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/*
* 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 "nodes.h"
#include <cfloat>
#include "code_generator.h"
#include "common_dominator.h"
#include "ssa_builder.h"
#include "base/bit_vector-inl.h"
#include "base/bit_utils.h"
#include "base/stl_util.h"
#include "intrinsics.h"
#include "mirror/class-inl.h"
#include "scoped_thread_state_change.h"
namespace art {
// Enable floating-point static evaluation during constant folding
// only if all floating-point operations and constants evaluate in the
// range and precision of the type used (i.e., 32-bit float, 64-bit
// double).
static constexpr bool kEnableFloatingPointStaticEvaluation = (FLT_EVAL_METHOD == 0);
void HGraph::InitializeInexactObjectRTI(StackHandleScopeCollection* handles) {
ScopedObjectAccess soa(Thread::Current());
// Create the inexact Object reference type and store it in the HGraph.
ClassLinker* linker = Runtime::Current()->GetClassLinker();
inexact_object_rti_ = ReferenceTypeInfo::Create(
handles->NewHandle(linker->GetClassRoot(ClassLinker::kJavaLangObject)),
/* is_exact */ false);
}
void HGraph::AddBlock(HBasicBlock* block) {
block->SetBlockId(blocks_.size());
blocks_.push_back(block);
}
void HGraph::FindBackEdges(ArenaBitVector* visited) {
// "visited" must be empty on entry, it's an output argument for all visited (i.e. live) blocks.
DCHECK_EQ(visited->GetHighestBitSet(), -1);
// Nodes that we're currently visiting, indexed by block id.
ArenaBitVector visiting(arena_, blocks_.size(), false, kArenaAllocGraphBuilder);
// Number of successors visited from a given node, indexed by block id.
ArenaVector<size_t> successors_visited(blocks_.size(), 0u, arena_->Adapter());
// Stack of nodes that we're currently visiting (same as marked in "visiting" above).
ArenaVector<HBasicBlock*> worklist(arena_->Adapter());
constexpr size_t kDefaultWorklistSize = 8;
worklist.reserve(kDefaultWorklistSize);
visited->SetBit(entry_block_->GetBlockId());
visiting.SetBit(entry_block_->GetBlockId());
worklist.push_back(entry_block_);
while (!worklist.empty()) {
HBasicBlock* current = worklist.back();
uint32_t current_id = current->GetBlockId();
if (successors_visited[current_id] == current->GetSuccessors().size()) {
visiting.ClearBit(current_id);
worklist.pop_back();
} else {
HBasicBlock* successor = current->GetSuccessors()[successors_visited[current_id]++];
uint32_t successor_id = successor->GetBlockId();
if (visiting.IsBitSet(successor_id)) {
DCHECK(ContainsElement(worklist, successor));
successor->AddBackEdge(current);
} else if (!visited->IsBitSet(successor_id)) {
visited->SetBit(successor_id);
visiting.SetBit(successor_id);
worklist.push_back(successor);
}
}
}
}
static void RemoveEnvironmentUses(HInstruction* instruction) {
for (HEnvironment* environment = instruction->GetEnvironment();
environment != nullptr;
environment = environment->GetParent()) {
for (size_t i = 0, e = environment->Size(); i < e; ++i) {
if (environment->GetInstructionAt(i) != nullptr) {
environment->RemoveAsUserOfInput(i);
}
}
}
}
static void RemoveAsUser(HInstruction* instruction) {
for (size_t i = 0; i < instruction->InputCount(); i++) {
instruction->RemoveAsUserOfInput(i);
}
RemoveEnvironmentUses(instruction);
}
void HGraph::RemoveInstructionsAsUsersFromDeadBlocks(const ArenaBitVector& visited) const {
for (size_t i = 0; i < blocks_.size(); ++i) {
if (!visited.IsBitSet(i)) {
HBasicBlock* block = blocks_[i];
if (block == nullptr) continue;
DCHECK(block->GetPhis().IsEmpty()) << "Phis are not inserted at this stage";
for (HInstructionIterator it(block->GetInstructions()); !it.Done(); it.Advance()) {
RemoveAsUser(it.Current());
}
}
}
}
void HGraph::RemoveDeadBlocks(const ArenaBitVector& visited) {
for (size_t i = 0; i < blocks_.size(); ++i) {
if (!visited.IsBitSet(i)) {
HBasicBlock* block = blocks_[i];
if (block == nullptr) continue;
// We only need to update the successor, which might be live.
for (HBasicBlock* successor : block->GetSuccessors()) {
successor->RemovePredecessor(block);
}
// Remove the block from the list of blocks, so that further analyses
// never see it.
blocks_[i] = nullptr;
if (block->IsExitBlock()) {
SetExitBlock(nullptr);
}
// Mark the block as removed. This is used by the HGraphBuilder to discard
// the block as a branch target.
block->SetGraph(nullptr);
}
}
}
GraphAnalysisResult HGraph::BuildDominatorTree() {
ArenaBitVector visited(arena_, blocks_.size(), false, kArenaAllocGraphBuilder);
// (1) Find the back edges in the graph doing a DFS traversal.
FindBackEdges(&visited);
// (2) Remove instructions and phis from blocks not visited during
// the initial DFS as users from other instructions, so that
// users can be safely removed before uses later.
RemoveInstructionsAsUsersFromDeadBlocks(visited);
// (3) Remove blocks not visited during the initial DFS.
// Step (5) requires dead blocks to be removed from the
// predecessors list of live blocks.
RemoveDeadBlocks(visited);
// (4) Simplify the CFG now, so that we don't need to recompute
// dominators and the reverse post order.
SimplifyCFG();
// (5) Compute the dominance information and the reverse post order.
ComputeDominanceInformation();
// (6) Analyze loops discovered through back edge analysis, and
// set the loop information on each block.
GraphAnalysisResult result = AnalyzeLoops();
if (result != kAnalysisSuccess) {
return result;
}
// (7) Precompute per-block try membership before entering the SSA builder,
// which needs the information to build catch block phis from values of
// locals at throwing instructions inside try blocks.
ComputeTryBlockInformation();
return kAnalysisSuccess;
}
void HGraph::ClearDominanceInformation() {
for (HReversePostOrderIterator it(*this); !it.Done(); it.Advance()) {
it.Current()->ClearDominanceInformation();
}
reverse_post_order_.clear();
}
void HGraph::ClearLoopInformation() {
SetHasIrreducibleLoops(false);
for (HReversePostOrderIterator it(*this); !it.Done(); it.Advance()) {
it.Current()->SetLoopInformation(nullptr);
}
}
void HBasicBlock::ClearDominanceInformation() {
dominated_blocks_.clear();
dominator_ = nullptr;
}
HInstruction* HBasicBlock::GetFirstInstructionDisregardMoves() const {
HInstruction* instruction = GetFirstInstruction();
while (instruction->IsParallelMove()) {
instruction = instruction->GetNext();
}
return instruction;
}
void HGraph::ComputeDominanceInformation() {
DCHECK(reverse_post_order_.empty());
reverse_post_order_.reserve(blocks_.size());
reverse_post_order_.push_back(entry_block_);
// Number of visits of a given node, indexed by block id.
ArenaVector<size_t> visits(blocks_.size(), 0u, arena_->Adapter());
// Number of successors visited from a given node, indexed by block id.
ArenaVector<size_t> successors_visited(blocks_.size(), 0u, arena_->Adapter());
// Nodes for which we need to visit successors.
ArenaVector<HBasicBlock*> worklist(arena_->Adapter());
constexpr size_t kDefaultWorklistSize = 8;
worklist.reserve(kDefaultWorklistSize);
worklist.push_back(entry_block_);
while (!worklist.empty()) {
HBasicBlock* current = worklist.back();
uint32_t current_id = current->GetBlockId();
if (successors_visited[current_id] == current->GetSuccessors().size()) {
worklist.pop_back();
} else {
HBasicBlock* successor = current->GetSuccessors()[successors_visited[current_id]++];
if (successor->GetDominator() == nullptr) {
successor->SetDominator(current);
} else {
// The CommonDominator can work for multiple blocks as long as the
// domination information doesn't change. However, since we're changing
// that information here, we can use the finder only for pairs of blocks.
successor->SetDominator(CommonDominator::ForPair(successor->GetDominator(), current));
}
// Once all the forward edges have been visited, we know the immediate
// dominator of the block. We can then start visiting its successors.
if (++visits[successor->GetBlockId()] ==
successor->GetPredecessors().size() - successor->NumberOfBackEdges()) {
reverse_post_order_.push_back(successor);
worklist.push_back(successor);
}
}
}
// Populate `dominated_blocks_` information after computing all dominators.
// The potential presence of irreducible loops requires to do it after.
for (HReversePostOrderIterator it(*this); !it.Done(); it.Advance()) {
HBasicBlock* block = it.Current();
if (!block->IsEntryBlock()) {
block->GetDominator()->AddDominatedBlock(block);
}
}
}
HBasicBlock* HGraph::SplitEdge(HBasicBlock* block, HBasicBlock* successor) {
HBasicBlock* new_block = new (arena_) HBasicBlock(this, successor->GetDexPc());
AddBlock(new_block);
// Use `InsertBetween` to ensure the predecessor index and successor index of
// `block` and `successor` are preserved.
new_block->InsertBetween(block, successor);
return new_block;
}
void HGraph::SplitCriticalEdge(HBasicBlock* block, HBasicBlock* successor) {
// Insert a new node between `block` and `successor` to split the
// critical edge.
HBasicBlock* new_block = SplitEdge(block, successor);
new_block->AddInstruction(new (arena_) HGoto(successor->GetDexPc()));
if (successor->IsLoopHeader()) {
// If we split at a back edge boundary, make the new block the back edge.
HLoopInformation* info = successor->GetLoopInformation();
if (info->IsBackEdge(*block)) {
info->RemoveBackEdge(block);
info->AddBackEdge(new_block);
}
}
}
void HGraph::SimplifyLoop(HBasicBlock* header) {
HLoopInformation* info = header->GetLoopInformation();
// Make sure the loop has only one pre header. This simplifies SSA building by having
// to just look at the pre header to know which locals are initialized at entry of the
// loop. Also, don't allow the entry block to be a pre header: this simplifies inlining
// this graph.
size_t number_of_incomings = header->GetPredecessors().size() - info->NumberOfBackEdges();
if (number_of_incomings != 1 || (GetEntryBlock()->GetSingleSuccessor() == header)) {
HBasicBlock* pre_header = new (arena_) HBasicBlock(this, header->GetDexPc());
AddBlock(pre_header);
pre_header->AddInstruction(new (arena_) HGoto(header->GetDexPc()));
for (size_t pred = 0; pred < header->GetPredecessors().size(); ++pred) {
HBasicBlock* predecessor = header->GetPredecessors()[pred];
if (!info->IsBackEdge(*predecessor)) {
predecessor->ReplaceSuccessor(header, pre_header);
pred--;
}
}
pre_header->AddSuccessor(header);
}
// Make sure the first predecessor of a loop header is the incoming block.
if (info->IsBackEdge(*header->GetPredecessors()[0])) {
HBasicBlock* to_swap = header->GetPredecessors()[0];
for (size_t pred = 1, e = header->GetPredecessors().size(); pred < e; ++pred) {
HBasicBlock* predecessor = header->GetPredecessors()[pred];
if (!info->IsBackEdge(*predecessor)) {
header->predecessors_[pred] = to_swap;
header->predecessors_[0] = predecessor;
break;
}
}
}
HInstruction* first_instruction = header->GetFirstInstruction();
if (first_instruction != nullptr && first_instruction->IsSuspendCheck()) {
// Called from DeadBlockElimination. Update SuspendCheck pointer.
info->SetSuspendCheck(first_instruction->AsSuspendCheck());
}
}
void HGraph::ComputeTryBlockInformation() {
// Iterate in reverse post order to propagate try membership information from
// predecessors to their successors.
for (HReversePostOrderIterator it(*this); !it.Done(); it.Advance()) {
HBasicBlock* block = it.Current();
if (block->IsEntryBlock() || block->IsCatchBlock()) {
// Catch blocks after simplification have only exceptional predecessors
// and hence are never in tries.
continue;
}
// Infer try membership from the first predecessor. Having simplified loops,
// the first predecessor can never be a back edge and therefore it must have
// been visited already and had its try membership set.
HBasicBlock* first_predecessor = block->GetPredecessors()[0];
DCHECK(!block->IsLoopHeader() || !block->GetLoopInformation()->IsBackEdge(*first_predecessor));
const HTryBoundary* try_entry = first_predecessor->ComputeTryEntryOfSuccessors();
if (try_entry != nullptr &&
(block->GetTryCatchInformation() == nullptr ||
try_entry != &block->GetTryCatchInformation()->GetTryEntry())) {
// We are either setting try block membership for the first time or it
// has changed.
block->SetTryCatchInformation(new (arena_) TryCatchInformation(*try_entry));
}
}
}
void HGraph::SimplifyCFG() {
// Simplify the CFG for future analysis, and code generation:
// (1): Split critical edges.
// (2): Simplify loops by having only one preheader.
// NOTE: We're appending new blocks inside the loop, so we need to use index because iterators
// can be invalidated. We remember the initial size to avoid iterating over the new blocks.
for (size_t block_id = 0u, end = blocks_.size(); block_id != end; ++block_id) {
HBasicBlock* block = blocks_[block_id];
if (block == nullptr) continue;
if (block->GetSuccessors().size() > 1) {
// Only split normal-flow edges. We cannot split exceptional edges as they
// are synthesized (approximate real control flow), and we do not need to
// anyway. Moves that would be inserted there are performed by the runtime.
ArrayRef<HBasicBlock* const> normal_successors = block->GetNormalSuccessors();
for (size_t j = 0, e = normal_successors.size(); j < e; ++j) {
HBasicBlock* successor = normal_successors[j];
DCHECK(!successor->IsCatchBlock());
if (successor == exit_block_) {
// (Throw/Return/ReturnVoid)->TryBoundary->Exit. Special case which we
// do not want to split because Goto->Exit is not allowed.
DCHECK(block->IsSingleTryBoundary());
} else if (successor->GetPredecessors().size() > 1) {
SplitCriticalEdge(block, successor);
// SplitCriticalEdge could have invalidated the `normal_successors`
// ArrayRef. We must re-acquire it.
normal_successors = block->GetNormalSuccessors();
DCHECK_EQ(normal_successors[j]->GetSingleSuccessor(), successor);
DCHECK_EQ(e, normal_successors.size());
}
}
}
if (block->IsLoopHeader()) {
SimplifyLoop(block);
} else if (!block->IsEntryBlock() &&
block->GetFirstInstruction() != nullptr &&
block->GetFirstInstruction()->IsSuspendCheck()) {
// We are being called by the dead code elimiation pass, and what used to be
// a loop got dismantled. Just remove the suspend check.
block->RemoveInstruction(block->GetFirstInstruction());
}
}
}
GraphAnalysisResult HGraph::AnalyzeLoops() const {
// Order does not matter.
for (HReversePostOrderIterator it(*this); !it.Done(); it.Advance()) {
HBasicBlock* block = it.Current();
if (block->IsLoopHeader()) {
if (block->IsCatchBlock()) {
// TODO: Dealing with exceptional back edges could be tricky because
// they only approximate the real control flow. Bail out for now.
return kAnalysisFailThrowCatchLoop;
}
block->GetLoopInformation()->Populate();
}
}
return kAnalysisSuccess;
}
void HLoopInformation::Dump(std::ostream& os) {
os << "header: " << header_->GetBlockId() << std::endl;
os << "pre header: " << GetPreHeader()->GetBlockId() << std::endl;
for (HBasicBlock* block : back_edges_) {
os << "back edge: " << block->GetBlockId() << std::endl;
}
for (HBasicBlock* block : header_->GetPredecessors()) {
os << "predecessor: " << block->GetBlockId() << std::endl;
}
for (uint32_t idx : blocks_.Indexes()) {
os << " in loop: " << idx << std::endl;
}
}
void HGraph::InsertConstant(HConstant* constant) {
// New constants are inserted before the SuspendCheck at the bottom of the
// entry block. Note that this method can be called from the graph builder and
// the entry block therefore may not end with SuspendCheck->Goto yet.
HInstruction* insert_before = nullptr;
HInstruction* gota = entry_block_->GetLastInstruction();
if (gota != nullptr && gota->IsGoto()) {
HInstruction* suspend_check = gota->GetPrevious();
if (suspend_check != nullptr && suspend_check->IsSuspendCheck()) {
insert_before = suspend_check;
} else {
insert_before = gota;
}
}
if (insert_before == nullptr) {
entry_block_->AddInstruction(constant);
} else {
entry_block_->InsertInstructionBefore(constant, insert_before);
}
}
HNullConstant* HGraph::GetNullConstant(uint32_t dex_pc) {
// For simplicity, don't bother reviving the cached null constant if it is
// not null and not in a block. Otherwise, we need to clear the instruction
// id and/or any invariants the graph is assuming when adding new instructions.
if ((cached_null_constant_ == nullptr) || (cached_null_constant_->GetBlock() == nullptr)) {
cached_null_constant_ = new (arena_) HNullConstant(dex_pc);
cached_null_constant_->SetReferenceTypeInfo(inexact_object_rti_);
InsertConstant(cached_null_constant_);
}
if (kIsDebugBuild) {
ScopedObjectAccess soa(Thread::Current());
DCHECK(cached_null_constant_->GetReferenceTypeInfo().IsValid());
}
return cached_null_constant_;
}
HCurrentMethod* HGraph::GetCurrentMethod() {
// For simplicity, don't bother reviving the cached current method if it is
// not null and not in a block. Otherwise, we need to clear the instruction
// id and/or any invariants the graph is assuming when adding new instructions.
if ((cached_current_method_ == nullptr) || (cached_current_method_->GetBlock() == nullptr)) {
cached_current_method_ = new (arena_) HCurrentMethod(
Is64BitInstructionSet(instruction_set_) ? Primitive::kPrimLong : Primitive::kPrimInt,
entry_block_->GetDexPc());
if (entry_block_->GetFirstInstruction() == nullptr) {
entry_block_->AddInstruction(cached_current_method_);
} else {
entry_block_->InsertInstructionBefore(
cached_current_method_, entry_block_->GetFirstInstruction());
}
}
return cached_current_method_;
}
HConstant* HGraph::GetConstant(Primitive::Type type, int64_t value, uint32_t dex_pc) {
switch (type) {
case Primitive::Type::kPrimBoolean:
DCHECK(IsUint<1>(value));
FALLTHROUGH_INTENDED;
case Primitive::Type::kPrimByte:
case Primitive::Type::kPrimChar:
case Primitive::Type::kPrimShort:
case Primitive::Type::kPrimInt:
DCHECK(IsInt(Primitive::ComponentSize(type) * kBitsPerByte, value));
return GetIntConstant(static_cast<int32_t>(value), dex_pc);
case Primitive::Type::kPrimLong:
return GetLongConstant(value, dex_pc);
default:
LOG(FATAL) << "Unsupported constant type";
UNREACHABLE();
}
}
void HGraph::CacheFloatConstant(HFloatConstant* constant) {
int32_t value = bit_cast<int32_t, float>(constant->GetValue());
DCHECK(cached_float_constants_.find(value) == cached_float_constants_.end());
cached_float_constants_.Overwrite(value, constant);
}
void HGraph::CacheDoubleConstant(HDoubleConstant* constant) {
int64_t value = bit_cast<int64_t, double>(constant->GetValue());
DCHECK(cached_double_constants_.find(value) == cached_double_constants_.end());
cached_double_constants_.Overwrite(value, constant);
}
void HLoopInformation::Add(HBasicBlock* block) {
blocks_.SetBit(block->GetBlockId());
}
void HLoopInformation::Remove(HBasicBlock* block) {
blocks_.ClearBit(block->GetBlockId());
}
void HLoopInformation::PopulateRecursive(HBasicBlock* block) {
if (blocks_.IsBitSet(block->GetBlockId())) {
return;
}
blocks_.SetBit(block->GetBlockId());
block->SetInLoop(this);
for (HBasicBlock* predecessor : block->GetPredecessors()) {
PopulateRecursive(predecessor);
}
}
void HLoopInformation::PopulateIrreducibleRecursive(HBasicBlock* block, ArenaBitVector* finalized) {
size_t block_id = block->GetBlockId();
// If `block` is in `finalized`, we know its membership in the loop has been
// decided and it does not need to be revisited.
if (finalized->IsBitSet(block_id)) {
return;
}
bool is_finalized = false;
if (block->IsLoopHeader()) {
// If we hit a loop header in an irreducible loop, we first check if the
// pre header of that loop belongs to the currently analyzed loop. If it does,
// then we visit the back edges.
// Note that we cannot use GetPreHeader, as the loop may have not been populated
// yet.
HBasicBlock* pre_header = block->GetPredecessors()[0];
PopulateIrreducibleRecursive(pre_header, finalized);
if (blocks_.IsBitSet(pre_header->GetBlockId())) {
block->SetInLoop(this);
blocks_.SetBit(block_id);
finalized->SetBit(block_id);
is_finalized = true;
HLoopInformation* info = block->GetLoopInformation();
for (HBasicBlock* back_edge : info->GetBackEdges()) {
PopulateIrreducibleRecursive(back_edge, finalized);
}
}
} else {
// Visit all predecessors. If one predecessor is part of the loop, this
// block is also part of this loop.
for (HBasicBlock* predecessor : block->GetPredecessors()) {
PopulateIrreducibleRecursive(predecessor, finalized);
if (!is_finalized && blocks_.IsBitSet(predecessor->GetBlockId())) {
block->SetInLoop(this);
blocks_.SetBit(block_id);
finalized->SetBit(block_id);
is_finalized = true;
}
}
}
// All predecessors have been recursively visited. Mark finalized if not marked yet.
if (!is_finalized) {
finalized->SetBit(block_id);
}
}
void HLoopInformation::Populate() {
DCHECK_EQ(blocks_.NumSetBits(), 0u) << "Loop information has already been populated";
// Populate this loop: starting with the back edge, recursively add predecessors
// that are not already part of that loop. Set the header as part of the loop
// to end the recursion.
// This is a recursive implementation of the algorithm described in
// "Advanced Compiler Design & Implementation" (Muchnick) p192.
HGraph* graph = header_->GetGraph();
blocks_.SetBit(header_->GetBlockId());
header_->SetInLoop(this);
bool is_irreducible_loop = false;
for (HBasicBlock* back_edge : GetBackEdges()) {
DCHECK(back_edge->GetDominator() != nullptr);
if (!header_->Dominates(back_edge)) {
is_irreducible_loop = true;
break;
}
}
if (is_irreducible_loop) {
ArenaBitVector visited(graph->GetArena(),
graph->GetBlocks().size(),
/* expandable */ false,
kArenaAllocGraphBuilder);
for (HBasicBlock* back_edge : GetBackEdges()) {
PopulateIrreducibleRecursive(back_edge, &visited);
}
} else {
for (HBasicBlock* back_edge : GetBackEdges()) {
PopulateRecursive(back_edge);
}
}
if (is_irreducible_loop || graph->IsCompilingOsr()) {
irreducible_ = true;
graph->SetHasIrreducibleLoops(true);
}
}
HBasicBlock* HLoopInformation::GetPreHeader() const {
HBasicBlock* block = header_->GetPredecessors()[0];
DCHECK(irreducible_ || (block == header_->GetDominator()));
return block;
}
bool HLoopInformation::Contains(const HBasicBlock& block) const {
return blocks_.IsBitSet(block.GetBlockId());
}
bool HLoopInformation::IsIn(const HLoopInformation& other) const {
return other.blocks_.IsBitSet(header_->GetBlockId());
}
bool HLoopInformation::IsDefinedOutOfTheLoop(HInstruction* instruction) const {
return !blocks_.IsBitSet(instruction->GetBlock()->GetBlockId());
}
size_t HLoopInformation::GetLifetimeEnd() const {
size_t last_position = 0;
for (HBasicBlock* back_edge : GetBackEdges()) {
last_position = std::max(back_edge->GetLifetimeEnd(), last_position);
}
return last_position;
}
bool HBasicBlock::Dominates(HBasicBlock* other) const {
// Walk up the dominator tree from `other`, to find out if `this`
// is an ancestor.
HBasicBlock* current = other;
while (current != nullptr) {
if (current == this) {
return true;
}
current = current->GetDominator();
}
return false;
}
static void UpdateInputsUsers(HInstruction* instruction) {
for (size_t i = 0, e = instruction->InputCount(); i < e; ++i) {
instruction->InputAt(i)->AddUseAt(instruction, i);
}
// Environment should be created later.
DCHECK(!instruction->HasEnvironment());
}
void HBasicBlock::ReplaceAndRemoveInstructionWith(HInstruction* initial,
HInstruction* replacement) {
DCHECK(initial->GetBlock() == this);
if (initial->IsControlFlow()) {
// We can only replace a control flow instruction with another control flow instruction.
DCHECK(replacement->IsControlFlow());
DCHECK_EQ(replacement->GetId(), -1);
DCHECK_EQ(replacement->GetType(), Primitive::kPrimVoid);
DCHECK_EQ(initial->GetBlock(), this);
DCHECK_EQ(initial->GetType(), Primitive::kPrimVoid);
DCHECK(initial->GetUses().IsEmpty());
DCHECK(initial->GetEnvUses().IsEmpty());
replacement->SetBlock(this);
replacement->SetId(GetGraph()->GetNextInstructionId());
instructions_.InsertInstructionBefore(replacement, initial);
UpdateInputsUsers(replacement);
} else {
InsertInstructionBefore(replacement, initial);
initial->ReplaceWith(replacement);
}
RemoveInstruction(initial);
}
void HBasicBlock::MoveInstructionBefore(HInstruction* insn, HInstruction* cursor) {
DCHECK(!cursor->IsPhi());
DCHECK(!insn->IsPhi());
DCHECK(!insn->IsControlFlow());
DCHECK(insn->CanBeMoved());
DCHECK(!insn->HasSideEffects());
HBasicBlock* from_block = insn->GetBlock();
HBasicBlock* to_block = cursor->GetBlock();
DCHECK(from_block != to_block);
from_block->RemoveInstruction(insn, /* ensure_safety */ false);
insn->SetBlock(to_block);
to_block->instructions_.InsertInstructionBefore(insn, cursor);
}
static void Add(HInstructionList* instruction_list,
HBasicBlock* block,
HInstruction* instruction) {
DCHECK(instruction->GetBlock() == nullptr);
DCHECK_EQ(instruction->GetId(), -1);
instruction->SetBlock(block);
instruction->SetId(block->GetGraph()->GetNextInstructionId());
UpdateInputsUsers(instruction);
instruction_list->AddInstruction(instruction);
}
void HBasicBlock::AddInstruction(HInstruction* instruction) {
Add(&instructions_, this, instruction);
}
void HBasicBlock::AddPhi(HPhi* phi) {
Add(&phis_, this, phi);
}
void HBasicBlock::InsertInstructionBefore(HInstruction* instruction, HInstruction* cursor) {
DCHECK(!cursor->IsPhi());
DCHECK(!instruction->IsPhi());
DCHECK_EQ(instruction->GetId(), -1);
DCHECK_NE(cursor->GetId(), -1);
DCHECK_EQ(cursor->GetBlock(), this);
DCHECK(!instruction->IsControlFlow());
instruction->SetBlock(this);
instruction->SetId(GetGraph()->GetNextInstructionId());
UpdateInputsUsers(instruction);
instructions_.InsertInstructionBefore(instruction, cursor);
}
void HBasicBlock::InsertInstructionAfter(HInstruction* instruction, HInstruction* cursor) {
DCHECK(!cursor->IsPhi());
DCHECK(!instruction->IsPhi());
DCHECK_EQ(instruction->GetId(), -1);
DCHECK_NE(cursor->GetId(), -1);
DCHECK_EQ(cursor->GetBlock(), this);
DCHECK(!instruction->IsControlFlow());
DCHECK(!cursor->IsControlFlow());
instruction->SetBlock(this);
instruction->SetId(GetGraph()->GetNextInstructionId());
UpdateInputsUsers(instruction);
instructions_.InsertInstructionAfter(instruction, cursor);
}
void HBasicBlock::InsertPhiAfter(HPhi* phi, HPhi* cursor) {
DCHECK_EQ(phi->GetId(), -1);
DCHECK_NE(cursor->GetId(), -1);
DCHECK_EQ(cursor->GetBlock(), this);
phi->SetBlock(this);
phi->SetId(GetGraph()->GetNextInstructionId());
UpdateInputsUsers(phi);
phis_.InsertInstructionAfter(phi, cursor);
}
static void Remove(HInstructionList* instruction_list,
HBasicBlock* block,
HInstruction* instruction,
bool ensure_safety) {
DCHECK_EQ(block, instruction->GetBlock());
instruction->SetBlock(nullptr);
instruction_list->RemoveInstruction(instruction);
if (ensure_safety) {
DCHECK(instruction->GetUses().IsEmpty());
DCHECK(instruction->GetEnvUses().IsEmpty());
RemoveAsUser(instruction);
}
}
void HBasicBlock::RemoveInstruction(HInstruction* instruction, bool ensure_safety) {
DCHECK(!instruction->IsPhi());
Remove(&instructions_, this, instruction, ensure_safety);
}
void HBasicBlock::RemovePhi(HPhi* phi, bool ensure_safety) {
Remove(&phis_, this, phi, ensure_safety);
}
void HBasicBlock::RemoveInstructionOrPhi(HInstruction* instruction, bool ensure_safety) {
if (instruction->IsPhi()) {
RemovePhi(instruction->AsPhi(), ensure_safety);
} else {
RemoveInstruction(instruction, ensure_safety);
}
}
void HEnvironment::CopyFrom(const ArenaVector<HInstruction*>& locals) {
for (size_t i = 0; i < locals.size(); i++) {
HInstruction* instruction = locals[i];
SetRawEnvAt(i, instruction);
if (instruction != nullptr) {
instruction->AddEnvUseAt(this, i);
}
}
}
void HEnvironment::CopyFrom(HEnvironment* env) {
for (size_t i = 0; i < env->Size(); i++) {
HInstruction* instruction = env->GetInstructionAt(i);
SetRawEnvAt(i, instruction);
if (instruction != nullptr) {
instruction->AddEnvUseAt(this, i);
}
}
}
void HEnvironment::CopyFromWithLoopPhiAdjustment(HEnvironment* env,
HBasicBlock* loop_header) {
DCHECK(loop_header->IsLoopHeader());
for (size_t i = 0; i < env->Size(); i++) {
HInstruction* instruction = env->GetInstructionAt(i);
SetRawEnvAt(i, instruction);
if (instruction == nullptr) {
continue;
}
if (instruction->IsLoopHeaderPhi() && (instruction->GetBlock() == loop_header)) {
// At the end of the loop pre-header, the corresponding value for instruction
// is the first input of the phi.
HInstruction* initial = instruction->AsPhi()->InputAt(0);
SetRawEnvAt(i, initial);
initial->AddEnvUseAt(this, i);
} else {
instruction->AddEnvUseAt(this, i);
}
}
}
void HEnvironment::RemoveAsUserOfInput(size_t index) const {
const HUserRecord<HEnvironment*>& user_record = vregs_[index];
user_record.GetInstruction()->RemoveEnvironmentUser(user_record.GetUseNode());
}
HInstruction::InstructionKind HInstruction::GetKind() const {
return GetKindInternal();
}
HInstruction* HInstruction::GetNextDisregardingMoves() const {
HInstruction* next = GetNext();
while (next != nullptr && next->IsParallelMove()) {
next = next->GetNext();
}
return next;
}
HInstruction* HInstruction::GetPreviousDisregardingMoves() const {
HInstruction* previous = GetPrevious();
while (previous != nullptr && previous->IsParallelMove()) {
previous = previous->GetPrevious();
}
return previous;
}
void HInstructionList::AddInstruction(HInstruction* instruction) {
if (first_instruction_ == nullptr) {
DCHECK(last_instruction_ == nullptr);
first_instruction_ = last_instruction_ = instruction;
} else {
last_instruction_->next_ = instruction;
instruction->previous_ = last_instruction_;
last_instruction_ = instruction;
}
}
void HInstructionList::InsertInstructionBefore(HInstruction* instruction, HInstruction* cursor) {
DCHECK(Contains(cursor));
if (cursor == first_instruction_) {
cursor->previous_ = instruction;
instruction->next_ = cursor;
first_instruction_ = instruction;
} else {
instruction->previous_ = cursor->previous_;
instruction->next_ = cursor;
cursor->previous_ = instruction;
instruction->previous_->next_ = instruction;
}
}
void HInstructionList::InsertInstructionAfter(HInstruction* instruction, HInstruction* cursor) {
DCHECK(Contains(cursor));
if (cursor == last_instruction_) {
cursor->next_ = instruction;
instruction->previous_ = cursor;
last_instruction_ = instruction;
} else {
instruction->next_ = cursor->next_;
instruction->previous_ = cursor;
cursor->next_ = instruction;
instruction->next_->previous_ = instruction;
}
}
void HInstructionList::RemoveInstruction(HInstruction* instruction) {
if (instruction->previous_ != nullptr) {
instruction->previous_->next_ = instruction->next_;
}
if (instruction->next_ != nullptr) {
instruction->next_->previous_ = instruction->previous_;
}
if (instruction == first_instruction_) {
first_instruction_ = instruction->next_;
}
if (instruction == last_instruction_) {
last_instruction_ = instruction->previous_;
}
}
bool HInstructionList::Contains(HInstruction* instruction) const {
for (HInstructionIterator it(*this); !it.Done(); it.Advance()) {
if (it.Current() == instruction) {
return true;
}
}
return false;
}
bool HInstructionList::FoundBefore(const HInstruction* instruction1,
const HInstruction* instruction2) const {
DCHECK_EQ(instruction1->GetBlock(), instruction2->GetBlock());
for (HInstructionIterator it(*this); !it.Done(); it.Advance()) {
if (it.Current() == instruction1) {
return true;
}
if (it.Current() == instruction2) {
return false;
}
}
LOG(FATAL) << "Did not find an order between two instructions of the same block.";
return true;
}
bool HInstruction::StrictlyDominates(HInstruction* other_instruction) const {
if (other_instruction == this) {
// An instruction does not strictly dominate itself.
return false;
}
HBasicBlock* block = GetBlock();
HBasicBlock* other_block = other_instruction->GetBlock();
if (block != other_block) {
return GetBlock()->Dominates(other_instruction->GetBlock());
} else {
// If both instructions are in the same block, ensure this
// instruction comes before `other_instruction`.
if (IsPhi()) {
if (!other_instruction->IsPhi()) {
// Phis appear before non phi-instructions so this instruction
// dominates `other_instruction`.
return true;
} else {
// There is no order among phis.
LOG(FATAL) << "There is no dominance between phis of a same block.";
return false;
}
} else {
// `this` is not a phi.
if (other_instruction->IsPhi()) {
// Phis appear before non phi-instructions so this instruction
// does not dominate `other_instruction`.
return false;
} else {
// Check whether this instruction comes before
// `other_instruction` in the instruction list.
return block->GetInstructions().FoundBefore(this, other_instruction);
}
}
}
}
void HInstruction::RemoveEnvironment() {
RemoveEnvironmentUses(this);
environment_ = nullptr;
}
void HInstruction::ReplaceWith(HInstruction* other) {
DCHECK(other != nullptr);
for (HUseIterator<HInstruction*> it(GetUses()); !it.Done(); it.Advance()) {
HUseListNode<HInstruction*>* current = it.Current();
HInstruction* user = current->GetUser();
size_t input_index = current->GetIndex();
user->SetRawInputAt(input_index, other);
other->AddUseAt(user, input_index);
}
for (HUseIterator<HEnvironment*> it(GetEnvUses()); !it.Done(); it.Advance()) {
HUseListNode<HEnvironment*>* current = it.Current();
HEnvironment* user = current->GetUser();
size_t input_index = current->GetIndex();
user->SetRawEnvAt(input_index, other);
other->AddEnvUseAt(user, input_index);
}
uses_.Clear();
env_uses_.Clear();
}
void HInstruction::ReplaceInput(HInstruction* replacement, size_t index) {
RemoveAsUserOfInput(index);
SetRawInputAt(index, replacement);
replacement->AddUseAt(this, index);
}
size_t HInstruction::EnvironmentSize() const {
return HasEnvironment() ? environment_->Size() : 0;
}
void HPhi::AddInput(HInstruction* input) {
DCHECK(input->GetBlock() != nullptr);
inputs_.push_back(HUserRecord<HInstruction*>(input));
input->AddUseAt(this, inputs_.size() - 1);
}
void HPhi::RemoveInputAt(size_t index) {
RemoveAsUserOfInput(index);
inputs_.erase(inputs_.begin() + index);
for (size_t i = index, e = InputCount(); i < e; ++i) {
DCHECK_EQ(InputRecordAt(i).GetUseNode()->GetIndex(), i + 1u);
InputRecordAt(i).GetUseNode()->SetIndex(i);
}
}
#define DEFINE_ACCEPT(name, super) \
void H##name::Accept(HGraphVisitor* visitor) { \
visitor->Visit##name(this); \
}
FOR_EACH_CONCRETE_INSTRUCTION(DEFINE_ACCEPT)
#undef DEFINE_ACCEPT
void HGraphVisitor::VisitInsertionOrder() {
const ArenaVector<HBasicBlock*>& blocks = graph_->GetBlocks();
for (HBasicBlock* block : blocks) {
if (block != nullptr) {
VisitBasicBlock(block);
}
}
}
void HGraphVisitor::VisitReversePostOrder() {
for (HReversePostOrderIterator it(*graph_); !it.Done(); it.Advance()) {
VisitBasicBlock(it.Current());
}
}
void HGraphVisitor::VisitBasicBlock(HBasicBlock* block) {
for (HInstructionIterator it(block->GetPhis()); !it.Done(); it.Advance()) {
it.Current()->Accept(this);
}
for (HInstructionIterator it(block->GetInstructions()); !it.Done(); it.Advance()) {
it.Current()->Accept(this);
}
}
HConstant* HTypeConversion::TryStaticEvaluation() const {
HGraph* graph = GetBlock()->GetGraph();
if (GetInput()->IsIntConstant()) {
int32_t value = GetInput()->AsIntConstant()->GetValue();
switch (GetResultType()) {
case Primitive::kPrimLong:
return graph->GetLongConstant(static_cast<int64_t>(value), GetDexPc());
case Primitive::kPrimFloat:
return graph->GetFloatConstant(static_cast<float>(value), GetDexPc());
case Primitive::kPrimDouble:
return graph->GetDoubleConstant(static_cast<double>(value), GetDexPc());
default:
return nullptr;
}
} else if (GetInput()->IsLongConstant()) {
int64_t value = GetInput()->AsLongConstant()->GetValue();
switch (GetResultType()) {
case Primitive::kPrimInt:
return graph->GetIntConstant(static_cast<int32_t>(value), GetDexPc());
case Primitive::kPrimFloat:
return graph->GetFloatConstant(static_cast<float>(value), GetDexPc());
case Primitive::kPrimDouble:
return graph->GetDoubleConstant(static_cast<double>(value), GetDexPc());
default:
return nullptr;
}
} else if (GetInput()->IsFloatConstant()) {
float value = GetInput()->AsFloatConstant()->GetValue();
switch (GetResultType()) {
case Primitive::kPrimInt:
if (std::isnan(value))
return graph->GetIntConstant(0, GetDexPc());
if (value >= kPrimIntMax)
return graph->GetIntConstant(kPrimIntMax, GetDexPc());
if (value <= kPrimIntMin)
return graph->GetIntConstant(kPrimIntMin, GetDexPc());
return graph->GetIntConstant(static_cast<int32_t>(value), GetDexPc());
case Primitive::kPrimLong:
if (std::isnan(value))
return graph->GetLongConstant(0, GetDexPc());
if (value >= kPrimLongMax)
return graph->GetLongConstant(kPrimLongMax, GetDexPc());
if (value <= kPrimLongMin)
return graph->GetLongConstant(kPrimLongMin, GetDexPc());
return graph->GetLongConstant(static_cast<int64_t>(value), GetDexPc());
case Primitive::kPrimDouble:
return graph->GetDoubleConstant(static_cast<double>(value), GetDexPc());
default:
return nullptr;
}
} else if (GetInput()->IsDoubleConstant()) {
double value = GetInput()->AsDoubleConstant()->GetValue();
switch (GetResultType()) {
case Primitive::kPrimInt:
if (std::isnan(value))
return graph->GetIntConstant(0, GetDexPc());
if (value >= kPrimIntMax)
return graph->GetIntConstant(kPrimIntMax, GetDexPc());
if (value <= kPrimLongMin)
return graph->GetIntConstant(kPrimIntMin, GetDexPc());
return graph->GetIntConstant(static_cast<int32_t>(value), GetDexPc());
case Primitive::kPrimLong:
if (std::isnan(value))
return graph->GetLongConstant(0, GetDexPc());
if (value >= kPrimLongMax)
return graph->GetLongConstant(kPrimLongMax, GetDexPc());
if (value <= kPrimLongMin)
return graph->GetLongConstant(kPrimLongMin, GetDexPc());
return graph->GetLongConstant(static_cast<int64_t>(value), GetDexPc());
case Primitive::kPrimFloat:
return graph->GetFloatConstant(static_cast<float>(value), GetDexPc());
default:
return nullptr;
}
}
return nullptr;
}
HConstant* HUnaryOperation::TryStaticEvaluation() const {
if (GetInput()->IsIntConstant()) {
return Evaluate(GetInput()->AsIntConstant());
} else if (GetInput()->IsLongConstant()) {
return Evaluate(GetInput()->AsLongConstant());
} else if (kEnableFloatingPointStaticEvaluation) {
if (GetInput()->IsFloatConstant()) {
return Evaluate(GetInput()->AsFloatConstant());
} else if (GetInput()->IsDoubleConstant()) {
return Evaluate(GetInput()->AsDoubleConstant());
}
}
return nullptr;
}
HConstant* HBinaryOperation::TryStaticEvaluation() const {
if (GetLeft()->IsIntConstant() && GetRight()->IsIntConstant()) {
return Evaluate(GetLeft()->AsIntConstant(), GetRight()->AsIntConstant());
} else if (GetLeft()->IsLongConstant()) {
if (GetRight()->IsIntConstant()) {
// The binop(long, int) case is only valid for shifts and rotations.
DCHECK(IsShl() || IsShr() || IsUShr() || IsRor()) << DebugName();
return Evaluate(GetLeft()->AsLongConstant(), GetRight()->AsIntConstant());
} else if (GetRight()->IsLongConstant()) {
return Evaluate(GetLeft()->AsLongConstant(), GetRight()->AsLongConstant());
}
} else if (GetLeft()->IsNullConstant() && GetRight()->IsNullConstant()) {
// The binop(null, null) case is only valid for equal and not-equal conditions.
DCHECK(IsEqual() || IsNotEqual()) << DebugName();
return Evaluate(GetLeft()->AsNullConstant(), GetRight()->AsNullConstant());
} else if (kEnableFloatingPointStaticEvaluation) {
if (GetLeft()->IsFloatConstant() && GetRight()->IsFloatConstant()) {
return Evaluate(GetLeft()->AsFloatConstant(), GetRight()->AsFloatConstant());
} else if (GetLeft()->IsDoubleConstant() && GetRight()->IsDoubleConstant()) {
return Evaluate(GetLeft()->AsDoubleConstant(), GetRight()->AsDoubleConstant());
}
}
return nullptr;
}
HConstant* HBinaryOperation::GetConstantRight() const {
if (GetRight()->IsConstant()) {
return GetRight()->AsConstant();
} else if (IsCommutative() && GetLeft()->IsConstant()) {
return GetLeft()->AsConstant();
} else {
return nullptr;
}
}
// If `GetConstantRight()` returns one of the input, this returns the other
// one. Otherwise it returns null.
HInstruction* HBinaryOperation::GetLeastConstantLeft() const {
HInstruction* most_constant_right = GetConstantRight();
if (most_constant_right == nullptr) {
return nullptr;
} else if (most_constant_right == GetLeft()) {
return GetRight();
} else {
return GetLeft();
}
}
std::ostream& operator<<(std::ostream& os, const ComparisonBias& rhs) {
switch (rhs) {
case ComparisonBias::kNoBias:
return os << "no_bias";
case ComparisonBias::kGtBias:
return os << "gt_bias";
case ComparisonBias::kLtBias:
return os << "lt_bias";
default:
LOG(FATAL) << "Unknown ComparisonBias: " << static_cast<int>(rhs);
UNREACHABLE();
}
}
bool HCondition::IsBeforeWhenDisregardMoves(HInstruction* instruction) const {
return this == instruction->GetPreviousDisregardingMoves();
}
bool HInstruction::Equals(HInstruction* other) const {
if (!InstructionTypeEquals(other)) return false;
DCHECK_EQ(GetKind(), other->GetKind());
if (!InstructionDataEquals(other)) return false;
if (GetType() != other->GetType()) return false;
if (InputCount() != other->InputCount()) return false;
for (size_t i = 0, e = InputCount(); i < e; ++i) {
if (InputAt(i) != other->InputAt(i)) return false;
}
DCHECK_EQ(ComputeHashCode(), other->ComputeHashCode());
return true;
}
std::ostream& operator<<(std::ostream& os, const HInstruction::InstructionKind& rhs) {
#define DECLARE_CASE(type, super) case HInstruction::k##type: os << #type; break;
switch (rhs) {
FOR_EACH_INSTRUCTION(DECLARE_CASE)
default:
os << "Unknown instruction kind " << static_cast<int>(rhs);
break;
}
#undef DECLARE_CASE
return os;
}
void HInstruction::MoveBefore(HInstruction* cursor) {
next_->previous_ = previous_;
if (previous_ != nullptr) {
previous_->next_ = next_;
}
if (block_->instructions_.first_instruction_ == this) {
block_->instructions_.first_instruction_ = next_;
}
DCHECK_NE(block_->instructions_.last_instruction_, this);
previous_ = cursor->previous_;
if (previous_ != nullptr) {
previous_->next_ = this;
}
next_ = cursor;
cursor->previous_ = this;
block_ = cursor->block_;
if (block_->instructions_.first_instruction_ == cursor) {
block_->instructions_.first_instruction_ = this;
}
}
void HInstruction::MoveBeforeFirstUserAndOutOfLoops() {
DCHECK(!CanThrow());
DCHECK(!HasSideEffects());
DCHECK(!HasEnvironmentUses());
DCHECK(HasNonEnvironmentUses());
DCHECK(!IsPhi()); // Makes no sense for Phi.
DCHECK_EQ(InputCount(), 0u);
// Find the target block.
HUseIterator<HInstruction*> uses_it(GetUses());
HBasicBlock* target_block = uses_it.Current()->GetUser()->GetBlock();
uses_it.Advance();
while (!uses_it.Done() && uses_it.Current()->GetUser()->GetBlock() == target_block) {
uses_it.Advance();
}
if (!uses_it.Done()) {
// This instruction has uses in two or more blocks. Find the common dominator.
CommonDominator finder(target_block);
for (; !uses_it.Done(); uses_it.Advance()) {
finder.Update(uses_it.Current()->GetUser()->GetBlock());
}
target_block = finder.Get();
DCHECK(target_block != nullptr);
}
// Move to the first dominator not in a loop.
while (target_block->IsInLoop()) {
target_block = target_block->GetDominator();
DCHECK(target_block != nullptr);
}
// Find insertion position.
HInstruction* insert_pos = nullptr;
for (HUseIterator<HInstruction*> uses_it2(GetUses()); !uses_it2.Done(); uses_it2.Advance()) {
if (uses_it2.Current()->GetUser()->GetBlock() == target_block &&
(insert_pos == nullptr || uses_it2.Current()->GetUser()->StrictlyDominates(insert_pos))) {
insert_pos = uses_it2.Current()->GetUser();
}
}
if (insert_pos == nullptr) {
// No user in `target_block`, insert before the control flow instruction.
insert_pos = target_block->GetLastInstruction();
DCHECK(insert_pos->IsControlFlow());
// Avoid splitting HCondition from HIf to prevent unnecessary materialization.
if (insert_pos->IsIf()) {
HInstruction* if_input = insert_pos->AsIf()->InputAt(0);
if (if_input == insert_pos->GetPrevious()) {
insert_pos = if_input;
}
}
}
MoveBefore(insert_pos);
}
HBasicBlock* HBasicBlock::SplitBefore(HInstruction* cursor) {
DCHECK(!graph_->IsInSsaForm()) << "Support for SSA form not implemented.";
DCHECK_EQ(cursor->GetBlock(), this);
HBasicBlock* new_block = new (GetGraph()->GetArena()) HBasicBlock(GetGraph(),
cursor->GetDexPc());
new_block->instructions_.first_instruction_ = cursor;
new_block->instructions_.last_instruction_ = instructions_.last_instruction_;
instructions_.last_instruction_ = cursor->previous_;
if (cursor->previous_ == nullptr) {
instructions_.first_instruction_ = nullptr;
} else {
cursor->previous_->next_ = nullptr;
cursor->previous_ = nullptr;
}
new_block->instructions_.SetBlockOfInstructions(new_block);
AddInstruction(new (GetGraph()->GetArena()) HGoto(new_block->GetDexPc()));
for (HBasicBlock* successor : GetSuccessors()) {
new_block->successors_.push_back(successor);
successor->predecessors_[successor->GetPredecessorIndexOf(this)] = new_block;
}
successors_.clear();
AddSuccessor(new_block);
GetGraph()->AddBlock(new_block);
return new_block;
}
HBasicBlock* HBasicBlock::CreateImmediateDominator() {
DCHECK(!graph_->IsInSsaForm()) << "Support for SSA form not implemented.";
DCHECK(!IsCatchBlock()) << "Support for updating try/catch information not implemented.";
HBasicBlock* new_block = new (GetGraph()->GetArena()) HBasicBlock(GetGraph(), GetDexPc());
for (HBasicBlock* predecessor : GetPredecessors()) {
new_block->predecessors_.push_back(predecessor);
predecessor->successors_[predecessor->GetSuccessorIndexOf(this)] = new_block;
}
predecessors_.clear();
AddPredecessor(new_block);
GetGraph()->AddBlock(new_block);
return new_block;
}
HBasicBlock* HBasicBlock::SplitBeforeForInlining(HInstruction* cursor) {
DCHECK_EQ(cursor->GetBlock(), this);
HBasicBlock* new_block = new (GetGraph()->GetArena()) HBasicBlock(GetGraph(),
cursor->GetDexPc());
new_block->instructions_.first_instruction_ = cursor;
new_block->instructions_.last_instruction_ = instructions_.last_instruction_;
instructions_.last_instruction_ = cursor->previous_;
if (cursor->previous_ == nullptr) {
instructions_.first_instruction_ = nullptr;
} else {
cursor->previous_->next_ = nullptr;
cursor->previous_ = nullptr;
}
new_block->instructions_.SetBlockOfInstructions(new_block);
for (HBasicBlock* successor : GetSuccessors()) {
new_block->successors_.push_back(successor);
successor->predecessors_[successor->GetPredecessorIndexOf(this)] = new_block;
}
successors_.clear();
for (HBasicBlock* dominated : GetDominatedBlocks()) {
dominated->dominator_ = new_block;
new_block->dominated_blocks_.push_back(dominated);
}
dominated_blocks_.clear();
return new_block;
}
HBasicBlock* HBasicBlock::SplitAfterForInlining(HInstruction* cursor) {
DCHECK(!cursor->IsControlFlow());
DCHECK_NE(instructions_.last_instruction_, cursor);
DCHECK_EQ(cursor->GetBlock(), this);
HBasicBlock* new_block = new (GetGraph()->GetArena()) HBasicBlock(GetGraph(), GetDexPc());
new_block->instructions_.first_instruction_ = cursor->GetNext();
new_block->instructions_.last_instruction_ = instructions_.last_instruction_;
cursor->next_->previous_ = nullptr;
cursor->next_ = nullptr;
instructions_.last_instruction_ = cursor;
new_block->instructions_.SetBlockOfInstructions(new_block);
for (HBasicBlock* successor : GetSuccessors()) {
new_block->successors_.push_back(successor);
successor->predecessors_[successor->GetPredecessorIndexOf(this)] = new_block;
}
successors_.clear();
for (HBasicBlock* dominated : GetDominatedBlocks()) {
dominated->dominator_ = new_block;
new_block->dominated_blocks_.push_back(dominated);
}
dominated_blocks_.clear();
return new_block;
}
const HTryBoundary* HBasicBlock::ComputeTryEntryOfSuccessors() const {
if (EndsWithTryBoundary()) {
HTryBoundary* try_boundary = GetLastInstruction()->AsTryBoundary();
if (try_boundary->IsEntry()) {
DCHECK(!IsTryBlock());
return try_boundary;
} else {
DCHECK(IsTryBlock());
DCHECK(try_catch_information_->GetTryEntry().HasSameExceptionHandlersAs(*try_boundary));
return nullptr;
}
} else if (IsTryBlock()) {
return &try_catch_information_->GetTryEntry();
} else {
return nullptr;
}
}
bool HBasicBlock::HasThrowingInstructions() const {
for (HInstructionIterator it(GetInstructions()); !it.Done(); it.Advance()) {
if (it.Current()->CanThrow()) {
return true;
}
}
return false;
}
static bool HasOnlyOneInstruction(const HBasicBlock& block) {
return block.GetPhis().IsEmpty()
&& !block.GetInstructions().IsEmpty()
&& block.GetFirstInstruction() == block.GetLastInstruction();
}
bool HBasicBlock::IsSingleGoto() const {
return HasOnlyOneInstruction(*this) && GetLastInstruction()->IsGoto();
}
bool HBasicBlock::IsSingleTryBoundary() const {
return HasOnlyOneInstruction(*this) && GetLastInstruction()->IsTryBoundary();
}
bool HBasicBlock::EndsWithControlFlowInstruction() const {
return !GetInstructions().IsEmpty() && GetLastInstruction()->IsControlFlow();
}
bool HBasicBlock::EndsWithIf() const {
return !GetInstructions().IsEmpty() && GetLastInstruction()->IsIf();
}
bool HBasicBlock::EndsWithTryBoundary() const {
return !GetInstructions().IsEmpty() && GetLastInstruction()->IsTryBoundary();
}
bool HBasicBlock::HasSinglePhi() const {
return !GetPhis().IsEmpty() && GetFirstPhi()->GetNext() == nullptr;
}
ArrayRef<HBasicBlock* const> HBasicBlock::GetNormalSuccessors() const {
if (EndsWithTryBoundary()) {
// The normal-flow successor of HTryBoundary is always stored at index zero.
DCHECK_EQ(successors_[0], GetLastInstruction()->AsTryBoundary()->GetNormalFlowSuccessor());
return ArrayRef<HBasicBlock* const>(successors_).SubArray(0u, 1u);
} else {
// All successors of blocks not ending with TryBoundary are normal.
return ArrayRef<HBasicBlock* const>(successors_);
}
}
ArrayRef<HBasicBlock* const> HBasicBlock::GetExceptionalSuccessors() const {
if (EndsWithTryBoundary()) {
return GetLastInstruction()->AsTryBoundary()->GetExceptionHandlers();
} else {
// Blocks not ending with TryBoundary do not have exceptional successors.
return ArrayRef<HBasicBlock* const>();
}
}
bool HTryBoundary::HasSameExceptionHandlersAs(const HTryBoundary& other) const {
ArrayRef<HBasicBlock* const> handlers1 = GetExceptionHandlers();
ArrayRef<HBasicBlock* const> handlers2 = other.GetExceptionHandlers();
size_t length = handlers1.size();
if (length != handlers2.size()) {
return false;
}
// Exception handlers need to be stored in the same order.
for (size_t i = 0; i < length; ++i) {
if (handlers1[i] != handlers2[i]) {
return false;
}
}
return true;
}
size_t HInstructionList::CountSize() const {
size_t size = 0;
HInstruction* current = first_instruction_;
for (; current != nullptr; current = current->GetNext()) {
size++;
}
return size;
}
void HInstructionList::SetBlockOfInstructions(HBasicBlock* block) const {
for (HInstruction* current = first_instruction_;
current != nullptr;
current = current->GetNext()) {
current->SetBlock(block);
}
}
void HInstructionList::AddAfter(HInstruction* cursor, const HInstructionList& instruction_list) {
DCHECK(Contains(cursor));
if (!instruction_list.IsEmpty()) {
if (cursor == last_instruction_) {
last_instruction_ = instruction_list.last_instruction_;
} else {
cursor->next_->previous_ = instruction_list.last_instruction_;
}
instruction_list.last_instruction_->next_ = cursor->next_;
cursor->next_ = instruction_list.first_instruction_;
instruction_list.first_instruction_->previous_ = cursor;
}
}
void HInstructionList::AddBefore(HInstruction* cursor, const HInstructionList& instruction_list) {
DCHECK(Contains(cursor));
if (!instruction_list.IsEmpty()) {
if (cursor == first_instruction_) {
first_instruction_ = instruction_list.first_instruction_;
} else {
cursor->previous_->next_ = instruction_list.first_instruction_;
}
instruction_list.last_instruction_->next_ = cursor;
instruction_list.first_instruction_->previous_ = cursor->previous_;
cursor->previous_ = instruction_list.last_instruction_;
}
}
void HInstructionList::Add(const HInstructionList& instruction_list) {
if (IsEmpty()) {
first_instruction_ = instruction_list.first_instruction_;
last_instruction_ = instruction_list.last_instruction_;
} else {
AddAfter(last_instruction_, instruction_list);
}
}
// Should be called on instructions in a dead block in post order. This method
// assumes `insn` has been removed from all users with the exception of catch
// phis because of missing exceptional edges in the graph. It removes the
// instruction from catch phi uses, together with inputs of other catch phis in
// the catch block at the same index, as these must be dead too.
static void RemoveUsesOfDeadInstruction(HInstruction* insn) {
DCHECK(!insn->HasEnvironmentUses());
while (insn->HasNonEnvironmentUses()) {
HUseListNode<HInstruction*>* use = insn->GetUses().GetFirst();
size_t use_index = use->GetIndex();
HBasicBlock* user_block = use->GetUser()->GetBlock();
DCHECK(use->GetUser()->IsPhi() && user_block->IsCatchBlock());
for (HInstructionIterator phi_it(user_block->GetPhis()); !phi_it.Done(); phi_it.Advance()) {
phi_it.Current()->AsPhi()->RemoveInputAt(use_index);
}
}
}
void HBasicBlock::DisconnectAndDelete() {
// Dominators must be removed after all the blocks they dominate. This way
// a loop header is removed last, a requirement for correct loop information
// iteration.
DCHECK(dominated_blocks_.empty());
// The following steps gradually remove the block from all its dependants in
// post order (b/27683071).
// (1) Store a basic block that we'll use in step (5) to find loops to be updated.
// We need to do this before step (4) which destroys the predecessor list.
HBasicBlock* loop_update_start = this;
if (IsLoopHeader()) {
HLoopInformation* loop_info = GetLoopInformation();
// All other blocks in this loop should have been removed because the header
// was their dominator.
// Note that we do not remove `this` from `loop_info` as it is unreachable.
DCHECK(!loop_info->IsIrreducible());
DCHECK_EQ(loop_info->GetBlocks().NumSetBits(), 1u);
DCHECK_EQ(static_cast<uint32_t>(loop_info->GetBlocks().GetHighestBitSet()), GetBlockId());
loop_update_start = loop_info->GetPreHeader();
}
// (2) Disconnect the block from its successors and update their phis.
for (HBasicBlock* successor : successors_) {
// Delete this block from the list of predecessors.
size_t this_index = successor->GetPredecessorIndexOf(this);
successor->predecessors_.erase(successor->predecessors_.begin() + this_index);
// Check that `successor` has other predecessors, otherwise `this` is the
// dominator of `successor` which violates the order DCHECKed at the top.
DCHECK(!successor->predecessors_.empty());
// Remove this block's entries in the successor's phis. Skip exceptional
// successors because catch phi inputs do not correspond to predecessor
// blocks but throwing instructions. The inputs of the catch phis will be
// updated in step (3).
if (!successor->IsCatchBlock()) {
if (successor->predecessors_.size() == 1u) {
// The successor has just one predecessor left. Replace phis with the only
// remaining input.
for (HInstructionIterator phi_it(successor->GetPhis()); !phi_it.Done(); phi_it.Advance()) {
HPhi* phi = phi_it.Current()->AsPhi();
phi->ReplaceWith(phi->InputAt(1 - this_index));
successor->RemovePhi(phi);
}
} else {
for (HInstructionIterator phi_it(successor->GetPhis()); !phi_it.Done(); phi_it.Advance()) {
phi_it.Current()->AsPhi()->RemoveInputAt(this_index);
}
}
}
}
successors_.clear();
// (3) Remove instructions and phis. Instructions should have no remaining uses
// except in catch phis. If an instruction is used by a catch phi at `index`,
// remove `index`-th input of all phis in the catch block since they are
// guaranteed dead. Note that we may miss dead inputs this way but the
// graph will always remain consistent.
for (HBackwardInstructionIterator it(GetInstructions()); !it.Done(); it.Advance()) {
HInstruction* insn = it.Current();
RemoveUsesOfDeadInstruction(insn);
RemoveInstruction(insn);
}
for (HInstructionIterator it(GetPhis()); !it.Done(); it.Advance()) {
HPhi* insn = it.Current()->AsPhi();
RemoveUsesOfDeadInstruction(insn);
RemovePhi(insn);
}
// (4) Disconnect the block from its predecessors and update their
// control-flow instructions.
for (HBasicBlock* predecessor : predecessors_) {
// We should not see any back edges as they would have been removed by step (3).
DCHECK(!IsInLoop() || !GetLoopInformation()->IsBackEdge(*predecessor));
HInstruction* last_instruction = predecessor->GetLastInstruction();
if (last_instruction->IsTryBoundary() && !IsCatchBlock()) {
// This block is the only normal-flow successor of the TryBoundary which
// makes `predecessor` dead. Since DCE removes blocks in post order,
// exception handlers of this TryBoundary were already visited and any
// remaining handlers therefore must be live. We remove `predecessor` from
// their list of predecessors.
DCHECK_EQ(last_instruction->AsTryBoundary()->GetNormalFlowSuccessor(), this);
while (predecessor->GetSuccessors().size() > 1) {
HBasicBlock* handler = predecessor->GetSuccessors()[1];
DCHECK(handler->IsCatchBlock());
predecessor->RemoveSuccessor(handler);
handler->RemovePredecessor(predecessor);
}
}
predecessor->RemoveSuccessor(this);
uint32_t num_pred_successors = predecessor->GetSuccessors().size();
if (num_pred_successors == 1u) {
// If we have one successor after removing one, then we must have
// had an HIf, HPackedSwitch or HTryBoundary, as they have more than one
// successor. Replace those with a HGoto.
DCHECK(last_instruction->IsIf() ||
last_instruction->IsPackedSwitch() ||
(last_instruction->IsTryBoundary() && IsCatchBlock()));
predecessor->RemoveInstruction(last_instruction);
predecessor->AddInstruction(new (graph_->GetArena()) HGoto(last_instruction->GetDexPc()));
} else if (num_pred_successors == 0u) {
// The predecessor has no remaining successors and therefore must be dead.
// We deliberately leave it without a control-flow instruction so that the
// GraphChecker fails unless it is not removed during the pass too.
predecessor->RemoveInstruction(last_instruction);
} else {
// There are multiple successors left. The removed block might be a successor
// of a PackedSwitch which will be completely removed (perhaps replaced with
// a Goto), or we are deleting a catch block from a TryBoundary. In either
// case, leave `last_instruction` as is for now.
DCHECK(last_instruction->IsPackedSwitch() ||
(last_instruction->IsTryBoundary() && IsCatchBlock()));
}
}
predecessors_.clear();
// (5) Remove the block from all loops it is included in. Skip the inner-most
// loop if this is the loop header (see definition of `loop_update_start`)
// because the loop header's predecessor list has been destroyed in step (4).
for (HLoopInformationOutwardIterator it(*loop_update_start); !it.Done(); it.Advance()) {
HLoopInformation* loop_info = it.Current();
loop_info->Remove(this);
if (loop_info->IsBackEdge(*this)) {
// If this was the last back edge of the loop, we deliberately leave the
// loop in an inconsistent state and will fail GraphChecker unless the
// entire loop is removed during the pass.
loop_info->RemoveBackEdge(this);
}
}
// (6) Disconnect from the dominator.
dominator_->RemoveDominatedBlock(this);
SetDominator(nullptr);
// (7) Delete from the graph, update reverse post order.
graph_->DeleteDeadEmptyBlock(this);
SetGraph(nullptr);
}
void HBasicBlock::MergeWith(HBasicBlock* other) {
DCHECK_EQ(GetGraph(), other->GetGraph());
DCHECK(ContainsElement(dominated_blocks_, other));
DCHECK_EQ(GetSingleSuccessor(), other);
DCHECK_EQ(other->GetSinglePredecessor(), this);
DCHECK(other->GetPhis().IsEmpty());
// Move instructions from `other` to `this`.
DCHECK(EndsWithControlFlowInstruction());
RemoveInstruction(GetLastInstruction());
instructions_.Add(other->GetInstructions());
other->instructions_.SetBlockOfInstructions(this);
other->instructions_.Clear();
// Remove `other` from the loops it is included in.
for (HLoopInformationOutwardIterator it(*other); !it.Done(); it.Advance()) {
HLoopInformation* loop_info = it.Current();
loop_info->Remove(other);
if (loop_info->IsBackEdge(*other)) {
loop_info->ReplaceBackEdge(other, this);
}
}
// Update links to the successors of `other`.
successors_.clear();
while (!other->successors_.empty()) {
HBasicBlock* successor = other->GetSuccessors()[0];
successor->ReplacePredecessor(other, this);
}
// Update the dominator tree.
RemoveDominatedBlock(other);
for (HBasicBlock* dominated : other->GetDominatedBlocks()) {
dominated_blocks_.push_back(dominated);
dominated->SetDominator(this);
}
other->dominated_blocks_.clear();
other->dominator_ = nullptr;
// Clear the list of predecessors of `other` in preparation of deleting it.
other->predecessors_.clear();
// Delete `other` from the graph. The function updates reverse post order.
graph_->DeleteDeadEmptyBlock(other);
other->SetGraph(nullptr);
}
void HBasicBlock::MergeWithInlined(HBasicBlock* other) {
DCHECK_NE(GetGraph(), other->GetGraph());
DCHECK(GetDominatedBlocks().empty());
DCHECK(GetSuccessors().empty());
DCHECK(!EndsWithControlFlowInstruction());
DCHECK(other->GetSinglePredecessor()->IsEntryBlock());
DCHECK(other->GetPhis().IsEmpty());
DCHECK(!other->IsInLoop());
// Move instructions from `other` to `this`.
instructions_.Add(other->GetInstructions());
other->instructions_.SetBlockOfInstructions(this);
// Update links to the successors of `other`.
successors_.clear();
while (!other->successors_.empty()) {
HBasicBlock* successor = other->GetSuccessors()[0];
successor->ReplacePredecessor(other, this);
}
// Update the dominator tree.
for (HBasicBlock* dominated : other->GetDominatedBlocks()) {
dominated_blocks_.push_back(dominated);
dominated->SetDominator(this);
}
other->dominated_blocks_.clear();
other->dominator_ = nullptr;
other->graph_ = nullptr;
}
void HBasicBlock::ReplaceWith(HBasicBlock* other) {
while (!GetPredecessors().empty()) {
HBasicBlock* predecessor = GetPredecessors()[0];
predecessor->ReplaceSuccessor(this, other);
}
while (!GetSuccessors().empty()) {
HBasicBlock* successor = GetSuccessors()[0];
successor->ReplacePredecessor(this, other);
}
for (HBasicBlock* dominated : GetDominatedBlocks()) {
other->AddDominatedBlock(dominated);
}
GetDominator()->ReplaceDominatedBlock(this, other);
other->SetDominator(GetDominator());
dominator_ = nullptr;
graph_ = nullptr;
}
void HGraph::DeleteDeadEmptyBlock(HBasicBlock* block) {
DCHECK_EQ(block->GetGraph(), this);
DCHECK(block->GetSuccessors().empty());
DCHECK(block->GetPredecessors().empty());
DCHECK(block->GetDominatedBlocks().empty());
DCHECK(block->GetDominator() == nullptr);
DCHECK(block->GetInstructions().IsEmpty());
DCHECK(block->GetPhis().IsEmpty());
if (block->IsExitBlock()) {
SetExitBlock(nullptr);
}
RemoveElement(reverse_post_order_, block);
blocks_[block->GetBlockId()] = nullptr;
block->SetGraph(nullptr);
}
void HGraph::UpdateLoopAndTryInformationOfNewBlock(HBasicBlock* block,
HBasicBlock* reference,
bool replace_if_back_edge) {
if (block->IsLoopHeader()) {
// Clear the information of which blocks are contained in that loop. Since the
// information is stored as a bit vector based on block ids, we have to update
// it, as those block ids were specific to the callee graph and we are now adding
// these blocks to the caller graph.
block->GetLoopInformation()->ClearAllBlocks();
}
// If not already in a loop, update the loop information.
if (!block->IsInLoop()) {
block->SetLoopInformation(reference->GetLoopInformation());
}
// If the block is in a loop, update all its outward loops.
HLoopInformation* loop_info = block->GetLoopInformation();
if (loop_info != nullptr) {
for (HLoopInformationOutwardIterator loop_it(*block);
!loop_it.Done();
loop_it.Advance()) {
loop_it.Current()->Add(block);
}
if (replace_if_back_edge && loop_info->IsBackEdge(*reference)) {
loop_info->ReplaceBackEdge(reference, block);
}
}
// Copy TryCatchInformation if `reference` is a try block, not if it is a catch block.
TryCatchInformation* try_catch_info = reference->IsTryBlock()
? reference->GetTryCatchInformation()
: nullptr;
block->SetTryCatchInformation(try_catch_info);
}
HInstruction* HGraph::InlineInto(HGraph* outer_graph, HInvoke* invoke) {
DCHECK(HasExitBlock()) << "Unimplemented scenario";
// Update the environments in this graph to have the invoke's environment
// as parent.
{
HReversePostOrderIterator it(*this);
it.Advance(); // Skip the entry block, we do not need to update the entry's suspend check.
for (; !it.Done(); it.Advance()) {
HBasicBlock* block = it.Current();
for (HInstructionIterator instr_it(block->GetInstructions());
!instr_it.Done();
instr_it.Advance()) {
HInstruction* current = instr_it.Current();
if (current->NeedsEnvironment()) {
DCHECK(current->HasEnvironment());
current->GetEnvironment()->SetAndCopyParentChain(
outer_graph->GetArena(), invoke->GetEnvironment());
}
}
}
}
outer_graph->UpdateMaximumNumberOfOutVRegs(GetMaximumNumberOfOutVRegs());
if (HasBoundsChecks()) {
outer_graph->SetHasBoundsChecks(true);
}
HInstruction* return_value = nullptr;
if (GetBlocks().size() == 3) {
// Simple case of an entry block, a body block, and an exit block.
// Put the body block's instruction into `invoke`'s block.
HBasicBlock* body = GetBlocks()[1];
DCHECK(GetBlocks()[0]->IsEntryBlock());
DCHECK(GetBlocks()[2]->IsExitBlock());
DCHECK(!body->IsExitBlock());
DCHECK(!body->IsInLoop());
HInstruction* last = body->GetLastInstruction();
// Note that we add instructions before the invoke only to simplify polymorphic inlining.
invoke->GetBlock()->instructions_.AddBefore(invoke, body->GetInstructions());
body->GetInstructions().SetBlockOfInstructions(invoke->GetBlock());
// Replace the invoke with the return value of the inlined graph.
if (last->IsReturn()) {
return_value = last->InputAt(0);
} else {
DCHECK(last->IsReturnVoid());
}
invoke->GetBlock()->RemoveInstruction(last);
} else {
// Need to inline multiple blocks. We split `invoke`'s block
// into two blocks, merge the first block of the inlined graph into
// the first half, and replace the exit block of the inlined graph
// with the second half.
ArenaAllocator* allocator = outer_graph->GetArena();
HBasicBlock* at = invoke->GetBlock();
// Note that we split before the invoke only to simplify polymorphic inlining.
HBasicBlock* to = at->SplitBeforeForInlining(invoke);
HBasicBlock* first = entry_block_->GetSuccessors()[0];
DCHECK(!first->IsInLoop());
at->MergeWithInlined(first);
exit_block_->ReplaceWith(to);
// Update the meta information surrounding blocks:
// (1) the graph they are now in,
// (2) the reverse post order of that graph,
// (3) their potential loop information, inner and outer,
// (4) try block membership.
// Note that we do not need to update catch phi inputs because they
// correspond to the register file of the outer method which the inlinee
// cannot modify.
// We don't add the entry block, the exit block, and the first block, which
// has been merged with `at`.
static constexpr int kNumberOfSkippedBlocksInCallee = 3;
// We add the `to` block.
static constexpr int kNumberOfNewBlocksInCaller = 1;
size_t blocks_added = (reverse_post_order_.size() - kNumberOfSkippedBlocksInCallee)
+ kNumberOfNewBlocksInCaller;
// Find the location of `at` in the outer graph's reverse post order. The new
// blocks will be added after it.
size_t index_of_at = IndexOfElement(outer_graph->reverse_post_order_, at);
MakeRoomFor(&outer_graph->reverse_post_order_, blocks_added, index_of_at);
// Do a reverse post order of the blocks in the callee and do (1), (2), (3)
// and (4) to the blocks that apply.
for (HReversePostOrderIterator it(*this); !it.Done(); it.Advance()) {
HBasicBlock* current = it.Current();
if (current != exit_block_ && current != entry_block_ && current != first) {
DCHECK(current->GetTryCatchInformation() == nullptr);
DCHECK(current->GetGraph() == this);
current->SetGraph(outer_graph);
outer_graph->AddBlock(current);
outer_graph->reverse_post_order_[++index_of_at] = current;
UpdateLoopAndTryInformationOfNewBlock(current, at, /* replace_if_back_edge */ false);
}
}
// Do (1), (2), (3) and (4) to `to`.
to->SetGraph(outer_graph);
outer_graph->AddBlock(to);
outer_graph->reverse_post_order_[++index_of_at] = to;
// Only `to` can become a back edge, as the inlined blocks
// are predecessors of `to`.
UpdateLoopAndTryInformationOfNewBlock(to, at, /* replace_if_back_edge */ true);
// Update all predecessors of the exit block (now the `to` block)
// to not `HReturn` but `HGoto` instead.
bool returns_void = to->GetPredecessors()[0]->GetLastInstruction()->IsReturnVoid();
if (to->GetPredecessors().size() == 1) {
HBasicBlock* predecessor = to->GetPredecessors()[0];
HInstruction* last = predecessor->GetLastInstruction();
if (!returns_void) {
return_value = last->InputAt(0);
}
predecessor->AddInstruction(new (allocator) HGoto(last->GetDexPc()));
predecessor->RemoveInstruction(last);
} else {
if (!returns_void) {
// There will be multiple returns.
return_value = new (allocator) HPhi(
allocator, kNoRegNumber, 0, HPhi::ToPhiType(invoke->GetType()), to->GetDexPc());
to->AddPhi(return_value->AsPhi());
}
for (HBasicBlock* predecessor : to->GetPredecessors()) {
HInstruction* last = predecessor->GetLastInstruction();
if (!returns_void) {
DCHECK(last->IsReturn());
return_value->AsPhi()->AddInput(last->InputAt(0));
}
predecessor->AddInstruction(new (allocator) HGoto(last->GetDexPc()));
predecessor->RemoveInstruction(last);
}
}
}
// Walk over the entry block and:
// - Move constants from the entry block to the outer_graph's entry block,
// - Replace HParameterValue instructions with their real value.
// - Remove suspend checks, that hold an environment.
// We must do this after the other blocks have been inlined, otherwise ids of
// constants could overlap with the inner graph.
size_t parameter_index = 0;
for (HInstructionIterator it(entry_block_->GetInstructions()); !it.Done(); it.Advance()) {
HInstruction* current = it.Current();
HInstruction* replacement = nullptr;
if (current->IsNullConstant()) {
replacement = outer_graph->GetNullConstant(current->GetDexPc());
} else if (current->IsIntConstant()) {
replacement = outer_graph->GetIntConstant(
current->AsIntConstant()->GetValue(), current->GetDexPc());
} else if (current->IsLongConstant()) {
replacement = outer_graph->GetLongConstant(
current->AsLongConstant()->GetValue(), current->GetDexPc());
} else if (current->IsFloatConstant()) {
replacement = outer_graph->GetFloatConstant(
current->AsFloatConstant()->GetValue(), current->GetDexPc());
} else if (current->IsDoubleConstant()) {
replacement = outer_graph->GetDoubleConstant(
current->AsDoubleConstant()->GetValue(), current->GetDexPc());
} else if (current->IsParameterValue()) {
if (kIsDebugBuild
&& invoke->IsInvokeStaticOrDirect()
&& invoke->AsInvokeStaticOrDirect()->IsStaticWithExplicitClinitCheck()) {
// Ensure we do not use the last input of `invoke`, as it
// contains a clinit check which is not an actual argument.
size_t last_input_index = invoke->InputCount() - 1;
DCHECK(parameter_index != last_input_index);
}
replacement = invoke->InputAt(parameter_index++);
} else if (current->IsCurrentMethod()) {
replacement = outer_graph->GetCurrentMethod();
} else {
DCHECK(current->IsGoto() || current->IsSuspendCheck());
entry_block_->RemoveInstruction(current);
}
if (replacement != nullptr) {
current->ReplaceWith(replacement);
// If the current is the return value then we need to update the latter.
if (current == return_value) {
DCHECK_EQ(entry_block_, return_value->GetBlock());
return_value = replacement;
}
}
}
return return_value;
}
/*
* Loop will be transformed to:
* old_pre_header
* |
* if_block
* / \
* true_block false_block
* \ /
* new_pre_header
* |
* header
*/
void HGraph::TransformLoopHeaderForBCE(HBasicBlock* header) {
DCHECK(header->IsLoopHeader());
HBasicBlock* old_pre_header = header->GetDominator();
// Need extra block to avoid critical edge.
HBasicBlock* if_block = new (arena_) HBasicBlock(this, header->GetDexPc());
HBasicBlock* true_block = new (arena_) HBasicBlock(this, header->GetDexPc());
HBasicBlock* false_block = new (arena_) HBasicBlock(this, header->GetDexPc());
HBasicBlock* new_pre_header = new (arena_) HBasicBlock(this, header->GetDexPc());
AddBlock(if_block);
AddBlock(true_block);
AddBlock(false_block);
AddBlock(new_pre_header);
header->ReplacePredecessor(old_pre_header, new_pre_header);
old_pre_header->successors_.clear();
old_pre_header->dominated_blocks_.clear();
old_pre_header->AddSuccessor(if_block);
if_block->AddSuccessor(true_block); // True successor
if_block->AddSuccessor(false_block); // False successor
true_block->AddSuccessor(new_pre_header);
false_block->AddSuccessor(new_pre_header);
old_pre_header->dominated_blocks_.push_back(if_block);
if_block->SetDominator(old_pre_header);
if_block->dominated_blocks_.push_back(true_block);
true_block->SetDominator(if_block);
if_block->dominated_blocks_.push_back(false_block);
false_block->SetDominator(if_block);
if_block->dominated_blocks_.push_back(new_pre_header);
new_pre_header->SetDominator(if_block);
new_pre_header->dominated_blocks_.push_back(header);
header->SetDominator(new_pre_header);
// Fix reverse post order.
size_t index_of_header = IndexOfElement(reverse_post_order_, header);
MakeRoomFor(&reverse_post_order_, 4, index_of_header - 1);
reverse_post_order_[index_of_header++] = if_block;
reverse_post_order_[index_of_header++] = true_block;
reverse_post_order_[index_of_header++] = false_block;
reverse_post_order_[index_of_header++] = new_pre_header;
// The pre_header can never be a back edge of a loop.
DCHECK((old_pre_header->GetLoopInformation() == nullptr) ||
!old_pre_header->GetLoopInformation()->IsBackEdge(*old_pre_header));
UpdateLoopAndTryInformationOfNewBlock(
if_block, old_pre_header, /* replace_if_back_edge */ false);
UpdateLoopAndTryInformationOfNewBlock(
true_block, old_pre_header, /* replace_if_back_edge */ false);
UpdateLoopAndTryInformationOfNewBlock(
false_block, old_pre_header, /* replace_if_back_edge */ false);
UpdateLoopAndTryInformationOfNewBlock(
new_pre_header, old_pre_header, /* replace_if_back_edge */ false);
}
static void CheckAgainstUpperBound(ReferenceTypeInfo rti, ReferenceTypeInfo upper_bound_rti)
SHARED_REQUIRES(Locks::mutator_lock_) {
if (rti.IsValid()) {
DCHECK(upper_bound_rti.IsSupertypeOf(rti))
<< " upper_bound_rti: " << upper_bound_rti
<< " rti: " << rti;
DCHECK(!upper_bound_rti.GetTypeHandle()->CannotBeAssignedFromOtherTypes() || rti.IsExact())
<< " upper_bound_rti: " << upper_bound_rti
<< " rti: " << rti;
}
}
void HInstruction::SetReferenceTypeInfo(ReferenceTypeInfo rti) {
if (kIsDebugBuild) {
DCHECK_EQ(GetType(), Primitive::kPrimNot);
ScopedObjectAccess soa(Thread::Current());
DCHECK(rti.IsValid()) << "Invalid RTI for " << DebugName();
if (IsBoundType()) {
// Having the test here spares us from making the method virtual just for
// the sake of a DCHECK.
CheckAgainstUpperBound(rti, AsBoundType()->GetUpperBound());
}
}
reference_type_handle_ = rti.GetTypeHandle();
SetPackedFlag<kFlagReferenceTypeIsExact>(rti.IsExact());
}
void HBoundType::SetUpperBound(const ReferenceTypeInfo& upper_bound, bool can_be_null) {
if (kIsDebugBuild) {
ScopedObjectAccess soa(Thread::Current());
DCHECK(upper_bound.IsValid());
DCHECK(!upper_bound_.IsValid()) << "Upper bound should only be set once.";
CheckAgainstUpperBound(GetReferenceTypeInfo(), upper_bound);
}
upper_bound_ = upper_bound;
SetPackedFlag<kFlagUpperCanBeNull>(can_be_null);
}
ReferenceTypeInfo ReferenceTypeInfo::Create(TypeHandle type_handle, bool is_exact) {
if (kIsDebugBuild) {
ScopedObjectAccess soa(Thread::Current());
DCHECK(IsValidHandle(type_handle));
DCHECK(!type_handle->IsErroneous());
if (!is_exact) {
DCHECK(!type_handle->CannotBeAssignedFromOtherTypes())
<< "Callers of ReferenceTypeInfo::Create should ensure is_exact is properly computed";
}
}
return ReferenceTypeInfo(type_handle, is_exact);
}
std::ostream& operator<<(std::ostream& os, const ReferenceTypeInfo& rhs) {
ScopedObjectAccess soa(Thread::Current());
os << "["
<< " is_valid=" << rhs.IsValid()
<< " type=" << (!rhs.IsValid() ? "?" : PrettyClass(rhs.GetTypeHandle().Get()))
<< " is_exact=" << rhs.IsExact()
<< " ]";
return os;
}
bool HInstruction::HasAnyEnvironmentUseBefore(HInstruction* other) {
// For now, assume that instructions in different blocks may use the
// environment.
// TODO: Use the control flow to decide if this is true.
if (GetBlock() != other->GetBlock()) {
return true;
}
// We know that we are in the same block. Walk from 'this' to 'other',
// checking to see if there is any instruction with an environment.
HInstruction* current = this;
for (; current != other && current != nullptr; current = current->GetNext()) {
// This is a conservative check, as the instruction result may not be in
// the referenced environment.
if (current->HasEnvironment()) {
return true;
}
}
// We should have been called with 'this' before 'other' in the block.
// Just confirm this.
DCHECK(current != nullptr);
return false;
}
void HInvoke::SetIntrinsic(Intrinsics intrinsic,
IntrinsicNeedsEnvironmentOrCache needs_env_or_cache,
IntrinsicSideEffects side_effects,
IntrinsicExceptions exceptions) {
intrinsic_ = intrinsic;
IntrinsicOptimizations opt(this);
// Adjust method's side effects from intrinsic table.
switch (side_effects) {
case kNoSideEffects: SetSideEffects(SideEffects::None()); break;
case kReadSideEffects: SetSideEffects(SideEffects::AllReads()); break;
case kWriteSideEffects: SetSideEffects(SideEffects::AllWrites()); break;
case kAllSideEffects: SetSideEffects(SideEffects::AllExceptGCDependency()); break;
}
if (needs_env_or_cache == kNoEnvironmentOrCache) {
opt.SetDoesNotNeedDexCache();
opt.SetDoesNotNeedEnvironment();
} else {
// If we need an environment, that means there will be a call, which can trigger GC.
SetSideEffects(GetSideEffects().Union(SideEffects::CanTriggerGC()));
}
// Adjust method's exception status from intrinsic table.
SetCanThrow(exceptions == kCanThrow);
}
bool HNewInstance::IsStringAlloc() const {
ScopedObjectAccess soa(Thread::Current());
return GetReferenceTypeInfo().IsStringClass();
}
bool HInvoke::NeedsEnvironment() const {
if (!IsIntrinsic()) {
return true;
}
IntrinsicOptimizations opt(*this);
return !opt.GetDoesNotNeedEnvironment();
}
bool HInvokeStaticOrDirect::NeedsDexCacheOfDeclaringClass() const {
if (GetMethodLoadKind() != MethodLoadKind::kDexCacheViaMethod) {
return false;
}
if (!IsIntrinsic()) {
return true;
}
IntrinsicOptimizations opt(*this);
return !opt.GetDoesNotNeedDexCache();
}
void HInvokeStaticOrDirect::InsertInputAt(size_t index, HInstruction* input) {
inputs_.insert(inputs_.begin() + index, HUserRecord<HInstruction*>(input));
input->AddUseAt(this, index);
// Update indexes in use nodes of inputs that have been pushed further back by the insert().
for (size_t i = index + 1u, size = inputs_.size(); i != size; ++i) {
DCHECK_EQ(InputRecordAt(i).GetUseNode()->GetIndex(), i - 1u);
InputRecordAt(i).GetUseNode()->SetIndex(i);
}
}
void HInvokeStaticOrDirect::RemoveInputAt(size_t index) {
RemoveAsUserOfInput(index);
inputs_.erase(inputs_.begin() + index);
// Update indexes in use nodes of inputs that have been pulled forward by the erase().
for (size_t i = index, e = InputCount(); i < e; ++i) {
DCHECK_EQ(InputRecordAt(i).GetUseNode()->GetIndex(), i + 1u);
InputRecordAt(i).GetUseNode()->SetIndex(i);
}
}
std::ostream& operator<<(std::ostream& os, HInvokeStaticOrDirect::MethodLoadKind rhs) {
switch (rhs) {
case HInvokeStaticOrDirect::MethodLoadKind::kStringInit:
return os << "string_init";
case HInvokeStaticOrDirect::MethodLoadKind::kRecursive:
return os << "recursive";
case HInvokeStaticOrDirect::MethodLoadKind::kDirectAddress:
return os << "direct";
case HInvokeStaticOrDirect::MethodLoadKind::kDirectAddressWithFixup:
return os << "direct_fixup";
case HInvokeStaticOrDirect::MethodLoadKind::kDexCachePcRelative:
return os << "dex_cache_pc_relative";
case HInvokeStaticOrDirect::MethodLoadKind::kDexCacheViaMethod:
return os << "dex_cache_via_method";
default:
LOG(FATAL) << "Unknown MethodLoadKind: " << static_cast<int>(rhs);
UNREACHABLE();
}
}
std::ostream& operator<<(std::ostream& os, HInvokeStaticOrDirect::ClinitCheckRequirement rhs) {
switch (rhs) {
case HInvokeStaticOrDirect::ClinitCheckRequirement::kExplicit:
return os << "explicit";
case HInvokeStaticOrDirect::ClinitCheckRequirement::kImplicit:
return os << "implicit";
case HInvokeStaticOrDirect::ClinitCheckRequirement::kNone:
return os << "none";
default:
LOG(FATAL) << "Unknown ClinitCheckRequirement: " << static_cast<int>(rhs);
UNREACHABLE();
}
}
bool HLoadString::InstructionDataEquals(HInstruction* other) const {
HLoadString* other_load_string = other->AsLoadString();
if (string_index_ != other_load_string->string_index_ ||
GetPackedFields() != other_load_string->GetPackedFields()) {
return false;
}
LoadKind load_kind = GetLoadKind();
if (HasAddress(load_kind)) {
return GetAddress() == other_load_string->GetAddress();
} else if (HasStringReference(load_kind)) {
return IsSameDexFile(GetDexFile(), other_load_string->GetDexFile());
} else {
DCHECK(HasDexCacheReference(load_kind)) << load_kind;
// If the string indexes and dex files are the same, dex cache element offsets
// must also be the same, so we don't need to compare them.
return IsSameDexFile(GetDexFile(), other_load_string->GetDexFile());
}
}
void HLoadString::SetLoadKindInternal(LoadKind load_kind) {
// Once sharpened, the load kind should not be changed again.
DCHECK_EQ(GetLoadKind(), LoadKind::kDexCacheViaMethod);
SetPackedField<LoadKindField>(load_kind);
if (load_kind != LoadKind::kDexCacheViaMethod) {
RemoveAsUserOfInput(0u);
SetRawInputAt(0u, nullptr);
}
if (!NeedsEnvironment()) {
RemoveEnvironment();
}
}
std::ostream& operator<<(std::ostream& os, HLoadString::LoadKind rhs) {
switch (rhs) {
case HLoadString::LoadKind::kBootImageLinkTimeAddress:
return os << "BootImageLinkTimeAddress";
case HLoadString::LoadKind::kBootImageLinkTimePcRelative:
return os << "BootImageLinkTimePcRelative";
case HLoadString::LoadKind::kBootImageAddress:
return os << "BootImageAddress";
case HLoadString::LoadKind::kDexCacheAddress:
return os << "DexCacheAddress";
case HLoadString::LoadKind::kDexCachePcRelative:
return os << "DexCachePcRelative";
case HLoadString::LoadKind::kDexCacheViaMethod:
return os << "DexCacheViaMethod";
default:
LOG(FATAL) << "Unknown HLoadString::LoadKind: " << static_cast<int>(rhs);
UNREACHABLE();
}
}
void HInstruction::RemoveEnvironmentUsers() {
for (HUseIterator<HEnvironment*> use_it(GetEnvUses()); !use_it.Done(); use_it.Advance()) {
HUseListNode<HEnvironment*>* user_node = use_it.Current();
HEnvironment* user = user_node->GetUser();
user->SetRawEnvAt(user_node->GetIndex(), nullptr);
}
env_uses_.Clear();
}
// Returns an instruction with the opposite Boolean value from 'cond'.
HInstruction* HGraph::InsertOppositeCondition(HInstruction* cond, HInstruction* cursor) {
ArenaAllocator* allocator = GetArena();
if (cond->IsCondition() &&
!Primitive::IsFloatingPointType(cond->InputAt(0)->GetType())) {
// Can't reverse floating point conditions. We have to use HBooleanNot in that case.
HInstruction* lhs = cond->InputAt(0);
HInstruction* rhs = cond->InputAt(1);
HInstruction* replacement = nullptr;
switch (cond->AsCondition()->GetOppositeCondition()) { // get *opposite*
case kCondEQ: replacement = new (allocator) HEqual(lhs, rhs); break;
case kCondNE: replacement = new (allocator) HNotEqual(lhs, rhs); break;
case kCondLT: replacement = new (allocator) HLessThan(lhs, rhs); break;
case kCondLE: replacement = new (allocator) HLessThanOrEqual(lhs, rhs); break;
case kCondGT: replacement = new (allocator) HGreaterThan(lhs, rhs); break;
case kCondGE: replacement = new (allocator) HGreaterThanOrEqual(lhs, rhs); break;
case kCondB: replacement = new (allocator) HBelow(lhs, rhs); break;
case kCondBE: replacement = new (allocator) HBelowOrEqual(lhs, rhs); break;
case kCondA: replacement = new (allocator) HAbove(lhs, rhs); break;
case kCondAE: replacement = new (allocator) HAboveOrEqual(lhs, rhs); break;
default:
LOG(FATAL) << "Unexpected condition";
UNREACHABLE();
}
cursor->GetBlock()->InsertInstructionBefore(replacement, cursor);
return replacement;
} else if (cond->IsIntConstant()) {
HIntConstant* int_const = cond->AsIntConstant();
if (int_const->IsFalse()) {
return GetIntConstant(1);
} else {
DCHECK(int_const->IsTrue()) << int_const->GetValue();
return GetIntConstant(0);
}
} else {
HInstruction* replacement = new (allocator) HBooleanNot(cond);
cursor->GetBlock()->InsertInstructionBefore(replacement, cursor);
return replacement;
}
}
std::ostream& operator<<(std::ostream& os, const MoveOperands& rhs) {
os << "["
<< " source=" << rhs.GetSource()
<< " destination=" << rhs.GetDestination()
<< " type=" << rhs.GetType()
<< " instruction=";
if (rhs.GetInstruction() != nullptr) {