| /* |
| * 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 "compiler_internals.h" |
| #include "global_value_numbering.h" |
| #include "local_value_numbering.h" |
| #include "dataflow_iterator-inl.h" |
| #include "dex/global_value_numbering.h" |
| #include "dex/quick/dex_file_method_inliner.h" |
| #include "dex/quick/dex_file_to_method_inliner_map.h" |
| #include "utils/scoped_arena_containers.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, int value) { |
| is_constant_v_->SetBit(ssa_reg); |
| constant_values_[ssa_reg] = value; |
| } |
| |
| void MIRGraph::SetConstantWide(int 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); |
| } |
| |
| 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; |
| if (mir == NULL) { |
| bb = GetBasicBlock(bb->fall_through); |
| if ((bb == NULL) || Predecessors(bb) != 1) { |
| mir = NULL; |
| } 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) { |
| 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 |
| }; |
| |
| COMPILE_ASSERT(arraysize(kIfCcZConditionCodes) == Instruction::IF_LEZ - Instruction::IF_EQZ + 1, |
| if_ccz_ccodes_size1); |
| |
| static constexpr bool IsInstructionIfCcZ(Instruction::Code opcode) { |
| return Instruction::IF_EQZ <= opcode && opcode <= Instruction::IF_LEZ; |
| } |
| |
| static constexpr ConditionCode ConditionCodeForIfCcZ(Instruction::Code opcode) { |
| return kIfCcZConditionCodes[opcode - Instruction::IF_EQZ]; |
| } |
| |
| COMPILE_ASSERT(ConditionCodeForIfCcZ(Instruction::IF_EQZ) == kCondEq, check_if_eqz_ccode); |
| COMPILE_ASSERT(ConditionCodeForIfCcZ(Instruction::IF_NEZ) == kCondNe, check_if_nez_ccode); |
| COMPILE_ASSERT(ConditionCodeForIfCcZ(Instruction::IF_LTZ) == kCondLt, check_if_ltz_ccode); |
| COMPILE_ASSERT(ConditionCodeForIfCcZ(Instruction::IF_GEZ) == kCondGe, check_if_gez_ccode); |
| COMPILE_ASSERT(ConditionCodeForIfCcZ(Instruction::IF_GTZ) == kCondGt, check_if_gtz_ccode); |
| COMPILE_ASSERT(ConditionCodeForIfCcZ(Instruction::IF_LEZ) == kCondLe, check_if_lez_ccode); |
| |
| int MIRGraph::GetSSAUseCount(int s_reg) { |
| return raw_use_counts_.Get(s_reg); |
| } |
| |
| size_t MIRGraph::GetNumAvailableNonSpecialCompilerTemps() { |
| if (num_non_special_compiler_temps_ >= max_available_non_special_compiler_temps_) { |
| return 0; |
| } else { |
| return max_available_non_special_compiler_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) { |
| // There is a limit to the number of non-special temps so check to make sure it wasn't exceeded. |
| if (ct_type == kCompilerTempVR) { |
| size_t available_temps = GetNumAvailableNonSpecialCompilerTemps(); |
| if (available_temps <= 0 || (available_temps <= 1 && wide)) { |
| return 0; |
| } |
| } |
| |
| 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) { |
| DCHECK_EQ(wide, false); |
| compiler_temp->v_reg = static_cast<int>(kVRegMethodPtrBaseReg); |
| compiler_temp->s_reg_low = AddNewSReg(compiler_temp->v_reg); |
| |
| // The MIR graph keeps track of the sreg for method pointer specially, so record that now. |
| method_sreg_ = compiler_temp->s_reg_low; |
| } else { |
| DCHECK_EQ(ct_type, kCompilerTempVR); |
| |
| // The new non-special compiler temp must receive a unique v_reg with a negative value. |
| compiler_temp->v_reg = static_cast<int>(kVRegNonSpecialTempBaseReg) - |
| num_non_special_compiler_temps_; |
| compiler_temp->s_reg_low = AddNewSReg(compiler_temp->v_reg); |
| num_non_special_compiler_temps_++; |
| |
| if (wide) { |
| // Create a new CompilerTemp for the high part. |
| CompilerTemp *compiler_temp_high = |
| static_cast<CompilerTemp *>(arena_->Alloc(sizeof(CompilerTemp), kArenaAllocRegAlloc)); |
| compiler_temp_high->v_reg = compiler_temp->v_reg; |
| compiler_temp_high->s_reg_low = compiler_temp->s_reg_low; |
| compiler_temps_.Insert(compiler_temp_high); |
| |
| // Ensure that the two registers are consecutive. Since the virtual registers used for temps |
| // grow in a negative fashion, we need the smaller to refer to the low part. Thus, we |
| // redefine the v_reg and s_reg_low. |
| compiler_temp->v_reg--; |
| int ssa_reg_high = compiler_temp->s_reg_low; |
| compiler_temp->s_reg_low = AddNewSReg(compiler_temp->v_reg); |
| int ssa_reg_low = compiler_temp->s_reg_low; |
| |
| // If needed initialize the register location for the high part. |
| // The low part is handled later in this method on a common path. |
| if (reg_location_ != nullptr) { |
| reg_location_[ssa_reg_high] = temp_loc; |
| reg_location_[ssa_reg_high].high_word = 1; |
| reg_location_[ssa_reg_high].s_reg_low = ssa_reg_low; |
| reg_location_[ssa_reg_high].wide = true; |
| } |
| |
| num_non_special_compiler_temps_++; |
| } |
| } |
| |
| // Have we already allocated the register locations? |
| 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; |
| } |
| |
| compiler_temps_.Insert(compiler_temp); |
| return compiler_temp; |
| } |
| |
| /* Do some MIR-level extended basic block optimizations */ |
| bool MIRGraph::BasicBlockOpt(BasicBlock* bb) { |
| if (bb->block_type == kDead) { |
| return true; |
| } |
| // Don't do a separate LVN if we did the GVN. |
| bool use_lvn = bb->use_lvn && (cu_->disable_opt & (1u << kGlobalValueNumbering)) != 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())); |
| 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::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); |
| // 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; |
| case Instruction::GOTO: |
| case Instruction::GOTO_16: |
| case Instruction::GOTO_32: |
| case Instruction::IF_EQ: |
| case Instruction::IF_NE: |
| case Instruction::IF_LT: |
| case Instruction::IF_GE: |
| case Instruction::IF_GT: |
| case Instruction::IF_LE: |
| case Instruction::IF_EQZ: |
| case Instruction::IF_NEZ: |
| case Instruction::IF_LTZ: |
| case Instruction::IF_GEZ: |
| case Instruction::IF_GTZ: |
| case Instruction::IF_LEZ: |
| // If we've got a backwards branch to return, no need to suspend check. |
| if ((IsBackedge(bb, bb->taken) && GetBasicBlock(bb->taken)->dominates_return) || |
| (IsBackedge(bb, bb->fall_through) && |
| GetBasicBlock(bb->fall_through)->dominates_return)) { |
| mir->optimization_flags |= MIR_IGNORE_SUSPEND_CHECK; |
| if (cu_->verbose) { |
| LOG(INFO) << "Suppressed suspend check on branch to return at 0x" << std::hex |
| << mir->offset; |
| } |
| } |
| 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_->compiler->IsPortable() && |
| (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. At the very least, we can eliminate the |
| * suspend check on the taken-taken branch back to the join point. |
| */ |
| if (SelectKind(tk->last_mir_insn) == kSelectGoto) { |
| tk->last_mir_insn->optimization_flags |= (MIR_IGNORE_SUSPEND_CHECK); |
| } |
| |
| // 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); |
| int* src_ssa = |
| static_cast<int*>(arena_->Alloc(sizeof(int) * 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 = |
| static_cast<int*>(arena_->Alloc(sizeof(int) * 1, kArenaAllocDFInfo)); |
| mir->ssa_rep->fp_def = |
| static_cast<bool*>(arena_->Alloc(sizeof(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 = |
| static_cast<bool*>(arena_->Alloc(sizeof(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 "true" path, delete the SSA name of the "false" 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]; |
| phi->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpNop); |
| } else { |
| int dead_def = if_false->ssa_rep->defs[0]; |
| int live_def = if_true->ssa_rep->defs[0]; |
| mir->ssa_rep->defs[0] = live_def; |
| BasicBlockId* incoming = phi->meta.phi_incoming; |
| for (int i = 0; i < phi->ssa_rep->num_uses; i++) { |
| if (phi->ssa_rep->uses[i] == live_def) { |
| incoming[i] = bb->id; |
| } |
| } |
| for (int i = 0; i < phi->ssa_rep->num_uses; i++) { |
| if (phi->ssa_rep->uses[i] == dead_def) { |
| int last_slot = phi->ssa_rep->num_uses - 1; |
| phi->ssa_rep->uses[i] = phi->ssa_rep->uses[last_slot]; |
| incoming[i] = incoming[last_slot]; |
| } |
| } |
| } |
| phi->ssa_rep->num_uses--; |
| bb->taken = NullBasicBlockId; |
| tk->block_type = kDead; |
| for (MIR* tmir = ft->first_mir_insn; tmir != NULL; tmir = tmir->next) { |
| tmir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpNop); |
| } |
| } |
| } |
| } |
| } |
| } |
| 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(struct 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; |
| } |
| BasicBlock* walker = bb; |
| while (true) { |
| // Check termination conditions |
| if ((walker->block_type == kEntryBlock) || (Predecessors(walker) != 1)) { |
| break; |
| } |
| BasicBlock* prev = GetBasicBlock(walker->predecessors->Get(0)); |
| 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(struct BasicBlock* bb) { |
| // Loop here to allow combining a sequence of blocks |
| while (true) { |
| // Check termination conditions |
| if ((bb->first_mir_insn == NULL) |
| || (bb->data_flow_info == NULL) |
| || (bb->block_type == kExceptionHandling) |
| || (bb->block_type == kExitBlock) |
| || (bb->block_type == kDead) |
| || (bb->taken == NullBasicBlockId) |
| || (GetBasicBlock(bb->taken)->block_type != kExceptionHandling) |
| || (bb->successor_block_list_type != kNotUsed) |
| || (static_cast<int>(bb->last_mir_insn->dalvikInsn.opcode) != kMirOpCheck)) { |
| break; |
| } |
| |
| // Test the kMirOpCheck instruction |
| MIR* mir = bb->last_mir_insn; |
| // Grab the attributes from the paired opcode |
| MIR* throw_insn = mir->meta.throw_insn; |
| uint64_t df_attributes = GetDataFlowAttributes(throw_insn); |
| bool can_combine = true; |
| if (df_attributes & DF_HAS_NULL_CHKS) { |
| can_combine &= ((throw_insn->optimization_flags & MIR_IGNORE_NULL_CHECK) != 0); |
| } |
| if (df_attributes & DF_HAS_RANGE_CHKS) { |
| can_combine &= ((throw_insn->optimization_flags & MIR_IGNORE_RANGE_CHECK) != 0); |
| } |
| if (!can_combine) { |
| break; |
| } |
| // OK - got one. Combine |
| BasicBlock* bb_next = GetBasicBlock(bb->fall_through); |
| DCHECK(!bb_next->catch_entry); |
| DCHECK_EQ(Predecessors(bb_next), 1U); |
| // Overwrite the kOpCheck insn with the paired opcode |
| DCHECK_EQ(bb_next->first_mir_insn, throw_insn); |
| *bb->last_mir_insn = *throw_insn; |
| // Use the successor info from the next block |
| bb->successor_block_list_type = bb_next->successor_block_list_type; |
| bb->successor_blocks = bb_next->successor_blocks; |
| // Use the ending block linkage from the next block |
| bb->fall_through = bb_next->fall_through; |
| GetBasicBlock(bb->taken)->block_type = kDead; // Kill the unused exception block |
| bb->taken = bb_next->taken; |
| // Include the rest of the instructions |
| bb->last_mir_insn = bb_next->last_mir_insn; |
| /* |
| * If lower-half of pair of blocks to combine contained a return, move the flag |
| * to the newly combined block. |
| */ |
| bb->terminated_by_return = bb_next->terminated_by_return; |
| |
| /* |
| * 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. |
| */ |
| |
| // Kill bb_next and remap now-dead id to parent |
| bb_next->block_type = kDead; |
| block_id_map_.Overwrite(bb_next->id, bb->id); |
| |
| // Now, loop back and see if we can keep going |
| } |
| } |
| |
| void MIRGraph::EliminateNullChecksAndInferTypesStart() { |
| if ((cu_->disable_opt & (1 << kNullCheckElimination)) == 0) { |
| if (kIsDebugBuild) { |
| AllNodesIterator iter(this); |
| for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) { |
| CHECK(bb->data_flow_info == nullptr || bb->data_flow_info->ending_check_v == nullptr); |
| } |
| } |
| |
| DCHECK(temp_scoped_alloc_.get() == nullptr); |
| temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack)); |
| temp_bit_vector_size_ = GetNumSSARegs(); |
| temp_bit_vector_ = new (temp_scoped_alloc_.get()) ArenaBitVector( |
| temp_scoped_alloc_.get(), temp_bit_vector_size_, false, kBitMapTempSSARegisterV); |
| } |
| } |
| |
| /* |
| * Eliminate unnecessary null checks for a basic block. Also, while we're doing |
| * an iterative walk go ahead and perform type and size inference. |
| */ |
| bool MIRGraph::EliminateNullChecksAndInferTypes(BasicBlock* bb) { |
| if (bb->data_flow_info == NULL) return false; |
| bool infer_changed = false; |
| bool do_nce = ((cu_->disable_opt & (1 << kNullCheckElimination)) == 0); |
| |
| ArenaBitVector* ssa_regs_to_check = temp_bit_vector_; |
| if (do_nce) { |
| /* |
| * Set initial state. Catch blocks don't need any special treatment. |
| */ |
| if (bb->block_type == kEntryBlock) { |
| ssa_regs_to_check->ClearAllBits(); |
| // Assume all ins are objects. |
| for (uint16_t in_reg = cu_->num_dalvik_registers - cu_->num_ins; |
| in_reg < cu_->num_dalvik_registers; in_reg++) { |
| ssa_regs_to_check->SetBit(in_reg); |
| } |
| if ((cu_->access_flags & kAccStatic) == 0) { |
| // If non-static method, mark "this" as non-null |
| int this_reg = cu_->num_dalvik_registers - cu_->num_ins; |
| ssa_regs_to_check->ClearBit(this_reg); |
| } |
| } else if (bb->predecessors->Size() == 1) { |
| BasicBlock* pred_bb = GetBasicBlock(bb->predecessors->Get(0)); |
| // pred_bb must have already been processed at least once. |
| DCHECK(pred_bb->data_flow_info->ending_check_v != nullptr); |
| ssa_regs_to_check->Copy(pred_bb->data_flow_info->ending_check_v); |
| 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) { |
| if (pred_bb->fall_through == bb->id) { |
| // The fall-through of a block following a IF_EQZ, set the vA of the IF_EQZ to show that |
| // it can't be null. |
| ssa_regs_to_check->ClearBit(last_insn->ssa_rep->uses[0]); |
| } |
| } else if (last_opcode == Instruction::IF_NEZ) { |
| if (pred_bb->taken == bb->id) { |
| // The taken block following a IF_NEZ, set the vA of the IF_NEZ to show that it can't be |
| // null. |
| ssa_regs_to_check->ClearBit(last_insn->ssa_rep->uses[0]); |
| } |
| } |
| } |
| } |
| } else { |
| // Starting state is union of all incoming arcs |
| GrowableArray<BasicBlockId>::Iterator iter(bb->predecessors); |
| BasicBlock* pred_bb = GetBasicBlock(iter.Next()); |
| CHECK(pred_bb != NULL); |
| while (pred_bb->data_flow_info->ending_check_v == nullptr) { |
| pred_bb = GetBasicBlock(iter.Next()); |
| // At least one predecessor must have been processed before this bb. |
| DCHECK(pred_bb != nullptr); |
| DCHECK(pred_bb->data_flow_info != nullptr); |
| } |
| ssa_regs_to_check->Copy(pred_bb->data_flow_info->ending_check_v); |
| while (true) { |
| pred_bb = GetBasicBlock(iter.Next()); |
| if (!pred_bb) break; |
| DCHECK(pred_bb->data_flow_info != nullptr); |
| if (pred_bb->data_flow_info->ending_check_v == nullptr) { |
| continue; |
| } |
| ssa_regs_to_check->Union(pred_bb->data_flow_info->ending_check_v); |
| } |
| } |
| // At this point, ssa_regs_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) { |
| if (mir->ssa_rep == NULL) { |
| continue; |
| } |
| |
| // Propagate type info. |
| infer_changed = InferTypeAndSize(bb, mir, infer_changed); |
| if (!do_nce) { |
| continue; |
| } |
| |
| uint64_t df_attributes = GetDataFlowAttributes(mir); |
| |
| // Might need a null check? |
| if (df_attributes & DF_HAS_NULL_CHKS) { |
| int src_idx; |
| if (df_attributes & DF_NULL_CHK_1) { |
| src_idx = 1; |
| } else if (df_attributes & DF_NULL_CHK_2) { |
| src_idx = 2; |
| } else { |
| src_idx = 0; |
| } |
| int src_sreg = mir->ssa_rep->uses[src_idx]; |
| if (!ssa_regs_to_check->IsBitSet(src_sreg)) { |
| // Eliminate the null check. |
| mir->optimization_flags |= MIR_IGNORE_NULL_CHECK; |
| } else { |
| // Do the null check. |
| mir->optimization_flags &= ~MIR_IGNORE_NULL_CHECK; |
| // Mark s_reg as null-checked |
| ssa_regs_to_check->ClearBit(src_sreg); |
| } |
| } |
| |
| 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)) { |
| ssa_regs_to_check->SetBit(mir->ssa_rep->defs[0]); |
| } |
| |
| // Now, 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 |
| ssa_regs_to_check->ClearBit(mir->ssa_rep->defs[0]); |
| } |
| |
| // 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 (next_mir && |
| next_mir->dalvikInsn.opcode == Instruction::MOVE_RESULT_OBJECT) { |
| // Mark as null checked |
| ssa_regs_to_check->ClearBit(next_mir->ssa_rep->defs[0]); |
| } else { |
| if (next_mir) { |
| LOG(WARNING) << "Unexpected opcode following new: " << next_mir->dalvikInsn.opcode; |
| } else if (bb->fall_through != NullBasicBlockId) { |
| // Look in next basic block |
| struct BasicBlock* next_bb = GetBasicBlock(bb->fall_through); |
| for (MIR* tmir = next_bb->first_mir_insn; tmir != NULL; |
| tmir =tmir->next) { |
| if (MIR::DecodedInstruction::IsPseudoMirOp(tmir->dalvikInsn.opcode)) { |
| continue; |
| } |
| // First non-pseudo should be MOVE_RESULT_OBJECT |
| if (tmir->dalvikInsn.opcode == Instruction::MOVE_RESULT_OBJECT) { |
| // Mark as null checked |
| ssa_regs_to_check->ClearBit(tmir->ssa_rep->defs[0]); |
| } else { |
| LOG(WARNING) << "Unexpected op after new: " << tmir->dalvikInsn.opcode; |
| } |
| break; |
| } |
| } |
| } |
| } |
| |
| /* |
| * Propagate nullcheck state on register copies (including |
| * Phi pseudo copies. For the latter, nullcheck state is |
| * the "or" of all the Phi's operands. |
| */ |
| if (df_attributes & (DF_NULL_TRANSFER_0 | DF_NULL_TRANSFER_N)) { |
| int tgt_sreg = mir->ssa_rep->defs[0]; |
| int operands = (df_attributes & DF_NULL_TRANSFER_0) ? 1 : |
| mir->ssa_rep->num_uses; |
| bool needs_null_check = false; |
| for (int i = 0; i < operands; i++) { |
| needs_null_check |= ssa_regs_to_check->IsBitSet(mir->ssa_rep->uses[i]); |
| } |
| if (needs_null_check) { |
| ssa_regs_to_check->SetBit(tgt_sreg); |
| } else { |
| ssa_regs_to_check->ClearBit(tgt_sreg); |
| } |
| } |
| } |
| |
| // Did anything change? |
| bool nce_changed = false; |
| if (do_nce) { |
| if (bb->data_flow_info->ending_check_v == nullptr) { |
| DCHECK(temp_scoped_alloc_.get() != nullptr); |
| bb->data_flow_info->ending_check_v = new (temp_scoped_alloc_.get()) ArenaBitVector( |
| temp_scoped_alloc_.get(), temp_bit_vector_size_, false, kBitMapNullCheck); |
| nce_changed = ssa_regs_to_check->GetHighestBitSet() != -1; |
| bb->data_flow_info->ending_check_v->Copy(ssa_regs_to_check); |
| } else if (!ssa_regs_to_check->SameBitsSet(bb->data_flow_info->ending_check_v)) { |
| nce_changed = true; |
| bb->data_flow_info->ending_check_v->Copy(ssa_regs_to_check); |
| } |
| } |
| return infer_changed | nce_changed; |
| } |
| |
| void MIRGraph::EliminateNullChecksAndInferTypesEnd() { |
| if ((cu_->disable_opt & (1 << kNullCheckElimination)) == 0) { |
| // Clean up temporaries. |
| temp_bit_vector_size_ = 0u; |
| temp_bit_vector_ = nullptr; |
| AllNodesIterator iter(this); |
| for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) { |
| if (bb->data_flow_info != nullptr) { |
| bb->data_flow_info->ending_check_v = nullptr; |
| } |
| } |
| DCHECK(temp_scoped_alloc_.get() != nullptr); |
| temp_scoped_alloc_.reset(); |
| } |
| } |
| |
| bool MIRGraph::EliminateClassInitChecksGate() { |
| if ((cu_->disable_opt & (1 << kClassInitCheckElimination)) != 0 || |
| !cu_->mir_graph->HasStaticFieldAccess()) { |
| return false; |
| } |
| |
| if (kIsDebugBuild) { |
| AllNodesIterator iter(this); |
| for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) { |
| CHECK(bb->data_flow_info == nullptr || bb->data_flow_info->ending_check_v == nullptr); |
| } |
| } |
| |
| 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 = (cu_->code_item->insns_size_in_code_units_ + 1u) / 2u; |
| temp_insn_data_ = static_cast<uint16_t*>( |
| temp_scoped_alloc_->Alloc(end * sizeof(*temp_insn_data_), kArenaAllocGrowableArray)); |
| |
| 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()) { |
| for (MIR* mir = bb->first_mir_insn; mir != nullptr; mir = mir->next) { |
| DCHECK(bb->data_flow_info != nullptr); |
| if (mir->dalvikInsn.opcode >= Instruction::SGET && |
| mir->dalvikInsn.opcode <= Instruction::SPUT_SHORT) { |
| const MirSFieldLoweringInfo& field_info = GetSFieldLoweringInfo(mir); |
| uint16_t index = 0xffffu; |
| if (!field_info.IsInitialized()) { |
| 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()) |
| }; |
| index = class_to_index_map.insert(entry).first->index; |
| } |
| // Using offset/2 for index into temp_insn_data_. |
| temp_insn_data_[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_insn_data_ = nullptr; |
| temp_scoped_alloc_.reset(); |
| return false; |
| } |
| |
| temp_bit_vector_size_ = unique_class_count; |
| temp_bit_vector_ = new (temp_scoped_alloc_.get()) ArenaBitVector( |
| temp_scoped_alloc_.get(), temp_bit_vector_size_, false, kBitMapClInitCheck); |
| DCHECK_GT(temp_bit_vector_size_, 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->data_flow_info == NULL) { |
| return false; |
| } |
| |
| /* |
| * Set initial state. Catch blocks don't need any special treatment. |
| */ |
| ArenaBitVector* classes_to_check = temp_bit_vector_; |
| DCHECK(classes_to_check != nullptr); |
| if (bb->block_type == kEntryBlock) { |
| classes_to_check->SetInitialBits(temp_bit_vector_size_); |
| } else if (bb->predecessors->Size() == 1) { |
| BasicBlock* pred_bb = GetBasicBlock(bb->predecessors->Get(0)); |
| // pred_bb must have already been processed at least once. |
| DCHECK(pred_bb != nullptr); |
| DCHECK(pred_bb->data_flow_info != nullptr); |
| DCHECK(pred_bb->data_flow_info->ending_check_v != nullptr); |
| classes_to_check->Copy(pred_bb->data_flow_info->ending_check_v); |
| } else { |
| // Starting state is union of all incoming arcs |
| GrowableArray<BasicBlockId>::Iterator iter(bb->predecessors); |
| BasicBlock* pred_bb = GetBasicBlock(iter.Next()); |
| DCHECK(pred_bb != NULL); |
| DCHECK(pred_bb->data_flow_info != NULL); |
| while (pred_bb->data_flow_info->ending_check_v == nullptr) { |
| pred_bb = GetBasicBlock(iter.Next()); |
| // At least one predecessor must have been processed before this bb. |
| DCHECK(pred_bb != nullptr); |
| DCHECK(pred_bb->data_flow_info != nullptr); |
| } |
| classes_to_check->Copy(pred_bb->data_flow_info->ending_check_v); |
| while (true) { |
| pred_bb = GetBasicBlock(iter.Next()); |
| if (!pred_bb) break; |
| DCHECK(pred_bb->data_flow_info != nullptr); |
| if (pred_bb->data_flow_info->ending_check_v == nullptr) { |
| continue; |
| } |
| classes_to_check->Union(pred_bb->data_flow_info->ending_check_v); |
| } |
| } |
| // 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) { |
| if (mir->dalvikInsn.opcode >= Instruction::SGET && |
| mir->dalvikInsn.opcode <= Instruction::SPUT_SHORT) { |
| uint16_t index = temp_insn_data_[mir->offset / 2u]; |
| if (index != 0xffffu) { |
| if (mir->dalvikInsn.opcode >= Instruction::SGET && |
| mir->dalvikInsn.opcode <= Instruction::SPUT_SHORT) { |
| if (!classes_to_check->IsBitSet(index)) { |
| // Eliminate the class init check. |
| mir->optimization_flags |= MIR_IGNORE_CLINIT_CHECK; |
| } else { |
| // Do the class init check. |
| mir->optimization_flags &= ~MIR_IGNORE_CLINIT_CHECK; |
| } |
| } |
| // Mark the class as initialized. |
| classes_to_check->ClearBit(index); |
| } |
| } |
| } |
| |
| // Did anything change? |
| bool changed = false; |
| if (bb->data_flow_info->ending_check_v == nullptr) { |
| DCHECK(temp_scoped_alloc_.get() != nullptr); |
| DCHECK(bb->data_flow_info != nullptr); |
| bb->data_flow_info->ending_check_v = new (temp_scoped_alloc_.get()) ArenaBitVector( |
| temp_scoped_alloc_.get(), temp_bit_vector_size_, false, kBitMapClInitCheck); |
| changed = classes_to_check->GetHighestBitSet() != -1; |
| bb->data_flow_info->ending_check_v->Copy(classes_to_check); |
| } else if (!classes_to_check->Equal(bb->data_flow_info->ending_check_v)) { |
| changed = true; |
| bb->data_flow_info->ending_check_v->Copy(classes_to_check); |
| } |
| return changed; |
| } |
| |
| void MIRGraph::EliminateClassInitChecksEnd() { |
| // Clean up temporaries. |
| temp_bit_vector_size_ = 0u; |
| temp_bit_vector_ = nullptr; |
| AllNodesIterator iter(this); |
| for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) { |
| if (bb->data_flow_info != nullptr) { |
| bb->data_flow_info->ending_check_v = nullptr; |
| } |
| } |
| |
| DCHECK(temp_insn_data_ != nullptr); |
| temp_insn_data_ = nullptr; |
| DCHECK(temp_scoped_alloc_.get() != nullptr); |
| temp_scoped_alloc_.reset(); |
| } |
| |
| bool MIRGraph::ApplyGlobalValueNumberingGate() { |
| if ((cu_->disable_opt & (1u << kGlobalValueNumbering)) != 0u) { |
| return false; |
| } |
| |
| DCHECK(temp_scoped_alloc_ == nullptr); |
| temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack)); |
| DCHECK(temp_gvn_ == nullptr); |
| temp_gvn_.reset( |
| new (temp_scoped_alloc_.get()) GlobalValueNumbering(cu_, temp_scoped_alloc_.get())); |
| return true; |
| } |
| |
| bool MIRGraph::ApplyGlobalValueNumbering(BasicBlock* bb) { |
| DCHECK(temp_gvn_ != nullptr); |
| LocalValueNumbering* lvn = temp_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_->FinishBasicBlock(bb); |
| return change; |
| } |
| |
| void MIRGraph::ApplyGlobalValueNumberingEnd() { |
| // Perform modifications. |
| if (temp_gvn_->Good()) { |
| temp_gvn_->AllowModifications(); |
| PreOrderDfsIterator 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_->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_->FinishBasicBlock(bb); |
| DCHECK(!change) << PrettyMethod(cu_->method_idx, *cu_->dex_file); |
| } |
| } |
| } else { |
| LOG(WARNING) << "GVN failed for " << PrettyMethod(cu_->method_idx, *cu_->dex_file); |
| } |
| |
| DCHECK(temp_gvn_ != nullptr); |
| temp_gvn_.reset(); |
| 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_bit_vector_->IsBitSet(method_index)) { |
| iget_or_iput->meta.ifield_lowering_info = temp_insn_data_[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 */); |
| MirIFieldLoweringInfo inlined_field_info(field_idx); |
| 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_.Insert(inlined_field_info); |
| temp_bit_vector_->SetBit(method_index); |
| temp_insn_data_[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_bit_vector_size_ = method_lowering_infos_.Size(); |
| temp_bit_vector_ = new (temp_scoped_alloc_.get()) ArenaBitVector( |
| temp_scoped_alloc_.get(), temp_bit_vector_size_, false, kBitMapMisc); |
| temp_bit_vector_->ClearAllBits(); |
| temp_insn_data_ = static_cast<uint16_t*>(temp_scoped_alloc_->Alloc( |
| temp_bit_vector_size_ * sizeof(*temp_insn_data_), 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 (!(Instruction::FlagsOf(mir->dalvikInsn.opcode) & 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 || method_info.NeedsClassInitialization())) { |
| 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() { |
| DCHECK(temp_insn_data_ != nullptr); |
| temp_insn_data_ = nullptr; |
| DCHECK(temp_bit_vector_ != nullptr); |
| temp_bit_vector_ = 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(struct 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::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); |
| } |
| } |
| } |
| |
| } // namespace art |
