1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "compiler_internals.h" 18 #include "global_value_numbering.h" 19 #include "local_value_numbering.h" 20 #include "dataflow_iterator-inl.h" 21 #include "dex/global_value_numbering.h" 22 #include "dex/quick/dex_file_method_inliner.h" 23 #include "dex/quick/dex_file_to_method_inliner_map.h" 24 #include "utils/scoped_arena_containers.h" 25 26 namespace art { 27 28 static unsigned int Predecessors(BasicBlock* bb) { 29 return bb->predecessors->Size(); 30 } 31 32 /* Setup a constant value for opcodes thare have the DF_SETS_CONST attribute */ 33 void MIRGraph::SetConstant(int32_t ssa_reg, int value) { 34 is_constant_v_->SetBit(ssa_reg); 35 constant_values_[ssa_reg] = value; 36 } 37 38 void MIRGraph::SetConstantWide(int ssa_reg, int64_t value) { 39 is_constant_v_->SetBit(ssa_reg); 40 is_constant_v_->SetBit(ssa_reg + 1); 41 constant_values_[ssa_reg] = Low32Bits(value); 42 constant_values_[ssa_reg + 1] = High32Bits(value); 43 } 44 45 void MIRGraph::DoConstantPropagation(BasicBlock* bb) { 46 MIR* mir; 47 48 for (mir = bb->first_mir_insn; mir != NULL; mir = mir->next) { 49 // Skip pass if BB has MIR without SSA representation. 50 if (mir->ssa_rep == nullptr) { 51 return; 52 } 53 54 uint64_t df_attributes = GetDataFlowAttributes(mir); 55 56 MIR::DecodedInstruction* d_insn = &mir->dalvikInsn; 57 58 if (!(df_attributes & DF_HAS_DEFS)) continue; 59 60 /* Handle instructions that set up constants directly */ 61 if (df_attributes & DF_SETS_CONST) { 62 if (df_attributes & DF_DA) { 63 int32_t vB = static_cast<int32_t>(d_insn->vB); 64 switch (d_insn->opcode) { 65 case Instruction::CONST_4: 66 case Instruction::CONST_16: 67 case Instruction::CONST: 68 SetConstant(mir->ssa_rep->defs[0], vB); 69 break; 70 case Instruction::CONST_HIGH16: 71 SetConstant(mir->ssa_rep->defs[0], vB << 16); 72 break; 73 case Instruction::CONST_WIDE_16: 74 case Instruction::CONST_WIDE_32: 75 SetConstantWide(mir->ssa_rep->defs[0], static_cast<int64_t>(vB)); 76 break; 77 case Instruction::CONST_WIDE: 78 SetConstantWide(mir->ssa_rep->defs[0], d_insn->vB_wide); 79 break; 80 case Instruction::CONST_WIDE_HIGH16: 81 SetConstantWide(mir->ssa_rep->defs[0], static_cast<int64_t>(vB) << 48); 82 break; 83 default: 84 break; 85 } 86 } 87 /* Handle instructions that set up constants directly */ 88 } else if (df_attributes & DF_IS_MOVE) { 89 int i; 90 91 for (i = 0; i < mir->ssa_rep->num_uses; i++) { 92 if (!is_constant_v_->IsBitSet(mir->ssa_rep->uses[i])) break; 93 } 94 /* Move a register holding a constant to another register */ 95 if (i == mir->ssa_rep->num_uses) { 96 SetConstant(mir->ssa_rep->defs[0], constant_values_[mir->ssa_rep->uses[0]]); 97 if (df_attributes & DF_A_WIDE) { 98 SetConstant(mir->ssa_rep->defs[1], constant_values_[mir->ssa_rep->uses[1]]); 99 } 100 } 101 } 102 } 103 /* TODO: implement code to handle arithmetic operations */ 104 } 105 106 /* Advance to next strictly dominated MIR node in an extended basic block */ 107 MIR* MIRGraph::AdvanceMIR(BasicBlock** p_bb, MIR* mir) { 108 BasicBlock* bb = *p_bb; 109 if (mir != NULL) { 110 mir = mir->next; 111 if (mir == NULL) { 112 bb = GetBasicBlock(bb->fall_through); 113 if ((bb == NULL) || Predecessors(bb) != 1) { 114 mir = NULL; 115 } else { 116 *p_bb = bb; 117 mir = bb->first_mir_insn; 118 } 119 } 120 } 121 return mir; 122 } 123 124 /* 125 * To be used at an invoke mir. If the logically next mir node represents 126 * a move-result, return it. Else, return NULL. If a move-result exists, 127 * it is required to immediately follow the invoke with no intervening 128 * opcodes or incoming arcs. However, if the result of the invoke is not 129 * used, a move-result may not be present. 130 */ 131 MIR* MIRGraph::FindMoveResult(BasicBlock* bb, MIR* mir) { 132 BasicBlock* tbb = bb; 133 mir = AdvanceMIR(&tbb, mir); 134 while (mir != NULL) { 135 if ((mir->dalvikInsn.opcode == Instruction::MOVE_RESULT) || 136 (mir->dalvikInsn.opcode == Instruction::MOVE_RESULT_OBJECT) || 137 (mir->dalvikInsn.opcode == Instruction::MOVE_RESULT_WIDE)) { 138 break; 139 } 140 // Keep going if pseudo op, otherwise terminate 141 if (MIR::DecodedInstruction::IsPseudoMirOp(mir->dalvikInsn.opcode)) { 142 mir = AdvanceMIR(&tbb, mir); 143 } else { 144 mir = NULL; 145 } 146 } 147 return mir; 148 } 149 150 BasicBlock* MIRGraph::NextDominatedBlock(BasicBlock* bb) { 151 if (bb->block_type == kDead) { 152 return NULL; 153 } 154 DCHECK((bb->block_type == kEntryBlock) || (bb->block_type == kDalvikByteCode) 155 || (bb->block_type == kExitBlock)); 156 BasicBlock* bb_taken = GetBasicBlock(bb->taken); 157 BasicBlock* bb_fall_through = GetBasicBlock(bb->fall_through); 158 if (((bb_fall_through == NULL) && (bb_taken != NULL)) && 159 ((bb_taken->block_type == kDalvikByteCode) || (bb_taken->block_type == kExitBlock))) { 160 // Follow simple unconditional branches. 161 bb = bb_taken; 162 } else { 163 // Follow simple fallthrough 164 bb = (bb_taken != NULL) ? NULL : bb_fall_through; 165 } 166 if (bb == NULL || (Predecessors(bb) != 1)) { 167 return NULL; 168 } 169 DCHECK((bb->block_type == kDalvikByteCode) || (bb->block_type == kExitBlock)); 170 return bb; 171 } 172 173 static MIR* FindPhi(BasicBlock* bb, int ssa_name) { 174 for (MIR* mir = bb->first_mir_insn; mir != NULL; mir = mir->next) { 175 if (static_cast<int>(mir->dalvikInsn.opcode) == kMirOpPhi) { 176 for (int i = 0; i < mir->ssa_rep->num_uses; i++) { 177 if (mir->ssa_rep->uses[i] == ssa_name) { 178 return mir; 179 } 180 } 181 } 182 } 183 return NULL; 184 } 185 186 static SelectInstructionKind SelectKind(MIR* mir) { 187 switch (mir->dalvikInsn.opcode) { 188 case Instruction::MOVE: 189 case Instruction::MOVE_OBJECT: 190 case Instruction::MOVE_16: 191 case Instruction::MOVE_OBJECT_16: 192 case Instruction::MOVE_FROM16: 193 case Instruction::MOVE_OBJECT_FROM16: 194 return kSelectMove; 195 case Instruction::CONST: 196 case Instruction::CONST_4: 197 case Instruction::CONST_16: 198 return kSelectConst; 199 case Instruction::GOTO: 200 case Instruction::GOTO_16: 201 case Instruction::GOTO_32: 202 return kSelectGoto; 203 default: 204 return kSelectNone; 205 } 206 } 207 208 static constexpr ConditionCode kIfCcZConditionCodes[] = { 209 kCondEq, kCondNe, kCondLt, kCondGe, kCondGt, kCondLe 210 }; 211 212 COMPILE_ASSERT(arraysize(kIfCcZConditionCodes) == Instruction::IF_LEZ - Instruction::IF_EQZ + 1, 213 if_ccz_ccodes_size1); 214 215 static constexpr bool IsInstructionIfCcZ(Instruction::Code opcode) { 216 return Instruction::IF_EQZ <= opcode && opcode <= Instruction::IF_LEZ; 217 } 218 219 static constexpr ConditionCode ConditionCodeForIfCcZ(Instruction::Code opcode) { 220 return kIfCcZConditionCodes[opcode - Instruction::IF_EQZ]; 221 } 222 223 COMPILE_ASSERT(ConditionCodeForIfCcZ(Instruction::IF_EQZ) == kCondEq, check_if_eqz_ccode); 224 COMPILE_ASSERT(ConditionCodeForIfCcZ(Instruction::IF_NEZ) == kCondNe, check_if_nez_ccode); 225 COMPILE_ASSERT(ConditionCodeForIfCcZ(Instruction::IF_LTZ) == kCondLt, check_if_ltz_ccode); 226 COMPILE_ASSERT(ConditionCodeForIfCcZ(Instruction::IF_GEZ) == kCondGe, check_if_gez_ccode); 227 COMPILE_ASSERT(ConditionCodeForIfCcZ(Instruction::IF_GTZ) == kCondGt, check_if_gtz_ccode); 228 COMPILE_ASSERT(ConditionCodeForIfCcZ(Instruction::IF_LEZ) == kCondLe, check_if_lez_ccode); 229 230 int MIRGraph::GetSSAUseCount(int s_reg) { 231 return raw_use_counts_.Get(s_reg); 232 } 233 234 size_t MIRGraph::GetNumAvailableNonSpecialCompilerTemps() { 235 if (num_non_special_compiler_temps_ >= max_available_non_special_compiler_temps_) { 236 return 0; 237 } else { 238 return max_available_non_special_compiler_temps_ - num_non_special_compiler_temps_; 239 } 240 } 241 242 243 // FIXME - will probably need to revisit all uses of this, as type not defined. 244 static const RegLocation temp_loc = {kLocCompilerTemp, 245 0, 1 /*defined*/, 0, 0, 0, 0, 0, 1 /*home*/, 246 RegStorage(), INVALID_SREG, INVALID_SREG}; 247 248 CompilerTemp* MIRGraph::GetNewCompilerTemp(CompilerTempType ct_type, bool wide) { 249 // There is a limit to the number of non-special temps so check to make sure it wasn't exceeded. 250 if (ct_type == kCompilerTempVR) { 251 size_t available_temps = GetNumAvailableNonSpecialCompilerTemps(); 252 if (available_temps <= 0 || (available_temps <= 1 && wide)) { 253 return 0; 254 } 255 } 256 257 CompilerTemp *compiler_temp = static_cast<CompilerTemp *>(arena_->Alloc(sizeof(CompilerTemp), 258 kArenaAllocRegAlloc)); 259 260 // Create the type of temp requested. Special temps need special handling because 261 // they have a specific virtual register assignment. 262 if (ct_type == kCompilerTempSpecialMethodPtr) { 263 DCHECK_EQ(wide, false); 264 compiler_temp->v_reg = static_cast<int>(kVRegMethodPtrBaseReg); 265 compiler_temp->s_reg_low = AddNewSReg(compiler_temp->v_reg); 266 267 // The MIR graph keeps track of the sreg for method pointer specially, so record that now. 268 method_sreg_ = compiler_temp->s_reg_low; 269 } else { 270 DCHECK_EQ(ct_type, kCompilerTempVR); 271 272 // The new non-special compiler temp must receive a unique v_reg with a negative value. 273 compiler_temp->v_reg = static_cast<int>(kVRegNonSpecialTempBaseReg) - 274 num_non_special_compiler_temps_; 275 compiler_temp->s_reg_low = AddNewSReg(compiler_temp->v_reg); 276 num_non_special_compiler_temps_++; 277 278 if (wide) { 279 // Create a new CompilerTemp for the high part. 280 CompilerTemp *compiler_temp_high = 281 static_cast<CompilerTemp *>(arena_->Alloc(sizeof(CompilerTemp), kArenaAllocRegAlloc)); 282 compiler_temp_high->v_reg = compiler_temp->v_reg; 283 compiler_temp_high->s_reg_low = compiler_temp->s_reg_low; 284 compiler_temps_.Insert(compiler_temp_high); 285 286 // Ensure that the two registers are consecutive. Since the virtual registers used for temps 287 // grow in a negative fashion, we need the smaller to refer to the low part. Thus, we 288 // redefine the v_reg and s_reg_low. 289 compiler_temp->v_reg--; 290 int ssa_reg_high = compiler_temp->s_reg_low; 291 compiler_temp->s_reg_low = AddNewSReg(compiler_temp->v_reg); 292 int ssa_reg_low = compiler_temp->s_reg_low; 293 294 // If needed initialize the register location for the high part. 295 // The low part is handled later in this method on a common path. 296 if (reg_location_ != nullptr) { 297 reg_location_[ssa_reg_high] = temp_loc; 298 reg_location_[ssa_reg_high].high_word = 1; 299 reg_location_[ssa_reg_high].s_reg_low = ssa_reg_low; 300 reg_location_[ssa_reg_high].wide = true; 301 } 302 303 num_non_special_compiler_temps_++; 304 } 305 } 306 307 // Have we already allocated the register locations? 308 if (reg_location_ != nullptr) { 309 int ssa_reg_low = compiler_temp->s_reg_low; 310 reg_location_[ssa_reg_low] = temp_loc; 311 reg_location_[ssa_reg_low].s_reg_low = ssa_reg_low; 312 reg_location_[ssa_reg_low].wide = wide; 313 } 314 315 compiler_temps_.Insert(compiler_temp); 316 return compiler_temp; 317 } 318 319 /* Do some MIR-level extended basic block optimizations */ 320 bool MIRGraph::BasicBlockOpt(BasicBlock* bb) { 321 if (bb->block_type == kDead) { 322 return true; 323 } 324 // Don't do a separate LVN if we did the GVN. 325 bool use_lvn = bb->use_lvn && (cu_->disable_opt & (1u << kGlobalValueNumbering)) != 0u; 326 std::unique_ptr<ScopedArenaAllocator> allocator; 327 std::unique_ptr<GlobalValueNumbering> global_valnum; 328 std::unique_ptr<LocalValueNumbering> local_valnum; 329 if (use_lvn) { 330 allocator.reset(ScopedArenaAllocator::Create(&cu_->arena_stack)); 331 global_valnum.reset(new (allocator.get()) GlobalValueNumbering(cu_, allocator.get())); 332 local_valnum.reset(new (allocator.get()) LocalValueNumbering(global_valnum.get(), bb->id, 333 allocator.get())); 334 } 335 while (bb != NULL) { 336 for (MIR* mir = bb->first_mir_insn; mir != NULL; mir = mir->next) { 337 // TUNING: use the returned value number for CSE. 338 if (use_lvn) { 339 local_valnum->GetValueNumber(mir); 340 } 341 // Look for interesting opcodes, skip otherwise 342 Instruction::Code opcode = mir->dalvikInsn.opcode; 343 switch (opcode) { 344 case Instruction::CMPL_FLOAT: 345 case Instruction::CMPL_DOUBLE: 346 case Instruction::CMPG_FLOAT: 347 case Instruction::CMPG_DOUBLE: 348 case Instruction::CMP_LONG: 349 if ((cu_->disable_opt & (1 << kBranchFusing)) != 0) { 350 // Bitcode doesn't allow this optimization. 351 break; 352 } 353 if (mir->next != NULL) { 354 MIR* mir_next = mir->next; 355 // Make sure result of cmp is used by next insn and nowhere else 356 if (IsInstructionIfCcZ(mir_next->dalvikInsn.opcode) && 357 (mir->ssa_rep->defs[0] == mir_next->ssa_rep->uses[0]) && 358 (GetSSAUseCount(mir->ssa_rep->defs[0]) == 1)) { 359 mir_next->meta.ccode = ConditionCodeForIfCcZ(mir_next->dalvikInsn.opcode); 360 switch (opcode) { 361 case Instruction::CMPL_FLOAT: 362 mir_next->dalvikInsn.opcode = 363 static_cast<Instruction::Code>(kMirOpFusedCmplFloat); 364 break; 365 case Instruction::CMPL_DOUBLE: 366 mir_next->dalvikInsn.opcode = 367 static_cast<Instruction::Code>(kMirOpFusedCmplDouble); 368 break; 369 case Instruction::CMPG_FLOAT: 370 mir_next->dalvikInsn.opcode = 371 static_cast<Instruction::Code>(kMirOpFusedCmpgFloat); 372 break; 373 case Instruction::CMPG_DOUBLE: 374 mir_next->dalvikInsn.opcode = 375 static_cast<Instruction::Code>(kMirOpFusedCmpgDouble); 376 break; 377 case Instruction::CMP_LONG: 378 mir_next->dalvikInsn.opcode = 379 static_cast<Instruction::Code>(kMirOpFusedCmpLong); 380 break; 381 default: LOG(ERROR) << "Unexpected opcode: " << opcode; 382 } 383 mir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpNop); 384 // Copy the SSA information that is relevant. 385 mir_next->ssa_rep->num_uses = mir->ssa_rep->num_uses; 386 mir_next->ssa_rep->uses = mir->ssa_rep->uses; 387 mir_next->ssa_rep->fp_use = mir->ssa_rep->fp_use; 388 mir_next->ssa_rep->num_defs = 0; 389 mir->ssa_rep->num_uses = 0; 390 mir->ssa_rep->num_defs = 0; 391 // Copy in the decoded instruction information for potential SSA re-creation. 392 mir_next->dalvikInsn.vA = mir->dalvikInsn.vB; 393 mir_next->dalvikInsn.vB = mir->dalvikInsn.vC; 394 } 395 } 396 break; 397 case Instruction::GOTO: 398 case Instruction::GOTO_16: 399 case Instruction::GOTO_32: 400 case Instruction::IF_EQ: 401 case Instruction::IF_NE: 402 case Instruction::IF_LT: 403 case Instruction::IF_GE: 404 case Instruction::IF_GT: 405 case Instruction::IF_LE: 406 case Instruction::IF_EQZ: 407 case Instruction::IF_NEZ: 408 case Instruction::IF_LTZ: 409 case Instruction::IF_GEZ: 410 case Instruction::IF_GTZ: 411 case Instruction::IF_LEZ: 412 // If we've got a backwards branch to return, no need to suspend check. 413 if ((IsBackedge(bb, bb->taken) && GetBasicBlock(bb->taken)->dominates_return) || 414 (IsBackedge(bb, bb->fall_through) && 415 GetBasicBlock(bb->fall_through)->dominates_return)) { 416 mir->optimization_flags |= MIR_IGNORE_SUSPEND_CHECK; 417 if (cu_->verbose) { 418 LOG(INFO) << "Suppressed suspend check on branch to return at 0x" << std::hex 419 << mir->offset; 420 } 421 } 422 break; 423 default: 424 break; 425 } 426 // Is this the select pattern? 427 // TODO: flesh out support for Mips. NOTE: llvm's select op doesn't quite work here. 428 // TUNING: expand to support IF_xx compare & branches 429 if (!cu_->compiler->IsPortable() && 430 (cu_->instruction_set == kArm64 || cu_->instruction_set == kThumb2 || 431 cu_->instruction_set == kX86 || cu_->instruction_set == kX86_64) && 432 IsInstructionIfCcZ(mir->dalvikInsn.opcode)) { 433 BasicBlock* ft = GetBasicBlock(bb->fall_through); 434 DCHECK(ft != NULL); 435 BasicBlock* ft_ft = GetBasicBlock(ft->fall_through); 436 BasicBlock* ft_tk = GetBasicBlock(ft->taken); 437 438 BasicBlock* tk = GetBasicBlock(bb->taken); 439 DCHECK(tk != NULL); 440 BasicBlock* tk_ft = GetBasicBlock(tk->fall_through); 441 BasicBlock* tk_tk = GetBasicBlock(tk->taken); 442 443 /* 444 * In the select pattern, the taken edge goes to a block that unconditionally 445 * transfers to the rejoin block and the fall_though edge goes to a block that 446 * unconditionally falls through to the rejoin block. 447 */ 448 if ((tk_ft == NULL) && (ft_tk == NULL) && (tk_tk == ft_ft) && 449 (Predecessors(tk) == 1) && (Predecessors(ft) == 1)) { 450 /* 451 * Okay - we have the basic diamond shape. At the very least, we can eliminate the 452 * suspend check on the taken-taken branch back to the join point. 453 */ 454 if (SelectKind(tk->last_mir_insn) == kSelectGoto) { 455 tk->last_mir_insn->optimization_flags |= (MIR_IGNORE_SUSPEND_CHECK); 456 } 457 458 // TODO: Add logic for LONG. 459 // Are the block bodies something we can handle? 460 if ((ft->first_mir_insn == ft->last_mir_insn) && 461 (tk->first_mir_insn != tk->last_mir_insn) && 462 (tk->first_mir_insn->next == tk->last_mir_insn) && 463 ((SelectKind(ft->first_mir_insn) == kSelectMove) || 464 (SelectKind(ft->first_mir_insn) == kSelectConst)) && 465 (SelectKind(ft->first_mir_insn) == SelectKind(tk->first_mir_insn)) && 466 (SelectKind(tk->last_mir_insn) == kSelectGoto)) { 467 // Almost there. Are the instructions targeting the same vreg? 468 MIR* if_true = tk->first_mir_insn; 469 MIR* if_false = ft->first_mir_insn; 470 // It's possible that the target of the select isn't used - skip those (rare) cases. 471 MIR* phi = FindPhi(tk_tk, if_true->ssa_rep->defs[0]); 472 if ((phi != NULL) && (if_true->dalvikInsn.vA == if_false->dalvikInsn.vA)) { 473 /* 474 * We'll convert the IF_EQZ/IF_NEZ to a SELECT. We need to find the 475 * Phi node in the merge block and delete it (while using the SSA name 476 * of the merge as the target of the SELECT. Delete both taken and 477 * fallthrough blocks, and set fallthrough to merge block. 478 * NOTE: not updating other dataflow info (no longer used at this point). 479 * If this changes, need to update i_dom, etc. here (and in CombineBlocks). 480 */ 481 mir->meta.ccode = ConditionCodeForIfCcZ(mir->dalvikInsn.opcode); 482 mir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpSelect); 483 bool const_form = (SelectKind(if_true) == kSelectConst); 484 if ((SelectKind(if_true) == kSelectMove)) { 485 if (IsConst(if_true->ssa_rep->uses[0]) && 486 IsConst(if_false->ssa_rep->uses[0])) { 487 const_form = true; 488 if_true->dalvikInsn.vB = ConstantValue(if_true->ssa_rep->uses[0]); 489 if_false->dalvikInsn.vB = ConstantValue(if_false->ssa_rep->uses[0]); 490 } 491 } 492 if (const_form) { 493 /* 494 * TODO: If both constants are the same value, then instead of generating 495 * a select, we should simply generate a const bytecode. This should be 496 * considered after inlining which can lead to CFG of this form. 497 */ 498 // "true" set val in vB 499 mir->dalvikInsn.vB = if_true->dalvikInsn.vB; 500 // "false" set val in vC 501 mir->dalvikInsn.vC = if_false->dalvikInsn.vB; 502 } else { 503 DCHECK_EQ(SelectKind(if_true), kSelectMove); 504 DCHECK_EQ(SelectKind(if_false), kSelectMove); 505 int* src_ssa = 506 static_cast<int*>(arena_->Alloc(sizeof(int) * 3, kArenaAllocDFInfo)); 507 src_ssa[0] = mir->ssa_rep->uses[0]; 508 src_ssa[1] = if_true->ssa_rep->uses[0]; 509 src_ssa[2] = if_false->ssa_rep->uses[0]; 510 mir->ssa_rep->uses = src_ssa; 511 mir->ssa_rep->num_uses = 3; 512 } 513 mir->ssa_rep->num_defs = 1; 514 mir->ssa_rep->defs = 515 static_cast<int*>(arena_->Alloc(sizeof(int) * 1, kArenaAllocDFInfo)); 516 mir->ssa_rep->fp_def = 517 static_cast<bool*>(arena_->Alloc(sizeof(bool) * 1, kArenaAllocDFInfo)); 518 mir->ssa_rep->fp_def[0] = if_true->ssa_rep->fp_def[0]; 519 // Match type of uses to def. 520 mir->ssa_rep->fp_use = 521 static_cast<bool*>(arena_->Alloc(sizeof(bool) * mir->ssa_rep->num_uses, 522 kArenaAllocDFInfo)); 523 for (int i = 0; i < mir->ssa_rep->num_uses; i++) { 524 mir->ssa_rep->fp_use[i] = mir->ssa_rep->fp_def[0]; 525 } 526 /* 527 * There is usually a Phi node in the join block for our two cases. If the 528 * Phi node only contains our two cases as input, we will use the result 529 * SSA name of the Phi node as our select result and delete the Phi. If 530 * the Phi node has more than two operands, we will arbitrarily use the SSA 531 * name of the "true" path, delete the SSA name of the "false" path from the 532 * Phi node (and fix up the incoming arc list). 533 */ 534 if (phi->ssa_rep->num_uses == 2) { 535 mir->ssa_rep->defs[0] = phi->ssa_rep->defs[0]; 536 phi->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpNop); 537 } else { 538 int dead_def = if_false->ssa_rep->defs[0]; 539 int live_def = if_true->ssa_rep->defs[0]; 540 mir->ssa_rep->defs[0] = live_def; 541 BasicBlockId* incoming = phi->meta.phi_incoming; 542 for (int i = 0; i < phi->ssa_rep->num_uses; i++) { 543 if (phi->ssa_rep->uses[i] == live_def) { 544 incoming[i] = bb->id; 545 } 546 } 547 for (int i = 0; i < phi->ssa_rep->num_uses; i++) { 548 if (phi->ssa_rep->uses[i] == dead_def) { 549 int last_slot = phi->ssa_rep->num_uses - 1; 550 phi->ssa_rep->uses[i] = phi->ssa_rep->uses[last_slot]; 551 incoming[i] = incoming[last_slot]; 552 } 553 } 554 } 555 phi->ssa_rep->num_uses--; 556 bb->taken = NullBasicBlockId; 557 tk->block_type = kDead; 558 for (MIR* tmir = ft->first_mir_insn; tmir != NULL; tmir = tmir->next) { 559 tmir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpNop); 560 } 561 } 562 } 563 } 564 } 565 } 566 bb = ((cu_->disable_opt & (1 << kSuppressExceptionEdges)) != 0) ? NextDominatedBlock(bb) : NULL; 567 } 568 if (use_lvn && UNLIKELY(!global_valnum->Good())) { 569 LOG(WARNING) << "LVN overflow in " << PrettyMethod(cu_->method_idx, *cu_->dex_file); 570 } 571 572 return true; 573 } 574 575 /* Collect stats on number of checks removed */ 576 void MIRGraph::CountChecks(struct BasicBlock* bb) { 577 if (bb->data_flow_info != NULL) { 578 for (MIR* mir = bb->first_mir_insn; mir != NULL; mir = mir->next) { 579 if (mir->ssa_rep == NULL) { 580 continue; 581 } 582 uint64_t df_attributes = GetDataFlowAttributes(mir); 583 if (df_attributes & DF_HAS_NULL_CHKS) { 584 checkstats_->null_checks++; 585 if (mir->optimization_flags & MIR_IGNORE_NULL_CHECK) { 586 checkstats_->null_checks_eliminated++; 587 } 588 } 589 if (df_attributes & DF_HAS_RANGE_CHKS) { 590 checkstats_->range_checks++; 591 if (mir->optimization_flags & MIR_IGNORE_RANGE_CHECK) { 592 checkstats_->range_checks_eliminated++; 593 } 594 } 595 } 596 } 597 } 598 599 /* Try to make common case the fallthrough path. */ 600 bool MIRGraph::LayoutBlocks(BasicBlock* bb) { 601 // TODO: For now, just looking for direct throws. Consider generalizing for profile feedback. 602 if (!bb->explicit_throw) { 603 return false; 604 } 605 606 // If we visited it, we are done. 607 if (bb->visited) { 608 return false; 609 } 610 bb->visited = true; 611 612 BasicBlock* walker = bb; 613 while (true) { 614 // Check termination conditions. 615 if ((walker->block_type == kEntryBlock) || (Predecessors(walker) != 1)) { 616 break; 617 } 618 BasicBlock* prev = GetBasicBlock(walker->predecessors->Get(0)); 619 620 // If we visited the predecessor, we are done. 621 if (prev->visited) { 622 return false; 623 } 624 prev->visited = true; 625 626 if (prev->conditional_branch) { 627 if (GetBasicBlock(prev->fall_through) == walker) { 628 // Already done - return. 629 break; 630 } 631 DCHECK_EQ(walker, GetBasicBlock(prev->taken)); 632 // Got one. Flip it and exit. 633 Instruction::Code opcode = prev->last_mir_insn->dalvikInsn.opcode; 634 switch (opcode) { 635 case Instruction::IF_EQ: opcode = Instruction::IF_NE; break; 636 case Instruction::IF_NE: opcode = Instruction::IF_EQ; break; 637 case Instruction::IF_LT: opcode = Instruction::IF_GE; break; 638 case Instruction::IF_GE: opcode = Instruction::IF_LT; break; 639 case Instruction::IF_GT: opcode = Instruction::IF_LE; break; 640 case Instruction::IF_LE: opcode = Instruction::IF_GT; break; 641 case Instruction::IF_EQZ: opcode = Instruction::IF_NEZ; break; 642 case Instruction::IF_NEZ: opcode = Instruction::IF_EQZ; break; 643 case Instruction::IF_LTZ: opcode = Instruction::IF_GEZ; break; 644 case Instruction::IF_GEZ: opcode = Instruction::IF_LTZ; break; 645 case Instruction::IF_GTZ: opcode = Instruction::IF_LEZ; break; 646 case Instruction::IF_LEZ: opcode = Instruction::IF_GTZ; break; 647 default: LOG(FATAL) << "Unexpected opcode " << opcode; 648 } 649 prev->last_mir_insn->dalvikInsn.opcode = opcode; 650 BasicBlockId t_bb = prev->taken; 651 prev->taken = prev->fall_through; 652 prev->fall_through = t_bb; 653 break; 654 } 655 walker = prev; 656 } 657 return false; 658 } 659 660 /* Combine any basic blocks terminated by instructions that we now know can't throw */ 661 void MIRGraph::CombineBlocks(struct BasicBlock* bb) { 662 // Loop here to allow combining a sequence of blocks 663 while (true) { 664 // Check termination conditions 665 if ((bb->first_mir_insn == NULL) 666 || (bb->data_flow_info == NULL) 667 || (bb->block_type == kExceptionHandling) 668 || (bb->block_type == kExitBlock) 669 || (bb->block_type == kDead) 670 || (bb->taken == NullBasicBlockId) 671 || (GetBasicBlock(bb->taken)->block_type != kExceptionHandling) 672 || (bb->successor_block_list_type != kNotUsed) 673 || (static_cast<int>(bb->last_mir_insn->dalvikInsn.opcode) != kMirOpCheck)) { 674 break; 675 } 676 677 // Test the kMirOpCheck instruction 678 MIR* mir = bb->last_mir_insn; 679 // Grab the attributes from the paired opcode 680 MIR* throw_insn = mir->meta.throw_insn; 681 uint64_t df_attributes = GetDataFlowAttributes(throw_insn); 682 bool can_combine = true; 683 if (df_attributes & DF_HAS_NULL_CHKS) { 684 can_combine &= ((throw_insn->optimization_flags & MIR_IGNORE_NULL_CHECK) != 0); 685 } 686 if (df_attributes & DF_HAS_RANGE_CHKS) { 687 can_combine &= ((throw_insn->optimization_flags & MIR_IGNORE_RANGE_CHECK) != 0); 688 } 689 if (!can_combine) { 690 break; 691 } 692 // OK - got one. Combine 693 BasicBlock* bb_next = GetBasicBlock(bb->fall_through); 694 DCHECK(!bb_next->catch_entry); 695 DCHECK_EQ(Predecessors(bb_next), 1U); 696 // Overwrite the kOpCheck insn with the paired opcode 697 DCHECK_EQ(bb_next->first_mir_insn, throw_insn); 698 *bb->last_mir_insn = *throw_insn; 699 // Use the successor info from the next block 700 bb->successor_block_list_type = bb_next->successor_block_list_type; 701 bb->successor_blocks = bb_next->successor_blocks; 702 // Use the ending block linkage from the next block 703 bb->fall_through = bb_next->fall_through; 704 GetBasicBlock(bb->taken)->block_type = kDead; // Kill the unused exception block 705 bb->taken = bb_next->taken; 706 // Include the rest of the instructions 707 bb->last_mir_insn = bb_next->last_mir_insn; 708 /* 709 * If lower-half of pair of blocks to combine contained a return, move the flag 710 * to the newly combined block. 711 */ 712 bb->terminated_by_return = bb_next->terminated_by_return; 713 714 /* 715 * NOTE: we aren't updating all dataflow info here. Should either make sure this pass 716 * happens after uses of i_dominated, dom_frontier or update the dataflow info here. 717 */ 718 719 // Kill bb_next and remap now-dead id to parent 720 bb_next->block_type = kDead; 721 block_id_map_.Overwrite(bb_next->id, bb->id); 722 723 // Now, loop back and see if we can keep going 724 } 725 } 726 727 void MIRGraph::EliminateNullChecksAndInferTypesStart() { 728 if ((cu_->disable_opt & (1 << kNullCheckElimination)) == 0) { 729 if (kIsDebugBuild) { 730 AllNodesIterator iter(this); 731 for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) { 732 CHECK(bb->data_flow_info == nullptr || bb->data_flow_info->ending_check_v == nullptr); 733 } 734 } 735 736 DCHECK(temp_scoped_alloc_.get() == nullptr); 737 temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack)); 738 temp_bit_vector_size_ = GetNumSSARegs(); 739 temp_bit_vector_ = new (temp_scoped_alloc_.get()) ArenaBitVector( 740 temp_scoped_alloc_.get(), temp_bit_vector_size_, false, kBitMapTempSSARegisterV); 741 } 742 } 743 744 /* 745 * Eliminate unnecessary null checks for a basic block. Also, while we're doing 746 * an iterative walk go ahead and perform type and size inference. 747 */ 748 bool MIRGraph::EliminateNullChecksAndInferTypes(BasicBlock* bb) { 749 if (bb->data_flow_info == NULL) return false; 750 bool infer_changed = false; 751 bool do_nce = ((cu_->disable_opt & (1 << kNullCheckElimination)) == 0); 752 753 ArenaBitVector* ssa_regs_to_check = temp_bit_vector_; 754 if (do_nce) { 755 /* 756 * Set initial state. Catch blocks don't need any special treatment. 757 */ 758 if (bb->block_type == kEntryBlock) { 759 ssa_regs_to_check->ClearAllBits(); 760 // Assume all ins are objects. 761 for (uint16_t in_reg = cu_->num_dalvik_registers - cu_->num_ins; 762 in_reg < cu_->num_dalvik_registers; in_reg++) { 763 ssa_regs_to_check->SetBit(in_reg); 764 } 765 if ((cu_->access_flags & kAccStatic) == 0) { 766 // If non-static method, mark "this" as non-null 767 int this_reg = cu_->num_dalvik_registers - cu_->num_ins; 768 ssa_regs_to_check->ClearBit(this_reg); 769 } 770 } else if (bb->predecessors->Size() == 1) { 771 BasicBlock* pred_bb = GetBasicBlock(bb->predecessors->Get(0)); 772 // pred_bb must have already been processed at least once. 773 DCHECK(pred_bb->data_flow_info->ending_check_v != nullptr); 774 ssa_regs_to_check->Copy(pred_bb->data_flow_info->ending_check_v); 775 if (pred_bb->block_type == kDalvikByteCode) { 776 // Check to see if predecessor had an explicit null-check. 777 MIR* last_insn = pred_bb->last_mir_insn; 778 if (last_insn != nullptr) { 779 Instruction::Code last_opcode = last_insn->dalvikInsn.opcode; 780 if (last_opcode == Instruction::IF_EQZ) { 781 if (pred_bb->fall_through == bb->id) { 782 // The fall-through of a block following a IF_EQZ, set the vA of the IF_EQZ to show that 783 // it can't be null. 784 ssa_regs_to_check->ClearBit(last_insn->ssa_rep->uses[0]); 785 } 786 } else if (last_opcode == Instruction::IF_NEZ) { 787 if (pred_bb->taken == bb->id) { 788 // The taken block following a IF_NEZ, set the vA of the IF_NEZ to show that it can't be 789 // null. 790 ssa_regs_to_check->ClearBit(last_insn->ssa_rep->uses[0]); 791 } 792 } 793 } 794 } 795 } else { 796 // Starting state is union of all incoming arcs 797 GrowableArray<BasicBlockId>::Iterator iter(bb->predecessors); 798 BasicBlock* pred_bb = GetBasicBlock(iter.Next()); 799 CHECK(pred_bb != NULL); 800 while (pred_bb->data_flow_info->ending_check_v == nullptr) { 801 pred_bb = GetBasicBlock(iter.Next()); 802 // At least one predecessor must have been processed before this bb. 803 DCHECK(pred_bb != nullptr); 804 DCHECK(pred_bb->data_flow_info != nullptr); 805 } 806 ssa_regs_to_check->Copy(pred_bb->data_flow_info->ending_check_v); 807 while (true) { 808 pred_bb = GetBasicBlock(iter.Next()); 809 if (!pred_bb) break; 810 DCHECK(pred_bb->data_flow_info != nullptr); 811 if (pred_bb->data_flow_info->ending_check_v == nullptr) { 812 continue; 813 } 814 ssa_regs_to_check->Union(pred_bb->data_flow_info->ending_check_v); 815 } 816 } 817 // At this point, ssa_regs_to_check shows which sregs have an object definition with 818 // no intervening uses. 819 } 820 821 // Walk through the instruction in the block, updating as necessary 822 for (MIR* mir = bb->first_mir_insn; mir != NULL; mir = mir->next) { 823 if (mir->ssa_rep == NULL) { 824 continue; 825 } 826 827 // Propagate type info. 828 infer_changed = InferTypeAndSize(bb, mir, infer_changed); 829 if (!do_nce) { 830 continue; 831 } 832 833 uint64_t df_attributes = GetDataFlowAttributes(mir); 834 835 // Might need a null check? 836 if (df_attributes & DF_HAS_NULL_CHKS) { 837 int src_idx; 838 if (df_attributes & DF_NULL_CHK_1) { 839 src_idx = 1; 840 } else if (df_attributes & DF_NULL_CHK_2) { 841 src_idx = 2; 842 } else { 843 src_idx = 0; 844 } 845 int src_sreg = mir->ssa_rep->uses[src_idx]; 846 if (!ssa_regs_to_check->IsBitSet(src_sreg)) { 847 // Eliminate the null check. 848 mir->optimization_flags |= MIR_IGNORE_NULL_CHECK; 849 } else { 850 // Do the null check. 851 mir->optimization_flags &= ~MIR_IGNORE_NULL_CHECK; 852 // Mark s_reg as null-checked 853 ssa_regs_to_check->ClearBit(src_sreg); 854 } 855 } 856 857 if ((df_attributes & DF_A_WIDE) || 858 (df_attributes & (DF_REF_A | DF_SETS_CONST | DF_NULL_TRANSFER)) == 0) { 859 continue; 860 } 861 862 /* 863 * First, mark all object definitions as requiring null check. 864 * Note: we can't tell if a CONST definition might be used as an object, so treat 865 * them all as object definitions. 866 */ 867 if (((df_attributes & (DF_DA | DF_REF_A)) == (DF_DA | DF_REF_A)) || 868 (df_attributes & DF_SETS_CONST)) { 869 ssa_regs_to_check->SetBit(mir->ssa_rep->defs[0]); 870 } 871 872 // Now, remove mark from all object definitions we know are non-null. 873 if (df_attributes & DF_NON_NULL_DST) { 874 // Mark target of NEW* as non-null 875 ssa_regs_to_check->ClearBit(mir->ssa_rep->defs[0]); 876 } 877 878 // Mark non-null returns from invoke-style NEW* 879 if (df_attributes & DF_NON_NULL_RET) { 880 MIR* next_mir = mir->next; 881 // Next should be an MOVE_RESULT_OBJECT 882 if (next_mir && 883 next_mir->dalvikInsn.opcode == Instruction::MOVE_RESULT_OBJECT) { 884 // Mark as null checked 885 ssa_regs_to_check->ClearBit(next_mir->ssa_rep->defs[0]); 886 } else { 887 if (next_mir) { 888 LOG(WARNING) << "Unexpected opcode following new: " << next_mir->dalvikInsn.opcode; 889 } else if (bb->fall_through != NullBasicBlockId) { 890 // Look in next basic block 891 struct BasicBlock* next_bb = GetBasicBlock(bb->fall_through); 892 for (MIR* tmir = next_bb->first_mir_insn; tmir != NULL; 893 tmir =tmir->next) { 894 if (MIR::DecodedInstruction::IsPseudoMirOp(tmir->dalvikInsn.opcode)) { 895 continue; 896 } 897 // First non-pseudo should be MOVE_RESULT_OBJECT 898 if (tmir->dalvikInsn.opcode == Instruction::MOVE_RESULT_OBJECT) { 899 // Mark as null checked 900 ssa_regs_to_check->ClearBit(tmir->ssa_rep->defs[0]); 901 } else { 902 LOG(WARNING) << "Unexpected op after new: " << tmir->dalvikInsn.opcode; 903 } 904 break; 905 } 906 } 907 } 908 } 909 910 /* 911 * Propagate nullcheck state on register copies (including 912 * Phi pseudo copies. For the latter, nullcheck state is 913 * the "or" of all the Phi's operands. 914 */ 915 if (df_attributes & (DF_NULL_TRANSFER_0 | DF_NULL_TRANSFER_N)) { 916 int tgt_sreg = mir->ssa_rep->defs[0]; 917 int operands = (df_attributes & DF_NULL_TRANSFER_0) ? 1 : 918 mir->ssa_rep->num_uses; 919 bool needs_null_check = false; 920 for (int i = 0; i < operands; i++) { 921 needs_null_check |= ssa_regs_to_check->IsBitSet(mir->ssa_rep->uses[i]); 922 } 923 if (needs_null_check) { 924 ssa_regs_to_check->SetBit(tgt_sreg); 925 } else { 926 ssa_regs_to_check->ClearBit(tgt_sreg); 927 } 928 } 929 } 930 931 // Did anything change? 932 bool nce_changed = false; 933 if (do_nce) { 934 if (bb->data_flow_info->ending_check_v == nullptr) { 935 DCHECK(temp_scoped_alloc_.get() != nullptr); 936 bb->data_flow_info->ending_check_v = new (temp_scoped_alloc_.get()) ArenaBitVector( 937 temp_scoped_alloc_.get(), temp_bit_vector_size_, false, kBitMapNullCheck); 938 nce_changed = ssa_regs_to_check->GetHighestBitSet() != -1; 939 bb->data_flow_info->ending_check_v->Copy(ssa_regs_to_check); 940 } else if (!ssa_regs_to_check->SameBitsSet(bb->data_flow_info->ending_check_v)) { 941 nce_changed = true; 942 bb->data_flow_info->ending_check_v->Copy(ssa_regs_to_check); 943 } 944 } 945 return infer_changed | nce_changed; 946 } 947 948 void MIRGraph::EliminateNullChecksAndInferTypesEnd() { 949 if ((cu_->disable_opt & (1 << kNullCheckElimination)) == 0) { 950 // Clean up temporaries. 951 temp_bit_vector_size_ = 0u; 952 temp_bit_vector_ = nullptr; 953 AllNodesIterator iter(this); 954 for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) { 955 if (bb->data_flow_info != nullptr) { 956 bb->data_flow_info->ending_check_v = nullptr; 957 } 958 } 959 DCHECK(temp_scoped_alloc_.get() != nullptr); 960 temp_scoped_alloc_.reset(); 961 } 962 } 963 964 bool MIRGraph::EliminateClassInitChecksGate() { 965 if ((cu_->disable_opt & (1 << kClassInitCheckElimination)) != 0 || 966 !cu_->mir_graph->HasStaticFieldAccess()) { 967 return false; 968 } 969 970 if (kIsDebugBuild) { 971 AllNodesIterator iter(this); 972 for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) { 973 CHECK(bb->data_flow_info == nullptr || bb->data_flow_info->ending_check_v == nullptr); 974 } 975 } 976 977 DCHECK(temp_scoped_alloc_.get() == nullptr); 978 temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack)); 979 980 // Each insn we use here has at least 2 code units, offset/2 will be a unique index. 981 const size_t end = (cu_->code_item->insns_size_in_code_units_ + 1u) / 2u; 982 temp_insn_data_ = static_cast<uint16_t*>( 983 temp_scoped_alloc_->Alloc(end * sizeof(*temp_insn_data_), kArenaAllocGrowableArray)); 984 985 uint32_t unique_class_count = 0u; 986 { 987 // Get unique_class_count and store indexes in temp_insn_data_ using a map on a nested 988 // ScopedArenaAllocator. 989 990 // Embed the map value in the entry to save space. 991 struct MapEntry { 992 // Map key: the class identified by the declaring dex file and type index. 993 const DexFile* declaring_dex_file; 994 uint16_t declaring_class_idx; 995 // Map value: index into bit vectors of classes requiring initialization checks. 996 uint16_t index; 997 }; 998 struct MapEntryComparator { 999 bool operator()(const MapEntry& lhs, const MapEntry& rhs) const { 1000 if (lhs.declaring_class_idx != rhs.declaring_class_idx) { 1001 return lhs.declaring_class_idx < rhs.declaring_class_idx; 1002 } 1003 return lhs.declaring_dex_file < rhs.declaring_dex_file; 1004 } 1005 }; 1006 1007 ScopedArenaAllocator allocator(&cu_->arena_stack); 1008 ScopedArenaSet<MapEntry, MapEntryComparator> class_to_index_map(MapEntryComparator(), 1009 allocator.Adapter()); 1010 1011 // First, find all SGET/SPUTs that may need class initialization checks, record INVOKE_STATICs. 1012 AllNodesIterator iter(this); 1013 for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) { 1014 for (MIR* mir = bb->first_mir_insn; mir != nullptr; mir = mir->next) { 1015 DCHECK(bb->data_flow_info != nullptr); 1016 if (mir->dalvikInsn.opcode >= Instruction::SGET && 1017 mir->dalvikInsn.opcode <= Instruction::SPUT_SHORT) { 1018 const MirSFieldLoweringInfo& field_info = GetSFieldLoweringInfo(mir); 1019 uint16_t index = 0xffffu; 1020 if (!field_info.IsInitialized()) { 1021 DCHECK_LT(class_to_index_map.size(), 0xffffu); 1022 MapEntry entry = { 1023 // Treat unresolved fields as if each had its own class. 1024 field_info.IsResolved() ? field_info.DeclaringDexFile() 1025 : nullptr, 1026 field_info.IsResolved() ? field_info.DeclaringClassIndex() 1027 : field_info.FieldIndex(), 1028 static_cast<uint16_t>(class_to_index_map.size()) 1029 }; 1030 index = class_to_index_map.insert(entry).first->index; 1031 } 1032 // Using offset/2 for index into temp_insn_data_. 1033 temp_insn_data_[mir->offset / 2u] = index; 1034 } 1035 } 1036 } 1037 unique_class_count = static_cast<uint32_t>(class_to_index_map.size()); 1038 } 1039 1040 if (unique_class_count == 0u) { 1041 // All SGET/SPUTs refer to initialized classes. Nothing to do. 1042 temp_insn_data_ = nullptr; 1043 temp_scoped_alloc_.reset(); 1044 return false; 1045 } 1046 1047 temp_bit_vector_size_ = unique_class_count; 1048 temp_bit_vector_ = new (temp_scoped_alloc_.get()) ArenaBitVector( 1049 temp_scoped_alloc_.get(), temp_bit_vector_size_, false, kBitMapClInitCheck); 1050 DCHECK_GT(temp_bit_vector_size_, 0u); 1051 return true; 1052 } 1053 1054 /* 1055 * Eliminate unnecessary class initialization checks for a basic block. 1056 */ 1057 bool MIRGraph::EliminateClassInitChecks(BasicBlock* bb) { 1058 DCHECK_EQ((cu_->disable_opt & (1 << kClassInitCheckElimination)), 0u); 1059 if (bb->data_flow_info == NULL) { 1060 return false; 1061 } 1062 1063 /* 1064 * Set initial state. Catch blocks don't need any special treatment. 1065 */ 1066 ArenaBitVector* classes_to_check = temp_bit_vector_; 1067 DCHECK(classes_to_check != nullptr); 1068 if (bb->block_type == kEntryBlock) { 1069 classes_to_check->SetInitialBits(temp_bit_vector_size_); 1070 } else if (bb->predecessors->Size() == 1) { 1071 BasicBlock* pred_bb = GetBasicBlock(bb->predecessors->Get(0)); 1072 // pred_bb must have already been processed at least once. 1073 DCHECK(pred_bb != nullptr); 1074 DCHECK(pred_bb->data_flow_info != nullptr); 1075 DCHECK(pred_bb->data_flow_info->ending_check_v != nullptr); 1076 classes_to_check->Copy(pred_bb->data_flow_info->ending_check_v); 1077 } else { 1078 // Starting state is union of all incoming arcs 1079 GrowableArray<BasicBlockId>::Iterator iter(bb->predecessors); 1080 BasicBlock* pred_bb = GetBasicBlock(iter.Next()); 1081 DCHECK(pred_bb != NULL); 1082 DCHECK(pred_bb->data_flow_info != NULL); 1083 while (pred_bb->data_flow_info->ending_check_v == nullptr) { 1084 pred_bb = GetBasicBlock(iter.Next()); 1085 // At least one predecessor must have been processed before this bb. 1086 DCHECK(pred_bb != nullptr); 1087 DCHECK(pred_bb->data_flow_info != nullptr); 1088 } 1089 classes_to_check->Copy(pred_bb->data_flow_info->ending_check_v); 1090 while (true) { 1091 pred_bb = GetBasicBlock(iter.Next()); 1092 if (!pred_bb) break; 1093 DCHECK(pred_bb->data_flow_info != nullptr); 1094 if (pred_bb->data_flow_info->ending_check_v == nullptr) { 1095 continue; 1096 } 1097 classes_to_check->Union(pred_bb->data_flow_info->ending_check_v); 1098 } 1099 } 1100 // At this point, classes_to_check shows which classes need clinit checks. 1101 1102 // Walk through the instruction in the block, updating as necessary 1103 for (MIR* mir = bb->first_mir_insn; mir != nullptr; mir = mir->next) { 1104 if (mir->dalvikInsn.opcode >= Instruction::SGET && 1105 mir->dalvikInsn.opcode <= Instruction::SPUT_SHORT) { 1106 uint16_t index = temp_insn_data_[mir->offset / 2u]; 1107 if (index != 0xffffu) { 1108 if (mir->dalvikInsn.opcode >= Instruction::SGET && 1109 mir->dalvikInsn.opcode <= Instruction::SPUT_SHORT) { 1110 if (!classes_to_check->IsBitSet(index)) { 1111 // Eliminate the class init check. 1112 mir->optimization_flags |= MIR_IGNORE_CLINIT_CHECK; 1113 } else { 1114 // Do the class init check. 1115 mir->optimization_flags &= ~MIR_IGNORE_CLINIT_CHECK; 1116 } 1117 } 1118 // Mark the class as initialized. 1119 classes_to_check->ClearBit(index); 1120 } 1121 } 1122 } 1123 1124 // Did anything change? 1125 bool changed = false; 1126 if (bb->data_flow_info->ending_check_v == nullptr) { 1127 DCHECK(temp_scoped_alloc_.get() != nullptr); 1128 DCHECK(bb->data_flow_info != nullptr); 1129 bb->data_flow_info->ending_check_v = new (temp_scoped_alloc_.get()) ArenaBitVector( 1130 temp_scoped_alloc_.get(), temp_bit_vector_size_, false, kBitMapClInitCheck); 1131 changed = classes_to_check->GetHighestBitSet() != -1; 1132 bb->data_flow_info->ending_check_v->Copy(classes_to_check); 1133 } else if (!classes_to_check->Equal(bb->data_flow_info->ending_check_v)) { 1134 changed = true; 1135 bb->data_flow_info->ending_check_v->Copy(classes_to_check); 1136 } 1137 return changed; 1138 } 1139 1140 void MIRGraph::EliminateClassInitChecksEnd() { 1141 // Clean up temporaries. 1142 temp_bit_vector_size_ = 0u; 1143 temp_bit_vector_ = nullptr; 1144 AllNodesIterator iter(this); 1145 for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) { 1146 if (bb->data_flow_info != nullptr) { 1147 bb->data_flow_info->ending_check_v = nullptr; 1148 } 1149 } 1150 1151 DCHECK(temp_insn_data_ != nullptr); 1152 temp_insn_data_ = nullptr; 1153 DCHECK(temp_scoped_alloc_.get() != nullptr); 1154 temp_scoped_alloc_.reset(); 1155 } 1156 1157 bool MIRGraph::ApplyGlobalValueNumberingGate() { 1158 if ((cu_->disable_opt & (1u << kGlobalValueNumbering)) != 0u) { 1159 return false; 1160 } 1161 1162 DCHECK(temp_scoped_alloc_ == nullptr); 1163 temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack)); 1164 DCHECK(temp_gvn_ == nullptr); 1165 temp_gvn_.reset( 1166 new (temp_scoped_alloc_.get()) GlobalValueNumbering(cu_, temp_scoped_alloc_.get())); 1167 return true; 1168 } 1169 1170 bool MIRGraph::ApplyGlobalValueNumbering(BasicBlock* bb) { 1171 DCHECK(temp_gvn_ != nullptr); 1172 LocalValueNumbering* lvn = temp_gvn_->PrepareBasicBlock(bb); 1173 if (lvn != nullptr) { 1174 for (MIR* mir = bb->first_mir_insn; mir != nullptr; mir = mir->next) { 1175 lvn->GetValueNumber(mir); 1176 } 1177 } 1178 bool change = (lvn != nullptr) && temp_gvn_->FinishBasicBlock(bb); 1179 return change; 1180 } 1181 1182 void MIRGraph::ApplyGlobalValueNumberingEnd() { 1183 // Perform modifications. 1184 if (temp_gvn_->Good()) { 1185 temp_gvn_->AllowModifications(); 1186 PreOrderDfsIterator iter(this); 1187 for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) { 1188 ScopedArenaAllocator allocator(&cu_->arena_stack); // Reclaim memory after each LVN. 1189 LocalValueNumbering* lvn = temp_gvn_->PrepareBasicBlock(bb, &allocator); 1190 if (lvn != nullptr) { 1191 for (MIR* mir = bb->first_mir_insn; mir != nullptr; mir = mir->next) { 1192 lvn->GetValueNumber(mir); 1193 } 1194 bool change = temp_gvn_->FinishBasicBlock(bb); 1195 DCHECK(!change) << PrettyMethod(cu_->method_idx, *cu_->dex_file); 1196 } 1197 } 1198 } else { 1199 LOG(WARNING) << "GVN failed for " << PrettyMethod(cu_->method_idx, *cu_->dex_file); 1200 } 1201 1202 DCHECK(temp_gvn_ != nullptr); 1203 temp_gvn_.reset(); 1204 DCHECK(temp_scoped_alloc_ != nullptr); 1205 temp_scoped_alloc_.reset(); 1206 } 1207 1208 void MIRGraph::ComputeInlineIFieldLoweringInfo(uint16_t field_idx, MIR* invoke, MIR* iget_or_iput) { 1209 uint32_t method_index = invoke->meta.method_lowering_info; 1210 if (temp_bit_vector_->IsBitSet(method_index)) { 1211 iget_or_iput->meta.ifield_lowering_info = temp_insn_data_[method_index]; 1212 DCHECK_EQ(field_idx, GetIFieldLoweringInfo(iget_or_iput).FieldIndex()); 1213 return; 1214 } 1215 1216 const MirMethodLoweringInfo& method_info = GetMethodLoweringInfo(invoke); 1217 MethodReference target = method_info.GetTargetMethod(); 1218 DexCompilationUnit inlined_unit( 1219 cu_, cu_->class_loader, cu_->class_linker, *target.dex_file, 1220 nullptr /* code_item not used */, 0u /* class_def_idx not used */, target.dex_method_index, 1221 0u /* access_flags not used */, nullptr /* verified_method not used */); 1222 MirIFieldLoweringInfo inlined_field_info(field_idx); 1223 MirIFieldLoweringInfo::Resolve(cu_->compiler_driver, &inlined_unit, &inlined_field_info, 1u); 1224 DCHECK(inlined_field_info.IsResolved()); 1225 1226 uint32_t field_info_index = ifield_lowering_infos_.Size(); 1227 ifield_lowering_infos_.Insert(inlined_field_info); 1228 temp_bit_vector_->SetBit(method_index); 1229 temp_insn_data_[method_index] = field_info_index; 1230 iget_or_iput->meta.ifield_lowering_info = field_info_index; 1231 } 1232 1233 bool MIRGraph::InlineSpecialMethodsGate() { 1234 if ((cu_->disable_opt & (1 << kSuppressMethodInlining)) != 0 || 1235 method_lowering_infos_.Size() == 0u) { 1236 return false; 1237 } 1238 if (cu_->compiler_driver->GetMethodInlinerMap() == nullptr) { 1239 // This isn't the Quick compiler. 1240 return false; 1241 } 1242 return true; 1243 } 1244 1245 void MIRGraph::InlineSpecialMethodsStart() { 1246 // Prepare for inlining getters/setters. Since we're inlining at most 1 IGET/IPUT from 1247 // each INVOKE, we can index the data by the MIR::meta::method_lowering_info index. 1248 1249 DCHECK(temp_scoped_alloc_.get() == nullptr); 1250 temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack)); 1251 temp_bit_vector_size_ = method_lowering_infos_.Size(); 1252 temp_bit_vector_ = new (temp_scoped_alloc_.get()) ArenaBitVector( 1253 temp_scoped_alloc_.get(), temp_bit_vector_size_, false, kBitMapMisc); 1254 temp_bit_vector_->ClearAllBits(); 1255 temp_insn_data_ = static_cast<uint16_t*>(temp_scoped_alloc_->Alloc( 1256 temp_bit_vector_size_ * sizeof(*temp_insn_data_), kArenaAllocGrowableArray)); 1257 } 1258 1259 void MIRGraph::InlineSpecialMethods(BasicBlock* bb) { 1260 if (bb->block_type != kDalvikByteCode) { 1261 return; 1262 } 1263 for (MIR* mir = bb->first_mir_insn; mir != NULL; mir = mir->next) { 1264 if (MIR::DecodedInstruction::IsPseudoMirOp(mir->dalvikInsn.opcode)) { 1265 continue; 1266 } 1267 if (!(Instruction::FlagsOf(mir->dalvikInsn.opcode) & Instruction::kInvoke)) { 1268 continue; 1269 } 1270 const MirMethodLoweringInfo& method_info = GetMethodLoweringInfo(mir); 1271 if (!method_info.FastPath()) { 1272 continue; 1273 } 1274 InvokeType sharp_type = method_info.GetSharpType(); 1275 if ((sharp_type != kDirect) && 1276 (sharp_type != kStatic || method_info.NeedsClassInitialization())) { 1277 continue; 1278 } 1279 DCHECK(cu_->compiler_driver->GetMethodInlinerMap() != nullptr); 1280 MethodReference target = method_info.GetTargetMethod(); 1281 if (cu_->compiler_driver->GetMethodInlinerMap()->GetMethodInliner(target.dex_file) 1282 ->GenInline(this, bb, mir, target.dex_method_index)) { 1283 if (cu_->verbose || cu_->print_pass) { 1284 LOG(INFO) << "SpecialMethodInliner: Inlined " << method_info.GetInvokeType() << " (" 1285 << sharp_type << ") call to \"" << PrettyMethod(target.dex_method_index, *target.dex_file) 1286 << "\" from \"" << PrettyMethod(cu_->method_idx, *cu_->dex_file) 1287 << "\" @0x" << std::hex << mir->offset; 1288 } 1289 } 1290 } 1291 } 1292 1293 void MIRGraph::InlineSpecialMethodsEnd() { 1294 DCHECK(temp_insn_data_ != nullptr); 1295 temp_insn_data_ = nullptr; 1296 DCHECK(temp_bit_vector_ != nullptr); 1297 temp_bit_vector_ = nullptr; 1298 DCHECK(temp_scoped_alloc_.get() != nullptr); 1299 temp_scoped_alloc_.reset(); 1300 } 1301 1302 void MIRGraph::DumpCheckStats() { 1303 Checkstats* stats = 1304 static_cast<Checkstats*>(arena_->Alloc(sizeof(Checkstats), kArenaAllocDFInfo)); 1305 checkstats_ = stats; 1306 AllNodesIterator iter(this); 1307 for (BasicBlock* bb = iter.Next(); bb != NULL; bb = iter.Next()) { 1308 CountChecks(bb); 1309 } 1310 if (stats->null_checks > 0) { 1311 float eliminated = static_cast<float>(stats->null_checks_eliminated); 1312 float checks = static_cast<float>(stats->null_checks); 1313 LOG(INFO) << "Null Checks: " << PrettyMethod(cu_->method_idx, *cu_->dex_file) << " " 1314 << stats->null_checks_eliminated << " of " << stats->null_checks << " -> " 1315 << (eliminated/checks) * 100.0 << "%"; 1316 } 1317 if (stats->range_checks > 0) { 1318 float eliminated = static_cast<float>(stats->range_checks_eliminated); 1319 float checks = static_cast<float>(stats->range_checks); 1320 LOG(INFO) << "Range Checks: " << PrettyMethod(cu_->method_idx, *cu_->dex_file) << " " 1321 << stats->range_checks_eliminated << " of " << stats->range_checks << " -> " 1322 << (eliminated/checks) * 100.0 << "%"; 1323 } 1324 } 1325 1326 bool MIRGraph::BuildExtendedBBList(struct BasicBlock* bb) { 1327 if (bb->visited) return false; 1328 if (!((bb->block_type == kEntryBlock) || (bb->block_type == kDalvikByteCode) 1329 || (bb->block_type == kExitBlock))) { 1330 // Ignore special blocks 1331 bb->visited = true; 1332 return false; 1333 } 1334 // Must be head of extended basic block. 1335 BasicBlock* start_bb = bb; 1336 extended_basic_blocks_.push_back(bb->id); 1337 bool terminated_by_return = false; 1338 bool do_local_value_numbering = false; 1339 // Visit blocks strictly dominated by this head. 1340 while (bb != NULL) { 1341 bb->visited = true; 1342 terminated_by_return |= bb->terminated_by_return; 1343 do_local_value_numbering |= bb->use_lvn; 1344 bb = NextDominatedBlock(bb); 1345 } 1346 if (terminated_by_return || do_local_value_numbering) { 1347 // Do lvn for all blocks in this extended set. 1348 bb = start_bb; 1349 while (bb != NULL) { 1350 bb->use_lvn = do_local_value_numbering; 1351 bb->dominates_return = terminated_by_return; 1352 bb = NextDominatedBlock(bb); 1353 } 1354 } 1355 return false; // Not iterative - return value will be ignored 1356 } 1357 1358 void MIRGraph::BasicBlockOptimization() { 1359 if ((cu_->disable_opt & (1 << kSuppressExceptionEdges)) != 0) { 1360 ClearAllVisitedFlags(); 1361 PreOrderDfsIterator iter2(this); 1362 for (BasicBlock* bb = iter2.Next(); bb != NULL; bb = iter2.Next()) { 1363 BuildExtendedBBList(bb); 1364 } 1365 // Perform extended basic block optimizations. 1366 for (unsigned int i = 0; i < extended_basic_blocks_.size(); i++) { 1367 BasicBlockOpt(GetBasicBlock(extended_basic_blocks_[i])); 1368 } 1369 } else { 1370 PreOrderDfsIterator iter(this); 1371 for (BasicBlock* bb = iter.Next(); bb != NULL; bb = iter.Next()) { 1372 BasicBlockOpt(bb); 1373 } 1374 } 1375 } 1376 1377 } // namespace art 1378
