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      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 "dex/compiler_internals.h"
     18 #include "dex_file-inl.h"
     19 #include "gc_map.h"
     20 #include "gc_map_builder.h"
     21 #include "mapping_table.h"
     22 #include "mir_to_lir-inl.h"
     23 #include "dex/quick/dex_file_method_inliner.h"
     24 #include "dex/quick/dex_file_to_method_inliner_map.h"
     25 #include "dex/verification_results.h"
     26 #include "dex/verified_method.h"
     27 #include "verifier/dex_gc_map.h"
     28 #include "verifier/method_verifier.h"
     29 #include "vmap_table.h"
     30 
     31 namespace art {
     32 
     33 namespace {
     34 
     35 /* Dump a mapping table */
     36 template <typename It>
     37 void DumpMappingTable(const char* table_name, const char* descriptor, const char* name,
     38                       const Signature& signature, uint32_t size, It first) {
     39   if (size != 0) {
     40     std::string line(StringPrintf("\n  %s %s%s_%s_table[%u] = {", table_name,
     41                      descriptor, name, signature.ToString().c_str(), size));
     42     std::replace(line.begin(), line.end(), ';', '_');
     43     LOG(INFO) << line;
     44     for (uint32_t i = 0; i != size; ++i) {
     45       line = StringPrintf("    {0x%05x, 0x%04x},", first.NativePcOffset(), first.DexPc());
     46       ++first;
     47       LOG(INFO) << line;
     48     }
     49     LOG(INFO) <<"  };\n\n";
     50   }
     51 }
     52 
     53 }  // anonymous namespace
     54 
     55 bool Mir2Lir::IsInexpensiveConstant(RegLocation rl_src) {
     56   bool res = false;
     57   if (rl_src.is_const) {
     58     if (rl_src.wide) {
     59       // For wide registers, check whether we're the high partner. In that case we need to switch
     60       // to the lower one for the correct value.
     61       if (rl_src.high_word) {
     62         rl_src.high_word = false;
     63         rl_src.s_reg_low--;
     64         rl_src.orig_sreg--;
     65       }
     66       if (rl_src.fp) {
     67         res = InexpensiveConstantDouble(mir_graph_->ConstantValueWide(rl_src));
     68       } else {
     69         res = InexpensiveConstantLong(mir_graph_->ConstantValueWide(rl_src));
     70       }
     71     } else {
     72       if (rl_src.fp) {
     73         res = InexpensiveConstantFloat(mir_graph_->ConstantValue(rl_src));
     74       } else {
     75         res = InexpensiveConstantInt(mir_graph_->ConstantValue(rl_src));
     76       }
     77     }
     78   }
     79   return res;
     80 }
     81 
     82 void Mir2Lir::MarkSafepointPC(LIR* inst) {
     83   DCHECK(!inst->flags.use_def_invalid);
     84   inst->u.m.def_mask = &kEncodeAll;
     85   LIR* safepoint_pc = NewLIR0(kPseudoSafepointPC);
     86   DCHECK(safepoint_pc->u.m.def_mask->Equals(kEncodeAll));
     87 }
     88 
     89 void Mir2Lir::MarkSafepointPCAfter(LIR* after) {
     90   DCHECK(!after->flags.use_def_invalid);
     91   after->u.m.def_mask = &kEncodeAll;
     92   // As NewLIR0 uses Append, we need to create the LIR by hand.
     93   LIR* safepoint_pc = RawLIR(current_dalvik_offset_, kPseudoSafepointPC);
     94   if (after->next == nullptr) {
     95     DCHECK_EQ(after, last_lir_insn_);
     96     AppendLIR(safepoint_pc);
     97   } else {
     98     InsertLIRAfter(after, safepoint_pc);
     99   }
    100   DCHECK(safepoint_pc->u.m.def_mask->Equals(kEncodeAll));
    101 }
    102 
    103 /* Remove a LIR from the list. */
    104 void Mir2Lir::UnlinkLIR(LIR* lir) {
    105   if (UNLIKELY(lir == first_lir_insn_)) {
    106     first_lir_insn_ = lir->next;
    107     if (lir->next != NULL) {
    108       lir->next->prev = NULL;
    109     } else {
    110       DCHECK(lir->next == NULL);
    111       DCHECK(lir == last_lir_insn_);
    112       last_lir_insn_ = NULL;
    113     }
    114   } else if (lir == last_lir_insn_) {
    115     last_lir_insn_ = lir->prev;
    116     lir->prev->next = NULL;
    117   } else if ((lir->prev != NULL) && (lir->next != NULL)) {
    118     lir->prev->next = lir->next;
    119     lir->next->prev = lir->prev;
    120   }
    121 }
    122 
    123 /* Convert an instruction to a NOP */
    124 void Mir2Lir::NopLIR(LIR* lir) {
    125   lir->flags.is_nop = true;
    126   if (!cu_->verbose) {
    127     UnlinkLIR(lir);
    128   }
    129 }
    130 
    131 void Mir2Lir::SetMemRefType(LIR* lir, bool is_load, int mem_type) {
    132   DCHECK(GetTargetInstFlags(lir->opcode) & (IS_LOAD | IS_STORE));
    133   DCHECK(!lir->flags.use_def_invalid);
    134   // TODO: Avoid the extra Arena allocation!
    135   const ResourceMask** mask_ptr;
    136   ResourceMask mask;
    137   if (is_load) {
    138     mask_ptr = &lir->u.m.use_mask;
    139   } else {
    140     mask_ptr = &lir->u.m.def_mask;
    141   }
    142   mask = **mask_ptr;
    143   /* Clear out the memref flags */
    144   mask.ClearBits(kEncodeMem);
    145   /* ..and then add back the one we need */
    146   switch (mem_type) {
    147     case ResourceMask::kLiteral:
    148       DCHECK(is_load);
    149       mask.SetBit(ResourceMask::kLiteral);
    150       break;
    151     case ResourceMask::kDalvikReg:
    152       mask.SetBit(ResourceMask::kDalvikReg);
    153       break;
    154     case ResourceMask::kHeapRef:
    155       mask.SetBit(ResourceMask::kHeapRef);
    156       break;
    157     case ResourceMask::kMustNotAlias:
    158       /* Currently only loads can be marked as kMustNotAlias */
    159       DCHECK(!(GetTargetInstFlags(lir->opcode) & IS_STORE));
    160       mask.SetBit(ResourceMask::kMustNotAlias);
    161       break;
    162     default:
    163       LOG(FATAL) << "Oat: invalid memref kind - " << mem_type;
    164   }
    165   *mask_ptr = mask_cache_.GetMask(mask);
    166 }
    167 
    168 /*
    169  * Mark load/store instructions that access Dalvik registers through the stack.
    170  */
    171 void Mir2Lir::AnnotateDalvikRegAccess(LIR* lir, int reg_id, bool is_load,
    172                                       bool is64bit) {
    173   DCHECK((is_load ? lir->u.m.use_mask : lir->u.m.def_mask)->Intersection(kEncodeMem).Equals(
    174       kEncodeDalvikReg));
    175 
    176   /*
    177    * Store the Dalvik register id in alias_info. Mark the MSB if it is a 64-bit
    178    * access.
    179    */
    180   lir->flags.alias_info = ENCODE_ALIAS_INFO(reg_id, is64bit);
    181 }
    182 
    183 /*
    184  * Debugging macros
    185  */
    186 #define DUMP_RESOURCE_MASK(X)
    187 
    188 /* Pretty-print a LIR instruction */
    189 void Mir2Lir::DumpLIRInsn(LIR* lir, unsigned char* base_addr) {
    190   int offset = lir->offset;
    191   int dest = lir->operands[0];
    192   const bool dump_nop = (cu_->enable_debug & (1 << kDebugShowNops));
    193 
    194   /* Handle pseudo-ops individually, and all regular insns as a group */
    195   switch (lir->opcode) {
    196     case kPseudoMethodEntry:
    197       LOG(INFO) << "-------- method entry "
    198                 << PrettyMethod(cu_->method_idx, *cu_->dex_file);
    199       break;
    200     case kPseudoMethodExit:
    201       LOG(INFO) << "-------- Method_Exit";
    202       break;
    203     case kPseudoBarrier:
    204       LOG(INFO) << "-------- BARRIER";
    205       break;
    206     case kPseudoEntryBlock:
    207       LOG(INFO) << "-------- entry offset: 0x" << std::hex << dest;
    208       break;
    209     case kPseudoDalvikByteCodeBoundary:
    210       if (lir->operands[0] == 0) {
    211          // NOTE: only used for debug listings.
    212          lir->operands[0] = WrapPointer(ArenaStrdup("No instruction string"));
    213       }
    214       LOG(INFO) << "-------- dalvik offset: 0x" << std::hex
    215                 << lir->dalvik_offset << " @ "
    216                 << reinterpret_cast<char*>(UnwrapPointer(lir->operands[0]));
    217       break;
    218     case kPseudoExitBlock:
    219       LOG(INFO) << "-------- exit offset: 0x" << std::hex << dest;
    220       break;
    221     case kPseudoPseudoAlign4:
    222       LOG(INFO) << reinterpret_cast<uintptr_t>(base_addr) + offset << " (0x" << std::hex
    223                 << offset << "): .align4";
    224       break;
    225     case kPseudoEHBlockLabel:
    226       LOG(INFO) << "Exception_Handling:";
    227       break;
    228     case kPseudoTargetLabel:
    229     case kPseudoNormalBlockLabel:
    230       LOG(INFO) << "L" << reinterpret_cast<void*>(lir) << ":";
    231       break;
    232     case kPseudoThrowTarget:
    233       LOG(INFO) << "LT" << reinterpret_cast<void*>(lir) << ":";
    234       break;
    235     case kPseudoIntrinsicRetry:
    236       LOG(INFO) << "IR" << reinterpret_cast<void*>(lir) << ":";
    237       break;
    238     case kPseudoSuspendTarget:
    239       LOG(INFO) << "LS" << reinterpret_cast<void*>(lir) << ":";
    240       break;
    241     case kPseudoSafepointPC:
    242       LOG(INFO) << "LsafepointPC_0x" << std::hex << lir->offset << "_" << lir->dalvik_offset << ":";
    243       break;
    244     case kPseudoExportedPC:
    245       LOG(INFO) << "LexportedPC_0x" << std::hex << lir->offset << "_" << lir->dalvik_offset << ":";
    246       break;
    247     case kPseudoCaseLabel:
    248       LOG(INFO) << "LC" << reinterpret_cast<void*>(lir) << ": Case target 0x"
    249                 << std::hex << lir->operands[0] << "|" << std::dec <<
    250         lir->operands[0];
    251       break;
    252     default:
    253       if (lir->flags.is_nop && !dump_nop) {
    254         break;
    255       } else {
    256         std::string op_name(BuildInsnString(GetTargetInstName(lir->opcode),
    257                                                lir, base_addr));
    258         std::string op_operands(BuildInsnString(GetTargetInstFmt(lir->opcode),
    259                                                     lir, base_addr));
    260         LOG(INFO) << StringPrintf("%5p: %-9s%s%s",
    261                                   base_addr + offset,
    262                                   op_name.c_str(), op_operands.c_str(),
    263                                   lir->flags.is_nop ? "(nop)" : "");
    264       }
    265       break;
    266   }
    267 
    268   if (lir->u.m.use_mask && (!lir->flags.is_nop || dump_nop)) {
    269     DUMP_RESOURCE_MASK(DumpResourceMask(lir, *lir->u.m.use_mask, "use"));
    270   }
    271   if (lir->u.m.def_mask && (!lir->flags.is_nop || dump_nop)) {
    272     DUMP_RESOURCE_MASK(DumpResourceMask(lir, *lir->u.m.def_mask, "def"));
    273   }
    274 }
    275 
    276 void Mir2Lir::DumpPromotionMap() {
    277   int num_regs = cu_->num_dalvik_registers + mir_graph_->GetNumUsedCompilerTemps();
    278   for (int i = 0; i < num_regs; i++) {
    279     PromotionMap v_reg_map = promotion_map_[i];
    280     std::string buf;
    281     if (v_reg_map.fp_location == kLocPhysReg) {
    282       StringAppendF(&buf, " : s%d", RegStorage::RegNum(v_reg_map.fp_reg));
    283     }
    284 
    285     std::string buf3;
    286     if (i < cu_->num_dalvik_registers) {
    287       StringAppendF(&buf3, "%02d", i);
    288     } else if (i == mir_graph_->GetMethodSReg()) {
    289       buf3 = "Method*";
    290     } else {
    291       StringAppendF(&buf3, "ct%d", i - cu_->num_dalvik_registers);
    292     }
    293 
    294     LOG(INFO) << StringPrintf("V[%s] -> %s%d%s", buf3.c_str(),
    295                               v_reg_map.core_location == kLocPhysReg ?
    296                               "r" : "SP+", v_reg_map.core_location == kLocPhysReg ?
    297                               v_reg_map.core_reg : SRegOffset(i),
    298                               buf.c_str());
    299   }
    300 }
    301 
    302 void Mir2Lir::UpdateLIROffsets() {
    303   // Only used for code listings.
    304   size_t offset = 0;
    305   for (LIR* lir = first_lir_insn_; lir != nullptr; lir = lir->next) {
    306     lir->offset = offset;
    307     if (!lir->flags.is_nop && !IsPseudoLirOp(lir->opcode)) {
    308       offset += GetInsnSize(lir);
    309     } else if (lir->opcode == kPseudoPseudoAlign4) {
    310       offset += (offset & 0x2);
    311     }
    312   }
    313 }
    314 
    315 /* Dump instructions and constant pool contents */
    316 void Mir2Lir::CodegenDump() {
    317   LOG(INFO) << "Dumping LIR insns for "
    318             << PrettyMethod(cu_->method_idx, *cu_->dex_file);
    319   LIR* lir_insn;
    320   int insns_size = cu_->code_item->insns_size_in_code_units_;
    321 
    322   LOG(INFO) << "Regs (excluding ins) : " << cu_->num_regs;
    323   LOG(INFO) << "Ins          : " << cu_->num_ins;
    324   LOG(INFO) << "Outs         : " << cu_->num_outs;
    325   LOG(INFO) << "CoreSpills       : " << num_core_spills_;
    326   LOG(INFO) << "FPSpills       : " << num_fp_spills_;
    327   LOG(INFO) << "CompilerTemps    : " << mir_graph_->GetNumUsedCompilerTemps();
    328   LOG(INFO) << "Frame size       : " << frame_size_;
    329   LOG(INFO) << "code size is " << total_size_ <<
    330     " bytes, Dalvik size is " << insns_size * 2;
    331   LOG(INFO) << "expansion factor: "
    332             << static_cast<float>(total_size_) / static_cast<float>(insns_size * 2);
    333   DumpPromotionMap();
    334   UpdateLIROffsets();
    335   for (lir_insn = first_lir_insn_; lir_insn != NULL; lir_insn = lir_insn->next) {
    336     DumpLIRInsn(lir_insn, 0);
    337   }
    338   for (lir_insn = literal_list_; lir_insn != NULL; lir_insn = lir_insn->next) {
    339     LOG(INFO) << StringPrintf("%x (%04x): .word (%#x)", lir_insn->offset, lir_insn->offset,
    340                               lir_insn->operands[0]);
    341   }
    342 
    343   const DexFile::MethodId& method_id =
    344       cu_->dex_file->GetMethodId(cu_->method_idx);
    345   const Signature signature = cu_->dex_file->GetMethodSignature(method_id);
    346   const char* name = cu_->dex_file->GetMethodName(method_id);
    347   const char* descriptor(cu_->dex_file->GetMethodDeclaringClassDescriptor(method_id));
    348 
    349   // Dump mapping tables
    350   if (!encoded_mapping_table_.empty()) {
    351     MappingTable table(&encoded_mapping_table_[0]);
    352     DumpMappingTable("PC2Dex_MappingTable", descriptor, name, signature,
    353                      table.PcToDexSize(), table.PcToDexBegin());
    354     DumpMappingTable("Dex2PC_MappingTable", descriptor, name, signature,
    355                      table.DexToPcSize(), table.DexToPcBegin());
    356   }
    357 }
    358 
    359 /*
    360  * Search the existing constants in the literal pool for an exact or close match
    361  * within specified delta (greater or equal to 0).
    362  */
    363 LIR* Mir2Lir::ScanLiteralPool(LIR* data_target, int value, unsigned int delta) {
    364   while (data_target) {
    365     if ((static_cast<unsigned>(value - data_target->operands[0])) <= delta)
    366       return data_target;
    367     data_target = data_target->next;
    368   }
    369   return NULL;
    370 }
    371 
    372 /* Search the existing constants in the literal pool for an exact wide match */
    373 LIR* Mir2Lir::ScanLiteralPoolWide(LIR* data_target, int val_lo, int val_hi) {
    374   bool lo_match = false;
    375   LIR* lo_target = NULL;
    376   while (data_target) {
    377     if (lo_match && (data_target->operands[0] == val_hi)) {
    378       // Record high word in case we need to expand this later.
    379       lo_target->operands[1] = val_hi;
    380       return lo_target;
    381     }
    382     lo_match = false;
    383     if (data_target->operands[0] == val_lo) {
    384       lo_match = true;
    385       lo_target = data_target;
    386     }
    387     data_target = data_target->next;
    388   }
    389   return NULL;
    390 }
    391 
    392 /* Search the existing constants in the literal pool for an exact method match */
    393 LIR* Mir2Lir::ScanLiteralPoolMethod(LIR* data_target, const MethodReference& method) {
    394   while (data_target) {
    395     if (static_cast<uint32_t>(data_target->operands[0]) == method.dex_method_index &&
    396         UnwrapPointer(data_target->operands[1]) == method.dex_file) {
    397       return data_target;
    398     }
    399     data_target = data_target->next;
    400   }
    401   return nullptr;
    402 }
    403 
    404 /*
    405  * The following are building blocks to insert constants into the pool or
    406  * instruction streams.
    407  */
    408 
    409 /* Add a 32-bit constant to the constant pool */
    410 LIR* Mir2Lir::AddWordData(LIR* *constant_list_p, int value) {
    411   /* Add the constant to the literal pool */
    412   if (constant_list_p) {
    413     LIR* new_value = static_cast<LIR*>(arena_->Alloc(sizeof(LIR), kArenaAllocData));
    414     new_value->operands[0] = value;
    415     new_value->next = *constant_list_p;
    416     *constant_list_p = new_value;
    417     estimated_native_code_size_ += sizeof(value);
    418     return new_value;
    419   }
    420   return NULL;
    421 }
    422 
    423 /* Add a 64-bit constant to the constant pool or mixed with code */
    424 LIR* Mir2Lir::AddWideData(LIR* *constant_list_p, int val_lo, int val_hi) {
    425   AddWordData(constant_list_p, val_hi);
    426   return AddWordData(constant_list_p, val_lo);
    427 }
    428 
    429 static void Push32(std::vector<uint8_t>&buf, int data) {
    430   buf.push_back(data & 0xff);
    431   buf.push_back((data >> 8) & 0xff);
    432   buf.push_back((data >> 16) & 0xff);
    433   buf.push_back((data >> 24) & 0xff);
    434 }
    435 
    436 // Push 8 bytes on 64-bit target systems; 4 on 32-bit target systems.
    437 static void PushPointer(std::vector<uint8_t>&buf, const void* pointer, bool target64) {
    438   uint64_t data = reinterpret_cast<uintptr_t>(pointer);
    439   if (target64) {
    440     Push32(buf, data & 0xFFFFFFFF);
    441     Push32(buf, (data >> 32) & 0xFFFFFFFF);
    442   } else {
    443     Push32(buf, static_cast<uint32_t>(data));
    444   }
    445 }
    446 
    447 static void AlignBuffer(std::vector<uint8_t>&buf, size_t offset) {
    448   while (buf.size() < offset) {
    449     buf.push_back(0);
    450   }
    451 }
    452 
    453 /* Write the literal pool to the output stream */
    454 void Mir2Lir::InstallLiteralPools() {
    455   AlignBuffer(code_buffer_, data_offset_);
    456   LIR* data_lir = literal_list_;
    457   while (data_lir != NULL) {
    458     Push32(code_buffer_, data_lir->operands[0]);
    459     data_lir = NEXT_LIR(data_lir);
    460   }
    461   // Push code and method literals, record offsets for the compiler to patch.
    462   data_lir = code_literal_list_;
    463   while (data_lir != NULL) {
    464     uint32_t target_method_idx = data_lir->operands[0];
    465     const DexFile* target_dex_file =
    466         reinterpret_cast<const DexFile*>(UnwrapPointer(data_lir->operands[1]));
    467     cu_->compiler_driver->AddCodePatch(cu_->dex_file,
    468                                        cu_->class_def_idx,
    469                                        cu_->method_idx,
    470                                        cu_->invoke_type,
    471                                        target_method_idx,
    472                                        target_dex_file,
    473                                        static_cast<InvokeType>(data_lir->operands[2]),
    474                                        code_buffer_.size());
    475     const DexFile::MethodId& target_method_id = target_dex_file->GetMethodId(target_method_idx);
    476     // unique value based on target to ensure code deduplication works
    477     PushPointer(code_buffer_, &target_method_id, cu_->target64);
    478     data_lir = NEXT_LIR(data_lir);
    479   }
    480   data_lir = method_literal_list_;
    481   while (data_lir != NULL) {
    482     uint32_t target_method_idx = data_lir->operands[0];
    483     const DexFile* target_dex_file =
    484         reinterpret_cast<const DexFile*>(UnwrapPointer(data_lir->operands[1]));
    485     cu_->compiler_driver->AddMethodPatch(cu_->dex_file,
    486                                          cu_->class_def_idx,
    487                                          cu_->method_idx,
    488                                          cu_->invoke_type,
    489                                          target_method_idx,
    490                                          target_dex_file,
    491                                          static_cast<InvokeType>(data_lir->operands[2]),
    492                                          code_buffer_.size());
    493     const DexFile::MethodId& target_method_id = target_dex_file->GetMethodId(target_method_idx);
    494     // unique value based on target to ensure code deduplication works
    495     PushPointer(code_buffer_, &target_method_id, cu_->target64);
    496     data_lir = NEXT_LIR(data_lir);
    497   }
    498   // Push class literals.
    499   data_lir = class_literal_list_;
    500   while (data_lir != NULL) {
    501     uint32_t target_method_idx = data_lir->operands[0];
    502     cu_->compiler_driver->AddClassPatch(cu_->dex_file,
    503                                         cu_->class_def_idx,
    504                                         cu_->method_idx,
    505                                         target_method_idx,
    506                                         code_buffer_.size());
    507     const DexFile::TypeId& target_method_id = cu_->dex_file->GetTypeId(target_method_idx);
    508     // unique value based on target to ensure code deduplication works
    509     PushPointer(code_buffer_, &target_method_id, cu_->target64);
    510     data_lir = NEXT_LIR(data_lir);
    511   }
    512   // Push the string literals.
    513   data_lir = string_literal_list_;
    514   while (data_lir != nullptr) {
    515     uint32_t string_idx = data_lir->operands[0];
    516     cu_->compiler_driver->AddStringPatch(cu_->dex_file,
    517                                          cu_->class_def_idx,
    518                                          cu_->method_idx,
    519                                          string_idx,
    520                                          code_buffer_.size());
    521     const auto& target_string_id = cu_->dex_file->GetStringId(string_idx);
    522     // unique value based on target to ensure code deduplication works
    523     PushPointer(code_buffer_, &target_string_id, cu_->target64);
    524     data_lir = NEXT_LIR(data_lir);
    525   }
    526 }
    527 
    528 /* Write the switch tables to the output stream */
    529 void Mir2Lir::InstallSwitchTables() {
    530   GrowableArray<SwitchTable*>::Iterator iterator(&switch_tables_);
    531   while (true) {
    532     Mir2Lir::SwitchTable* tab_rec = iterator.Next();
    533     if (tab_rec == NULL) break;
    534     AlignBuffer(code_buffer_, tab_rec->offset);
    535     /*
    536      * For Arm, our reference point is the address of the bx
    537      * instruction that does the launch, so we have to subtract
    538      * the auto pc-advance.  For other targets the reference point
    539      * is a label, so we can use the offset as-is.
    540      */
    541     int bx_offset = INVALID_OFFSET;
    542     switch (cu_->instruction_set) {
    543       case kThumb2:
    544         DCHECK(tab_rec->anchor->flags.fixup != kFixupNone);
    545         bx_offset = tab_rec->anchor->offset + 4;
    546         break;
    547       case kX86:
    548       case kX86_64:
    549         bx_offset = 0;
    550         break;
    551       case kArm64:
    552       case kMips:
    553         bx_offset = tab_rec->anchor->offset;
    554         break;
    555       default: LOG(FATAL) << "Unexpected instruction set: " << cu_->instruction_set;
    556     }
    557     if (cu_->verbose) {
    558       LOG(INFO) << "Switch table for offset 0x" << std::hex << bx_offset;
    559     }
    560     if (tab_rec->table[0] == Instruction::kSparseSwitchSignature) {
    561       const int32_t* keys = reinterpret_cast<const int32_t*>(&(tab_rec->table[2]));
    562       for (int elems = 0; elems < tab_rec->table[1]; elems++) {
    563         int disp = tab_rec->targets[elems]->offset - bx_offset;
    564         if (cu_->verbose) {
    565           LOG(INFO) << "  Case[" << elems << "] key: 0x"
    566                     << std::hex << keys[elems] << ", disp: 0x"
    567                     << std::hex << disp;
    568         }
    569         Push32(code_buffer_, keys[elems]);
    570         Push32(code_buffer_,
    571           tab_rec->targets[elems]->offset - bx_offset);
    572       }
    573     } else {
    574       DCHECK_EQ(static_cast<int>(tab_rec->table[0]),
    575                 static_cast<int>(Instruction::kPackedSwitchSignature));
    576       for (int elems = 0; elems < tab_rec->table[1]; elems++) {
    577         int disp = tab_rec->targets[elems]->offset - bx_offset;
    578         if (cu_->verbose) {
    579           LOG(INFO) << "  Case[" << elems << "] disp: 0x"
    580                     << std::hex << disp;
    581         }
    582         Push32(code_buffer_, tab_rec->targets[elems]->offset - bx_offset);
    583       }
    584     }
    585   }
    586 }
    587 
    588 /* Write the fill array dta to the output stream */
    589 void Mir2Lir::InstallFillArrayData() {
    590   GrowableArray<FillArrayData*>::Iterator iterator(&fill_array_data_);
    591   while (true) {
    592     Mir2Lir::FillArrayData *tab_rec = iterator.Next();
    593     if (tab_rec == NULL) break;
    594     AlignBuffer(code_buffer_, tab_rec->offset);
    595     for (int i = 0; i < (tab_rec->size + 1) / 2; i++) {
    596       code_buffer_.push_back(tab_rec->table[i] & 0xFF);
    597       code_buffer_.push_back((tab_rec->table[i] >> 8) & 0xFF);
    598     }
    599   }
    600 }
    601 
    602 static int AssignLiteralOffsetCommon(LIR* lir, CodeOffset offset) {
    603   for (; lir != NULL; lir = lir->next) {
    604     lir->offset = offset;
    605     offset += 4;
    606   }
    607   return offset;
    608 }
    609 
    610 static int AssignLiteralPointerOffsetCommon(LIR* lir, CodeOffset offset,
    611                                             unsigned int element_size) {
    612   // Align to natural pointer size.
    613   offset = RoundUp(offset, element_size);
    614   for (; lir != NULL; lir = lir->next) {
    615     lir->offset = offset;
    616     offset += element_size;
    617   }
    618   return offset;
    619 }
    620 
    621 // Make sure we have a code address for every declared catch entry
    622 bool Mir2Lir::VerifyCatchEntries() {
    623   MappingTable table(&encoded_mapping_table_[0]);
    624   std::vector<uint32_t> dex_pcs;
    625   dex_pcs.reserve(table.DexToPcSize());
    626   for (auto it = table.DexToPcBegin(), end = table.DexToPcEnd(); it != end; ++it) {
    627     dex_pcs.push_back(it.DexPc());
    628   }
    629   // Sort dex_pcs, so that we can quickly check it against the ordered mir_graph_->catches_.
    630   std::sort(dex_pcs.begin(), dex_pcs.end());
    631 
    632   bool success = true;
    633   auto it = dex_pcs.begin(), end = dex_pcs.end();
    634   for (uint32_t dex_pc : mir_graph_->catches_) {
    635     while (it != end && *it < dex_pc) {
    636       LOG(INFO) << "Unexpected catch entry @ dex pc 0x" << std::hex << *it;
    637       ++it;
    638       success = false;
    639     }
    640     if (it == end || *it > dex_pc) {
    641       LOG(INFO) << "Missing native PC for catch entry @ 0x" << std::hex << dex_pc;
    642       success = false;
    643     } else {
    644       ++it;
    645     }
    646   }
    647   if (!success) {
    648     LOG(INFO) << "Bad dex2pcMapping table in " << PrettyMethod(cu_->method_idx, *cu_->dex_file);
    649     LOG(INFO) << "Entries @ decode: " << mir_graph_->catches_.size() << ", Entries in table: "
    650               << table.DexToPcSize();
    651   }
    652   return success;
    653 }
    654 
    655 
    656 void Mir2Lir::CreateMappingTables() {
    657   uint32_t pc2dex_data_size = 0u;
    658   uint32_t pc2dex_entries = 0u;
    659   uint32_t pc2dex_offset = 0u;
    660   uint32_t pc2dex_dalvik_offset = 0u;
    661   uint32_t dex2pc_data_size = 0u;
    662   uint32_t dex2pc_entries = 0u;
    663   uint32_t dex2pc_offset = 0u;
    664   uint32_t dex2pc_dalvik_offset = 0u;
    665   for (LIR* tgt_lir = first_lir_insn_; tgt_lir != NULL; tgt_lir = NEXT_LIR(tgt_lir)) {
    666     if (!tgt_lir->flags.is_nop && (tgt_lir->opcode == kPseudoSafepointPC)) {
    667       pc2dex_entries += 1;
    668       DCHECK(pc2dex_offset <= tgt_lir->offset);
    669       pc2dex_data_size += UnsignedLeb128Size(tgt_lir->offset - pc2dex_offset);
    670       pc2dex_data_size += SignedLeb128Size(static_cast<int32_t>(tgt_lir->dalvik_offset) -
    671                                            static_cast<int32_t>(pc2dex_dalvik_offset));
    672       pc2dex_offset = tgt_lir->offset;
    673       pc2dex_dalvik_offset = tgt_lir->dalvik_offset;
    674     }
    675     if (!tgt_lir->flags.is_nop && (tgt_lir->opcode == kPseudoExportedPC)) {
    676       dex2pc_entries += 1;
    677       DCHECK(dex2pc_offset <= tgt_lir->offset);
    678       dex2pc_data_size += UnsignedLeb128Size(tgt_lir->offset - dex2pc_offset);
    679       dex2pc_data_size += SignedLeb128Size(static_cast<int32_t>(tgt_lir->dalvik_offset) -
    680                                            static_cast<int32_t>(dex2pc_dalvik_offset));
    681       dex2pc_offset = tgt_lir->offset;
    682       dex2pc_dalvik_offset = tgt_lir->dalvik_offset;
    683     }
    684   }
    685 
    686   uint32_t total_entries = pc2dex_entries + dex2pc_entries;
    687   uint32_t hdr_data_size = UnsignedLeb128Size(total_entries) + UnsignedLeb128Size(pc2dex_entries);
    688   uint32_t data_size = hdr_data_size + pc2dex_data_size + dex2pc_data_size;
    689   encoded_mapping_table_.resize(data_size);
    690   uint8_t* write_pos = &encoded_mapping_table_[0];
    691   write_pos = EncodeUnsignedLeb128(write_pos, total_entries);
    692   write_pos = EncodeUnsignedLeb128(write_pos, pc2dex_entries);
    693   DCHECK_EQ(static_cast<size_t>(write_pos - &encoded_mapping_table_[0]), hdr_data_size);
    694   uint8_t* write_pos2 = write_pos + pc2dex_data_size;
    695 
    696   pc2dex_offset = 0u;
    697   pc2dex_dalvik_offset = 0u;
    698   dex2pc_offset = 0u;
    699   dex2pc_dalvik_offset = 0u;
    700   for (LIR* tgt_lir = first_lir_insn_; tgt_lir != NULL; tgt_lir = NEXT_LIR(tgt_lir)) {
    701     if (!tgt_lir->flags.is_nop && (tgt_lir->opcode == kPseudoSafepointPC)) {
    702       DCHECK(pc2dex_offset <= tgt_lir->offset);
    703       write_pos = EncodeUnsignedLeb128(write_pos, tgt_lir->offset - pc2dex_offset);
    704       write_pos = EncodeSignedLeb128(write_pos, static_cast<int32_t>(tgt_lir->dalvik_offset) -
    705                                      static_cast<int32_t>(pc2dex_dalvik_offset));
    706       pc2dex_offset = tgt_lir->offset;
    707       pc2dex_dalvik_offset = tgt_lir->dalvik_offset;
    708     }
    709     if (!tgt_lir->flags.is_nop && (tgt_lir->opcode == kPseudoExportedPC)) {
    710       DCHECK(dex2pc_offset <= tgt_lir->offset);
    711       write_pos2 = EncodeUnsignedLeb128(write_pos2, tgt_lir->offset - dex2pc_offset);
    712       write_pos2 = EncodeSignedLeb128(write_pos2, static_cast<int32_t>(tgt_lir->dalvik_offset) -
    713                                       static_cast<int32_t>(dex2pc_dalvik_offset));
    714       dex2pc_offset = tgt_lir->offset;
    715       dex2pc_dalvik_offset = tgt_lir->dalvik_offset;
    716     }
    717   }
    718   DCHECK_EQ(static_cast<size_t>(write_pos - &encoded_mapping_table_[0]),
    719             hdr_data_size + pc2dex_data_size);
    720   DCHECK_EQ(static_cast<size_t>(write_pos2 - &encoded_mapping_table_[0]), data_size);
    721 
    722   if (kIsDebugBuild) {
    723     CHECK(VerifyCatchEntries());
    724 
    725     // Verify the encoded table holds the expected data.
    726     MappingTable table(&encoded_mapping_table_[0]);
    727     CHECK_EQ(table.TotalSize(), total_entries);
    728     CHECK_EQ(table.PcToDexSize(), pc2dex_entries);
    729     auto it = table.PcToDexBegin();
    730     auto it2 = table.DexToPcBegin();
    731     for (LIR* tgt_lir = first_lir_insn_; tgt_lir != NULL; tgt_lir = NEXT_LIR(tgt_lir)) {
    732       if (!tgt_lir->flags.is_nop && (tgt_lir->opcode == kPseudoSafepointPC)) {
    733         CHECK_EQ(tgt_lir->offset, it.NativePcOffset());
    734         CHECK_EQ(tgt_lir->dalvik_offset, it.DexPc());
    735         ++it;
    736       }
    737       if (!tgt_lir->flags.is_nop && (tgt_lir->opcode == kPseudoExportedPC)) {
    738         CHECK_EQ(tgt_lir->offset, it2.NativePcOffset());
    739         CHECK_EQ(tgt_lir->dalvik_offset, it2.DexPc());
    740         ++it2;
    741       }
    742     }
    743     CHECK(it == table.PcToDexEnd());
    744     CHECK(it2 == table.DexToPcEnd());
    745   }
    746 }
    747 
    748 void Mir2Lir::CreateNativeGcMap() {
    749   DCHECK(!encoded_mapping_table_.empty());
    750   MappingTable mapping_table(&encoded_mapping_table_[0]);
    751   uint32_t max_native_offset = 0;
    752   for (auto it = mapping_table.PcToDexBegin(), end = mapping_table.PcToDexEnd(); it != end; ++it) {
    753     uint32_t native_offset = it.NativePcOffset();
    754     if (native_offset > max_native_offset) {
    755       max_native_offset = native_offset;
    756     }
    757   }
    758   MethodReference method_ref(cu_->dex_file, cu_->method_idx);
    759   const std::vector<uint8_t>& gc_map_raw =
    760       mir_graph_->GetCurrentDexCompilationUnit()->GetVerifiedMethod()->GetDexGcMap();
    761   verifier::DexPcToReferenceMap dex_gc_map(&(gc_map_raw)[0]);
    762   DCHECK_EQ(gc_map_raw.size(), dex_gc_map.RawSize());
    763   // Compute native offset to references size.
    764   GcMapBuilder native_gc_map_builder(&native_gc_map_,
    765                                      mapping_table.PcToDexSize(),
    766                                      max_native_offset, dex_gc_map.RegWidth());
    767 
    768   for (auto it = mapping_table.PcToDexBegin(), end = mapping_table.PcToDexEnd(); it != end; ++it) {
    769     uint32_t native_offset = it.NativePcOffset();
    770     uint32_t dex_pc = it.DexPc();
    771     const uint8_t* references = dex_gc_map.FindBitMap(dex_pc, false);
    772     CHECK(references != NULL) << "Missing ref for dex pc 0x" << std::hex << dex_pc <<
    773         ": " << PrettyMethod(cu_->method_idx, *cu_->dex_file);
    774     native_gc_map_builder.AddEntry(native_offset, references);
    775   }
    776 
    777   // Maybe not necessary, but this could help prevent errors where we access the verified method
    778   // after it has been deleted.
    779   mir_graph_->GetCurrentDexCompilationUnit()->ClearVerifiedMethod();
    780 }
    781 
    782 /* Determine the offset of each literal field */
    783 int Mir2Lir::AssignLiteralOffset(CodeOffset offset) {
    784   offset = AssignLiteralOffsetCommon(literal_list_, offset);
    785   unsigned int ptr_size = GetInstructionSetPointerSize(cu_->instruction_set);
    786   offset = AssignLiteralPointerOffsetCommon(code_literal_list_, offset, ptr_size);
    787   offset = AssignLiteralPointerOffsetCommon(method_literal_list_, offset, ptr_size);
    788   offset = AssignLiteralPointerOffsetCommon(class_literal_list_, offset, ptr_size);
    789   offset = AssignLiteralPointerOffsetCommon(string_literal_list_, offset, ptr_size);
    790   return offset;
    791 }
    792 
    793 int Mir2Lir::AssignSwitchTablesOffset(CodeOffset offset) {
    794   GrowableArray<SwitchTable*>::Iterator iterator(&switch_tables_);
    795   while (true) {
    796     Mir2Lir::SwitchTable* tab_rec = iterator.Next();
    797     if (tab_rec == NULL) break;
    798     tab_rec->offset = offset;
    799     if (tab_rec->table[0] == Instruction::kSparseSwitchSignature) {
    800       offset += tab_rec->table[1] * (sizeof(int) * 2);
    801     } else {
    802       DCHECK_EQ(static_cast<int>(tab_rec->table[0]),
    803                 static_cast<int>(Instruction::kPackedSwitchSignature));
    804       offset += tab_rec->table[1] * sizeof(int);
    805     }
    806   }
    807   return offset;
    808 }
    809 
    810 int Mir2Lir::AssignFillArrayDataOffset(CodeOffset offset) {
    811   GrowableArray<FillArrayData*>::Iterator iterator(&fill_array_data_);
    812   while (true) {
    813     Mir2Lir::FillArrayData *tab_rec = iterator.Next();
    814     if (tab_rec == NULL) break;
    815     tab_rec->offset = offset;
    816     offset += tab_rec->size;
    817     // word align
    818     offset = RoundUp(offset, 4);
    819     }
    820   return offset;
    821 }
    822 
    823 /*
    824  * Insert a kPseudoCaseLabel at the beginning of the Dalvik
    825  * offset vaddr if pretty-printing, otherise use the standard block
    826  * label.  The selected label will be used to fix up the case
    827  * branch table during the assembly phase.  All resource flags
    828  * are set to prevent code motion.  KeyVal is just there for debugging.
    829  */
    830 LIR* Mir2Lir::InsertCaseLabel(DexOffset vaddr, int keyVal) {
    831   LIR* boundary_lir = &block_label_list_[mir_graph_->FindBlock(vaddr)->id];
    832   LIR* res = boundary_lir;
    833   if (cu_->verbose) {
    834     // Only pay the expense if we're pretty-printing.
    835     LIR* new_label = static_cast<LIR*>(arena_->Alloc(sizeof(LIR), kArenaAllocLIR));
    836     new_label->dalvik_offset = vaddr;
    837     new_label->opcode = kPseudoCaseLabel;
    838     new_label->operands[0] = keyVal;
    839     new_label->flags.fixup = kFixupLabel;
    840     DCHECK(!new_label->flags.use_def_invalid);
    841     new_label->u.m.def_mask = &kEncodeAll;
    842     InsertLIRAfter(boundary_lir, new_label);
    843     res = new_label;
    844   }
    845   return res;
    846 }
    847 
    848 void Mir2Lir::MarkPackedCaseLabels(Mir2Lir::SwitchTable* tab_rec) {
    849   const uint16_t* table = tab_rec->table;
    850   DexOffset base_vaddr = tab_rec->vaddr;
    851   const int32_t *targets = reinterpret_cast<const int32_t*>(&table[4]);
    852   int entries = table[1];
    853   int low_key = s4FromSwitchData(&table[2]);
    854   for (int i = 0; i < entries; i++) {
    855     tab_rec->targets[i] = InsertCaseLabel(base_vaddr + targets[i], i + low_key);
    856   }
    857 }
    858 
    859 void Mir2Lir::MarkSparseCaseLabels(Mir2Lir::SwitchTable* tab_rec) {
    860   const uint16_t* table = tab_rec->table;
    861   DexOffset base_vaddr = tab_rec->vaddr;
    862   int entries = table[1];
    863   const int32_t* keys = reinterpret_cast<const int32_t*>(&table[2]);
    864   const int32_t* targets = &keys[entries];
    865   for (int i = 0; i < entries; i++) {
    866     tab_rec->targets[i] = InsertCaseLabel(base_vaddr + targets[i], keys[i]);
    867   }
    868 }
    869 
    870 void Mir2Lir::ProcessSwitchTables() {
    871   GrowableArray<SwitchTable*>::Iterator iterator(&switch_tables_);
    872   while (true) {
    873     Mir2Lir::SwitchTable *tab_rec = iterator.Next();
    874     if (tab_rec == NULL) break;
    875     if (tab_rec->table[0] == Instruction::kPackedSwitchSignature) {
    876       MarkPackedCaseLabels(tab_rec);
    877     } else if (tab_rec->table[0] == Instruction::kSparseSwitchSignature) {
    878       MarkSparseCaseLabels(tab_rec);
    879     } else {
    880       LOG(FATAL) << "Invalid switch table";
    881     }
    882   }
    883 }
    884 
    885 void Mir2Lir::DumpSparseSwitchTable(const uint16_t* table) {
    886   /*
    887    * Sparse switch data format:
    888    *  ushort ident = 0x0200   magic value
    889    *  ushort size       number of entries in the table; > 0
    890    *  int keys[size]      keys, sorted low-to-high; 32-bit aligned
    891    *  int targets[size]     branch targets, relative to switch opcode
    892    *
    893    * Total size is (2+size*4) 16-bit code units.
    894    */
    895   uint16_t ident = table[0];
    896   int entries = table[1];
    897   const int32_t* keys = reinterpret_cast<const int32_t*>(&table[2]);
    898   const int32_t* targets = &keys[entries];
    899   LOG(INFO) <<  "Sparse switch table - ident:0x" << std::hex << ident
    900             << ", entries: " << std::dec << entries;
    901   for (int i = 0; i < entries; i++) {
    902     LOG(INFO) << "  Key[" << keys[i] << "] -> 0x" << std::hex << targets[i];
    903   }
    904 }
    905 
    906 void Mir2Lir::DumpPackedSwitchTable(const uint16_t* table) {
    907   /*
    908    * Packed switch data format:
    909    *  ushort ident = 0x0100   magic value
    910    *  ushort size       number of entries in the table
    911    *  int first_key       first (and lowest) switch case value
    912    *  int targets[size]     branch targets, relative to switch opcode
    913    *
    914    * Total size is (4+size*2) 16-bit code units.
    915    */
    916   uint16_t ident = table[0];
    917   const int32_t* targets = reinterpret_cast<const int32_t*>(&table[4]);
    918   int entries = table[1];
    919   int low_key = s4FromSwitchData(&table[2]);
    920   LOG(INFO) << "Packed switch table - ident:0x" << std::hex << ident
    921             << ", entries: " << std::dec << entries << ", low_key: " << low_key;
    922   for (int i = 0; i < entries; i++) {
    923     LOG(INFO) << "  Key[" << (i + low_key) << "] -> 0x" << std::hex
    924               << targets[i];
    925   }
    926 }
    927 
    928 /* Set up special LIR to mark a Dalvik byte-code instruction start for pretty printing */
    929 void Mir2Lir::MarkBoundary(DexOffset offset, const char* inst_str) {
    930   // NOTE: only used for debug listings.
    931   NewLIR1(kPseudoDalvikByteCodeBoundary, WrapPointer(ArenaStrdup(inst_str)));
    932 }
    933 
    934 bool Mir2Lir::EvaluateBranch(Instruction::Code opcode, int32_t src1, int32_t src2) {
    935   bool is_taken;
    936   switch (opcode) {
    937     case Instruction::IF_EQ: is_taken = (src1 == src2); break;
    938     case Instruction::IF_NE: is_taken = (src1 != src2); break;
    939     case Instruction::IF_LT: is_taken = (src1 < src2); break;
    940     case Instruction::IF_GE: is_taken = (src1 >= src2); break;
    941     case Instruction::IF_GT: is_taken = (src1 > src2); break;
    942     case Instruction::IF_LE: is_taken = (src1 <= src2); break;
    943     case Instruction::IF_EQZ: is_taken = (src1 == 0); break;
    944     case Instruction::IF_NEZ: is_taken = (src1 != 0); break;
    945     case Instruction::IF_LTZ: is_taken = (src1 < 0); break;
    946     case Instruction::IF_GEZ: is_taken = (src1 >= 0); break;
    947     case Instruction::IF_GTZ: is_taken = (src1 > 0); break;
    948     case Instruction::IF_LEZ: is_taken = (src1 <= 0); break;
    949     default:
    950       LOG(FATAL) << "Unexpected opcode " << opcode;
    951       is_taken = false;
    952   }
    953   return is_taken;
    954 }
    955 
    956 // Convert relation of src1/src2 to src2/src1
    957 ConditionCode Mir2Lir::FlipComparisonOrder(ConditionCode before) {
    958   ConditionCode res;
    959   switch (before) {
    960     case kCondEq: res = kCondEq; break;
    961     case kCondNe: res = kCondNe; break;
    962     case kCondLt: res = kCondGt; break;
    963     case kCondGt: res = kCondLt; break;
    964     case kCondLe: res = kCondGe; break;
    965     case kCondGe: res = kCondLe; break;
    966     default:
    967       res = static_cast<ConditionCode>(0);
    968       LOG(FATAL) << "Unexpected ccode " << before;
    969   }
    970   return res;
    971 }
    972 
    973 ConditionCode Mir2Lir::NegateComparison(ConditionCode before) {
    974   ConditionCode res;
    975   switch (before) {
    976     case kCondEq: res = kCondNe; break;
    977     case kCondNe: res = kCondEq; break;
    978     case kCondLt: res = kCondGe; break;
    979     case kCondGt: res = kCondLe; break;
    980     case kCondLe: res = kCondGt; break;
    981     case kCondGe: res = kCondLt; break;
    982     default:
    983       res = static_cast<ConditionCode>(0);
    984       LOG(FATAL) << "Unexpected ccode " << before;
    985   }
    986   return res;
    987 }
    988 
    989 // TODO: move to mir_to_lir.cc
    990 Mir2Lir::Mir2Lir(CompilationUnit* cu, MIRGraph* mir_graph, ArenaAllocator* arena)
    991     : Backend(arena),
    992       literal_list_(NULL),
    993       method_literal_list_(NULL),
    994       class_literal_list_(NULL),
    995       string_literal_list_(NULL),
    996       code_literal_list_(NULL),
    997       first_fixup_(NULL),
    998       cu_(cu),
    999       mir_graph_(mir_graph),
   1000       switch_tables_(arena, 4, kGrowableArraySwitchTables),
   1001       fill_array_data_(arena, 4, kGrowableArrayFillArrayData),
   1002       tempreg_info_(arena, 20, kGrowableArrayMisc),
   1003       reginfo_map_(arena, RegStorage::kMaxRegs, kGrowableArrayMisc),
   1004       pointer_storage_(arena, 128, kGrowableArrayMisc),
   1005       data_offset_(0),
   1006       total_size_(0),
   1007       block_label_list_(NULL),
   1008       promotion_map_(NULL),
   1009       current_dalvik_offset_(0),
   1010       estimated_native_code_size_(0),
   1011       reg_pool_(NULL),
   1012       live_sreg_(0),
   1013       core_vmap_table_(mir_graph->GetArena()->Adapter()),
   1014       fp_vmap_table_(mir_graph->GetArena()->Adapter()),
   1015       num_core_spills_(0),
   1016       num_fp_spills_(0),
   1017       frame_size_(0),
   1018       core_spill_mask_(0),
   1019       fp_spill_mask_(0),
   1020       first_lir_insn_(NULL),
   1021       last_lir_insn_(NULL),
   1022       slow_paths_(arena, 32, kGrowableArraySlowPaths),
   1023       mem_ref_type_(ResourceMask::kHeapRef),
   1024       mask_cache_(arena) {
   1025   // Reserve pointer id 0 for NULL.
   1026   size_t null_idx = WrapPointer(NULL);
   1027   DCHECK_EQ(null_idx, 0U);
   1028 }
   1029 
   1030 void Mir2Lir::Materialize() {
   1031   cu_->NewTimingSplit("RegisterAllocation");
   1032   CompilerInitializeRegAlloc();  // Needs to happen after SSA naming
   1033 
   1034   /* Allocate Registers using simple local allocation scheme */
   1035   SimpleRegAlloc();
   1036 
   1037   /* First try the custom light codegen for special cases. */
   1038   DCHECK(cu_->compiler_driver->GetMethodInlinerMap() != nullptr);
   1039   bool special_worked = cu_->compiler_driver->GetMethodInlinerMap()->GetMethodInliner(cu_->dex_file)
   1040       ->GenSpecial(this, cu_->method_idx);
   1041 
   1042   /* Take normal path for converting MIR to LIR only if the special codegen did not succeed. */
   1043   if (special_worked == false) {
   1044     MethodMIR2LIR();
   1045   }
   1046 
   1047   /* Method is not empty */
   1048   if (first_lir_insn_) {
   1049     // mark the targets of switch statement case labels
   1050     ProcessSwitchTables();
   1051 
   1052     /* Convert LIR into machine code. */
   1053     AssembleLIR();
   1054 
   1055     if ((cu_->enable_debug & (1 << kDebugCodegenDump)) != 0) {
   1056       CodegenDump();
   1057     }
   1058   }
   1059 }
   1060 
   1061 CompiledMethod* Mir2Lir::GetCompiledMethod() {
   1062   // Combine vmap tables - core regs, then fp regs - into vmap_table.
   1063   Leb128EncodingVector vmap_encoder;
   1064   if (frame_size_ > 0) {
   1065     // Prefix the encoded data with its size.
   1066     size_t size = core_vmap_table_.size() + 1 /* marker */ + fp_vmap_table_.size();
   1067     vmap_encoder.Reserve(size + 1u);  // All values are likely to be one byte in ULEB128 (<128).
   1068     vmap_encoder.PushBackUnsigned(size);
   1069     // Core regs may have been inserted out of order - sort first.
   1070     std::sort(core_vmap_table_.begin(), core_vmap_table_.end());
   1071     for (size_t i = 0 ; i < core_vmap_table_.size(); ++i) {
   1072       // Copy, stripping out the phys register sort key.
   1073       vmap_encoder.PushBackUnsigned(
   1074           ~(-1 << VREG_NUM_WIDTH) & (core_vmap_table_[i] + VmapTable::kEntryAdjustment));
   1075     }
   1076     // Push a marker to take place of lr.
   1077     vmap_encoder.PushBackUnsigned(VmapTable::kAdjustedFpMarker);
   1078     if (cu_->instruction_set == kThumb2) {
   1079       // fp regs already sorted.
   1080       for (uint32_t i = 0; i < fp_vmap_table_.size(); i++) {
   1081         vmap_encoder.PushBackUnsigned(fp_vmap_table_[i] + VmapTable::kEntryAdjustment);
   1082       }
   1083     } else {
   1084       // For other platforms regs may have been inserted out of order - sort first.
   1085       std::sort(fp_vmap_table_.begin(), fp_vmap_table_.end());
   1086       for (size_t i = 0 ; i < fp_vmap_table_.size(); ++i) {
   1087         // Copy, stripping out the phys register sort key.
   1088         vmap_encoder.PushBackUnsigned(
   1089             ~(-1 << VREG_NUM_WIDTH) & (fp_vmap_table_[i] + VmapTable::kEntryAdjustment));
   1090       }
   1091     }
   1092   } else {
   1093     DCHECK_EQ(POPCOUNT(core_spill_mask_), 0);
   1094     DCHECK_EQ(POPCOUNT(fp_spill_mask_), 0);
   1095     DCHECK_EQ(core_vmap_table_.size(), 0u);
   1096     DCHECK_EQ(fp_vmap_table_.size(), 0u);
   1097     vmap_encoder.PushBackUnsigned(0u);  // Size is 0.
   1098   }
   1099 
   1100   std::unique_ptr<std::vector<uint8_t>> cfi_info(ReturnCallFrameInformation());
   1101   ArrayRef<const uint8_t> cfi_ref;
   1102   if (cfi_info.get() != nullptr) {
   1103     cfi_ref = ArrayRef<const uint8_t>(*cfi_info);
   1104   }
   1105   return CompiledMethod::SwapAllocCompiledMethod(
   1106       cu_->compiler_driver, cu_->instruction_set,
   1107       ArrayRef<const uint8_t>(code_buffer_),
   1108       frame_size_, core_spill_mask_, fp_spill_mask_,
   1109       ArrayRef<const uint8_t>(encoded_mapping_table_),
   1110       ArrayRef<const uint8_t>(vmap_encoder.GetData()),
   1111       ArrayRef<const uint8_t>(native_gc_map_),
   1112       cfi_ref);
   1113 }
   1114 
   1115 size_t Mir2Lir::GetMaxPossibleCompilerTemps() const {
   1116   // Chose a reasonably small value in order to contain stack growth.
   1117   // Backends that are smarter about spill region can return larger values.
   1118   const size_t max_compiler_temps = 10;
   1119   return max_compiler_temps;
   1120 }
   1121 
   1122 size_t Mir2Lir::GetNumBytesForCompilerTempSpillRegion() {
   1123   // By default assume that the Mir2Lir will need one slot for each temporary.
   1124   // If the backend can better determine temps that have non-overlapping ranges and
   1125   // temps that do not need spilled, it can actually provide a small region.
   1126   return (mir_graph_->GetNumUsedCompilerTemps() * sizeof(uint32_t));
   1127 }
   1128 
   1129 int Mir2Lir::ComputeFrameSize() {
   1130   /* Figure out the frame size */
   1131   uint32_t size = num_core_spills_ * GetBytesPerGprSpillLocation(cu_->instruction_set)
   1132                   + num_fp_spills_ * GetBytesPerFprSpillLocation(cu_->instruction_set)
   1133                   + sizeof(uint32_t)  // Filler.
   1134                   + (cu_->num_regs + cu_->num_outs) * sizeof(uint32_t)
   1135                   + GetNumBytesForCompilerTempSpillRegion();
   1136   /* Align and set */
   1137   return RoundUp(size, kStackAlignment);
   1138 }
   1139 
   1140 /*
   1141  * Append an LIR instruction to the LIR list maintained by a compilation
   1142  * unit
   1143  */
   1144 void Mir2Lir::AppendLIR(LIR* lir) {
   1145   if (first_lir_insn_ == NULL) {
   1146     DCHECK(last_lir_insn_ == NULL);
   1147     last_lir_insn_ = first_lir_insn_ = lir;
   1148     lir->prev = lir->next = NULL;
   1149   } else {
   1150     last_lir_insn_->next = lir;
   1151     lir->prev = last_lir_insn_;
   1152     lir->next = NULL;
   1153     last_lir_insn_ = lir;
   1154   }
   1155 }
   1156 
   1157 /*
   1158  * Insert an LIR instruction before the current instruction, which cannot be the
   1159  * first instruction.
   1160  *
   1161  * prev_lir <-> new_lir <-> current_lir
   1162  */
   1163 void Mir2Lir::InsertLIRBefore(LIR* current_lir, LIR* new_lir) {
   1164   DCHECK(current_lir->prev != NULL);
   1165   LIR *prev_lir = current_lir->prev;
   1166 
   1167   prev_lir->next = new_lir;
   1168   new_lir->prev = prev_lir;
   1169   new_lir->next = current_lir;
   1170   current_lir->prev = new_lir;
   1171 }
   1172 
   1173 /*
   1174  * Insert an LIR instruction after the current instruction, which cannot be the
   1175  * last instruction.
   1176  *
   1177  * current_lir -> new_lir -> old_next
   1178  */
   1179 void Mir2Lir::InsertLIRAfter(LIR* current_lir, LIR* new_lir) {
   1180   new_lir->prev = current_lir;
   1181   new_lir->next = current_lir->next;
   1182   current_lir->next = new_lir;
   1183   new_lir->next->prev = new_lir;
   1184 }
   1185 
   1186 bool Mir2Lir::IsPowerOfTwo(uint64_t x) {
   1187   return (x & (x - 1)) == 0;
   1188 }
   1189 
   1190 // Returns the index of the lowest set bit in 'x'.
   1191 int32_t Mir2Lir::LowestSetBit(uint64_t x) {
   1192   int bit_posn = 0;
   1193   while ((x & 0xf) == 0) {
   1194     bit_posn += 4;
   1195     x >>= 4;
   1196   }
   1197   while ((x & 1) == 0) {
   1198     bit_posn++;
   1199     x >>= 1;
   1200   }
   1201   return bit_posn;
   1202 }
   1203 
   1204 bool Mir2Lir::BadOverlap(RegLocation rl_src, RegLocation rl_dest) {
   1205   DCHECK(rl_src.wide);
   1206   DCHECK(rl_dest.wide);
   1207   return (abs(mir_graph_->SRegToVReg(rl_src.s_reg_low) - mir_graph_->SRegToVReg(rl_dest.s_reg_low)) == 1);
   1208 }
   1209 
   1210 LIR *Mir2Lir::OpCmpMemImmBranch(ConditionCode cond, RegStorage temp_reg, RegStorage base_reg,
   1211                                 int offset, int check_value, LIR* target, LIR** compare) {
   1212   // Handle this for architectures that can't compare to memory.
   1213   LIR* inst = Load32Disp(base_reg, offset, temp_reg);
   1214   if (compare != nullptr) {
   1215     *compare = inst;
   1216   }
   1217   LIR* branch = OpCmpImmBranch(cond, temp_reg, check_value, target);
   1218   return branch;
   1219 }
   1220 
   1221 void Mir2Lir::AddSlowPath(LIRSlowPath* slowpath) {
   1222   slow_paths_.Insert(slowpath);
   1223 }
   1224 
   1225 void Mir2Lir::LoadCodeAddress(const MethodReference& target_method, InvokeType type,
   1226                               SpecialTargetRegister symbolic_reg) {
   1227   LIR* data_target = ScanLiteralPoolMethod(code_literal_list_, target_method);
   1228   if (data_target == NULL) {
   1229     data_target = AddWordData(&code_literal_list_, target_method.dex_method_index);
   1230     data_target->operands[1] = WrapPointer(const_cast<DexFile*>(target_method.dex_file));
   1231     // NOTE: The invoke type doesn't contribute to the literal identity. In fact, we can have
   1232     // the same method invoked with kVirtual, kSuper and kInterface but the class linker will
   1233     // resolve these invokes to the same method, so we don't care which one we record here.
   1234     data_target->operands[2] = type;
   1235   }
   1236   // Loads a code pointer. Code from oat file can be mapped anywhere.
   1237   LIR* load_pc_rel = OpPcRelLoad(TargetPtrReg(symbolic_reg), data_target);
   1238   AppendLIR(load_pc_rel);
   1239   DCHECK_NE(cu_->instruction_set, kMips) << reinterpret_cast<void*>(data_target);
   1240 }
   1241 
   1242 void Mir2Lir::LoadMethodAddress(const MethodReference& target_method, InvokeType type,
   1243                                 SpecialTargetRegister symbolic_reg) {
   1244   LIR* data_target = ScanLiteralPoolMethod(method_literal_list_, target_method);
   1245   if (data_target == NULL) {
   1246     data_target = AddWordData(&method_literal_list_, target_method.dex_method_index);
   1247     data_target->operands[1] = WrapPointer(const_cast<DexFile*>(target_method.dex_file));
   1248     // NOTE: The invoke type doesn't contribute to the literal identity. In fact, we can have
   1249     // the same method invoked with kVirtual, kSuper and kInterface but the class linker will
   1250     // resolve these invokes to the same method, so we don't care which one we record here.
   1251     data_target->operands[2] = type;
   1252   }
   1253   // Loads an ArtMethod pointer, which is a reference as it lives in the heap.
   1254   LIR* load_pc_rel = OpPcRelLoad(TargetReg(symbolic_reg, kRef), data_target);
   1255   AppendLIR(load_pc_rel);
   1256   DCHECK_NE(cu_->instruction_set, kMips) << reinterpret_cast<void*>(data_target);
   1257 }
   1258 
   1259 void Mir2Lir::LoadClassType(uint32_t type_idx, SpecialTargetRegister symbolic_reg) {
   1260   // Use the literal pool and a PC-relative load from a data word.
   1261   LIR* data_target = ScanLiteralPool(class_literal_list_, type_idx, 0);
   1262   if (data_target == nullptr) {
   1263     data_target = AddWordData(&class_literal_list_, type_idx);
   1264   }
   1265   // Loads a Class pointer, which is a reference as it lives in the heap.
   1266   LIR* load_pc_rel = OpPcRelLoad(TargetReg(symbolic_reg, kRef), data_target);
   1267   AppendLIR(load_pc_rel);
   1268 }
   1269 
   1270 void Mir2Lir::LoadString(uint32_t string_idx, RegStorage target_reg) {
   1271   // Use the literal pool and a PC-relative load from a data word.
   1272   LIR* data_target = ScanLiteralPool(string_literal_list_, string_idx, 0);
   1273   if (data_target == nullptr) {
   1274     data_target = AddWordData(&string_literal_list_, string_idx);
   1275   }
   1276   // Loads a Class pointer, which is a reference as it lives in the heap.
   1277   LIR* load_pc_rel = OpPcRelLoad(target_reg, data_target);
   1278   AppendLIR(load_pc_rel);
   1279 }
   1280 
   1281 std::vector<uint8_t>* Mir2Lir::ReturnCallFrameInformation() {
   1282   // Default case is to do nothing.
   1283   return nullptr;
   1284 }
   1285 
   1286 RegLocation Mir2Lir::NarrowRegLoc(RegLocation loc) {
   1287   if (loc.location == kLocPhysReg) {
   1288     DCHECK(!loc.reg.Is32Bit());
   1289     if (loc.reg.IsPair()) {
   1290       RegisterInfo* info_lo = GetRegInfo(loc.reg.GetLow());
   1291       RegisterInfo* info_hi = GetRegInfo(loc.reg.GetHigh());
   1292       info_lo->SetIsWide(false);
   1293       info_hi->SetIsWide(false);
   1294       loc.reg = info_lo->GetReg();
   1295     } else {
   1296       RegisterInfo* info = GetRegInfo(loc.reg);
   1297       RegisterInfo* info_new = info->FindMatchingView(RegisterInfo::k32SoloStorageMask);
   1298       DCHECK(info_new != nullptr);
   1299       if (info->IsLive() && (info->SReg() == loc.s_reg_low)) {
   1300         info->MarkDead();
   1301         info_new->MarkLive(loc.s_reg_low);
   1302       }
   1303       loc.reg = info_new->GetReg();
   1304     }
   1305     DCHECK(loc.reg.Valid());
   1306   }
   1307   loc.wide = false;
   1308   return loc;
   1309 }
   1310 
   1311 void Mir2Lir::GenMachineSpecificExtendedMethodMIR(BasicBlock* bb, MIR* mir) {
   1312   LOG(FATAL) << "Unknown MIR opcode not supported on this architecture";
   1313 }
   1314 
   1315 }  // namespace art
   1316