| /* |
| * Copyright (C) 2011 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 "base/bit_vector-inl.h" |
| #include "base/logging.h" |
| #include "base/scoped_arena_containers.h" |
| #include "dataflow_iterator-inl.h" |
| #include "dex_flags.h" |
| #include "driver/compiler_driver.h" |
| #include "driver/dex_compilation_unit.h" |
| #include "global_value_numbering.h" |
| #include "gvn_dead_code_elimination.h" |
| #include "local_value_numbering.h" |
| #include "mir_field_info.h" |
| #include "quick/dex_file_method_inliner.h" |
| #include "quick/dex_file_to_method_inliner_map.h" |
| #include "stack.h" |
| |
| namespace art { |
| |
| static unsigned int Predecessors(BasicBlock* bb) { |
| return bb->predecessors.size(); |
| } |
| |
| /* Setup a constant value for opcodes thare have the DF_SETS_CONST attribute */ |
| void MIRGraph::SetConstant(int32_t ssa_reg, int32_t value) { |
| is_constant_v_->SetBit(ssa_reg); |
| constant_values_[ssa_reg] = value; |
| reg_location_[ssa_reg].is_const = true; |
| } |
| |
| void MIRGraph::SetConstantWide(int32_t ssa_reg, int64_t value) { |
| is_constant_v_->SetBit(ssa_reg); |
| is_constant_v_->SetBit(ssa_reg + 1); |
| constant_values_[ssa_reg] = Low32Bits(value); |
| constant_values_[ssa_reg + 1] = High32Bits(value); |
| reg_location_[ssa_reg].is_const = true; |
| reg_location_[ssa_reg + 1].is_const = true; |
| } |
| |
| void MIRGraph::DoConstantPropagation(BasicBlock* bb) { |
| MIR* mir; |
| |
| for (mir = bb->first_mir_insn; mir != NULL; mir = mir->next) { |
| // Skip pass if BB has MIR without SSA representation. |
| if (mir->ssa_rep == nullptr) { |
| return; |
| } |
| |
| uint64_t df_attributes = GetDataFlowAttributes(mir); |
| |
| MIR::DecodedInstruction* d_insn = &mir->dalvikInsn; |
| |
| if (!(df_attributes & DF_HAS_DEFS)) continue; |
| |
| /* Handle instructions that set up constants directly */ |
| if (df_attributes & DF_SETS_CONST) { |
| if (df_attributes & DF_DA) { |
| int32_t vB = static_cast<int32_t>(d_insn->vB); |
| switch (d_insn->opcode) { |
| case Instruction::CONST_4: |
| case Instruction::CONST_16: |
| case Instruction::CONST: |
| SetConstant(mir->ssa_rep->defs[0], vB); |
| break; |
| case Instruction::CONST_HIGH16: |
| SetConstant(mir->ssa_rep->defs[0], vB << 16); |
| break; |
| case Instruction::CONST_WIDE_16: |
| case Instruction::CONST_WIDE_32: |
| SetConstantWide(mir->ssa_rep->defs[0], static_cast<int64_t>(vB)); |
| break; |
| case Instruction::CONST_WIDE: |
| SetConstantWide(mir->ssa_rep->defs[0], d_insn->vB_wide); |
| break; |
| case Instruction::CONST_WIDE_HIGH16: |
| SetConstantWide(mir->ssa_rep->defs[0], static_cast<int64_t>(vB) << 48); |
| break; |
| default: |
| break; |
| } |
| } |
| /* Handle instructions that set up constants directly */ |
| } else if (df_attributes & DF_IS_MOVE) { |
| int i; |
| |
| for (i = 0; i < mir->ssa_rep->num_uses; i++) { |
| if (!is_constant_v_->IsBitSet(mir->ssa_rep->uses[i])) break; |
| } |
| /* Move a register holding a constant to another register */ |
| if (i == mir->ssa_rep->num_uses) { |
| SetConstant(mir->ssa_rep->defs[0], constant_values_[mir->ssa_rep->uses[0]]); |
| if (df_attributes & DF_A_WIDE) { |
| SetConstant(mir->ssa_rep->defs[1], constant_values_[mir->ssa_rep->uses[1]]); |
| } |
| } |
| } |
| } |
| /* TODO: implement code to handle arithmetic operations */ |
| } |
| |
| /* Advance to next strictly dominated MIR node in an extended basic block */ |
| MIR* MIRGraph::AdvanceMIR(BasicBlock** p_bb, MIR* mir) { |
| BasicBlock* bb = *p_bb; |
| if (mir != NULL) { |
| mir = mir->next; |
| while (mir == NULL) { |
| bb = GetBasicBlock(bb->fall_through); |
| if ((bb == NULL) || Predecessors(bb) != 1) { |
| // mir is null and we cannot proceed further. |
| break; |
| } else { |
| *p_bb = bb; |
| mir = bb->first_mir_insn; |
| } |
| } |
| } |
| return mir; |
| } |
| |
| /* |
| * To be used at an invoke mir. If the logically next mir node represents |
| * a move-result, return it. Else, return NULL. If a move-result exists, |
| * it is required to immediately follow the invoke with no intervening |
| * opcodes or incoming arcs. However, if the result of the invoke is not |
| * used, a move-result may not be present. |
| */ |
| MIR* MIRGraph::FindMoveResult(BasicBlock* bb, MIR* mir) { |
| BasicBlock* tbb = bb; |
| mir = AdvanceMIR(&tbb, mir); |
| while (mir != NULL) { |
| if ((mir->dalvikInsn.opcode == Instruction::MOVE_RESULT) || |
| (mir->dalvikInsn.opcode == Instruction::MOVE_RESULT_OBJECT) || |
| (mir->dalvikInsn.opcode == Instruction::MOVE_RESULT_WIDE)) { |
| break; |
| } |
| // Keep going if pseudo op, otherwise terminate |
| if (MIR::DecodedInstruction::IsPseudoMirOp(mir->dalvikInsn.opcode)) { |
| mir = AdvanceMIR(&tbb, mir); |
| } else { |
| mir = NULL; |
| } |
| } |
| return mir; |
| } |
| |
| BasicBlock* MIRGraph::NextDominatedBlock(BasicBlock* bb) { |
| if (bb->block_type == kDead) { |
| return NULL; |
| } |
| DCHECK((bb->block_type == kEntryBlock) || (bb->block_type == kDalvikByteCode) |
| || (bb->block_type == kExitBlock)); |
| BasicBlock* bb_taken = GetBasicBlock(bb->taken); |
| BasicBlock* bb_fall_through = GetBasicBlock(bb->fall_through); |
| if (((bb_fall_through == NULL) && (bb_taken != NULL)) && |
| ((bb_taken->block_type == kDalvikByteCode) || (bb_taken->block_type == kExitBlock))) { |
| // Follow simple unconditional branches. |
| bb = bb_taken; |
| } else { |
| // Follow simple fallthrough |
| bb = (bb_taken != NULL) ? NULL : bb_fall_through; |
| } |
| if (bb == NULL || (Predecessors(bb) != 1)) { |
| return NULL; |
| } |
| DCHECK((bb->block_type == kDalvikByteCode) || (bb->block_type == kExitBlock)); |
| return bb; |
| } |
| |
| static MIR* FindPhi(BasicBlock* bb, int ssa_name) { |
| for (MIR* mir = bb->first_mir_insn; mir != NULL; mir = mir->next) { |
| if (static_cast<int>(mir->dalvikInsn.opcode) == kMirOpPhi) { |
| for (int i = 0; i < mir->ssa_rep->num_uses; i++) { |
| if (mir->ssa_rep->uses[i] == ssa_name) { |
| return mir; |
| } |
| } |
| } |
| } |
| return NULL; |
| } |
| |
| static SelectInstructionKind SelectKind(MIR* mir) { |
| // Work with the case when mir is nullptr. |
| if (mir == nullptr) { |
| return kSelectNone; |
| } |
| switch (mir->dalvikInsn.opcode) { |
| case Instruction::MOVE: |
| case Instruction::MOVE_OBJECT: |
| case Instruction::MOVE_16: |
| case Instruction::MOVE_OBJECT_16: |
| case Instruction::MOVE_FROM16: |
| case Instruction::MOVE_OBJECT_FROM16: |
| return kSelectMove; |
| case Instruction::CONST: |
| case Instruction::CONST_4: |
| case Instruction::CONST_16: |
| return kSelectConst; |
| case Instruction::GOTO: |
| case Instruction::GOTO_16: |
| case Instruction::GOTO_32: |
| return kSelectGoto; |
| default: |
| return kSelectNone; |
| } |
| } |
| |
| static constexpr ConditionCode kIfCcZConditionCodes[] = { |
| kCondEq, kCondNe, kCondLt, kCondGe, kCondGt, kCondLe |
| }; |
| |
| static_assert(arraysize(kIfCcZConditionCodes) == Instruction::IF_LEZ - Instruction::IF_EQZ + 1, |
| "if_ccz_ccodes_size1"); |
| |
| static constexpr ConditionCode ConditionCodeForIfCcZ(Instruction::Code opcode) { |
| return kIfCcZConditionCodes[opcode - Instruction::IF_EQZ]; |
| } |
| |
| static_assert(ConditionCodeForIfCcZ(Instruction::IF_EQZ) == kCondEq, "if_eqz ccode"); |
| static_assert(ConditionCodeForIfCcZ(Instruction::IF_NEZ) == kCondNe, "if_nez ccode"); |
| static_assert(ConditionCodeForIfCcZ(Instruction::IF_LTZ) == kCondLt, "if_ltz ccode"); |
| static_assert(ConditionCodeForIfCcZ(Instruction::IF_GEZ) == kCondGe, "if_gez ccode"); |
| static_assert(ConditionCodeForIfCcZ(Instruction::IF_GTZ) == kCondGt, "if_gtz ccode"); |
| static_assert(ConditionCodeForIfCcZ(Instruction::IF_LEZ) == kCondLe, "if_lez ccode"); |
| |
| int MIRGraph::GetSSAUseCount(int s_reg) { |
| DCHECK_LT(static_cast<size_t>(s_reg), ssa_subscripts_.size()); |
| return raw_use_counts_[s_reg]; |
| } |
| |
| size_t MIRGraph::GetNumBytesForSpecialTemps() const { |
| // This logic is written with assumption that Method* is only special temp. |
| DCHECK_EQ(max_available_special_compiler_temps_, 1u); |
| return sizeof(StackReference<mirror::ArtMethod>); |
| } |
| |
| size_t MIRGraph::GetNumAvailableVRTemps() { |
| // First take into account all temps reserved for backend. |
| if (max_available_non_special_compiler_temps_ < reserved_temps_for_backend_) { |
| return 0; |
| } |
| |
| // Calculate remaining ME temps available. |
| size_t remaining_me_temps = max_available_non_special_compiler_temps_ - reserved_temps_for_backend_; |
| |
| if (num_non_special_compiler_temps_ >= remaining_me_temps) { |
| return 0; |
| } else { |
| return remaining_me_temps - num_non_special_compiler_temps_; |
| } |
| } |
| |
| // FIXME - will probably need to revisit all uses of this, as type not defined. |
| static const RegLocation temp_loc = {kLocCompilerTemp, |
| 0, 1 /*defined*/, 0, 0, 0, 0, 0, 1 /*home*/, |
| RegStorage(), INVALID_SREG, INVALID_SREG}; |
| |
| CompilerTemp* MIRGraph::GetNewCompilerTemp(CompilerTempType ct_type, bool wide) { |
| // Once the compiler temps have been committed, new ones cannot be requested anymore. |
| DCHECK_EQ(compiler_temps_committed_, false); |
| // Make sure that reserved for BE set is sane. |
| DCHECK_LE(reserved_temps_for_backend_, max_available_non_special_compiler_temps_); |
| |
| bool verbose = cu_->verbose; |
| const char* ct_type_str = nullptr; |
| |
| if (verbose) { |
| switch (ct_type) { |
| case kCompilerTempBackend: |
| ct_type_str = "backend"; |
| break; |
| case kCompilerTempSpecialMethodPtr: |
| ct_type_str = "method*"; |
| break; |
| case kCompilerTempVR: |
| ct_type_str = "VR"; |
| break; |
| default: |
| ct_type_str = "unknown"; |
| break; |
| } |
| LOG(INFO) << "CompilerTemps: A compiler temp of type " << ct_type_str << " that is " |
| << (wide ? "wide is being requested." : "not wide is being requested."); |
| } |
| |
| CompilerTemp *compiler_temp = static_cast<CompilerTemp *>(arena_->Alloc(sizeof(CompilerTemp), |
| kArenaAllocRegAlloc)); |
| |
| // Create the type of temp requested. Special temps need special handling because |
| // they have a specific virtual register assignment. |
| if (ct_type == kCompilerTempSpecialMethodPtr) { |
| // This has a special location on stack which is 32-bit or 64-bit depending |
| // on mode. However, we don't want to overlap with non-special section |
| // and thus even for 64-bit, we allow only a non-wide temp to be requested. |
| DCHECK_EQ(wide, false); |
| |
| // The vreg is always the first special temp for method ptr. |
| compiler_temp->v_reg = GetFirstSpecialTempVR(); |
| |
| } else if (ct_type == kCompilerTempBackend) { |
| requested_backend_temp_ = true; |
| |
| // Make sure that we are not exceeding temps reserved for BE. |
| // Since VR temps cannot be requested once the BE temps are requested, we |
| // allow reservation of VR temps as well for BE. We |
| size_t available_temps = reserved_temps_for_backend_ + GetNumAvailableVRTemps(); |
| if (available_temps <= 0 || (available_temps <= 1 && wide)) { |
| if (verbose) { |
| LOG(INFO) << "CompilerTemps: Not enough temp(s) of type " << ct_type_str << " are available."; |
| } |
| return nullptr; |
| } |
| |
| // Update the remaining reserved temps since we have now used them. |
| // Note that the code below is actually subtracting to remove them from reserve |
| // once they have been claimed. It is careful to not go below zero. |
| if (reserved_temps_for_backend_ >= 1) { |
| reserved_temps_for_backend_--; |
| } |
| if (wide && reserved_temps_for_backend_ >= 1) { |
| reserved_temps_for_backend_--; |
| } |
| |
| // The new non-special compiler temp must receive a unique v_reg. |
| compiler_temp->v_reg = GetFirstNonSpecialTempVR() + num_non_special_compiler_temps_; |
| num_non_special_compiler_temps_++; |
| } else if (ct_type == kCompilerTempVR) { |
| // Once we start giving out BE temps, we don't allow anymore ME temps to be requested. |
| // This is done in order to prevent problems with ssa since these structures are allocated |
| // and managed by the ME. |
| DCHECK_EQ(requested_backend_temp_, false); |
| |
| // There is a limit to the number of non-special temps so check to make sure it wasn't exceeded. |
| size_t available_temps = GetNumAvailableVRTemps(); |
| if (available_temps <= 0 || (available_temps <= 1 && wide)) { |
| if (verbose) { |
| LOG(INFO) << "CompilerTemps: Not enough temp(s) of type " << ct_type_str << " are available."; |
| } |
| return nullptr; |
| } |
| |
| // The new non-special compiler temp must receive a unique v_reg. |
| compiler_temp->v_reg = GetFirstNonSpecialTempVR() + num_non_special_compiler_temps_; |
| num_non_special_compiler_temps_++; |
| } else { |
| UNIMPLEMENTED(FATAL) << "No handling for compiler temp type " << ct_type_str << "."; |
| } |
| |
| // We allocate an sreg as well to make developer life easier. |
| // However, if this is requested from an ME pass that will recalculate ssa afterwards, |
| // this sreg is no longer valid. The caller should be aware of this. |
| compiler_temp->s_reg_low = AddNewSReg(compiler_temp->v_reg); |
| |
| if (verbose) { |
| LOG(INFO) << "CompilerTemps: New temp of type " << ct_type_str << " with v" << compiler_temp->v_reg |
| << " and s" << compiler_temp->s_reg_low << " has been created."; |
| } |
| |
| if (wide) { |
| // Only non-special temps are handled as wide for now. |
| // Note that the number of non special temps is incremented below. |
| DCHECK(ct_type == kCompilerTempBackend || ct_type == kCompilerTempVR); |
| |
| // Ensure that the two registers are consecutive. |
| int ssa_reg_low = compiler_temp->s_reg_low; |
| int ssa_reg_high = AddNewSReg(compiler_temp->v_reg + 1); |
| num_non_special_compiler_temps_++; |
| |
| if (verbose) { |
| LOG(INFO) << "CompilerTemps: The wide part of temp of type " << ct_type_str << " is v" |
| << compiler_temp->v_reg + 1 << " and s" << ssa_reg_high << "."; |
| } |
| |
| if (reg_location_ != nullptr) { |
| reg_location_[ssa_reg_high] = temp_loc; |
| reg_location_[ssa_reg_high].high_word = true; |
| reg_location_[ssa_reg_high].s_reg_low = ssa_reg_low; |
| reg_location_[ssa_reg_high].wide = true; |
| } |
| } |
| |
| // If the register locations have already been allocated, add the information |
| // about the temp. We will not overflow because they have been initialized |
| // to support the maximum number of temps. For ME temps that have multiple |
| // ssa versions, the structures below will be expanded on the post pass cleanup. |
| if (reg_location_ != nullptr) { |
| int ssa_reg_low = compiler_temp->s_reg_low; |
| reg_location_[ssa_reg_low] = temp_loc; |
| reg_location_[ssa_reg_low].s_reg_low = ssa_reg_low; |
| reg_location_[ssa_reg_low].wide = wide; |
| } |
| |
| return compiler_temp; |
| } |
| |
| static bool EvaluateBranch(Instruction::Code opcode, int32_t src1, int32_t src2) { |
| bool is_taken; |
| switch (opcode) { |
| case Instruction::IF_EQ: is_taken = (src1 == src2); break; |
| case Instruction::IF_NE: is_taken = (src1 != src2); break; |
| case Instruction::IF_LT: is_taken = (src1 < src2); break; |
| case Instruction::IF_GE: is_taken = (src1 >= src2); break; |
| case Instruction::IF_GT: is_taken = (src1 > src2); break; |
| case Instruction::IF_LE: is_taken = (src1 <= src2); break; |
| case Instruction::IF_EQZ: is_taken = (src1 == 0); break; |
| case Instruction::IF_NEZ: is_taken = (src1 != 0); break; |
| case Instruction::IF_LTZ: is_taken = (src1 < 0); break; |
| case Instruction::IF_GEZ: is_taken = (src1 >= 0); break; |
| case Instruction::IF_GTZ: is_taken = (src1 > 0); break; |
| case Instruction::IF_LEZ: is_taken = (src1 <= 0); break; |
| default: |
| LOG(FATAL) << "Unexpected opcode " << opcode; |
| UNREACHABLE(); |
| } |
| return is_taken; |
| } |
| |
| /* Do some MIR-level extended basic block optimizations */ |
| bool MIRGraph::BasicBlockOpt(BasicBlock* bb) { |
| if (bb->block_type == kDead) { |
| return true; |
| } |
| // Currently multiply-accumulate backend supports are only available on arm32 and arm64. |
| if (cu_->instruction_set == kArm64 || cu_->instruction_set == kThumb2) { |
| MultiplyAddOpt(bb); |
| } |
| bool use_lvn = bb->use_lvn && (cu_->disable_opt & (1u << kLocalValueNumbering)) == 0u; |
| std::unique_ptr<ScopedArenaAllocator> allocator; |
| std::unique_ptr<GlobalValueNumbering> global_valnum; |
| std::unique_ptr<LocalValueNumbering> local_valnum; |
| if (use_lvn) { |
| allocator.reset(ScopedArenaAllocator::Create(&cu_->arena_stack)); |
| global_valnum.reset(new (allocator.get()) GlobalValueNumbering(cu_, allocator.get(), |
| GlobalValueNumbering::kModeLvn)); |
| local_valnum.reset(new (allocator.get()) LocalValueNumbering(global_valnum.get(), bb->id, |
| allocator.get())); |
| } |
| while (bb != NULL) { |
| for (MIR* mir = bb->first_mir_insn; mir != NULL; mir = mir->next) { |
| // TUNING: use the returned value number for CSE. |
| if (use_lvn) { |
| local_valnum->GetValueNumber(mir); |
| } |
| // Look for interesting opcodes, skip otherwise |
| Instruction::Code opcode = mir->dalvikInsn.opcode; |
| switch (opcode) { |
| case Instruction::IF_EQ: |
| case Instruction::IF_NE: |
| case Instruction::IF_LT: |
| case Instruction::IF_GE: |
| case Instruction::IF_GT: |
| case Instruction::IF_LE: |
| if (!IsConst(mir->ssa_rep->uses[1])) { |
| break; |
| } |
| FALLTHROUGH_INTENDED; |
| case Instruction::IF_EQZ: |
| case Instruction::IF_NEZ: |
| case Instruction::IF_LTZ: |
| case Instruction::IF_GEZ: |
| case Instruction::IF_GTZ: |
| case Instruction::IF_LEZ: |
| // Result known at compile time? |
| if (IsConst(mir->ssa_rep->uses[0])) { |
| int32_t rhs = (mir->ssa_rep->num_uses == 2) ? ConstantValue(mir->ssa_rep->uses[1]) : 0; |
| bool is_taken = EvaluateBranch(opcode, ConstantValue(mir->ssa_rep->uses[0]), rhs); |
| BasicBlockId edge_to_kill = is_taken ? bb->fall_through : bb->taken; |
| if (is_taken) { |
| // Replace with GOTO. |
| bb->fall_through = NullBasicBlockId; |
| mir->dalvikInsn.opcode = Instruction::GOTO; |
| mir->dalvikInsn.vA = |
| IsInstructionIfCc(opcode) ? mir->dalvikInsn.vC : mir->dalvikInsn.vB; |
| } else { |
| // Make NOP. |
| bb->taken = NullBasicBlockId; |
| mir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpNop); |
| } |
| mir->ssa_rep->num_uses = 0; |
| BasicBlock* successor_to_unlink = GetBasicBlock(edge_to_kill); |
| successor_to_unlink->ErasePredecessor(bb->id); |
| // We have changed the graph structure. |
| dfs_orders_up_to_date_ = false; |
| domination_up_to_date_ = false; |
| topological_order_up_to_date_ = false; |
| // Keep MIR SSA rep, the worst that can happen is a Phi with just 1 input. |
| } |
| break; |
| case Instruction::CMPL_FLOAT: |
| case Instruction::CMPL_DOUBLE: |
| case Instruction::CMPG_FLOAT: |
| case Instruction::CMPG_DOUBLE: |
| case Instruction::CMP_LONG: |
| if ((cu_->disable_opt & (1 << kBranchFusing)) != 0) { |
| // Bitcode doesn't allow this optimization. |
| break; |
| } |
| if (mir->next != NULL) { |
| MIR* mir_next = mir->next; |
| // Make sure result of cmp is used by next insn and nowhere else |
| if (IsInstructionIfCcZ(mir_next->dalvikInsn.opcode) && |
| (mir->ssa_rep->defs[0] == mir_next->ssa_rep->uses[0]) && |
| (GetSSAUseCount(mir->ssa_rep->defs[0]) == 1)) { |
| mir_next->meta.ccode = ConditionCodeForIfCcZ(mir_next->dalvikInsn.opcode); |
| switch (opcode) { |
| case Instruction::CMPL_FLOAT: |
| mir_next->dalvikInsn.opcode = |
| static_cast<Instruction::Code>(kMirOpFusedCmplFloat); |
| break; |
| case Instruction::CMPL_DOUBLE: |
| mir_next->dalvikInsn.opcode = |
| static_cast<Instruction::Code>(kMirOpFusedCmplDouble); |
| break; |
| case Instruction::CMPG_FLOAT: |
| mir_next->dalvikInsn.opcode = |
| static_cast<Instruction::Code>(kMirOpFusedCmpgFloat); |
| break; |
| case Instruction::CMPG_DOUBLE: |
| mir_next->dalvikInsn.opcode = |
| static_cast<Instruction::Code>(kMirOpFusedCmpgDouble); |
| break; |
| case Instruction::CMP_LONG: |
| mir_next->dalvikInsn.opcode = |
| static_cast<Instruction::Code>(kMirOpFusedCmpLong); |
| break; |
| default: LOG(ERROR) << "Unexpected opcode: " << opcode; |
| } |
| mir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpNop); |
| // Clear use count of temp VR. |
| use_counts_[mir->ssa_rep->defs[0]] = 0; |
| raw_use_counts_[mir->ssa_rep->defs[0]] = 0; |
| // Copy the SSA information that is relevant. |
| mir_next->ssa_rep->num_uses = mir->ssa_rep->num_uses; |
| mir_next->ssa_rep->uses = mir->ssa_rep->uses; |
| mir_next->ssa_rep->fp_use = mir->ssa_rep->fp_use; |
| mir_next->ssa_rep->num_defs = 0; |
| mir->ssa_rep->num_uses = 0; |
| mir->ssa_rep->num_defs = 0; |
| // Copy in the decoded instruction information for potential SSA re-creation. |
| mir_next->dalvikInsn.vA = mir->dalvikInsn.vB; |
| mir_next->dalvikInsn.vB = mir->dalvikInsn.vC; |
| } |
| } |
| break; |
| default: |
| break; |
| } |
| // Is this the select pattern? |
| // TODO: flesh out support for Mips. NOTE: llvm's select op doesn't quite work here. |
| // TUNING: expand to support IF_xx compare & branches |
| if ((cu_->instruction_set == kArm64 || cu_->instruction_set == kThumb2 || |
| cu_->instruction_set == kX86 || cu_->instruction_set == kX86_64) && |
| IsInstructionIfCcZ(mir->dalvikInsn.opcode)) { |
| BasicBlock* ft = GetBasicBlock(bb->fall_through); |
| DCHECK(ft != NULL); |
| BasicBlock* ft_ft = GetBasicBlock(ft->fall_through); |
| BasicBlock* ft_tk = GetBasicBlock(ft->taken); |
| |
| BasicBlock* tk = GetBasicBlock(bb->taken); |
| DCHECK(tk != NULL); |
| BasicBlock* tk_ft = GetBasicBlock(tk->fall_through); |
| BasicBlock* tk_tk = GetBasicBlock(tk->taken); |
| |
| /* |
| * In the select pattern, the taken edge goes to a block that unconditionally |
| * transfers to the rejoin block and the fall_though edge goes to a block that |
| * unconditionally falls through to the rejoin block. |
| */ |
| if ((tk_ft == NULL) && (ft_tk == NULL) && (tk_tk == ft_ft) && |
| (Predecessors(tk) == 1) && (Predecessors(ft) == 1)) { |
| /* |
| * Okay - we have the basic diamond shape. |
| */ |
| |
| // TODO: Add logic for LONG. |
| // Are the block bodies something we can handle? |
| if ((ft->first_mir_insn == ft->last_mir_insn) && |
| (tk->first_mir_insn != tk->last_mir_insn) && |
| (tk->first_mir_insn->next == tk->last_mir_insn) && |
| ((SelectKind(ft->first_mir_insn) == kSelectMove) || |
| (SelectKind(ft->first_mir_insn) == kSelectConst)) && |
| (SelectKind(ft->first_mir_insn) == SelectKind(tk->first_mir_insn)) && |
| (SelectKind(tk->last_mir_insn) == kSelectGoto)) { |
| // Almost there. Are the instructions targeting the same vreg? |
| MIR* if_true = tk->first_mir_insn; |
| MIR* if_false = ft->first_mir_insn; |
| // It's possible that the target of the select isn't used - skip those (rare) cases. |
| MIR* phi = FindPhi(tk_tk, if_true->ssa_rep->defs[0]); |
| if ((phi != NULL) && (if_true->dalvikInsn.vA == if_false->dalvikInsn.vA)) { |
| /* |
| * We'll convert the IF_EQZ/IF_NEZ to a SELECT. We need to find the |
| * Phi node in the merge block and delete it (while using the SSA name |
| * of the merge as the target of the SELECT. Delete both taken and |
| * fallthrough blocks, and set fallthrough to merge block. |
| * NOTE: not updating other dataflow info (no longer used at this point). |
| * If this changes, need to update i_dom, etc. here (and in CombineBlocks). |
| */ |
| mir->meta.ccode = ConditionCodeForIfCcZ(mir->dalvikInsn.opcode); |
| mir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpSelect); |
| bool const_form = (SelectKind(if_true) == kSelectConst); |
| if ((SelectKind(if_true) == kSelectMove)) { |
| if (IsConst(if_true->ssa_rep->uses[0]) && |
| IsConst(if_false->ssa_rep->uses[0])) { |
| const_form = true; |
| if_true->dalvikInsn.vB = ConstantValue(if_true->ssa_rep->uses[0]); |
| if_false->dalvikInsn.vB = ConstantValue(if_false->ssa_rep->uses[0]); |
| } |
| } |
| if (const_form) { |
| /* |
| * TODO: If both constants are the same value, then instead of generating |
| * a select, we should simply generate a const bytecode. This should be |
| * considered after inlining which can lead to CFG of this form. |
| */ |
| // "true" set val in vB |
| mir->dalvikInsn.vB = if_true->dalvikInsn.vB; |
| // "false" set val in vC |
| mir->dalvikInsn.vC = if_false->dalvikInsn.vB; |
| } else { |
| DCHECK_EQ(SelectKind(if_true), kSelectMove); |
| DCHECK_EQ(SelectKind(if_false), kSelectMove); |
| int32_t* src_ssa = arena_->AllocArray<int32_t>(3, kArenaAllocDFInfo); |
| src_ssa[0] = mir->ssa_rep->uses[0]; |
| src_ssa[1] = if_true->ssa_rep->uses[0]; |
| src_ssa[2] = if_false->ssa_rep->uses[0]; |
| mir->ssa_rep->uses = src_ssa; |
| mir->ssa_rep->num_uses = 3; |
| } |
| mir->ssa_rep->num_defs = 1; |
| mir->ssa_rep->defs = arena_->AllocArray<int32_t>(1, kArenaAllocDFInfo); |
| mir->ssa_rep->fp_def = arena_->AllocArray<bool>(1, kArenaAllocDFInfo); |
| mir->ssa_rep->fp_def[0] = if_true->ssa_rep->fp_def[0]; |
| // Match type of uses to def. |
| mir->ssa_rep->fp_use = arena_->AllocArray<bool>(mir->ssa_rep->num_uses, |
| kArenaAllocDFInfo); |
| for (int i = 0; i < mir->ssa_rep->num_uses; i++) { |
| mir->ssa_rep->fp_use[i] = mir->ssa_rep->fp_def[0]; |
| } |
| /* |
| * There is usually a Phi node in the join block for our two cases. If the |
| * Phi node only contains our two cases as input, we will use the result |
| * SSA name of the Phi node as our select result and delete the Phi. If |
| * the Phi node has more than two operands, we will arbitrarily use the SSA |
| * name of the "false" path, delete the SSA name of the "true" path from the |
| * Phi node (and fix up the incoming arc list). |
| */ |
| if (phi->ssa_rep->num_uses == 2) { |
| mir->ssa_rep->defs[0] = phi->ssa_rep->defs[0]; |
| // Rather than changing the Phi to kMirOpNop, remove it completely. |
| // This avoids leaving other Phis after kMirOpNop (i.e. a non-Phi) insn. |
| tk_tk->RemoveMIR(phi); |
| int dead_false_def = if_false->ssa_rep->defs[0]; |
| raw_use_counts_[dead_false_def] = use_counts_[dead_false_def] = 0; |
| } else { |
| int live_def = if_false->ssa_rep->defs[0]; |
| mir->ssa_rep->defs[0] = live_def; |
| } |
| int dead_true_def = if_true->ssa_rep->defs[0]; |
| raw_use_counts_[dead_true_def] = use_counts_[dead_true_def] = 0; |
| // We want to remove ft and tk and link bb directly to ft_ft. First, we need |
| // to update all Phi inputs correctly with UpdatePredecessor(ft->id, bb->id) |
| // since the live_def above comes from ft->first_mir_insn (if_false). |
| DCHECK(if_false == ft->first_mir_insn); |
| ft_ft->UpdatePredecessor(ft->id, bb->id); |
| // Correct the rest of the links between bb, ft and ft_ft. |
| ft->ErasePredecessor(bb->id); |
| ft->fall_through = NullBasicBlockId; |
| bb->fall_through = ft_ft->id; |
| // Now we can kill tk and ft. |
| tk->Kill(this); |
| ft->Kill(this); |
| // NOTE: DFS order, domination info and topological order are still usable |
| // despite the newly dead blocks. |
| } |
| } |
| } |
| } |
| } |
| bb = ((cu_->disable_opt & (1 << kSuppressExceptionEdges)) != 0) ? NextDominatedBlock(bb) : NULL; |
| } |
| if (use_lvn && UNLIKELY(!global_valnum->Good())) { |
| LOG(WARNING) << "LVN overflow in " << PrettyMethod(cu_->method_idx, *cu_->dex_file); |
| } |
| |
| return true; |
| } |
| |
| /* Collect stats on number of checks removed */ |
| void MIRGraph::CountChecks(class BasicBlock* bb) { |
| if (bb->data_flow_info != NULL) { |
| for (MIR* mir = bb->first_mir_insn; mir != NULL; mir = mir->next) { |
| if (mir->ssa_rep == NULL) { |
| continue; |
| } |
| uint64_t df_attributes = GetDataFlowAttributes(mir); |
| if (df_attributes & DF_HAS_NULL_CHKS) { |
| checkstats_->null_checks++; |
| if (mir->optimization_flags & MIR_IGNORE_NULL_CHECK) { |
| checkstats_->null_checks_eliminated++; |
| } |
| } |
| if (df_attributes & DF_HAS_RANGE_CHKS) { |
| checkstats_->range_checks++; |
| if (mir->optimization_flags & MIR_IGNORE_RANGE_CHECK) { |
| checkstats_->range_checks_eliminated++; |
| } |
| } |
| } |
| } |
| } |
| |
| /* Try to make common case the fallthrough path. */ |
| bool MIRGraph::LayoutBlocks(BasicBlock* bb) { |
| // TODO: For now, just looking for direct throws. Consider generalizing for profile feedback. |
| if (!bb->explicit_throw) { |
| return false; |
| } |
| |
| // If we visited it, we are done. |
| if (bb->visited) { |
| return false; |
| } |
| bb->visited = true; |
| |
| BasicBlock* walker = bb; |
| while (true) { |
| // Check termination conditions. |
| if ((walker->block_type == kEntryBlock) || (Predecessors(walker) != 1)) { |
| break; |
| } |
| DCHECK(!walker->predecessors.empty()); |
| BasicBlock* prev = GetBasicBlock(walker->predecessors[0]); |
| |
| // If we visited the predecessor, we are done. |
| if (prev->visited) { |
| return false; |
| } |
| prev->visited = true; |
| |
| if (prev->conditional_branch) { |
| if (GetBasicBlock(prev->fall_through) == walker) { |
| // Already done - return. |
| break; |
| } |
| DCHECK_EQ(walker, GetBasicBlock(prev->taken)); |
| // Got one. Flip it and exit. |
| Instruction::Code opcode = prev->last_mir_insn->dalvikInsn.opcode; |
| switch (opcode) { |
| case Instruction::IF_EQ: opcode = Instruction::IF_NE; break; |
| case Instruction::IF_NE: opcode = Instruction::IF_EQ; break; |
| case Instruction::IF_LT: opcode = Instruction::IF_GE; break; |
| case Instruction::IF_GE: opcode = Instruction::IF_LT; break; |
| case Instruction::IF_GT: opcode = Instruction::IF_LE; break; |
| case Instruction::IF_LE: opcode = Instruction::IF_GT; break; |
| case Instruction::IF_EQZ: opcode = Instruction::IF_NEZ; break; |
| case Instruction::IF_NEZ: opcode = Instruction::IF_EQZ; break; |
| case Instruction::IF_LTZ: opcode = Instruction::IF_GEZ; break; |
| case Instruction::IF_GEZ: opcode = Instruction::IF_LTZ; break; |
| case Instruction::IF_GTZ: opcode = Instruction::IF_LEZ; break; |
| case Instruction::IF_LEZ: opcode = Instruction::IF_GTZ; break; |
| default: LOG(FATAL) << "Unexpected opcode " << opcode; |
| } |
| prev->last_mir_insn->dalvikInsn.opcode = opcode; |
| BasicBlockId t_bb = prev->taken; |
| prev->taken = prev->fall_through; |
| prev->fall_through = t_bb; |
| break; |
| } |
| walker = prev; |
| } |
| return false; |
| } |
| |
| /* Combine any basic blocks terminated by instructions that we now know can't throw */ |
| void MIRGraph::CombineBlocks(class BasicBlock* bb) { |
| // Loop here to allow combining a sequence of blocks |
| while ((bb->block_type == kDalvikByteCode) && |
| (bb->last_mir_insn != nullptr) && |
| (static_cast<int>(bb->last_mir_insn->dalvikInsn.opcode) == kMirOpCheck)) { |
| MIR* mir = bb->last_mir_insn; |
| DCHECK(bb->first_mir_insn != nullptr); |
| |
| // Get the paired insn and check if it can still throw. |
| MIR* throw_insn = mir->meta.throw_insn; |
| if (CanThrow(throw_insn)) { |
| break; |
| } |
| |
| // OK - got one. Combine |
| BasicBlock* bb_next = GetBasicBlock(bb->fall_through); |
| DCHECK(!bb_next->catch_entry); |
| DCHECK_EQ(bb_next->predecessors.size(), 1u); |
| |
| // Now move instructions from bb_next to bb. Start off with doing a sanity check |
| // that kMirOpCheck's throw instruction is first one in the bb_next. |
| DCHECK_EQ(bb_next->first_mir_insn, throw_insn); |
| // Now move all instructions (throw instruction to last one) from bb_next to bb. |
| MIR* last_to_move = bb_next->last_mir_insn; |
| bb_next->RemoveMIRList(throw_insn, last_to_move); |
| bb->InsertMIRListAfter(bb->last_mir_insn, throw_insn, last_to_move); |
| // The kMirOpCheck instruction is not needed anymore. |
| mir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpNop); |
| bb->RemoveMIR(mir); |
| |
| // Before we overwrite successors, remove their predecessor links to bb. |
| bb_next->ErasePredecessor(bb->id); |
| if (bb->taken != NullBasicBlockId) { |
| DCHECK_EQ(bb->successor_block_list_type, kNotUsed); |
| BasicBlock* bb_taken = GetBasicBlock(bb->taken); |
| // bb->taken will be overwritten below. |
| DCHECK_EQ(bb_taken->block_type, kExceptionHandling); |
| DCHECK_EQ(bb_taken->predecessors.size(), 1u); |
| DCHECK_EQ(bb_taken->predecessors[0], bb->id); |
| bb_taken->predecessors.clear(); |
| bb_taken->block_type = kDead; |
| DCHECK(bb_taken->data_flow_info == nullptr); |
| } else { |
| DCHECK_EQ(bb->successor_block_list_type, kCatch); |
| for (SuccessorBlockInfo* succ_info : bb->successor_blocks) { |
| if (succ_info->block != NullBasicBlockId) { |
| BasicBlock* succ_bb = GetBasicBlock(succ_info->block); |
| DCHECK(succ_bb->catch_entry); |
| succ_bb->ErasePredecessor(bb->id); |
| } |
| } |
| } |
| // Use the successor info from the next block |
| bb->successor_block_list_type = bb_next->successor_block_list_type; |
| bb->successor_blocks.swap(bb_next->successor_blocks); // Swap instead of copying. |
| bb_next->successor_block_list_type = kNotUsed; |
| // Use the ending block linkage from the next block |
| bb->fall_through = bb_next->fall_through; |
| bb_next->fall_through = NullBasicBlockId; |
| bb->taken = bb_next->taken; |
| bb_next->taken = NullBasicBlockId; |
| /* |
| * If lower-half of pair of blocks to combine contained |
| * a return or a conditional branch or an explicit throw, |
| * move the flag to the newly combined block. |
| */ |
| bb->terminated_by_return = bb_next->terminated_by_return; |
| bb->conditional_branch = bb_next->conditional_branch; |
| bb->explicit_throw = bb_next->explicit_throw; |
| // Merge the use_lvn flag. |
| bb->use_lvn |= bb_next->use_lvn; |
| |
| // Kill the unused block. |
| bb_next->data_flow_info = nullptr; |
| |
| /* |
| * NOTE: we aren't updating all dataflow info here. Should either make sure this pass |
| * happens after uses of i_dominated, dom_frontier or update the dataflow info here. |
| * NOTE: GVN uses bb->data_flow_info->live_in_v which is unaffected by the block merge. |
| */ |
| |
| // Kill bb_next and remap now-dead id to parent. |
| bb_next->block_type = kDead; |
| bb_next->data_flow_info = nullptr; // Must be null for dead blocks. (Relied on by the GVN.) |
| block_id_map_.Overwrite(bb_next->id, bb->id); |
| // Update predecessors in children. |
| ChildBlockIterator iter(bb, this); |
| for (BasicBlock* child = iter.Next(); child != nullptr; child = iter.Next()) { |
| child->UpdatePredecessor(bb_next->id, bb->id); |
| } |
| |
| // DFS orders, domination and topological order are not up to date anymore. |
| dfs_orders_up_to_date_ = false; |
| domination_up_to_date_ = false; |
| topological_order_up_to_date_ = false; |
| |
| // Now, loop back and see if we can keep going |
| } |
| } |
| |
| bool MIRGraph::EliminateNullChecksGate() { |
| if ((cu_->disable_opt & (1 << kNullCheckElimination)) != 0 || |
| (merged_df_flags_ & DF_HAS_NULL_CHKS) == 0) { |
| return false; |
| } |
| |
| DCHECK(temp_scoped_alloc_.get() == nullptr); |
| temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack)); |
| temp_.nce.num_vregs = GetNumOfCodeAndTempVRs(); |
| temp_.nce.work_vregs_to_check = new (temp_scoped_alloc_.get()) ArenaBitVector( |
| temp_scoped_alloc_.get(), temp_.nce.num_vregs, false, kBitMapNullCheck); |
| temp_.nce.ending_vregs_to_check_matrix = |
| temp_scoped_alloc_->AllocArray<ArenaBitVector*>(GetNumBlocks(), kArenaAllocMisc); |
| std::fill_n(temp_.nce.ending_vregs_to_check_matrix, GetNumBlocks(), nullptr); |
| |
| // reset MIR_MARK |
| AllNodesIterator iter(this); |
| for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) { |
| for (MIR* mir = bb->first_mir_insn; mir != NULL; mir = mir->next) { |
| mir->optimization_flags &= ~MIR_MARK; |
| } |
| } |
| |
| return true; |
| } |
| |
| /* |
| * Eliminate unnecessary null checks for a basic block. |
| */ |
| bool MIRGraph::EliminateNullChecks(BasicBlock* bb) { |
| if (bb->block_type != kDalvikByteCode && bb->block_type != kEntryBlock) { |
| // Ignore the kExitBlock as well. |
| DCHECK(bb->first_mir_insn == nullptr); |
| return false; |
| } |
| |
| ArenaBitVector* vregs_to_check = temp_.nce.work_vregs_to_check; |
| /* |
| * Set initial state. Catch blocks don't need any special treatment. |
| */ |
| if (bb->block_type == kEntryBlock) { |
| vregs_to_check->ClearAllBits(); |
| // Assume all ins are objects. |
| for (uint16_t in_reg = GetFirstInVR(); |
| in_reg < GetNumOfCodeVRs(); in_reg++) { |
| vregs_to_check->SetBit(in_reg); |
| } |
| if ((cu_->access_flags & kAccStatic) == 0) { |
| // If non-static method, mark "this" as non-null. |
| int this_reg = GetFirstInVR(); |
| vregs_to_check->ClearBit(this_reg); |
| } |
| } else { |
| DCHECK_EQ(bb->block_type, kDalvikByteCode); |
| // Starting state is union of all incoming arcs. |
| bool copied_first = false; |
| for (BasicBlockId pred_id : bb->predecessors) { |
| if (temp_.nce.ending_vregs_to_check_matrix[pred_id] == nullptr) { |
| continue; |
| } |
| BasicBlock* pred_bb = GetBasicBlock(pred_id); |
| DCHECK(pred_bb != nullptr); |
| MIR* null_check_insn = nullptr; |
| if (pred_bb->block_type == kDalvikByteCode) { |
| // Check to see if predecessor had an explicit null-check. |
| MIR* last_insn = pred_bb->last_mir_insn; |
| if (last_insn != nullptr) { |
| Instruction::Code last_opcode = last_insn->dalvikInsn.opcode; |
| if ((last_opcode == Instruction::IF_EQZ && pred_bb->fall_through == bb->id) || |
| (last_opcode == Instruction::IF_NEZ && pred_bb->taken == bb->id)) { |
| // Remember the null check insn if there's no other predecessor requiring null check. |
| if (!copied_first || !vregs_to_check->IsBitSet(last_insn->dalvikInsn.vA)) { |
| null_check_insn = last_insn; |
| } |
| } |
| } |
| } |
| if (!copied_first) { |
| copied_first = true; |
| vregs_to_check->Copy(temp_.nce.ending_vregs_to_check_matrix[pred_id]); |
| } else { |
| vregs_to_check->Union(temp_.nce.ending_vregs_to_check_matrix[pred_id]); |
| } |
| if (null_check_insn != nullptr) { |
| vregs_to_check->ClearBit(null_check_insn->dalvikInsn.vA); |
| } |
| } |
| DCHECK(copied_first); // At least one predecessor must have been processed before this bb. |
| } |
| // At this point, vregs_to_check shows which sregs have an object definition with |
| // no intervening uses. |
| |
| // Walk through the instruction in the block, updating as necessary |
| for (MIR* mir = bb->first_mir_insn; mir != NULL; mir = mir->next) { |
| uint64_t df_attributes = GetDataFlowAttributes(mir); |
| |
| if ((df_attributes & DF_NULL_TRANSFER_N) != 0u) { |
| // The algorithm was written in a phi agnostic way. |
| continue; |
| } |
| |
| // Might need a null check? |
| if (df_attributes & DF_HAS_NULL_CHKS) { |
| int src_vreg; |
| if (df_attributes & DF_NULL_CHK_OUT0) { |
| DCHECK_NE(df_attributes & DF_IS_INVOKE, 0u); |
| src_vreg = mir->dalvikInsn.vC; |
| } else if (df_attributes & DF_NULL_CHK_B) { |
| DCHECK_NE(df_attributes & DF_REF_B, 0u); |
| src_vreg = mir->dalvikInsn.vB; |
| } else { |
| DCHECK_NE(df_attributes & DF_NULL_CHK_A, 0u); |
| DCHECK_NE(df_attributes & DF_REF_A, 0u); |
| src_vreg = mir->dalvikInsn.vA; |
| } |
| if (!vregs_to_check->IsBitSet(src_vreg)) { |
| // Eliminate the null check. |
| mir->optimization_flags |= MIR_MARK; |
| } else { |
| // Do the null check. |
| mir->optimization_flags &= ~MIR_MARK; |
| // Mark src_vreg as null-checked. |
| vregs_to_check->ClearBit(src_vreg); |
| } |
| } |
| |
| if ((df_attributes & DF_A_WIDE) || |
| (df_attributes & (DF_REF_A | DF_SETS_CONST | DF_NULL_TRANSFER)) == 0) { |
| continue; |
| } |
| |
| /* |
| * First, mark all object definitions as requiring null check. |
| * Note: we can't tell if a CONST definition might be used as an object, so treat |
| * them all as object definitions. |
| */ |
| if ((df_attributes & (DF_DA | DF_REF_A)) == (DF_DA | DF_REF_A) || |
| (df_attributes & DF_SETS_CONST)) { |
| vregs_to_check->SetBit(mir->dalvikInsn.vA); |
| } |
| |
| // Then, remove mark from all object definitions we know are non-null. |
| if (df_attributes & DF_NON_NULL_DST) { |
| // Mark target of NEW* as non-null |
| DCHECK_NE(df_attributes & DF_REF_A, 0u); |
| vregs_to_check->ClearBit(mir->dalvikInsn.vA); |
| } |
| |
| // Mark non-null returns from invoke-style NEW* |
| if (df_attributes & DF_NON_NULL_RET) { |
| MIR* next_mir = mir->next; |
| // Next should be an MOVE_RESULT_OBJECT |
| if (UNLIKELY(next_mir == nullptr)) { |
| // The MethodVerifier makes sure there's no MOVE_RESULT at the catch entry or branch |
| // target, so the MOVE_RESULT cannot be broken away into another block. |
| LOG(WARNING) << "Unexpected end of block following new"; |
| } else if (UNLIKELY(next_mir->dalvikInsn.opcode != Instruction::MOVE_RESULT_OBJECT)) { |
| LOG(WARNING) << "Unexpected opcode following new: " << next_mir->dalvikInsn.opcode; |
| } else { |
| // Mark as null checked. |
| vregs_to_check->ClearBit(next_mir->dalvikInsn.vA); |
| } |
| } |
| |
| // Propagate null check state on register copies. |
| if (df_attributes & DF_NULL_TRANSFER_0) { |
| DCHECK_EQ(df_attributes | ~(DF_DA | DF_REF_A | DF_UB | DF_REF_B), static_cast<uint64_t>(-1)); |
| if (vregs_to_check->IsBitSet(mir->dalvikInsn.vB)) { |
| vregs_to_check->SetBit(mir->dalvikInsn.vA); |
| } else { |
| vregs_to_check->ClearBit(mir->dalvikInsn.vA); |
| } |
| } |
| } |
| |
| // Did anything change? |
| bool nce_changed = false; |
| ArenaBitVector* old_ending_ssa_regs_to_check = temp_.nce.ending_vregs_to_check_matrix[bb->id]; |
| if (old_ending_ssa_regs_to_check == nullptr) { |
| DCHECK(temp_scoped_alloc_.get() != nullptr); |
| nce_changed = vregs_to_check->GetHighestBitSet() != -1; |
| temp_.nce.ending_vregs_to_check_matrix[bb->id] = vregs_to_check; |
| // Create a new vregs_to_check for next BB. |
| temp_.nce.work_vregs_to_check = new (temp_scoped_alloc_.get()) ArenaBitVector( |
| temp_scoped_alloc_.get(), temp_.nce.num_vregs, false, kBitMapNullCheck); |
| } else if (!vregs_to_check->SameBitsSet(old_ending_ssa_regs_to_check)) { |
| nce_changed = true; |
| temp_.nce.ending_vregs_to_check_matrix[bb->id] = vregs_to_check; |
| temp_.nce.work_vregs_to_check = old_ending_ssa_regs_to_check; // Reuse for next BB. |
| } |
| return nce_changed; |
| } |
| |
| void MIRGraph::EliminateNullChecksEnd() { |
| // Clean up temporaries. |
| temp_.nce.num_vregs = 0u; |
| temp_.nce.work_vregs_to_check = nullptr; |
| temp_.nce.ending_vregs_to_check_matrix = nullptr; |
| DCHECK(temp_scoped_alloc_.get() != nullptr); |
| temp_scoped_alloc_.reset(); |
| |
| // converge MIR_MARK with MIR_IGNORE_NULL_CHECK |
| AllNodesIterator iter(this); |
| for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) { |
| for (MIR* mir = bb->first_mir_insn; mir != NULL; mir = mir->next) { |
| constexpr int kMarkToIgnoreNullCheckShift = kMIRMark - kMIRIgnoreNullCheck; |
| static_assert(kMarkToIgnoreNullCheckShift > 0, "Not a valid right-shift"); |
| uint16_t mirMarkAdjustedToIgnoreNullCheck = |
| (mir->optimization_flags & MIR_MARK) >> kMarkToIgnoreNullCheckShift; |
| mir->optimization_flags |= mirMarkAdjustedToIgnoreNullCheck; |
| } |
| } |
| } |
| |
| /* |
| * Perform type and size inference for a basic block. |
| */ |
| bool MIRGraph::InferTypes(BasicBlock* bb) { |
| if (bb->data_flow_info == nullptr) return false; |
| |
| bool infer_changed = false; |
| for (MIR* mir = bb->first_mir_insn; mir != NULL; mir = mir->next) { |
| if (mir->ssa_rep == NULL) { |
| continue; |
| } |
| |
| // Propagate type info. |
| infer_changed = InferTypeAndSize(bb, mir, infer_changed); |
| } |
| |
| return infer_changed; |
| } |
| |
| bool MIRGraph::EliminateClassInitChecksGate() { |
| if ((cu_->disable_opt & (1 << kClassInitCheckElimination)) != 0 || |
| (merged_df_flags_ & DF_CLINIT) == 0) { |
| return false; |
| } |
| |
| DCHECK(temp_scoped_alloc_.get() == nullptr); |
| temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack)); |
| |
| // Each insn we use here has at least 2 code units, offset/2 will be a unique index. |
| const size_t end = (GetNumDalvikInsns() + 1u) / 2u; |
| temp_.cice.indexes = temp_scoped_alloc_->AllocArray<uint16_t>(end, kArenaAllocGrowableArray); |
| std::fill_n(temp_.cice.indexes, end, 0xffffu); |
| |
| uint32_t unique_class_count = 0u; |
| { |
| // Get unique_class_count and store indexes in temp_insn_data_ using a map on a nested |
| // ScopedArenaAllocator. |
| |
| // Embed the map value in the entry to save space. |
| struct MapEntry { |
| // Map key: the class identified by the declaring dex file and type index. |
| const DexFile* declaring_dex_file; |
| uint16_t declaring_class_idx; |
| // Map value: index into bit vectors of classes requiring initialization checks. |
| uint16_t index; |
| }; |
| struct MapEntryComparator { |
| bool operator()(const MapEntry& lhs, const MapEntry& rhs) const { |
| if (lhs.declaring_class_idx != rhs.declaring_class_idx) { |
| return lhs.declaring_class_idx < rhs.declaring_class_idx; |
| } |
| return lhs.declaring_dex_file < rhs.declaring_dex_file; |
| } |
| }; |
| |
| ScopedArenaAllocator allocator(&cu_->arena_stack); |
| ScopedArenaSet<MapEntry, MapEntryComparator> class_to_index_map(MapEntryComparator(), |
| allocator.Adapter()); |
| |
| // First, find all SGET/SPUTs that may need class initialization checks, record INVOKE_STATICs. |
| AllNodesIterator iter(this); |
| for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) { |
| if (bb->block_type == kDalvikByteCode) { |
| for (MIR* mir = bb->first_mir_insn; mir != nullptr; mir = mir->next) { |
| if (IsInstructionSGetOrSPut(mir->dalvikInsn.opcode)) { |
| const MirSFieldLoweringInfo& field_info = GetSFieldLoweringInfo(mir); |
| if (!field_info.IsReferrersClass()) { |
| DCHECK_LT(class_to_index_map.size(), 0xffffu); |
| MapEntry entry = { |
| // Treat unresolved fields as if each had its own class. |
| field_info.IsResolved() ? field_info.DeclaringDexFile() |
| : nullptr, |
| field_info.IsResolved() ? field_info.DeclaringClassIndex() |
| : field_info.FieldIndex(), |
| static_cast<uint16_t>(class_to_index_map.size()) |
| }; |
| uint16_t index = class_to_index_map.insert(entry).first->index; |
| // Using offset/2 for index into temp_.cice.indexes. |
| temp_.cice.indexes[mir->offset / 2u] = index; |
| } |
| } else if (IsInstructionInvokeStatic(mir->dalvikInsn.opcode)) { |
| const MirMethodLoweringInfo& method_info = GetMethodLoweringInfo(mir); |
| DCHECK(method_info.IsStatic()); |
| if (method_info.FastPath() && !method_info.IsReferrersClass()) { |
| MapEntry entry = { |
| method_info.DeclaringDexFile(), |
| method_info.DeclaringClassIndex(), |
| static_cast<uint16_t>(class_to_index_map.size()) |
| }; |
| uint16_t index = class_to_index_map.insert(entry).first->index; |
| // Using offset/2 for index into temp_.cice.indexes. |
| temp_.cice.indexes[mir->offset / 2u] = index; |
| } |
| } |
| } |
| } |
| } |
| unique_class_count = static_cast<uint32_t>(class_to_index_map.size()); |
| } |
| |
| if (unique_class_count == 0u) { |
| // All SGET/SPUTs refer to initialized classes. Nothing to do. |
| temp_.cice.indexes = nullptr; |
| temp_scoped_alloc_.reset(); |
| return false; |
| } |
| |
| // 2 bits for each class: is class initialized, is class in dex cache. |
| temp_.cice.num_class_bits = 2u * unique_class_count; |
| temp_.cice.work_classes_to_check = new (temp_scoped_alloc_.get()) ArenaBitVector( |
| temp_scoped_alloc_.get(), temp_.cice.num_class_bits, false, kBitMapClInitCheck); |
| temp_.cice.ending_classes_to_check_matrix = |
| temp_scoped_alloc_->AllocArray<ArenaBitVector*>(GetNumBlocks(), kArenaAllocMisc); |
| std::fill_n(temp_.cice.ending_classes_to_check_matrix, GetNumBlocks(), nullptr); |
| DCHECK_GT(temp_.cice.num_class_bits, 0u); |
| return true; |
| } |
| |
| /* |
| * Eliminate unnecessary class initialization checks for a basic block. |
| */ |
| bool MIRGraph::EliminateClassInitChecks(BasicBlock* bb) { |
| DCHECK_EQ((cu_->disable_opt & (1 << kClassInitCheckElimination)), 0u); |
| if (bb->block_type != kDalvikByteCode && bb->block_type != kEntryBlock) { |
| // Ignore the kExitBlock as well. |
| DCHECK(bb->first_mir_insn == nullptr); |
| return false; |
| } |
| |
| /* |
| * Set initial state. Catch blocks don't need any special treatment. |
| */ |
| ArenaBitVector* classes_to_check = temp_.cice.work_classes_to_check; |
| DCHECK(classes_to_check != nullptr); |
| if (bb->block_type == kEntryBlock) { |
| classes_to_check->SetInitialBits(temp_.cice.num_class_bits); |
| } else { |
| // Starting state is union of all incoming arcs. |
| bool copied_first = false; |
| for (BasicBlockId pred_id : bb->predecessors) { |
| if (temp_.cice.ending_classes_to_check_matrix[pred_id] == nullptr) { |
| continue; |
| } |
| if (!copied_first) { |
| copied_first = true; |
| classes_to_check->Copy(temp_.cice.ending_classes_to_check_matrix[pred_id]); |
| } else { |
| classes_to_check->Union(temp_.cice.ending_classes_to_check_matrix[pred_id]); |
| } |
| } |
| DCHECK(copied_first); // At least one predecessor must have been processed before this bb. |
| } |
| // At this point, classes_to_check shows which classes need clinit checks. |
| |
| // Walk through the instruction in the block, updating as necessary |
| for (MIR* mir = bb->first_mir_insn; mir != nullptr; mir = mir->next) { |
| uint16_t index = temp_.cice.indexes[mir->offset / 2u]; |
| if (index != 0xffffu) { |
| bool check_initialization = false; |
| bool check_dex_cache = false; |
| |
| // NOTE: index != 0xffff does not guarantee that this is an SGET/SPUT/INVOKE_STATIC. |
| // Dex instructions with width 1 can have the same offset/2. |
| |
| if (IsInstructionSGetOrSPut(mir->dalvikInsn.opcode)) { |
| check_initialization = true; |
| check_dex_cache = true; |
| } else if (IsInstructionInvokeStatic(mir->dalvikInsn.opcode)) { |
| check_initialization = true; |
| // NOTE: INVOKE_STATIC doesn't guarantee that the type will be in the dex cache. |
| } |
| |
| if (check_dex_cache) { |
| uint32_t check_dex_cache_index = 2u * index + 1u; |
| if (!classes_to_check->IsBitSet(check_dex_cache_index)) { |
| // Eliminate the class init check. |
| mir->optimization_flags |= MIR_CLASS_IS_IN_DEX_CACHE; |
| } else { |
| // Do the class init check. |
| mir->optimization_flags &= ~MIR_CLASS_IS_IN_DEX_CACHE; |
| } |
| classes_to_check->ClearBit(check_dex_cache_index); |
| } |
| if (check_initialization) { |
| uint32_t check_clinit_index = 2u * index; |
| if (!classes_to_check->IsBitSet(check_clinit_index)) { |
| // Eliminate the class init check. |
| mir->optimization_flags |= MIR_CLASS_IS_INITIALIZED; |
| } else { |
| // Do the class init check. |
| mir->optimization_flags &= ~MIR_CLASS_IS_INITIALIZED; |
| } |
| // Mark the class as initialized. |
| classes_to_check->ClearBit(check_clinit_index); |
| } |
| } |
| } |
| |
| // Did anything change? |
| bool changed = false; |
| ArenaBitVector* old_ending_classes_to_check = temp_.cice.ending_classes_to_check_matrix[bb->id]; |
| if (old_ending_classes_to_check == nullptr) { |
| DCHECK(temp_scoped_alloc_.get() != nullptr); |
| changed = classes_to_check->GetHighestBitSet() != -1; |
| temp_.cice.ending_classes_to_check_matrix[bb->id] = classes_to_check; |
| // Create a new classes_to_check for next BB. |
| temp_.cice.work_classes_to_check = new (temp_scoped_alloc_.get()) ArenaBitVector( |
| temp_scoped_alloc_.get(), temp_.cice.num_class_bits, false, kBitMapClInitCheck); |
| } else if (!classes_to_check->Equal(old_ending_classes_to_check)) { |
| changed = true; |
| temp_.cice.ending_classes_to_check_matrix[bb->id] = classes_to_check; |
| temp_.cice.work_classes_to_check = old_ending_classes_to_check; // Reuse for next BB. |
| } |
| return changed; |
| } |
| |
| void MIRGraph::EliminateClassInitChecksEnd() { |
| // Clean up temporaries. |
| temp_.cice.num_class_bits = 0u; |
| temp_.cice.work_classes_to_check = nullptr; |
| temp_.cice.ending_classes_to_check_matrix = nullptr; |
| DCHECK(temp_.cice.indexes != nullptr); |
| temp_.cice.indexes = nullptr; |
| DCHECK(temp_scoped_alloc_.get() != nullptr); |
| temp_scoped_alloc_.reset(); |
| } |
| |
| bool MIRGraph::ApplyGlobalValueNumberingGate() { |
| if (GlobalValueNumbering::Skip(cu_)) { |
| return false; |
| } |
| |
| DCHECK(temp_scoped_alloc_ == nullptr); |
| temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack)); |
| temp_.gvn.ifield_ids = |
| GlobalValueNumbering::PrepareGvnFieldIds(temp_scoped_alloc_.get(), ifield_lowering_infos_); |
| temp_.gvn.sfield_ids = |
| GlobalValueNumbering::PrepareGvnFieldIds(temp_scoped_alloc_.get(), sfield_lowering_infos_); |
| DCHECK(temp_.gvn.gvn == nullptr); |
| temp_.gvn.gvn = new (temp_scoped_alloc_.get()) GlobalValueNumbering( |
| cu_, temp_scoped_alloc_.get(), GlobalValueNumbering::kModeGvn); |
| return true; |
| } |
| |
| bool MIRGraph::ApplyGlobalValueNumbering(BasicBlock* bb) { |
| DCHECK(temp_.gvn.gvn != nullptr); |
| LocalValueNumbering* lvn = temp_.gvn.gvn->PrepareBasicBlock(bb); |
| if (lvn != nullptr) { |
| for (MIR* mir = bb->first_mir_insn; mir != nullptr; mir = mir->next) { |
| lvn->GetValueNumber(mir); |
| } |
| } |
| bool change = (lvn != nullptr) && temp_.gvn.gvn->FinishBasicBlock(bb); |
| return change; |
| } |
| |
| void MIRGraph::ApplyGlobalValueNumberingEnd() { |
| // Perform modifications. |
| DCHECK(temp_.gvn.gvn != nullptr); |
| if (temp_.gvn.gvn->Good()) { |
| temp_.gvn.gvn->StartPostProcessing(); |
| if (max_nested_loops_ != 0u) { |
| TopologicalSortIterator iter(this); |
| for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) { |
| ScopedArenaAllocator allocator(&cu_->arena_stack); // Reclaim memory after each LVN. |
| LocalValueNumbering* lvn = temp_.gvn.gvn->PrepareBasicBlock(bb, &allocator); |
| if (lvn != nullptr) { |
| for (MIR* mir = bb->first_mir_insn; mir != nullptr; mir = mir->next) { |
| lvn->GetValueNumber(mir); |
| } |
| bool change = temp_.gvn.gvn->FinishBasicBlock(bb); |
| DCHECK(!change) << PrettyMethod(cu_->method_idx, *cu_->dex_file); |
| } |
| } |
| } |
| // GVN was successful, running the LVN would be useless. |
| cu_->disable_opt |= (1u << kLocalValueNumbering); |
| } else { |
| LOG(WARNING) << "GVN failed for " << PrettyMethod(cu_->method_idx, *cu_->dex_file); |
| cu_->disable_opt |= (1u << kGvnDeadCodeElimination); |
| } |
| |
| if ((cu_->disable_opt & (1 << kGvnDeadCodeElimination)) != 0) { |
| EliminateDeadCodeEnd(); |
| } // else preserve GVN data for CSE. |
| } |
| |
| bool MIRGraph::EliminateDeadCodeGate() { |
| if ((cu_->disable_opt & (1 << kGvnDeadCodeElimination)) != 0) { |
| return false; |
| } |
| DCHECK(temp_scoped_alloc_ != nullptr); |
| temp_.gvn.dce = new (temp_scoped_alloc_.get()) GvnDeadCodeElimination(temp_.gvn.gvn, |
| temp_scoped_alloc_.get()); |
| return true; |
| } |
| |
| bool MIRGraph::EliminateDeadCode(BasicBlock* bb) { |
| DCHECK(temp_scoped_alloc_ != nullptr); |
| DCHECK(temp_.gvn.gvn != nullptr); |
| if (bb->block_type != kDalvikByteCode) { |
| return false; |
| } |
| DCHECK(temp_.gvn.dce != nullptr); |
| temp_.gvn.dce->Apply(bb); |
| return false; // No need to repeat. |
| } |
| |
| void MIRGraph::EliminateDeadCodeEnd() { |
| DCHECK_EQ(temp_.gvn.dce != nullptr, (cu_->disable_opt & (1 << kGvnDeadCodeElimination)) == 0); |
| if (temp_.gvn.dce != nullptr) { |
| delete temp_.gvn.dce; |
| temp_.gvn.dce = nullptr; |
| } |
| delete temp_.gvn.gvn; |
| temp_.gvn.gvn = nullptr; |
| temp_.gvn.ifield_ids = nullptr; |
| temp_.gvn.sfield_ids = nullptr; |
| DCHECK(temp_scoped_alloc_ != nullptr); |
| temp_scoped_alloc_.reset(); |
| } |
| |
| void MIRGraph::ComputeInlineIFieldLoweringInfo(uint16_t field_idx, MIR* invoke, MIR* iget_or_iput) { |
| uint32_t method_index = invoke->meta.method_lowering_info; |
| if (temp_.smi.processed_indexes->IsBitSet(method_index)) { |
| iget_or_iput->meta.ifield_lowering_info = temp_.smi.lowering_infos[method_index]; |
| DCHECK_EQ(field_idx, GetIFieldLoweringInfo(iget_or_iput).FieldIndex()); |
| return; |
| } |
| |
| const MirMethodLoweringInfo& method_info = GetMethodLoweringInfo(invoke); |
| MethodReference target = method_info.GetTargetMethod(); |
| DexCompilationUnit inlined_unit( |
| cu_, cu_->class_loader, cu_->class_linker, *target.dex_file, |
| nullptr /* code_item not used */, 0u /* class_def_idx not used */, target.dex_method_index, |
| 0u /* access_flags not used */, nullptr /* verified_method not used */); |
| DexMemAccessType type = IGetOrIPutMemAccessType(iget_or_iput->dalvikInsn.opcode); |
| MirIFieldLoweringInfo inlined_field_info(field_idx, type, false); |
| MirIFieldLoweringInfo::Resolve(cu_->compiler_driver, &inlined_unit, &inlined_field_info, 1u); |
| DCHECK(inlined_field_info.IsResolved()); |
| |
| uint32_t field_info_index = ifield_lowering_infos_.size(); |
| ifield_lowering_infos_.push_back(inlined_field_info); |
| temp_.smi.processed_indexes->SetBit(method_index); |
| temp_.smi.lowering_infos[method_index] = field_info_index; |
| iget_or_iput->meta.ifield_lowering_info = field_info_index; |
| } |
| |
| bool MIRGraph::InlineSpecialMethodsGate() { |
| if ((cu_->disable_opt & (1 << kSuppressMethodInlining)) != 0 || |
| method_lowering_infos_.size() == 0u) { |
| return false; |
| } |
| if (cu_->compiler_driver->GetMethodInlinerMap() == nullptr) { |
| // This isn't the Quick compiler. |
| return false; |
| } |
| return true; |
| } |
| |
| void MIRGraph::InlineSpecialMethodsStart() { |
| // Prepare for inlining getters/setters. Since we're inlining at most 1 IGET/IPUT from |
| // each INVOKE, we can index the data by the MIR::meta::method_lowering_info index. |
| |
| DCHECK(temp_scoped_alloc_.get() == nullptr); |
| temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack)); |
| temp_.smi.num_indexes = method_lowering_infos_.size(); |
| temp_.smi.processed_indexes = new (temp_scoped_alloc_.get()) ArenaBitVector( |
| temp_scoped_alloc_.get(), temp_.smi.num_indexes, false, kBitMapMisc); |
| temp_.smi.processed_indexes->ClearAllBits(); |
| temp_.smi.lowering_infos = |
| temp_scoped_alloc_->AllocArray<uint16_t>(temp_.smi.num_indexes, kArenaAllocGrowableArray); |
| } |
| |
| void MIRGraph::InlineSpecialMethods(BasicBlock* bb) { |
| if (bb->block_type != kDalvikByteCode) { |
| return; |
| } |
| for (MIR* mir = bb->first_mir_insn; mir != NULL; mir = mir->next) { |
| if (MIR::DecodedInstruction::IsPseudoMirOp(mir->dalvikInsn.opcode)) { |
| continue; |
| } |
| if (!(mir->dalvikInsn.FlagsOf() & Instruction::kInvoke)) { |
| continue; |
| } |
| const MirMethodLoweringInfo& method_info = GetMethodLoweringInfo(mir); |
| if (!method_info.FastPath()) { |
| continue; |
| } |
| |
| InvokeType sharp_type = method_info.GetSharpType(); |
| if ((sharp_type != kDirect) && (sharp_type != kStatic)) { |
| continue; |
| } |
| |
| if (sharp_type == kStatic) { |
| bool needs_clinit = !method_info.IsClassInitialized() && |
| ((mir->optimization_flags & MIR_CLASS_IS_INITIALIZED) == 0); |
| if (needs_clinit) { |
| continue; |
| } |
| } |
| |
| DCHECK(cu_->compiler_driver->GetMethodInlinerMap() != nullptr); |
| MethodReference target = method_info.GetTargetMethod(); |
| if (cu_->compiler_driver->GetMethodInlinerMap()->GetMethodInliner(target.dex_file) |
| ->GenInline(this, bb, mir, target.dex_method_index)) { |
| if (cu_->verbose || cu_->print_pass) { |
| LOG(INFO) << "SpecialMethodInliner: Inlined " << method_info.GetInvokeType() << " (" |
| << sharp_type << ") call to \"" << PrettyMethod(target.dex_method_index, *target.dex_file) |
| << "\" from \"" << PrettyMethod(cu_->method_idx, *cu_->dex_file) |
| << "\" @0x" << std::hex << mir->offset; |
| } |
| } |
| } |
| } |
| |
| void MIRGraph::InlineSpecialMethodsEnd() { |
| // Clean up temporaries. |
| DCHECK(temp_.smi.lowering_infos != nullptr); |
| temp_.smi.lowering_infos = nullptr; |
| temp_.smi.num_indexes = 0u; |
| DCHECK(temp_.smi.processed_indexes != nullptr); |
| temp_.smi.processed_indexes = nullptr; |
| DCHECK(temp_scoped_alloc_.get() != nullptr); |
| temp_scoped_alloc_.reset(); |
| } |
| |
| void MIRGraph::DumpCheckStats() { |
| Checkstats* stats = |
| static_cast<Checkstats*>(arena_->Alloc(sizeof(Checkstats), kArenaAllocDFInfo)); |
| checkstats_ = stats; |
| AllNodesIterator iter(this); |
| for (BasicBlock* bb = iter.Next(); bb != NULL; bb = iter.Next()) { |
| CountChecks(bb); |
| } |
| if (stats->null_checks > 0) { |
| float eliminated = static_cast<float>(stats->null_checks_eliminated); |
| float checks = static_cast<float>(stats->null_checks); |
| LOG(INFO) << "Null Checks: " << PrettyMethod(cu_->method_idx, *cu_->dex_file) << " " |
| << stats->null_checks_eliminated << " of " << stats->null_checks << " -> " |
| << (eliminated/checks) * 100.0 << "%"; |
| } |
| if (stats->range_checks > 0) { |
| float eliminated = static_cast<float>(stats->range_checks_eliminated); |
| float checks = static_cast<float>(stats->range_checks); |
| LOG(INFO) << "Range Checks: " << PrettyMethod(cu_->method_idx, *cu_->dex_file) << " " |
| << stats->range_checks_eliminated << " of " << stats->range_checks << " -> " |
| << (eliminated/checks) * 100.0 << "%"; |
| } |
| } |
| |
| bool MIRGraph::BuildExtendedBBList(class BasicBlock* bb) { |
| if (bb->visited) return false; |
| if (!((bb->block_type == kEntryBlock) || (bb->block_type == kDalvikByteCode) |
| || (bb->block_type == kExitBlock))) { |
| // Ignore special blocks |
| bb->visited = true; |
| return false; |
| } |
| // Must be head of extended basic block. |
| BasicBlock* start_bb = bb; |
| extended_basic_blocks_.push_back(bb->id); |
| bool terminated_by_return = false; |
| bool do_local_value_numbering = false; |
| // Visit blocks strictly dominated by this head. |
| while (bb != NULL) { |
| bb->visited = true; |
| terminated_by_return |= bb->terminated_by_return; |
| do_local_value_numbering |= bb->use_lvn; |
| bb = NextDominatedBlock(bb); |
| } |
| if (terminated_by_return || do_local_value_numbering) { |
| // Do lvn for all blocks in this extended set. |
| bb = start_bb; |
| while (bb != NULL) { |
| bb->use_lvn = do_local_value_numbering; |
| bb->dominates_return = terminated_by_return; |
| bb = NextDominatedBlock(bb); |
| } |
| } |
| return false; // Not iterative - return value will be ignored |
| } |
| |
| void MIRGraph::BasicBlockOptimizationStart() { |
| if ((cu_->disable_opt & (1 << kLocalValueNumbering)) == 0) { |
| temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack)); |
| temp_.gvn.ifield_ids = |
| GlobalValueNumbering::PrepareGvnFieldIds(temp_scoped_alloc_.get(), ifield_lowering_infos_); |
| temp_.gvn.sfield_ids = |
| GlobalValueNumbering::PrepareGvnFieldIds(temp_scoped_alloc_.get(), sfield_lowering_infos_); |
| } |
| } |
| |
| void MIRGraph::BasicBlockOptimization() { |
| if ((cu_->disable_opt & (1 << kSuppressExceptionEdges)) != 0) { |
| ClearAllVisitedFlags(); |
| PreOrderDfsIterator iter2(this); |
| for (BasicBlock* bb = iter2.Next(); bb != NULL; bb = iter2.Next()) { |
| BuildExtendedBBList(bb); |
| } |
| // Perform extended basic block optimizations. |
| for (unsigned int i = 0; i < extended_basic_blocks_.size(); i++) { |
| BasicBlockOpt(GetBasicBlock(extended_basic_blocks_[i])); |
| } |
| } else { |
| PreOrderDfsIterator iter(this); |
| for (BasicBlock* bb = iter.Next(); bb != NULL; bb = iter.Next()) { |
| BasicBlockOpt(bb); |
| } |
| } |
| } |
| |
| void MIRGraph::BasicBlockOptimizationEnd() { |
| // Clean up after LVN. |
| temp_.gvn.ifield_ids = nullptr; |
| temp_.gvn.sfield_ids = nullptr; |
| temp_scoped_alloc_.reset(); |
| } |
| |
| bool MIRGraph::EliminateSuspendChecksGate() { |
| if ((cu_->disable_opt & (1 << kSuspendCheckElimination)) != 0 || // Disabled. |
| GetMaxNestedLoops() == 0u || // Nothing to do. |
| GetMaxNestedLoops() >= 32u || // Only 32 bits in suspend_checks_in_loops_[.]. |
| // Exclude 32 as well to keep bit shifts well-defined. |
| !HasInvokes()) { // No invokes to actually eliminate any suspend checks. |
| return false; |
| } |
| if (cu_->compiler_driver != nullptr && cu_->compiler_driver->GetMethodInlinerMap() != nullptr) { |
| temp_.sce.inliner = |
| cu_->compiler_driver->GetMethodInlinerMap()->GetMethodInliner(cu_->dex_file); |
| } |
| suspend_checks_in_loops_ = arena_->AllocArray<uint32_t>(GetNumBlocks(), kArenaAllocMisc); |
| return true; |
| } |
| |
| bool MIRGraph::EliminateSuspendChecks(BasicBlock* bb) { |
| if (bb->block_type != kDalvikByteCode) { |
| return false; |
| } |
| DCHECK_EQ(GetTopologicalSortOrderLoopHeadStack()->size(), bb->nesting_depth); |
| if (bb->nesting_depth == 0u) { |
| // Out of loops. |
| DCHECK_EQ(suspend_checks_in_loops_[bb->id], 0u); // The array was zero-initialized. |
| return false; |
| } |
| uint32_t suspend_checks_in_loops = (1u << bb->nesting_depth) - 1u; // Start with all loop heads. |
| bool found_invoke = false; |
| for (MIR* mir = bb->first_mir_insn; mir != nullptr; mir = mir->next) { |
| if (IsInstructionInvoke(mir->dalvikInsn.opcode) && |
| (temp_.sce.inliner == nullptr || |
| !temp_.sce.inliner->IsIntrinsic(mir->dalvikInsn.vB, nullptr))) { |
| // Non-intrinsic invoke, rely on a suspend point in the invoked method. |
| found_invoke = true; |
| break; |
| } |
| } |
| if (!found_invoke) { |
| // Intersect suspend checks from predecessors. |
| uint16_t bb_topo_idx = topological_order_indexes_[bb->id]; |
| uint32_t pred_mask_union = 0u; |
| for (BasicBlockId pred_id : bb->predecessors) { |
| uint16_t pred_topo_idx = topological_order_indexes_[pred_id]; |
| if (pred_topo_idx < bb_topo_idx) { |
| // Determine the loop depth of the predecessors relative to this block. |
| size_t pred_loop_depth = topological_order_loop_head_stack_.size(); |
| while (pred_loop_depth != 0u && |
| pred_topo_idx < topological_order_loop_head_stack_[pred_loop_depth - 1].first) { |
| --pred_loop_depth; |
| } |
| DCHECK_LE(pred_loop_depth, GetBasicBlock(pred_id)->nesting_depth); |
| uint32_t pred_mask = (1u << pred_loop_depth) - 1u; |
| // Intersect pred_mask bits in suspend_checks_in_loops with |
| // suspend_checks_in_loops_[pred_id]. |
| uint32_t pred_loops_without_checks = pred_mask & ~suspend_checks_in_loops_[pred_id]; |
| suspend_checks_in_loops = suspend_checks_in_loops & ~pred_loops_without_checks; |
| pred_mask_union |= pred_mask; |
| } |
| } |
| DCHECK_EQ(((1u << (IsLoopHead(bb->id) ? bb->nesting_depth - 1u: bb->nesting_depth)) - 1u), |
| pred_mask_union); |
| suspend_checks_in_loops &= pred_mask_union; |
| } |
| suspend_checks_in_loops_[bb->id] = suspend_checks_in_loops; |
| if (suspend_checks_in_loops == 0u) { |
| return false; |
| } |
| // Apply MIR_IGNORE_SUSPEND_CHECK if appropriate. |
| if (bb->taken != NullBasicBlockId) { |
| DCHECK(bb->last_mir_insn != nullptr); |
| DCHECK(IsInstructionIfCc(bb->last_mir_insn->dalvikInsn.opcode) || |
| IsInstructionIfCcZ(bb->last_mir_insn->dalvikInsn.opcode) || |
| IsInstructionGoto(bb->last_mir_insn->dalvikInsn.opcode) || |
| (static_cast<int>(bb->last_mir_insn->dalvikInsn.opcode) >= kMirOpFusedCmplFloat && |
| static_cast<int>(bb->last_mir_insn->dalvikInsn.opcode) <= kMirOpFusedCmpLong)); |
| if (!IsSuspendCheckEdge(bb, bb->taken) && |
| (bb->fall_through == NullBasicBlockId || !IsSuspendCheckEdge(bb, bb->fall_through))) { |
| bb->last_mir_insn->optimization_flags |= MIR_IGNORE_SUSPEND_CHECK; |
| } |
| } else if (bb->fall_through != NullBasicBlockId && IsSuspendCheckEdge(bb, bb->fall_through)) { |
| // We've got a fall-through suspend edge. Add an artificial GOTO to force suspend check. |
| MIR* mir = NewMIR(); |
| mir->dalvikInsn.opcode = Instruction::GOTO; |
| mir->dalvikInsn.vA = 0; // Branch offset. |
| mir->offset = GetBasicBlock(bb->fall_through)->start_offset; |
| mir->m_unit_index = current_method_; |
| mir->ssa_rep = reinterpret_cast<SSARepresentation*>( |
| arena_->Alloc(sizeof(SSARepresentation), kArenaAllocDFInfo)); // Zero-initialized. |
| bb->AppendMIR(mir); |
| std::swap(bb->fall_through, bb->taken); // The fall-through has become taken. |
| } |
| return true; |
| } |
| |
| void MIRGraph::EliminateSuspendChecksEnd() { |
| temp_.sce.inliner = nullptr; |
| } |
| |
| bool MIRGraph::CanThrow(MIR* mir) const { |
| if ((mir->dalvikInsn.FlagsOf() & Instruction::kThrow) == 0) { |
| return false; |
| } |
| const int opt_flags = mir->optimization_flags; |
| uint64_t df_attributes = GetDataFlowAttributes(mir); |
| |
| // First, check if the insn can still throw NPE. |
| if (((df_attributes & DF_HAS_NULL_CHKS) != 0) && ((opt_flags & MIR_IGNORE_NULL_CHECK) == 0)) { |
| return true; |
| } |
| |
| // Now process specific instructions. |
| if ((df_attributes & DF_IFIELD) != 0) { |
| // The IGET/IPUT family. We have processed the IGET/IPUT null check above. |
| DCHECK_NE(opt_flags & MIR_IGNORE_NULL_CHECK, 0); |
| // If not fast, weird things can happen and the insn can throw. |
| const MirIFieldLoweringInfo& field_info = GetIFieldLoweringInfo(mir); |
| bool fast = (df_attributes & DF_DA) != 0 ? field_info.FastGet() : field_info.FastPut(); |
| return !fast; |
| } else if ((df_attributes & DF_SFIELD) != 0) { |
| // The SGET/SPUT family. Check for potentially throwing class initialization. |
| // Also, if not fast, weird things can happen and the insn can throw. |
| const MirSFieldLoweringInfo& field_info = GetSFieldLoweringInfo(mir); |
| bool fast = (df_attributes & DF_DA) != 0 ? field_info.FastGet() : field_info.FastPut(); |
| bool is_class_initialized = field_info.IsClassInitialized() || |
| ((mir->optimization_flags & MIR_CLASS_IS_INITIALIZED) != 0); |
| return !(fast && is_class_initialized); |
| } else if ((df_attributes & DF_HAS_RANGE_CHKS) != 0) { |
| // Only AGET/APUT have range checks. We have processed the AGET/APUT null check above. |
| DCHECK_NE(opt_flags & MIR_IGNORE_NULL_CHECK, 0); |
| // Non-throwing only if range check has been eliminated. |
| return ((opt_flags & MIR_IGNORE_RANGE_CHECK) == 0); |
| } else if (mir->dalvikInsn.opcode == Instruction::ARRAY_LENGTH || |
| static_cast<int>(mir->dalvikInsn.opcode) == kMirOpNullCheck) { |
| // No more checks for these (null check was processed above). |
| return false; |
| } |
| return true; |
| } |
| |
| bool MIRGraph::HasAntiDependency(MIR* first, MIR* second) { |
| DCHECK(first->ssa_rep != nullptr); |
| DCHECK(second->ssa_rep != nullptr); |
| if ((second->ssa_rep->num_defs > 0) && (first->ssa_rep->num_uses > 0)) { |
| int vreg0 = SRegToVReg(second->ssa_rep->defs[0]); |
| int vreg1 = (second->ssa_rep->num_defs == 2) ? |
| SRegToVReg(second->ssa_rep->defs[1]) : INVALID_VREG; |
| for (int i = 0; i < first->ssa_rep->num_uses; i++) { |
| int32_t use = SRegToVReg(first->ssa_rep->uses[i]); |
| if (use == vreg0 || use == vreg1) { |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| void MIRGraph::CombineMultiplyAdd(MIR* mul_mir, MIR* add_mir, bool mul_is_first_addend, |
| bool is_wide, bool is_sub) { |
| if (is_wide) { |
| if (is_sub) { |
| add_mir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpMsubLong); |
| } else { |
| add_mir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpMaddLong); |
| } |
| } else { |
| if (is_sub) { |
| add_mir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpMsubInt); |
| } else { |
| add_mir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpMaddInt); |
| } |
| } |
| add_mir->ssa_rep->num_uses = is_wide ? 6 : 3; |
| int32_t addend0 = INVALID_SREG; |
| int32_t addend1 = INVALID_SREG; |
| if (is_wide) { |
| addend0 = mul_is_first_addend ? add_mir->ssa_rep->uses[2] : add_mir->ssa_rep->uses[0]; |
| addend1 = mul_is_first_addend ? add_mir->ssa_rep->uses[3] : add_mir->ssa_rep->uses[1]; |
| } else { |
| addend0 = mul_is_first_addend ? add_mir->ssa_rep->uses[1] : add_mir->ssa_rep->uses[0]; |
| } |
| |
| AllocateSSAUseData(add_mir, add_mir->ssa_rep->num_uses); |
| add_mir->ssa_rep->uses[0] = mul_mir->ssa_rep->uses[0]; |
| add_mir->ssa_rep->uses[1] = mul_mir->ssa_rep->uses[1]; |
| // Clear the original multiply product ssa use count, as it is not used anymore. |
| raw_use_counts_[mul_mir->ssa_rep->defs[0]] = 0; |
| use_counts_[mul_mir->ssa_rep->defs[0]] = 0; |
| if (is_wide) { |
| DCHECK_EQ(add_mir->ssa_rep->num_uses, 6); |
| add_mir->ssa_rep->uses[2] = mul_mir->ssa_rep->uses[2]; |
| add_mir->ssa_rep->uses[3] = mul_mir->ssa_rep->uses[3]; |
| add_mir->ssa_rep->uses[4] = addend0; |
| add_mir->ssa_rep->uses[5] = addend1; |
| raw_use_counts_[mul_mir->ssa_rep->defs[1]] = 0; |
| use_counts_[mul_mir->ssa_rep->defs[1]] = 0; |
| } else { |
| DCHECK_EQ(add_mir->ssa_rep->num_uses, 3); |
| add_mir->ssa_rep->uses[2] = addend0; |
| } |
| // Copy in the decoded instruction information. |
| add_mir->dalvikInsn.vB = SRegToVReg(add_mir->ssa_rep->uses[0]); |
| if (is_wide) { |
| add_mir->dalvikInsn.vC = SRegToVReg(add_mir->ssa_rep->uses[2]); |
| add_mir->dalvikInsn.arg[0] = SRegToVReg(add_mir->ssa_rep->uses[4]); |
| } else { |
| add_mir->dalvikInsn.vC = SRegToVReg(add_mir->ssa_rep->uses[1]); |
| add_mir->dalvikInsn.arg[0] = SRegToVReg(add_mir->ssa_rep->uses[2]); |
| } |
| // Original multiply MIR is set to Nop. |
| mul_mir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpNop); |
| } |
| |
| void MIRGraph::MultiplyAddOpt(BasicBlock* bb) { |
| if (bb->block_type == kDead) { |
| return; |
| } |
| ScopedArenaAllocator allocator(&cu_->arena_stack); |
| ScopedArenaSafeMap<uint32_t, MIR*> ssa_mul_map(std::less<uint32_t>(), allocator.Adapter()); |
| ScopedArenaSafeMap<uint32_t, MIR*>::iterator map_it; |
| for (MIR* mir = bb->first_mir_insn; mir != nullptr; mir = mir->next) { |
| Instruction::Code opcode = mir->dalvikInsn.opcode; |
| bool is_sub = true; |
| bool is_candidate_multiply = false; |
| switch (opcode) { |
| case Instruction::MUL_INT: |
| case Instruction::MUL_INT_2ADDR: |
| is_candidate_multiply = true; |
| break; |
| case Instruction::MUL_LONG: |
| case Instruction::MUL_LONG_2ADDR: |
| if (cu_->target64) { |
| is_candidate_multiply = true; |
| } |
| break; |
| case Instruction::ADD_INT: |
| case Instruction::ADD_INT_2ADDR: |
| is_sub = false; |
| FALLTHROUGH_INTENDED; |
| case Instruction::SUB_INT: |
| case Instruction::SUB_INT_2ADDR: |
| if (((map_it = ssa_mul_map.find(mir->ssa_rep->uses[0])) != ssa_mul_map.end()) && !is_sub) { |
| // a*b+c |
| CombineMultiplyAdd(map_it->second, mir, true /* product is the first addend */, |
| false /* is_wide */, false /* is_sub */); |
| ssa_mul_map.erase(mir->ssa_rep->uses[0]); |
| } else if ((map_it = ssa_mul_map.find(mir->ssa_rep->uses[1])) != ssa_mul_map.end()) { |
| // c+a*b or c-a*b |
| CombineMultiplyAdd(map_it->second, mir, false /* product is the second addend */, |
| false /* is_wide */, is_sub); |
| ssa_mul_map.erase(map_it); |
| } |
| break; |
| case Instruction::ADD_LONG: |
| case Instruction::ADD_LONG_2ADDR: |
| is_sub = false; |
| FALLTHROUGH_INTENDED; |
| case Instruction::SUB_LONG: |
| case Instruction::SUB_LONG_2ADDR: |
| if (!cu_->target64) { |
| break; |
| } |
| if ((map_it = ssa_mul_map.find(mir->ssa_rep->uses[0])) != ssa_mul_map.end() && !is_sub) { |
| // a*b+c |
| CombineMultiplyAdd(map_it->second, mir, true /* product is the first addend */, |
| true /* is_wide */, false /* is_sub */); |
| ssa_mul_map.erase(map_it); |
| } else if ((map_it = ssa_mul_map.find(mir->ssa_rep->uses[2])) != ssa_mul_map.end()) { |
| // c+a*b or c-a*b |
| CombineMultiplyAdd(map_it->second, mir, false /* product is the second addend */, |
| true /* is_wide */, is_sub); |
| ssa_mul_map.erase(map_it); |
| } |
| break; |
| default: |
| if (!ssa_mul_map.empty() && CanThrow(mir)) { |
| // Should not combine multiply and add MIRs across potential exception. |
| ssa_mul_map.clear(); |
| } |
| break; |
| } |
| |
| // Exclude the case when an MIR writes a vreg which is previous candidate multiply MIR's uses. |
| // It is because that current RA may allocate the same physical register to them. For this |
| // kind of cases, the multiplier has been updated, we should not use updated value to the |
| // multiply-add insn. |
| if (ssa_mul_map.size() > 0) { |
| for (auto it = ssa_mul_map.begin(); it != ssa_mul_map.end();) { |
| MIR* mul = it->second; |
| if (HasAntiDependency(mul, mir)) { |
| it = ssa_mul_map.erase(it); |
| } else { |
| ++it; |
| } |
| } |
| } |
| |
| if (is_candidate_multiply && |
| (GetRawUseCount(mir->ssa_rep->defs[0]) == 1) && (mir->next != nullptr)) { |
| ssa_mul_map.Put(mir->ssa_rep->defs[0], mir); |
| } |
| } |
| } |
| |
| } // namespace art |