen, LocationSummary* locations) {
RegisterSet* register_set = locations->GetLiveRegisters();
size_t stack_offset = codegen->GetFirstRegisterSlotInSlowPath();
for (size_t i = 0, e = codegen->GetNumberOfCoreRegisters(); i < e; ++i) {
if (!codegen->IsCoreCalleeSaveRegister(i)) {
if (register_set->ContainsCoreRegister(i)) {
DCHECK_LT(stack_offset, codegen->GetFrameSize() - codegen->FrameEntrySpillSize());
stack_offset += codegen->RestoreCoreRegister(stack_offset, i);
}
}
}
for (size_t i = 0, e = codegen->GetNumberOfFloatingPointRegisters(); i < e; ++i) {
if (!codegen->IsFloatingPointCalleeSaveRegister(i)) {
if (register_set->ContainsFloatingPointRegister(i)) {
DCHECK_LT(stack_offset, codegen->GetFrameSize() - codegen->FrameEntrySpillSize());
stack_offset += codegen->RestoreFloatingPointRegister(stack_offset, i);
}
}
}
}
} // namespace art