/* * 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 "art_method-inl.h" #include "base/bit_utils.h" #include "base/bit_vector-inl.h" #include "base/logging.h" #include "base/stl_util.h" #include "class_linker-inl.h" #include "class_root.h" #include "code_generator.h" #include "common_dominator.h" #include "intrinsics.h" #include "mirror/class-inl.h" #include "scoped_thread_state_change-inl.h" #include "ssa_builder.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(VariableSizedHandleScope* handles) { ScopedObjectAccess soa(Thread::Current()); // Create the inexact Object reference type and store it in the HGraph. inexact_object_rti_ = ReferenceTypeInfo::Create( handles->NewHandle(GetClassRoot<mirror::Object>()), /* 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); // Allocate memory from local ScopedArenaAllocator. ScopedArenaAllocator allocator(GetArenaStack()); // Nodes that we're currently visiting, indexed by block id. ArenaBitVector visiting( &allocator, blocks_.size(), /* expandable= */ false, kArenaAllocGraphBuilder); visiting.ClearAllBits(); // Number of successors visited from a given node, indexed by block id. ScopedArenaVector<size_t> successors_visited(blocks_.size(), 0u, allocator.Adapter(kArenaAllocGraphBuilder)); // Stack of nodes that we're currently visiting (same as marked in "visiting" above). ScopedArenaVector<HBasicBlock*> worklist(allocator.Adapter(kArenaAllocGraphBuilder)); 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); } } } } // Remove the environment use records of the instruction for users. 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); } } } } // Return whether the instruction has an environment and it's used by others. bool HasEnvironmentUsedByOthers(HInstruction* instruction) { for (HEnvironment* environment = instruction->GetEnvironment(); environment != nullptr; environment = environment->GetParent()) { for (size_t i = 0, e = environment->Size(); i < e; ++i) { HInstruction* user = environment->GetInstructionAt(i); if (user != nullptr) { return true; } } } return false; } // Reset environment records of the instruction itself. void ResetEnvironmentInputRecords(HInstruction* instruction) { for (HEnvironment* environment = instruction->GetEnvironment(); environment != nullptr; environment = environment->GetParent()) { for (size_t i = 0, e = environment->Size(); i < e; ++i) { DCHECK(environment->GetHolder() == instruction); if (environment->GetInstructionAt(i) != nullptr) { environment->SetRawEnvAt(i, nullptr); } } } } static void RemoveAsUser(HInstruction* instruction) { instruction->RemoveAsUserOfAllInputs(); 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; for (HInstructionIterator it(block->GetPhis()); !it.Done(); it.Advance()) { RemoveAsUser(it.Current()); } 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() { // Allocate memory from local ScopedArenaAllocator. ScopedArenaAllocator allocator(GetArenaStack()); ArenaBitVector visited(&allocator, blocks_.size(), false, kArenaAllocGraphBuilder); visited.ClearAllBits(); // (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 (HBasicBlock* block : GetReversePostOrder()) { block->ClearDominanceInformation(); } reverse_post_order_.clear(); } void HGraph::ClearLoopInformation() { SetHasIrreducibleLoops(false); for (HBasicBlock* block : GetReversePostOrder()) { block->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; } static bool UpdateDominatorOfSuccessor(HBasicBlock* block, HBasicBlock* successor) { DCHECK(ContainsElement(block->GetSuccessors(), successor)); HBasicBlock* old_dominator = successor->GetDominator(); HBasicBlock* new_dominator = (old_dominator == nullptr) ? block : CommonDominator::ForPair(old_dominator, block); if (old_dominator == new_dominator) { return false; } else { successor->SetDominator(new_dominator); return true; } } void HGraph::ComputeDominanceInformation() { DCHECK(reverse_post_order_.empty()); reverse_post_order_.reserve(blocks_.size()); reverse_post_order_.push_back(entry_block_); // Allocate memory from local ScopedArenaAllocator. ScopedArenaAllocator allocator(GetArenaStack()); // Number of visits of a given node, indexed by block id. ScopedArenaVector<size_t> visits(blocks_.size(), 0u, allocator.Adapter(kArenaAllocGraphBuilder)); // Number of successors visited from a given node, indexed by block id. ScopedArenaVector<size_t> successors_visited(blocks_.size(), 0u, allocator.Adapter(kArenaAllocGraphBuilder)); // Nodes for which we need to visit successors. ScopedArenaVector<HBasicBlock*> worklist(allocator.Adapter(kArenaAllocGraphBuilder)); 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]++]; UpdateDominatorOfSuccessor(current, successor); // 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); } } } // Check if the graph has back edges not dominated by their respective headers. // If so, we need to update the dominators of those headers and recursively of // their successors. We do that with a fix-point iteration over all blocks. // The algorithm is guaranteed to terminate because it loops only if the sum // of all dominator chains has decreased in the current iteration. bool must_run_fix_point = false; for (HBasicBlock* block : blocks_) { if (block != nullptr && block->IsLoopHeader() && block->GetLoopInformation()->HasBackEdgeNotDominatedByHeader()) { must_run_fix_point = true; break; } } if (must_run_fix_point) { bool update_occurred = true; while (update_occurred) { update_occurred = false; for (HBasicBlock* block : GetReversePostOrder()) { for (HBasicBlock* successor : block->GetSuccessors()) { update_occurred |= UpdateDominatorOfSuccessor(block, successor); } } } } // Make sure that there are no remaining blocks whose dominator information // needs to be updated. if (kIsDebugBuild) { for (HBasicBlock* block : GetReversePostOrder()) { for (HBasicBlock* successor : block->GetSuccessors()) { DCHECK(!UpdateDominatorOfSuccessor(block, successor)); } } } // Populate `dominated_blocks_` information after computing all dominators. // The potential presence of irreducible loops requires to do it after. for (HBasicBlock* block : GetReversePostOrder()) { if (!block->IsEntryBlock()) { block->GetDominator()->AddDominatedBlock(block); } } } HBasicBlock* HGraph::SplitEdge(HBasicBlock* block, HBasicBlock* successor) { HBasicBlock* new_block = new (allocator_) 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 (allocator_) 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); } } } // Reorder phi inputs to match reordering of the block's predecessors. static void FixPhisAfterPredecessorsReodering(HBasicBlock* block, size_t first, size_t second) { for (HInstructionIterator it(block->GetPhis()); !it.Done(); it.Advance()) { HPhi* phi = it.Current()->AsPhi(); HInstruction* first_instr = phi->InputAt(first); HInstruction* second_instr = phi->InputAt(second); phi->ReplaceInput(first_instr, second); phi->ReplaceInput(second_instr, first); } } // Make sure that the first predecessor of a loop header is the incoming block. void HGraph::OrderLoopHeaderPredecessors(HBasicBlock* header) { DCHECK(header->IsLoopHeader()); HLoopInformation* info = header->GetLoopInformation(); 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; FixPhisAfterPredecessorsReodering(header, 0, pred); break; } } } } // Transform control flow of the loop to a single preheader format (don't touch the data flow). // New_preheader can be already among the header predecessors - this situation will be correctly // processed. static void FixControlForNewSinglePreheader(HBasicBlock* header, HBasicBlock* new_preheader) { HLoopInformation* loop_info = header->GetLoopInformation(); for (size_t pred = 0; pred < header->GetPredecessors().size(); ++pred) { HBasicBlock* predecessor = header->GetPredecessors()[pred]; if (!loop_info->IsBackEdge(*predecessor) && predecessor != new_preheader) { predecessor->ReplaceSuccessor(header, new_preheader); pred--; } } } // == Before == == After == // _________ _________ _________ _________ // | B0 | | B1 | (old preheaders) | B0 | | B1 | // |=========| |=========| |=========| |=========| // | i0 = .. | | i1 = .. | | i0 = .. | | i1 = .. | // |_________| |_________| |_________| |_________| // \ / \ / // \ / ___v____________v___ // \ / (new preheader) | B20 <- B0, B1 | // | | |====================| // | | | i20 = phi(i0, i1) | // | | |____________________| // | | | // /\ | | /\ /\ | /\ // / v_______v_________v_______v \ / v___________v_____________v \ // | | B10 <- B0, B1, B2, B3 | | | | B10 <- B20, B2, B3 | | // | |===========================| | (header) | |===========================| | // | | i10 = phi(i0, i1, i2, i3) | | | | i10 = phi(i20, i2, i3) | | // | |___________________________| | | |___________________________| | // | / \ | | / \ | // | ... ... | | ... ... | // | _________ _________ | | _________ _________ | // | | B2 | | B3 | | | | B2 | | B3 | | // | |=========| |=========| | (back edges) | |=========| |=========| | // | | i2 = .. | | i3 = .. | | | | i2 = .. | | i3 = .. | | // | |_________| |_________| | | |_________| |_________| | // \ / \ / \ / \ / // \___/ \___/ \___/ \___/ // void HGraph::TransformLoopToSinglePreheaderFormat(HBasicBlock* header) { HLoopInformation* loop_info = header->GetLoopInformation(); HBasicBlock* preheader = new (allocator_) HBasicBlock(this, header->GetDexPc()); AddBlock(preheader); preheader->AddInstruction(new (allocator_) HGoto(header->GetDexPc())); // If the old header has no Phis then we only need to fix the control flow. if (header->GetPhis().IsEmpty()) { FixControlForNewSinglePreheader(header, preheader); preheader->AddSuccessor(header); return; } // Find the first non-back edge block in the header's predecessors list. size_t first_nonbackedge_pred_pos = 0; bool found = false; for (size_t pred = 0; pred < header->GetPredecessors().size(); ++pred) { HBasicBlock* predecessor = header->GetPredecessors()[pred]; if (!loop_info->IsBackEdge(*predecessor)) { first_nonbackedge_pred_pos = pred; found = true; break; } } DCHECK(found); // Fix the data-flow. for (HInstructionIterator it(header->GetPhis()); !it.Done(); it.Advance()) { HPhi* header_phi = it.Current()->AsPhi(); HPhi* preheader_phi = new (GetAllocator()) HPhi(GetAllocator(), header_phi->GetRegNumber(), 0, header_phi->GetType()); if (header_phi->GetType() == DataType::Type::kReference) { preheader_phi->SetReferenceTypeInfo(header_phi->GetReferenceTypeInfo()); } preheader->AddPhi(preheader_phi); HInstruction* orig_input = header_phi->InputAt(first_nonbackedge_pred_pos); header_phi->ReplaceInput(preheader_phi, first_nonbackedge_pred_pos); preheader_phi->AddInput(orig_input); for (size_t input_pos = first_nonbackedge_pred_pos + 1; input_pos < header_phi->InputCount(); input_pos++) { HInstruction* input = header_phi->InputAt(input_pos); HBasicBlock* pred_block = header->GetPredecessors()[input_pos]; if (loop_info->Contains(*pred_block)) { DCHECK(loop_info->IsBackEdge(*pred_block)); } else { preheader_phi->AddInput(input); header_phi->RemoveInputAt(input_pos); input_pos--; } } } // Fix the control-flow. HBasicBlock* first_pred = header->GetPredecessors()[first_nonbackedge_pred_pos]; preheader->InsertBetween(first_pred, header); FixControlForNewSinglePreheader(header, preheader); } 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)) { TransformLoopToSinglePreheaderFormat(header); } OrderLoopHeaderPredecessors(header); 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 (HBasicBlock* block : GetReversePostOrder()) { 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 (allocator_) 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 { // We iterate post order to ensure we visit inner loops before outer loops. // `PopulateRecursive` needs this guarantee to know whether a natural loop // contains an irreducible loop. for (HBasicBlock* block : GetPostOrder()) { 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. VLOG(compiler) << "Not compiled: Exceptional back edges"; 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 (allocator_) 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 (allocator_) HCurrentMethod( Is64BitInstructionSet(instruction_set_) ? DataType::Type::kInt64 : DataType::Type::kInt32, 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_; } const char* HGraph::GetMethodName() const { const dex::MethodId& method_id = dex_file_.GetMethodId(method_idx_); return dex_file_.GetMethodName(method_id); } std::string HGraph::PrettyMethod(bool with_signature) const { return dex_file_.PrettyMethod(method_idx_, with_signature); } HConstant* HGraph::GetConstant(DataType::Type type, int64_t value, uint32_t dex_pc) { switch (type) { case DataType::Type::kBool: DCHECK(IsUint<1>(value)); FALLTHROUGH_INTENDED; case DataType::Type::kUint8: case DataType::Type::kInt8: case DataType::Type::kUint16: case DataType::Type::kInt16: case DataType::Type::kInt32: DCHECK(IsInt(DataType::Size(type) * kBitsPerByte, value)); return GetIntConstant(static_cast<int32_t>(value), dex_pc); case DataType::Type::kInt64: 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); if (block->IsLoopHeader()) { // We're visiting loops in post-order, so inner loops must have been // populated already. DCHECK(block->GetLoopInformation()->IsPopulated()); if (block->GetLoopInformation()->IsIrreducible()) { contains_irreducible_loop_ = true; } } 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 = HasBackEdgeNotDominatedByHeader(); if (is_irreducible_loop) { // Allocate memory from local ScopedArenaAllocator. ScopedArenaAllocator allocator(graph->GetArenaStack()); ArenaBitVector visited(&allocator, graph->GetBlocks().size(), /* expandable= */ false, kArenaAllocGraphBuilder); visited.ClearAllBits(); // Stop marking blocks at the loop header. visited.SetBit(header_->GetBlockId()); for (HBasicBlock* back_edge : GetBackEdges()) { PopulateIrreducibleRecursive(back_edge, &visited); } } else { for (HBasicBlock* back_edge : GetBackEdges()) { PopulateRecursive(back_edge); } } if (!is_irreducible_loop && graph->IsCompilingOsr()) { // When compiling in OSR mode, all loops in the compiled method may be entered // from the interpreter. We treat this OSR entry point just like an extra entry // to an irreducible loop, so we need to mark the method's loops as irreducible. // This does not apply to inlined loops which do not act as OSR entry points. if (suspend_check_ == nullptr) { // Just building the graph in OSR mode, this loop is not inlined. We never build an // inner graph in OSR mode as we can do OSR transition only from the outer method. is_irreducible_loop = true; } else { // Look at the suspend check's environment to determine if the loop was inlined. DCHECK(suspend_check_->HasEnvironment()); if (!suspend_check_->GetEnvironment()->IsFromInlinedInvoke()) { is_irreducible_loop = true; } } } if (is_irreducible_loop) { irreducible_ = true; contains_irreducible_loop_ = true; graph->SetHasIrreducibleLoops(true); } graph->SetHasLoops(true); } void HLoopInformation::PopulateInnerLoopUpwards(HLoopInformation* inner_loop) { DCHECK(inner_loop->GetPreHeader()->GetLoopInformation() == this); blocks_.Union(&inner_loop->blocks_); HLoopInformation* outer_loop = GetPreHeader()->GetLoopInformation(); if (outer_loop != nullptr) { outer_loop->PopulateInnerLoopUpwards(this); } } 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 HLoopInformation::HasBackEdgeNotDominatedByHeader() const { for (HBasicBlock* back_edge : GetBackEdges()) { DCHECK(back_edge->GetDominator() != nullptr); if (!header_->Dominates(back_edge)) { return true; } } return false; } bool HLoopInformation::DominatesAllBackEdges(HBasicBlock* block) { for (HBasicBlock* back_edge : GetBackEdges()) { if (!block->Dominates(back_edge)) { return false; } } return true; } bool HLoopInformation::HasExitEdge() const { // Determine if this loop has at least one exit edge. HBlocksInLoopReversePostOrderIterator it_loop(*this); for (; !it_loop.Done(); it_loop.Advance()) { for (HBasicBlock* successor : it_loop.Current()->GetSuccessors()) { if (!Contains(*successor)) { return true; } } } return false; } 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) { HInputsRef inputs = instruction->GetInputs(); for (size_t i = 0; i < inputs.size(); ++i) { inputs[i]->AddUseAt(instruction, i); } // Environment should be created later. DCHECK(!instruction->HasEnvironment()); } void HBasicBlock::ReplaceAndRemovePhiWith(HPhi* initial, HPhi* replacement) { DCHECK(initial->GetBlock() == this); InsertPhiAfter(replacement, initial); initial->ReplaceWith(replacement); RemovePhi(initial); } 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(), DataType::Type::kVoid); DCHECK_EQ(initial->GetBlock(), this); DCHECK_EQ(initial->GetType(), DataType::Type::kVoid); DCHECK(initial->GetUses().empty()); DCHECK(initial->GetEnvUses().empty()); replacement->SetBlock(this); replacement->SetId(GetGraph()->GetNextInstructionId()); instructions_.InsertInstructionBefore(replacement, initial); UpdateInputsUsers(replacement); } else { InsertInstructionBefore(replacement, initial); initial->ReplaceWith(replacement); } RemoveInstruction(initial); } 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().empty()); DCHECK(instruction->GetEnvUses().empty()); 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(ArrayRef<HInstruction* const> 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*>& env_use = vregs_[index]; HInstruction* user = env_use.GetInstruction(); auto before_env_use_node = env_use.GetBeforeUseNode(); user->env_uses_.erase_after(before_env_use_node); user->FixUpUserRecordsAfterEnvUseRemoval(before_env_use_node); } void HEnvironment::ReplaceInput(HInstruction* replacement, size_t index) { const HUserRecord<HEnvironment*>& env_use_record = vregs_[index]; HInstruction* orig_instr = env_use_record.GetInstruction(); DCHECK(orig_instr != replacement); HUseList<HEnvironment*>::iterator before_use_node = env_use_record.GetBeforeUseNode(); // Note: fixup_end remains valid across splice_after(). auto fixup_end = replacement->env_uses_.empty() ? replacement->env_uses_.begin() : ++replacement->env_uses_.begin(); replacement->env_uses_.splice_after(replacement->env_uses_.before_begin(), env_use_record.GetInstruction()->env_uses_, before_use_node); replacement->FixUpUserRecordsAfterEnvUseInsertion(fixup_end); orig_instr->FixUpUserRecordsAfterEnvUseRemoval(before_use_node); } 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 { DCHECK(last_instruction_ != nullptr); 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."; UNREACHABLE(); } 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."; UNREACHABLE(); } } 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); // Note: fixup_end remains valid across splice_after(). auto fixup_end = other->uses_.empty() ? other->uses_.begin() : ++other->uses_.begin(); other->uses_.splice_after(other->uses_.before_begin(), uses_); other->FixUpUserRecordsAfterUseInsertion(fixup_end); // Note: env_fixup_end remains valid across splice_after(). auto env_fixup_end = other->env_uses_.empty() ? other->env_uses_.begin() : ++other->env_uses_.begin(); other->env_uses_.splice_after(other->env_uses_.before_begin(), env_uses_); other->FixUpUserRecordsAfterEnvUseInsertion(env_fixup_end); DCHECK(uses_.empty()); DCHECK(env_uses_.empty()); } void HInstruction::ReplaceUsesDominatedBy(HInstruction* dominator, HInstruction* replacement) { const HUseList<HInstruction*>& uses = GetUses(); for (auto it = uses.begin(), end = uses.end(); it != end; /* ++it below */) { HInstruction* user = it->GetUser(); size_t index = it->GetIndex(); // Increment `it` now because `*it` may disappear thanks to user->ReplaceInput(). ++it; if (dominator->StrictlyDominates(user)) { user->ReplaceInput(replacement, index); } else if (user->IsPhi() && !user->AsPhi()->IsCatchPhi()) { // If the input flows from a block dominated by `dominator`, we can replace it. // We do not perform this for catch phis as we don't have control flow support // for their inputs. const ArenaVector<HBasicBlock*>& predecessors = user->GetBlock()->GetPredecessors(); HBasicBlock* predecessor = predecessors[index]; if (dominator->GetBlock()->Dominates(predecessor)) { user->ReplaceInput(replacement, index); } } } } void HInstruction::ReplaceEnvUsesDominatedBy(HInstruction* dominator, HInstruction* replacement) { const HUseList<HEnvironment*>& uses = GetEnvUses(); for (auto it = uses.begin(), end = uses.end(); it != end; /* ++it below */) { HEnvironment* user = it->GetUser(); size_t index = it->GetIndex(); // Increment `it` now because `*it` may disappear thanks to user->ReplaceInput(). ++it; if (dominator->StrictlyDominates(user->GetHolder())) { user->ReplaceInput(replacement, index); } } } void HInstruction::ReplaceInput(HInstruction* replacement, size_t index) { HUserRecord<HInstruction*> input_use = InputRecordAt(index); if (input_use.GetInstruction() == replacement) { // Nothing to do. return; } HUseList<HInstruction*>::iterator before_use_node = input_use.GetBeforeUseNode(); // Note: fixup_end remains valid across splice_after(). auto fixup_end = replacement->uses_.empty() ? replacement->uses_.begin() : ++replacement->uses_.begin(); replacement->uses_.splice_after(replacement->uses_.before_begin(), input_use.GetInstruction()->uses_, before_use_node); replacement->FixUpUserRecordsAfterUseInsertion(fixup_end); input_use.GetInstruction()->FixUpUserRecordsAfterUseRemoval(before_use_node); } size_t HInstruction::EnvironmentSize() const { return HasEnvironment() ? environment_->Size() : 0; } void HVariableInputSizeInstruction::AddInput(HInstruction* input) { DCHECK(input->GetBlock() != nullptr); inputs_.push_back(HUserRecord<HInstruction*>(input)); input->AddUseAt(this, inputs_.size() - 1); } void HVariableInputSizeInstruction::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, e = inputs_.size(); i < e; ++i) { DCHECK_EQ(inputs_[i].GetUseNode()->GetIndex(), i - 1u); inputs_[i].GetUseNode()->SetIndex(i); } } void HVariableInputSizeInstruction::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 = inputs_.size(); i < e; ++i) { DCHECK_EQ(inputs_[i].GetUseNode()->GetIndex(), i + 1u); inputs_[i].GetUseNode()->SetIndex(i); } } void HVariableInputSizeInstruction::RemoveAllInputs() { RemoveAsUserOfAllInputs(); DCHECK(!HasNonEnvironmentUses()); inputs_.clear(); DCHECK_EQ(0u, InputCount()); } size_t HConstructorFence::RemoveConstructorFences(HInstruction* instruction) { DCHECK(instruction->GetBlock() != nullptr); // Removing constructor fences only makes sense for instructions with an object return type. DCHECK_EQ(DataType::Type::kReference, instruction->GetType()); // Return how many instructions were removed for statistic purposes. size_t remove_count = 0; // Efficient implementation that simultaneously (in one pass): // * Scans the uses list for all constructor fences. // * Deletes that constructor fence from the uses list of `instruction`. // * Deletes `instruction` from the constructor fence's inputs. // * Deletes the constructor fence if it now has 0 inputs. const HUseList<HInstruction*>& uses = instruction->GetUses(); // Warning: Although this is "const", we might mutate the list when calling RemoveInputAt. for (auto it = uses.begin(), end = uses.end(); it != end; ) { const HUseListNode<HInstruction*>& use_node = *it; HInstruction* const use_instruction = use_node.GetUser(); // Advance the iterator immediately once we fetch the use_node. // Warning: If the input is removed, the current iterator becomes invalid. ++it; if (use_instruction->IsConstructorFence()) { HConstructorFence* ctor_fence = use_instruction->AsConstructorFence(); size_t input_index = use_node.GetIndex(); // Process the candidate instruction for removal // from the graph. // Constructor fence instructions are never // used by other instructions. // // If we wanted to make this more generic, it // could be a runtime if statement. DCHECK(!ctor_fence->HasUses()); // A constructor fence's return type is "kPrimVoid" // and therefore it can't have any environment uses. DCHECK(!ctor_fence->HasEnvironmentUses()); // Remove the inputs first, otherwise removing the instruction // will try to remove its uses while we are already removing uses // and this operation will fail. DCHECK_EQ(instruction, ctor_fence->InputAt(input_index)); // Removing the input will also remove the `use_node`. // (Do not look at `use_node` after this, it will be a dangling reference). ctor_fence->RemoveInputAt(input_index); // Once all inputs are removed, the fence is considered dead and // is removed. if (ctor_fence->InputCount() == 0u) { ctor_fence->GetBlock()->RemoveInstruction(ctor_fence); ++remove_count; } } } if (kIsDebugBuild) { // Post-condition checks: // * None of the uses of `instruction` are a constructor fence. // * The `instruction` itself did not get removed from a block. for (const HUseListNode<HInstruction*>& use_node : instruction->GetUses()) { CHECK(!use_node.GetUser()->IsConstructorFence()); } CHECK(instruction->GetBlock() != nullptr); } return remove_count; } void HConstructorFence::Merge(HConstructorFence* other) { // Do not delete yourself from the graph. DCHECK(this != other); // Don't try to merge with an instruction not associated with a block. DCHECK(other->GetBlock() != nullptr); // A constructor fence's return type is "kPrimVoid" // and therefore it cannot have any environment uses. DCHECK(!other->HasEnvironmentUses()); auto has_input = [](HInstruction* haystack, HInstruction* needle) { // Check if `haystack` has `needle` as any of its inputs. for (size_t input_count = 0; input_count < haystack->InputCount(); ++input_count) { if (haystack->InputAt(input_count) == needle) { return true; } } return false; }; // Add any inputs from `other` into `this` if it wasn't already an input. for (size_t input_count = 0; input_count < other->InputCount(); ++input_count) { HInstruction* other_input = other->InputAt(input_count); if (!has_input(this, other_input)) { AddInput(other_input); } } other->GetBlock()->RemoveInstruction(other); } HInstruction* HConstructorFence::GetAssociatedAllocation(bool ignore_inputs) { HInstruction* new_instance_inst = GetPrevious(); // Check if the immediately preceding instruction is a new-instance/new-array. // Otherwise this fence is for protecting final fields. if (new_instance_inst != nullptr && (new_instance_inst->IsNewInstance() || new_instance_inst->IsNewArray())) { if (ignore_inputs) { // If inputs are ignored, simply check if the predecessor is // *any* HNewInstance/HNewArray. // // Inputs are normally only ignored for prepare_for_register_allocation, // at which point *any* prior HNewInstance/Array can be considered // associated. return new_instance_inst; } else { // Normal case: There must be exactly 1 input and the previous instruction // must be that input. if (InputCount() == 1u && InputAt(0) == new_instance_inst) { return new_instance_inst; } } } return nullptr; } #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 (HBasicBlock* block : graph_->GetReversePostOrder()) { VisitBasicBlock(block); } } 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 DataType::Type::kInt8: return graph->GetIntConstant(static_cast<int8_t>(value), GetDexPc()); case DataType::Type::kUint8: return graph->GetIntConstant(static_cast<uint8_t>(value), GetDexPc()); case DataType::Type::kInt16: return graph->GetIntConstant(static_cast<int16_t>(value), GetDexPc()); case DataType::Type::kUint16: return graph->GetIntConstant(static_cast<uint16_t>(value), GetDexPc()); case DataType::Type::kInt64: return graph->GetLongConstant(static_cast<int64_t>(value), GetDexPc()); case DataType::Type::kFloat32: return graph->GetFloatConstant(static_cast<float>(value), GetDexPc()); case DataType::Type::kFloat64: return graph->GetDoubleConstant(static_cast<double>(value), GetDexPc()); default: return nullptr; } } else if (GetInput()->IsLongConstant()) { int64_t value = GetInput()->AsLongConstant()->GetValue(); switch (GetResultType()) { case DataType::Type::kInt8: return graph->GetIntConstant(static_cast<int8_t>(value), GetDexPc()); case DataType::Type::kUint8: return graph->GetIntConstant(static_cast<uint8_t>(value), GetDexPc()); case DataType::Type::kInt16: return graph->GetIntConstant(static_cast<int16_t>(value), GetDexPc()); case DataType::Type::kUint16: return graph->GetIntConstant(static_cast<uint16_t>(value), GetDexPc()); case DataType::Type::kInt32: return graph->GetIntConstant(static_cast<int32_t>(value), GetDexPc()); case DataType::Type::kFloat32: return graph->GetFloatConstant(static_cast<float>(value), GetDexPc()); case DataType::Type::kFloat64: return graph->GetDoubleConstant(static_cast<double>(value), GetDexPc()); default: return nullptr; } } else if (GetInput()->IsFloatConstant()) { float value = GetInput()->AsFloatConstant()->GetValue(); switch (GetResultType()) { case DataType::Type::kInt32: 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 DataType::Type::kInt64: 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 DataType::Type::kFloat64: return graph->GetDoubleConstant(static_cast<double>(value), GetDexPc()); default: return nullptr; } } else if (GetInput()->IsDoubleConstant()) { double value = GetInput()->AsDoubleConstant()->GetValue(); switch (GetResultType()) { case DataType::Type::kInt32: 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 DataType::Type::kInt64: 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 DataType::Type::kFloat32: 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(const HInstruction* other) const { if (GetKind() != other->GetKind()) return false; if (GetType() != other->GetType()) return false; if (!InstructionDataEquals(other)) return false; HConstInputsRef inputs = GetInputs(); HConstInputsRef other_inputs = other->GetInputs(); if (inputs.size() != other_inputs.size()) return false; for (size_t i = 0; i != inputs.size(); ++i) { if (inputs[i] != other_inputs[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_CONCRETE_INSTRUCTION(DECLARE_CASE) default: os << "Unknown instruction kind " << static_cast<int>(rhs); break; } #undef DECLARE_CASE return os; } void HInstruction::MoveBefore(HInstruction* cursor, bool do_checks) { if (do_checks) { DCHECK(!IsPhi()); DCHECK(!IsControlFlow()); DCHECK(CanBeMoved() || // HShouldDeoptimizeFlag can only be moved by CHAGuardOptimization. IsShouldDeoptimizeFlag()); DCHECK(!cursor->IsPhi()); } 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. auto uses_it = GetUses().begin(); auto uses_end = GetUses().end(); HBasicBlock* target_block = uses_it->GetUser()->GetBlock(); ++uses_it; while (uses_it != uses_end && uses_it->GetUser()->GetBlock() == target_block) { ++uses_it; } if (uses_it != uses_end) { // This instruction has uses in two or more blocks. Find the common dominator. CommonDominator finder(target_block); for (; uses_it != uses_end; ++uses_it) { finder.Update(uses_it->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 (const HUseListNode<HInstruction*>& use : GetUses()) { if (use.GetUser()->GetBlock() == target_block && (insert_pos == nullptr || use.GetUser()->StrictlyDominates(insert_pos))) { insert_pos = use.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()->GetAllocator()) 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()->GetAllocator()) HGoto(new_block->GetDexPc())); for (HBasicBlock* successor : GetSuccessors()) { successor->predecessors_[successor->GetPredecessorIndexOf(this)] = new_block; } new_block->successors_.swap(successors_); DCHECK(successors_.empty()); 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()->GetAllocator()) HBasicBlock(GetGraph(), GetDexPc()); for (HBasicBlock* predecessor : GetPredecessors()) { predecessor->successors_[predecessor->GetSuccessorIndexOf(this)] = new_block; } new_block->predecessors_.swap(predecessors_); DCHECK(predecessors_.empty()); 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()->GetAllocator()) 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()) { successor->predecessors_[successor->GetPredecessorIndexOf(this)] = new_block; } new_block->successors_.swap(successors_); DCHECK(successors_.empty()); for (HBasicBlock* dominated : GetDominatedBlocks()) { dominated->dominator_ = new_block; } new_block->dominated_blocks_.swap(dominated_blocks_); DCHECK(dominated_blocks_.empty()); 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()->GetAllocator()) 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()) { successor->predecessors_[successor->GetPredecessorIndexOf(this)] = new_block; } new_block->successors_.swap(successors_); DCHECK(successors_.empty()); for (HBasicBlock* dominated : GetDominatedBlocks()) { dominated->dominator_ = new_block; } new_block->dominated_blocks_.swap(dominated_blocks_); DCHECK(dominated_blocks_.empty()); 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::IsSingleReturn() const { return HasOnlyOneInstruction(*this) && GetLastInstruction()->IsReturn(); } bool HBasicBlock::IsSingleReturnOrReturnVoidAllowingPhis() const { return (GetFirstInstruction() == GetLastInstruction()) && (GetLastInstruction()->IsReturn() || GetLastInstruction()->IsReturnVoid()); } bool HBasicBlock::IsSingleTryBoundary() const { return HasOnlyOneInstruction(*this) && GetLastInstruction()->IsTryBoundary(); } bool HBasicBlock::EndsWithControlFlowInstruction() const { return !GetInstructions().IsEmpty() && GetLastInstruction()->IsControlFlow(); } bool HBasicBlock::EndsWithReturn() const { return !GetInstructions().IsEmpty() && (GetLastInstruction()->IsReturn() || GetLastInstruction()->IsReturnVoid()); } 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()) { const HUseListNode<HInstruction*>& use = insn->GetUses().front(); 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_->GetAllocator()) 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::MergeInstructionsWith(HBasicBlock* other) { DCHECK(EndsWithControlFlowInstruction()); RemoveInstruction(GetLastInstruction()); instructions_.Add(other->GetInstructions()); other->instructions_.SetBlockOfInstructions(this); other->instructions_.Clear(); } 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`. MergeInstructionsWith(other); // 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(); for (HBasicBlock* successor : other->GetSuccessors()) { successor->predecessors_[successor->GetPredecessorIndexOf(other)] = this; } successors_.swap(other->successors_); DCHECK(other->successors_.empty()); // Update the dominator tree. RemoveDominatedBlock(other); for (HBasicBlock* dominated : other->GetDominatedBlocks()) { dominated->SetDominator(this); } dominated_blocks_.insert( dominated_blocks_.end(), other->dominated_blocks_.begin(), other->dominated_blocks_.end()); 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(); for (HBasicBlock* successor : other->GetSuccessors()) { successor->predecessors_[successor->GetPredecessorIndexOf(other)] = this; } successors_.swap(other->successors_); DCHECK(other->successors_.empty()); // Update the dominator tree. for (HBasicBlock* dominated : other->GetDominatedBlocks()) { dominated->SetDominator(this); } dominated_blocks_.insert( dominated_blocks_.end(), other->dominated_blocks_.begin(), other->dominated_blocks_.end()); 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. { // Skip the entry block, we do not need to update the entry's suspend check. for (HBasicBlock* block : GetReversePostOrderSkipEntryBlock()) { 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->GetAllocator(), invoke->GetEnvironment()); } } } } outer_graph->UpdateMaximumNumberOfOutVRegs(GetMaximumNumberOfOutVRegs()); if (HasBoundsChecks()) { outer_graph->SetHasBoundsChecks(true); } if (HasLoops()) { outer_graph->SetHasLoops(true); } if (HasIrreducibleLoops()) { outer_graph->SetHasIrreducibleLoops(true); } if (HasTryCatch()) { outer_graph->SetHasTryCatch(true); } if (HasSIMD()) { outer_graph->SetHasSIMD(true); } HInstruction* return_value = nullptr; if (GetBlocks().size() == 3) { // Inliner already made sure we don't inline methods that always throw. DCHECK(!GetBlocks()[1]->GetLastInstruction()->IsThrow()); // 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->GetAllocator(); 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 (HBasicBlock* current : GetReversePostOrder()) { 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. Special case throwing blocks // to now get the outer graph exit block as successor. Note that the inliner // currently doesn't support inlining methods with try/catch. HPhi* return_value_phi = nullptr; bool rerun_dominance = false; bool rerun_loop_analysis = false; for (size_t pred = 0; pred < to->GetPredecessors().size(); ++pred) { HBasicBlock* predecessor = to->GetPredecessors()[pred]; HInstruction* last = predecessor->GetLastInstruction(); if (last->IsThrow()) { DCHECK(!at->IsTryBlock()); predecessor->ReplaceSuccessor(to, outer_graph->GetExitBlock()); --pred; // We need to re-run dominance information, as the exit block now has // a new dominator. rerun_dominance = true; if (predecessor->GetLoopInformation() != nullptr) { // The exit block and blocks post dominated by the exit block do not belong // to any loop. Because we do not compute the post dominators, we need to re-run // loop analysis to get the loop information correct. rerun_loop_analysis = true; } } else { if (last->IsReturnVoid()) { DCHECK(return_value == nullptr); DCHECK(return_value_phi == nullptr); } else { DCHECK(last->IsReturn()); if (return_value_phi != nullptr) { return_value_phi->AddInput(last->InputAt(0)); } else if (return_value == nullptr) { return_value = last->InputAt(0); } else { // There will be multiple returns. return_value_phi = new (allocator) HPhi( allocator, kNoRegNumber, 0, HPhi::ToPhiType(invoke->GetType()), to->GetDexPc()); to->AddPhi(return_value_phi); return_value_phi->AddInput(return_value); return_value_phi->AddInput(last->InputAt(0)); return_value = return_value_phi; } } predecessor->AddInstruction(new (allocator) HGoto(last->GetDexPc())); predecessor->RemoveInstruction(last); } } if (rerun_loop_analysis) { DCHECK(!outer_graph->HasIrreducibleLoops()) << "Recomputing loop information in graphs with irreducible loops " << "is unsupported, as it could lead to loop header changes"; outer_graph->ClearLoopInformation(); outer_graph->ClearDominanceInformation(); outer_graph->BuildDominatorTree(); } else if (rerun_dominance) { outer_graph->ClearDominanceInformation(); outer_graph->ComputeDominanceInformation(); } } // 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 (allocator_) HBasicBlock(this, header->GetDexPc()); HBasicBlock* true_block = new (allocator_) HBasicBlock(this, header->GetDexPc()); HBasicBlock* false_block = new (allocator_) HBasicBlock(this, header->GetDexPc()); HBasicBlock* new_pre_header = new (allocator_) 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); } HBasicBlock* HGraph::TransformLoopForVectorization(HBasicBlock* header, HBasicBlock* body, HBasicBlock* exit) { DCHECK(header->IsLoopHeader()); HLoopInformation* loop = header->GetLoopInformation(); // Add new loop blocks. HBasicBlock* new_pre_header = new (allocator_) HBasicBlock(this, header->GetDexPc()); HBasicBlock* new_header = new (allocator_) HBasicBlock(this, header->GetDexPc()); HBasicBlock* new_body = new (allocator_) HBasicBlock(this, header->GetDexPc()); AddBlock(new_pre_header); AddBlock(new_header); AddBlock(new_body); // Set up control flow. header->ReplaceSuccessor(exit, new_pre_header); new_pre_header->AddSuccessor(new_header); new_header->AddSuccessor(exit); new_header->AddSuccessor(new_body); new_body->AddSuccessor(new_header); // Set up dominators. header->ReplaceDominatedBlock(exit, new_pre_header); new_pre_header->SetDominator(header); new_pre_header->dominated_blocks_.push_back(new_header); new_header->SetDominator(new_pre_header); new_header->dominated_blocks_.push_back(new_body); new_body->SetDominator(new_header); new_header->dominated_blocks_.push_back(exit); exit->SetDominator(new_header); // Fix reverse post order. size_t index_of_header = IndexOfElement(reverse_post_order_, header); MakeRoomFor(&reverse_post_order_, 2, index_of_header); reverse_post_order_[++index_of_header] = new_pre_header; reverse_post_order_[++index_of_header] = new_header; size_t index_of_body = IndexOfElement(reverse_post_order_, body); MakeRoomFor(&reverse_post_order_, 1, index_of_body - 1); reverse_post_order_[index_of_body] = new_body; // Add gotos and suspend check (client must add conditional in header). new_pre_header->AddInstruction(new (allocator_) HGoto()); HSuspendCheck* suspend_check = new (allocator_) HSuspendCheck(header->GetDexPc()); new_header->AddInstruction(suspend_check); new_body->AddInstruction(new (allocator_) HGoto()); suspend_check->CopyEnvironmentFromWithLoopPhiAdjustment( loop->GetSuspendCheck()->GetEnvironment(), header); // Update loop information. new_header->AddBackEdge(new_body); new_header->GetLoopInformation()->SetSuspendCheck(suspend_check); new_header->GetLoopInformation()->Populate(); new_pre_header->SetLoopInformation(loop->GetPreHeader()->GetLoopInformation()); // outward HLoopInformationOutwardIterator it(*new_header); for (it.Advance(); !it.Done(); it.Advance()) { it.Current()->Add(new_pre_header); it.Current()->Add(new_header); it.Current()->Add(new_body); } return new_pre_header; } static void CheckAgainstUpperBound(ReferenceTypeInfo rti, ReferenceTypeInfo upper_bound_rti) REQUIRES_SHARED(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(), DataType::Type::kReference); 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()); } bool HBoundType::InstructionDataEquals(const HInstruction* other) const { const HBoundType* other_bt = other->AsBoundType(); ScopedObjectAccess soa(Thread::Current()); return GetUpperBound().IsEqual(other_bt->GetUpperBound()) && GetUpperCanBeNull() == other_bt->GetUpperCanBeNull() && CanBeNull() == other_bt->CanBeNull(); } 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)); 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() ? "?" : mirror::Class::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 { return GetEntrypoint() == kQuickAllocStringObject; } bool HInvoke::NeedsEnvironment() const { if (!IsIntrinsic()) { return true; } IntrinsicOptimizations opt(*this); return !opt.GetDoesNotNeedEnvironment(); } const DexFile& HInvokeStaticOrDirect::GetDexFileForPcRelativeDexCache() const { ArtMethod* caller = GetEnvironment()->GetMethod(); ScopedObjectAccess soa(Thread::Current()); // `caller` is null for a top-level graph representing a method whose declaring // class was not resolved. return caller == nullptr ? GetBlock()->GetGraph()->GetDexFile() : *caller->GetDexFile(); } bool HInvokeStaticOrDirect::NeedsDexCacheOfDeclaringClass() const { if (GetMethodLoadKind() != MethodLoadKind::kRuntimeCall) { return false; } if (!IsIntrinsic()) { return true; } IntrinsicOptimizations opt(*this); return !opt.GetDoesNotNeedDexCache(); } std::ostream& operator<<(std::ostream& os, HInvokeStaticOrDirect::MethodLoadKind rhs) { switch (rhs) { case HInvokeStaticOrDirect::MethodLoadKind::kStringInit: return os << "StringInit"; case HInvokeStaticOrDirect::MethodLoadKind::kRecursive: return os << "Recursive"; case HInvokeStaticOrDirect::MethodLoadKind::kBootImageLinkTimePcRelative: return os << "BootImageLinkTimePcRelative"; case HInvokeStaticOrDirect::MethodLoadKind::kBootImageRelRo: return os << "BootImageRelRo"; case HInvokeStaticOrDirect::MethodLoadKind::kBssEntry: return os << "BssEntry"; case HInvokeStaticOrDirect::MethodLoadKind::kJitDirectAddress: return os << "JitDirectAddress"; case HInvokeStaticOrDirect::MethodLoadKind::kRuntimeCall: return os << "RuntimeCall"; 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 HLoadClass::InstructionDataEquals(const HInstruction* other) const { const HLoadClass* other_load_class = other->AsLoadClass(); // TODO: To allow GVN for HLoadClass from different dex files, we should compare the type // names rather than type indexes. However, we shall also have to re-think the hash code. if (type_index_ != other_load_class->type_index_ || GetPackedFields() != other_load_class->GetPackedFields()) { return false; } switch (GetLoadKind()) { case LoadKind::kBootImageRelRo: case LoadKind::kJitBootImageAddress: case LoadKind::kJitTableAddress: { ScopedObjectAccess soa(Thread::Current()); return GetClass().Get() == other_load_class->GetClass().Get(); } default: DCHECK(HasTypeReference(GetLoadKind())); return IsSameDexFile(GetDexFile(), other_load_class->GetDexFile()); } } std::ostream& operator<<(std::ostream& os, HLoadClass::LoadKind rhs) { switch (rhs) { case HLoadClass::LoadKind::kReferrersClass: return os << "ReferrersClass"; case HLoadClass::LoadKind::kBootImageLinkTimePcRelative: return os << "BootImageLinkTimePcRelative"; case HLoadClass::LoadKind::kBootImageRelRo: return os << "BootImageRelRo"; case HLoadClass::LoadKind::kBssEntry: return os << "BssEntry"; case HLoadClass::LoadKind::kJitBootImageAddress: return os << "JitBootImageAddress"; case HLoadClass::LoadKind::kJitTableAddress: return os << "JitTableAddress"; case HLoadClass::LoadKind::kRuntimeCall: return os << "RuntimeCall"; default: LOG(FATAL) << "Unknown HLoadClass::LoadKind: " << static_cast<int>(rhs); UNREACHABLE(); } } bool HLoadString::InstructionDataEquals(const HInstruction* other) const { const HLoadString* other_load_string = other->AsLoadString(); // TODO: To allow GVN for HLoadString from different dex files, we should compare the strings // rather than their indexes. However, we shall also have to re-think the hash code. if (string_index_ != other_load_string->string_index_ || GetPackedFields() != other_load_string->GetPackedFields()) { return false; } switch (GetLoadKind()) { case LoadKind::kBootImageRelRo: case LoadKind::kJitBootImageAddress: case LoadKind::kJitTableAddress: { ScopedObjectAccess soa(Thread::Current()); return GetString().Get() == other_load_string->GetString().Get(); } default: return IsSameDexFile(GetDexFile(), other_load_string->GetDexFile()); } } std::ostream& operator<<(std::ostream& os, HLoadString::LoadKind rhs) { switch (rhs) { case HLoadString::LoadKind::kBootImageLinkTimePcRelative: return os << "BootImageLinkTimePcRelative"; case HLoadString::LoadKind::kBootImageRelRo: return os << "BootImageRelRo"; case HLoadString::LoadKind::kBssEntry: return os << "BssEntry"; case HLoadString::LoadKind::kJitBootImageAddress: return os << "JitBootImageAddress"; case HLoadString::LoadKind::kJitTableAddress: return os << "JitTableAddress"; case HLoadString::LoadKind::kRuntimeCall: return os << "RuntimeCall"; default: LOG(FATAL) << "Unknown HLoadString::LoadKind: " << static_cast<int>(rhs); UNREACHABLE(); } } void HInstruction::RemoveEnvironmentUsers() { for (const HUseListNode<HEnvironment*>& use : GetEnvUses()) { HEnvironment* user = use.GetUser(); user->SetRawEnvAt(use.GetIndex(), nullptr); } env_uses_.clear(); } HInstruction* ReplaceInstrOrPhiByClone(HInstruction* instr) { HInstruction* clone = instr->Clone(instr->GetBlock()->GetGraph()->GetAllocator()); HBasicBlock* block = instr->GetBlock(); if (instr->IsPhi()) { HPhi* phi = instr->AsPhi(); DCHECK(!phi->HasEnvironment()); HPhi* phi_clone = clone->AsPhi(); block->ReplaceAndRemovePhiWith(phi, phi_clone); } else { block->ReplaceAndRemoveInstructionWith(instr, clone); if (instr->HasEnvironment()) { clone->CopyEnvironmentFrom(instr->GetEnvironment()); HLoopInformation* loop_info = block->GetLoopInformation(); if (instr->IsSuspendCheck() && loop_info != nullptr) { loop_info->SetSuspendCheck(clone->AsSuspendCheck()); } } } return clone; } // Returns an instruction with the opposite Boolean value from 'cond'. HInstruction* HGraph::InsertOppositeCondition(HInstruction* cond, HInstruction* cursor) { ArenaAllocator* allocator = GetAllocator(); if (cond->IsCondition() && !DataType::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) { os << rhs.GetInstruction()->DebugName() << ' ' << rhs.GetInstruction()->GetId(); } else { os << "null"; } os << " ]"; return os; } std::ostream& operator<<(std::ostream& os, TypeCheckKind rhs) { switch (rhs) { case TypeCheckKind::kUnresolvedCheck: return os << "unresolved_check"; case TypeCheckKind::kExactCheck: return os << "exact_check"; case TypeCheckKind::kClassHierarchyCheck: return os << "class_hierarchy_check"; case TypeCheckKind::kAbstractClassCheck: return os << "abstract_class_check"; case TypeCheckKind::kInterfaceCheck: return os << "interface_check"; case TypeCheckKind::kArrayObjectCheck: return os << "array_object_check"; case TypeCheckKind::kArrayCheck: return os << "array_check"; case TypeCheckKind::kBitstringCheck: return os << "bitstring_check"; default: LOG(FATAL) << "Unknown TypeCheckKind: " << static_cast<int>(rhs); UNREACHABLE(); } } std::ostream& operator<<(std::ostream& os, const MemBarrierKind& kind) { switch (kind) { case MemBarrierKind::kAnyStore: return os << "AnyStore"; case MemBarrierKind::kLoadAny: return os << "LoadAny"; case MemBarrierKind::kStoreStore: return os << "StoreStore"; case MemBarrierKind::kAnyAny: return os << "AnyAny"; case MemBarrierKind::kNTStoreStore: return os << "NTStoreStore"; default: LOG(FATAL) << "Unknown MemBarrierKind: " << static_cast<int>(kind); UNREACHABLE(); } } // Check that intrinsic enum values fit within space set aside in ArtMethod modifier flags. #define CHECK_INTRINSICS_ENUM_VALUES(Name, InvokeType, _, SideEffects, Exceptions, ...) \ static_assert( \ static_cast<uint32_t>(Intrinsics::k ## Name) <= (kAccIntrinsicBits >> CTZ(kAccIntrinsicBits)), \ "Instrinsics enumeration space overflow."); #include "intrinsics_list.h" INTRINSICS_LIST(CHECK_INTRINSICS_ENUM_VALUES) #undef INTRINSICS_LIST #undef CHECK_INTRINSICS_ENUM_VALUES // Function that returns whether an intrinsic needs an environment or not. static inline IntrinsicNeedsEnvironmentOrCache NeedsEnvironmentOrCacheIntrinsic(Intrinsics i) { switch (i) { case Intrinsics::kNone: return kNeedsEnvironmentOrCache; // Non-sensical for intrinsic. #define OPTIMIZING_INTRINSICS(Name, InvokeType, NeedsEnvOrCache, SideEffects, Exceptions, ...) \ case Intrinsics::k ## Name: \ return NeedsEnvOrCache; #include "intrinsics_list.h" INTRINSICS_LIST(OPTIMIZING_INTRINSICS) #undef INTRINSICS_LIST #undef OPTIMIZING_INTRINSICS } return kNeedsEnvironmentOrCache; } // Function that returns whether an intrinsic has side effects. static inline IntrinsicSideEffects GetSideEffectsIntrinsic(Intrinsics i) { switch (i) { case Intrinsics::kNone: return kAllSideEffects; #define OPTIMIZING_INTRINSICS(Name, InvokeType, NeedsEnvOrCache, SideEffects, Exceptions, ...) \ case Intrinsics::k ## Name: \ return SideEffects; #include "intrinsics_list.h" INTRINSICS_LIST(OPTIMIZING_INTRINSICS) #undef INTRINSICS_LIST #undef OPTIMIZING_INTRINSICS } return kAllSideEffects; } // Function that returns whether an intrinsic can throw exceptions. static inline IntrinsicExceptions GetExceptionsIntrinsic(Intrinsics i) { switch (i) { case Intrinsics::kNone: return kCanThrow; #define OPTIMIZING_INTRINSICS(Name, InvokeType, NeedsEnvOrCache, SideEffects, Exceptions, ...) \ case Intrinsics::k ## Name: \ return Exceptions; #include "intrinsics_list.h" INTRINSICS_LIST(OPTIMIZING_INTRINSICS) #undef INTRINSICS_LIST #undef OPTIMIZING_INTRINSICS } return kCanThrow; } void HInvoke::SetResolvedMethod(ArtMethod* method) { // TODO: b/65872996 The intent is that polymorphic signature methods should // be compiler intrinsics. At present, they are only interpreter intrinsics. if (method != nullptr && method->IsIntrinsic() && !method->IsPolymorphicSignature()) { Intrinsics intrinsic = static_cast<Intrinsics>(method->GetIntrinsic()); SetIntrinsic(intrinsic, NeedsEnvironmentOrCacheIntrinsic(intrinsic), GetSideEffectsIntrinsic(intrinsic), GetExceptionsIntrinsic(intrinsic)); } resolved_method_ = method; } } // namespace art