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* Copyright (C) 2013 The Android Open Source Project
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* See the License for the specific language governing permissions and
* limitations under the License.
#include <stdint.h>
#include "dex_file.h"
#include "dex_instruction.h"
#include "compiler_ir.h"
#include "invoke_type.h"
#include "mir_field_info.h"
#include "mir_method_info.h"
#include "utils/arena_bit_vector.h"
#include "utils/growable_array.h"
#include "reg_location.h"
#include "reg_storage.h"
namespace art {
class GlobalValueNumbering;
enum InstructionAnalysisAttributePos {
kUninterestingOp = 0,
#define AN_NONE (1 << kUninterestingOp)
#define AN_MATH (1 << kArithmeticOp)
#define AN_FP (1 << kFPOp)
#define AN_LONG (1 << kLongOp)
#define AN_INT (1 << kIntOp)
#define AN_SINGLE (1 << kSingleOp)
#define AN_DOUBLE (1 << kDoubleOp)
#define AN_FLOATMATH (1 << kFPOp)
#define AN_BRANCH (1 << kBranchOp)
#define AN_INVOKE (1 << kInvokeOp)
#define AN_ARRAYOP (1 << kArrayOp)
#define AN_HEAVYWEIGHT (1 << kHeavyweightOp)
#define AN_SIMPLECONST (1 << kSimpleConstOp)
#define AN_MOVE (1 << kMoveOp)
#define AN_SWITCH (1 << kSwitch)
enum DataFlowAttributePos {
kUA = 0,
kFormatExtended, // Extended format for extended MIRs.
kNullCheckSrc0, // Null check of uses[0].
kNullCheckSrc1, // Null check of uses[1].
kNullCheckSrc2, // Null check of uses[2].
kNullCheckOut0, // Null check out outgoing arg0.
kDstNonNull, // May assume dst is non-null.
kRetNonNull, // May assume retval is non-null.
kNullTransferSrc0, // Object copy src[0] -> dst.
kNullTransferSrcN, // Phi null check state transfer.
kRangeCheckSrc1, // Range check of uses[1].
kRangeCheckSrc2, // Range check of uses[2].
kRangeCheckSrc3, // Range check of uses[3].
kUsesMethodStar, // Implicit use of Method*.
kUsesIField, // Accesses an instance field (IGET/IPUT).
kUsesSField, // Accesses a static field (SGET/SPUT).
kDoLVN, // Worth computing local value numbers.
#define DF_NOP UINT64_C(0)
#define DF_UA (UINT64_C(1) << kUA)
#define DF_UB (UINT64_C(1) << kUB)
#define DF_UC (UINT64_C(1) << kUC)
#define DF_A_WIDE (UINT64_C(1) << kAWide)
#define DF_B_WIDE (UINT64_C(1) << kBWide)
#define DF_C_WIDE (UINT64_C(1) << kCWide)
#define DF_DA (UINT64_C(1) << kDA)
#define DF_IS_MOVE (UINT64_C(1) << kIsMove)
#define DF_SETS_CONST (UINT64_C(1) << kSetsConst)
#define DF_FORMAT_35C (UINT64_C(1) << kFormat35c)
#define DF_FORMAT_3RC (UINT64_C(1) << kFormat3rc)
#define DF_FORMAT_EXTENDED (UINT64_C(1) << kFormatExtended)
#define DF_NULL_CHK_0 (UINT64_C(1) << kNullCheckSrc0)
#define DF_NULL_CHK_1 (UINT64_C(1) << kNullCheckSrc1)
#define DF_NULL_CHK_2 (UINT64_C(1) << kNullCheckSrc2)
#define DF_NULL_CHK_OUT0 (UINT64_C(1) << kNullCheckOut0)
#define DF_NON_NULL_DST (UINT64_C(1) << kDstNonNull)
#define DF_NON_NULL_RET (UINT64_C(1) << kRetNonNull)
#define DF_NULL_TRANSFER_0 (UINT64_C(1) << kNullTransferSrc0)
#define DF_NULL_TRANSFER_N (UINT64_C(1) << kNullTransferSrcN)
#define DF_RANGE_CHK_1 (UINT64_C(1) << kRangeCheckSrc1)
#define DF_RANGE_CHK_2 (UINT64_C(1) << kRangeCheckSrc2)
#define DF_RANGE_CHK_3 (UINT64_C(1) << kRangeCheckSrc3)
#define DF_FP_A (UINT64_C(1) << kFPA)
#define DF_FP_B (UINT64_C(1) << kFPB)
#define DF_FP_C (UINT64_C(1) << kFPC)
#define DF_CORE_A (UINT64_C(1) << kCoreA)
#define DF_CORE_B (UINT64_C(1) << kCoreB)
#define DF_CORE_C (UINT64_C(1) << kCoreC)
#define DF_REF_A (UINT64_C(1) << kRefA)
#define DF_REF_B (UINT64_C(1) << kRefB)
#define DF_REF_C (UINT64_C(1) << kRefC)
#define DF_UMS (UINT64_C(1) << kUsesMethodStar)
#define DF_IFIELD (UINT64_C(1) << kUsesIField)
#define DF_SFIELD (UINT64_C(1) << kUsesSField)
#define DF_LVN (UINT64_C(1) << kDoLVN)
#define DF_HAS_USES (DF_UA | DF_UB | DF_UC)
#define DF_HAS_DEFS (DF_DA)
#define DF_A_IS_REG (DF_UA | DF_DA)
#define DF_B_IS_REG (DF_UB)
#define DF_C_IS_REG (DF_UC)
#define DF_USES_FP (DF_FP_A | DF_FP_B | DF_FP_C)
enum OatMethodAttributes {
kIsLeaf, // Method is leaf.
kHasLoop, // Method contains simple loop.
#define METHOD_IS_LEAF (1 << kIsLeaf)
#define METHOD_HAS_LOOP (1 << kHasLoop)
// Minimum field size to contain Dalvik v_reg number.
#define VREG_NUM_WIDTH 16
#define INVALID_SREG (-1)
#define MIR_IGNORE_NULL_CHECK (1 << kMIRIgnoreNullCheck)
#define MIR_NULL_CHECK_ONLY (1 << kMIRNullCheckOnly)
#define MIR_IGNORE_RANGE_CHECK (1 << kMIRIgnoreRangeCheck)
#define MIR_RANGE_CHECK_ONLY (1 << kMIRRangeCheckOnly)
#define MIR_IGNORE_CLINIT_CHECK (1 << kMIRIgnoreClInitCheck)
#define MIR_INLINED (1 << kMIRInlined)
#define MIR_INLINED_PRED (1 << kMIRInlinedPred)
#define MIR_CALLEE (1 << kMIRCallee)
#define MIR_IGNORE_SUSPEND_CHECK (1 << kMIRIgnoreSuspendCheck)
#define MIR_DUP (1 << kMIRDup)
#define BLOCK_NAME_LEN 80
typedef uint16_t BasicBlockId;
static const BasicBlockId NullBasicBlockId = 0;
static constexpr bool kLeafOptimization = false;
* In general, vreg/sreg describe Dalvik registers that originated with dx. However,
* it is useful to have compiler-generated temporary registers and have them treated
* in the same manner as dx-generated virtual registers. This struct records the SSA
* name of compiler-introduced temporaries.
struct CompilerTemp {
int32_t v_reg; // Virtual register number for temporary.
int32_t s_reg_low; // SSA name for low Dalvik word.
enum CompilerTempType {
kCompilerTempVR, // A virtual register temporary.
kCompilerTempSpecialMethodPtr, // Temporary that keeps track of current method pointer.
// When debug option enabled, records effectiveness of null and range check elimination.
struct Checkstats {
int32_t null_checks;
int32_t null_checks_eliminated;
int32_t range_checks;
int32_t range_checks_eliminated;
// Dataflow attributes of a basic block.
struct BasicBlockDataFlow {
ArenaBitVector* use_v;
ArenaBitVector* def_v;
ArenaBitVector* live_in_v;
ArenaBitVector* phi_v;
int32_t* vreg_to_ssa_map_exit;
ArenaBitVector* ending_check_v; // For null check and class init check elimination.
* Normalized use/def for a MIR operation using SSA names rather than vregs. Note that
* uses/defs retain the Dalvik convention that long operations operate on a pair of 32-bit
* vregs. For example, "ADD_LONG v0, v2, v3" would have 2 defs (v0/v1) and 4 uses (v2/v3, v4/v5).
* Following SSA renaming, this is the primary struct used by code generators to locate
* operand and result registers. This is a somewhat confusing and unhelpful convention that
* we may want to revisit in the future.
* 1. Add accessors for uses/defs and make data private
* 2. Change fp_use/fp_def to a bit array (could help memory usage)
* 3. Combine array storage into internal array and handled via accessors from 1.
struct SSARepresentation {
int32_t* uses;
bool* fp_use;
int32_t* defs;
bool* fp_def;
int16_t num_uses_allocated;
int16_t num_defs_allocated;
int16_t num_uses;
int16_t num_defs;
static uint32_t GetStartUseIndex(Instruction::Code opcode);
* The Midlevel Intermediate Representation node, which may be largely considered a
* wrapper around a Dalvik byte code.
struct MIR {
* TODO: remove embedded DecodedInstruction to save space, keeping only opcode. Recover
* additional fields on as-needed basis. Question: how to support MIR Pseudo-ops; probably
* need to carry aux data pointer.
struct DecodedInstruction {
uint32_t vA;
uint32_t vB;
uint64_t vB_wide; /* for k51l */
uint32_t vC;
uint32_t arg[5]; /* vC/D/E/F/G in invoke or filled-new-array */
Instruction::Code opcode;
explicit DecodedInstruction():vA(0), vB(0), vB_wide(0), vC(0), opcode(Instruction::NOP) {
* Given a decoded instruction representing a const bytecode, it updates
* the out arguments with proper values as dictated by the constant bytecode.
bool GetConstant(int64_t* ptr_value, bool* wide) const;
static bool IsPseudoMirOp(Instruction::Code opcode) {
return static_cast<int>(opcode) >= static_cast<int>(kMirOpFirst);
static bool IsPseudoMirOp(int opcode) {
return opcode >= static_cast<int>(kMirOpFirst);
bool IsInvoke() const {
return !IsPseudoMirOp(opcode) && ((Instruction::FlagsOf(opcode) & Instruction::kInvoke) == Instruction::kInvoke);
bool IsStore() const {
return !IsPseudoMirOp(opcode) && ((Instruction::FlagsOf(opcode) & Instruction::kStore) == Instruction::kStore);
bool IsLoad() const {
return !IsPseudoMirOp(opcode) && ((Instruction::FlagsOf(opcode) & Instruction::kLoad) == Instruction::kLoad);
bool IsConditionalBranch() const {
return !IsPseudoMirOp(opcode) && (Instruction::FlagsOf(opcode) == (Instruction::kContinue | Instruction::kBranch));
* @brief Is the register C component of the decoded instruction a constant?
bool IsCFieldOrConstant() const {
return !IsPseudoMirOp(opcode) && ((Instruction::FlagsOf(opcode) & Instruction::kRegCFieldOrConstant) == Instruction::kRegCFieldOrConstant);
* @brief Is the register C component of the decoded instruction a constant?
bool IsBFieldOrConstant() const {
return !IsPseudoMirOp(opcode) && ((Instruction::FlagsOf(opcode) & Instruction::kRegBFieldOrConstant) == Instruction::kRegBFieldOrConstant);
bool IsCast() const {
return !IsPseudoMirOp(opcode) && ((Instruction::FlagsOf(opcode) & Instruction::kCast) == Instruction::kCast);
* @brief Does the instruction clobber memory?
* @details Clobber means that the instruction changes the memory not in a punctual way.
* Therefore any supposition on memory aliasing or memory contents should be disregarded
* when crossing such an instruction.
bool Clobbers() const {
return !IsPseudoMirOp(opcode) && ((Instruction::FlagsOf(opcode) & Instruction::kClobber) == Instruction::kClobber);
bool IsLinear() const {
return !IsPseudoMirOp(opcode) && (Instruction::FlagsOf(opcode) & (Instruction::kAdd | Instruction::kSubtract)) != 0;
} dalvikInsn;
NarrowDexOffset offset; // Offset of the instruction in code units.
uint16_t optimization_flags;
int16_t m_unit_index; // From which method was this MIR included
BasicBlockId bb;
MIR* next;
SSARepresentation* ssa_rep;
union {
// Incoming edges for phi node.
BasicBlockId* phi_incoming;
// Establish link from check instruction (kMirOpCheck) to the actual throwing instruction.
MIR* throw_insn;
// Branch condition for fused cmp or select.
ConditionCode ccode;
// IGET/IPUT lowering info index, points to MIRGraph::ifield_lowering_infos_. Due to limit on
// the number of code points (64K) and size of IGET/IPUT insn (2), this will never exceed 32K.
uint32_t ifield_lowering_info;
// SGET/SPUT lowering info index, points to MIRGraph::sfield_lowering_infos_. Due to limit on
// the number of code points (64K) and size of SGET/SPUT insn (2), this will never exceed 32K.
uint32_t sfield_lowering_info;
// INVOKE data index, points to MIRGraph::method_lowering_infos_.
uint32_t method_lowering_info;
} meta;
explicit MIR():offset(0), optimization_flags(0), m_unit_index(0), bb(NullBasicBlockId),
next(nullptr), ssa_rep(nullptr) {
memset(&meta, 0, sizeof(meta));
uint32_t GetStartUseIndex() const {
return SSARepresentation::GetStartUseIndex(dalvikInsn.opcode);
MIR* Copy(CompilationUnit *c_unit);
MIR* Copy(MIRGraph* mir_Graph);
static void* operator new(size_t size, ArenaAllocator* arena) {
return arena->Alloc(sizeof(MIR), kArenaAllocMIR);
static void operator delete(void* p) {} // Nop.
struct SuccessorBlockInfo;
struct BasicBlock {
BasicBlockId id;
BasicBlockId dfs_id;
NarrowDexOffset start_offset; // Offset in code units.
BasicBlockId fall_through;
BasicBlockId taken;
BasicBlockId i_dom; // Immediate dominator.
uint16_t nesting_depth;
BBType block_type:4;
BlockListType successor_block_list_type:4;
bool visited:1;
bool hidden:1;
bool catch_entry:1;
bool explicit_throw:1;
bool conditional_branch:1;
bool terminated_by_return:1; // Block ends with a Dalvik return opcode.
bool dominates_return:1; // Is a member of return extended basic block.
bool use_lvn:1; // Run local value numbering on this block.
MIR* first_mir_insn;
MIR* last_mir_insn;
BasicBlockDataFlow* data_flow_info;
ArenaBitVector* dominators;
ArenaBitVector* i_dominated; // Set nodes being immediately dominated.
ArenaBitVector* dom_frontier; // Dominance frontier.
GrowableArray<BasicBlockId>* predecessors;
GrowableArray<SuccessorBlockInfo*>* successor_blocks;
void AppendMIR(MIR* mir);
void AppendMIRList(MIR* first_list_mir, MIR* last_list_mir);
void AppendMIRList(const std::vector<MIR*>& insns);
void PrependMIR(MIR* mir);
void PrependMIRList(MIR* first_list_mir, MIR* last_list_mir);
void PrependMIRList(const std::vector<MIR*>& to_add);
void InsertMIRAfter(MIR* current_mir, MIR* new_mir);
void InsertMIRListAfter(MIR* insert_after, MIR* first_list_mir, MIR* last_list_mir);
MIR* FindPreviousMIR(MIR* mir);
void InsertMIRBefore(MIR* insert_before, MIR* list);
void InsertMIRListBefore(MIR* insert_before, MIR* first_list_mir, MIR* last_list_mir);
bool RemoveMIR(MIR* mir);
bool RemoveMIRList(MIR* first_list_mir, MIR* last_list_mir);
BasicBlock* Copy(CompilationUnit* c_unit);
BasicBlock* Copy(MIRGraph* mir_graph);
* @brief Reset the optimization_flags field of each MIR.
void ResetOptimizationFlags(uint16_t reset_flags);
* @brief Hide the BasicBlock.
* @details Set it to kDalvikByteCode, set hidden to true, remove all MIRs,
* remove itself from any predecessor edges, remove itself from any
* child's predecessor growable array.
void Hide(CompilationUnit* c_unit);
* @brief Is ssa_reg the last SSA definition of that VR in the block?
bool IsSSALiveOut(const CompilationUnit* c_unit, int ssa_reg);
* @brief Replace the edge going to old_bb to now go towards new_bb.
bool ReplaceChild(BasicBlockId old_bb, BasicBlockId new_bb);
* @brief Update the predecessor growable array from old_pred to new_pred.
void UpdatePredecessor(BasicBlockId old_pred, BasicBlockId new_pred);
* @brief Used to obtain the next MIR that follows unconditionally.
* @details The implementation does not guarantee that a MIR does not
* follow even if this method returns nullptr.
* @param mir_graph the MIRGraph.
* @param current The MIR for which to find an unconditional follower.
* @return Returns the following MIR if one can be found.
MIR* GetNextUnconditionalMir(MIRGraph* mir_graph, MIR* current);
bool IsExceptionBlock() const;
static void* operator new(size_t size, ArenaAllocator* arena) {
return arena->Alloc(sizeof(BasicBlock), kArenaAllocBB);
static void operator delete(void* p) {} // Nop.
* The "blocks" field in "successor_block_list" points to an array of elements with the type
* "SuccessorBlockInfo". For catch blocks, key is type index for the exception. For switch
* blocks, key is the case value.
struct SuccessorBlockInfo {
BasicBlockId block;
int key;
* @class ChildBlockIterator
* @brief Enable an easy iteration of the children.
class ChildBlockIterator {
* @brief Constructs a child iterator.
* @param bb The basic whose children we need to iterate through.
* @param mir_graph The MIRGraph used to get the basic block during iteration.
ChildBlockIterator(BasicBlock* bb, MIRGraph* mir_graph);
BasicBlock* Next();
BasicBlock* basic_block_;
MIRGraph* mir_graph_;
bool visited_fallthrough_;
bool visited_taken_;
bool have_successors_;
GrowableArray<SuccessorBlockInfo*>::Iterator successor_iter_;
* Collection of information describing an invoke, and the destination of
* the subsequent MOVE_RESULT (if applicable). Collected as a unit to enable
* more efficient invoke code generation.
struct CallInfo {
int num_arg_words; // Note: word count, not arg count.
RegLocation* args; // One for each word of arguments.
RegLocation result; // Eventual target of MOVE_RESULT.
int opt_flags;
InvokeType type;
uint32_t dex_idx;
uint32_t index; // Method idx for invokes, type idx for FilledNewArray.
uintptr_t direct_code;
uintptr_t direct_method;
RegLocation target; // Target of following move_result.
bool skip_this;
bool is_range;
DexOffset offset; // Offset in code units.
MIR* mir;
const RegLocation bad_loc = {kLocDalvikFrame, 0, 0, 0, 0, 0, 0, 0, 0, RegStorage(), INVALID_SREG,
class MIRGraph {
MIRGraph(CompilationUnit* cu, ArenaAllocator* arena);
* Examine the graph to determine whether it's worthwile to spend the time compiling
* this method.
bool SkipCompilation(std::string* skip_message);
* Should we skip the compilation of this method based on its name?
bool SkipCompilationByName(const std::string& methodname);
* Parse dex method and add MIR at current insert point. Returns id (which is
* actually the index of the method in the m_units_ array).
void InlineMethod(const DexFile::CodeItem* code_item, uint32_t access_flags,
InvokeType invoke_type, uint16_t class_def_idx,
uint32_t method_idx, jobject class_loader, const DexFile& dex_file);
/* Find existing block */
BasicBlock* FindBlock(DexOffset code_offset) {
return FindBlock(code_offset, false, false, NULL);
const uint16_t* GetCurrentInsns() const {
return current_code_item_->insns_;
const uint16_t* GetInsns(int m_unit_index) const {
return m_units_[m_unit_index]->GetCodeItem()->insns_;
unsigned int GetNumBlocks() const {
return num_blocks_;
size_t GetNumDalvikInsns() const {
return cu_->code_item->insns_size_in_code_units_;
ArenaBitVector* GetTryBlockAddr() const {
return try_block_addr_;
BasicBlock* GetEntryBlock() const {
return entry_block_;
BasicBlock* GetExitBlock() const {
return exit_block_;
BasicBlock* GetBasicBlock(unsigned int block_id) const {
return (block_id == NullBasicBlockId) ? NULL : block_list_.Get(block_id);
size_t GetBasicBlockListCount() const {
return block_list_.Size();
GrowableArray<BasicBlock*>* GetBlockList() {
return &block_list_;
GrowableArray<BasicBlockId>* GetDfsOrder() {
return dfs_order_;
GrowableArray<BasicBlockId>* GetDfsPostOrder() {
return dfs_post_order_;
GrowableArray<BasicBlockId>* GetDomPostOrder() {
return dom_post_order_traversal_;
int GetDefCount() const {
return def_count_;
ArenaAllocator* GetArena() {
return arena_;
void EnableOpcodeCounting() {
opcode_count_ = static_cast<int*>(arena_->Alloc(kNumPackedOpcodes * sizeof(int),
void ShowOpcodeStats();
DexCompilationUnit* GetCurrentDexCompilationUnit() const {
return m_units_[current_method_];
* @brief Dump a CFG into a dot file format.
* @param dir_prefix the directory the file will be created in.
* @param all_blocks does the dumper use all the basic blocks or use the reachable blocks.
* @param suffix does the filename require a suffix or not (default = nullptr).
void DumpCFG(const char* dir_prefix, bool all_blocks, const char* suffix = nullptr);
bool HasFieldAccess() const {
return (merged_df_flags_ & (DF_IFIELD | DF_SFIELD)) != 0u;
bool HasStaticFieldAccess() const {
return (merged_df_flags_ & DF_SFIELD) != 0u;
bool HasInvokes() const {
// NOTE: These formats include the rare filled-new-array/range.
return (merged_df_flags_ & (DF_FORMAT_35C | DF_FORMAT_3RC)) != 0u;
void DoCacheFieldLoweringInfo();
const MirIFieldLoweringInfo& GetIFieldLoweringInfo(MIR* mir) const {
DCHECK_LT(mir->meta.ifield_lowering_info, ifield_lowering_infos_.Size());
return ifield_lowering_infos_.GetRawStorage()[mir->meta.ifield_lowering_info];
const MirSFieldLoweringInfo& GetSFieldLoweringInfo(MIR* mir) const {
DCHECK_LT(mir->meta.sfield_lowering_info, sfield_lowering_infos_.Size());
return sfield_lowering_infos_.GetRawStorage()[mir->meta.sfield_lowering_info];
void DoCacheMethodLoweringInfo();
const MirMethodLoweringInfo& GetMethodLoweringInfo(MIR* mir) {
DCHECK_LT(mir->meta.method_lowering_info, method_lowering_infos_.Size());
return method_lowering_infos_.GetRawStorage()[mir->meta.method_lowering_info];
void ComputeInlineIFieldLoweringInfo(uint16_t field_idx, MIR* invoke, MIR* iget_or_iput);
void InitRegLocations();
void RemapRegLocations();
void DumpRegLocTable(RegLocation* table, int count);
void BasicBlockOptimization();
GrowableArray<BasicBlockId>* GetTopologicalSortOrder() {
DCHECK(topological_order_ != nullptr);
return topological_order_;
bool IsConst(int32_t s_reg) const {
return is_constant_v_->IsBitSet(s_reg);
bool IsConst(RegLocation loc) const {
return loc.orig_sreg < 0 ? false : IsConst(loc.orig_sreg);
int32_t ConstantValue(RegLocation loc) const {
return constant_values_[loc.orig_sreg];
int32_t ConstantValue(int32_t s_reg) const {
return constant_values_[s_reg];
int64_t ConstantValueWide(RegLocation loc) const {
return (static_cast<int64_t>(constant_values_[loc.orig_sreg + 1]) << 32) |
bool IsConstantNullRef(RegLocation loc) const {
return loc.ref && loc.is_const && (ConstantValue(loc) == 0);
int GetNumSSARegs() const {
return num_ssa_regs_;
void SetNumSSARegs(int new_num) {
* TODO: It's theoretically possible to exceed 32767, though any cases which did
* would be filtered out with current settings. When orig_sreg field is removed
* from RegLocation, expand s_reg_low to handle all possible cases and remove DCHECK().
DCHECK_EQ(new_num, static_cast<int16_t>(new_num));
num_ssa_regs_ = new_num;
unsigned int GetNumReachableBlocks() const {
return num_reachable_blocks_;
int GetUseCount(int vreg) const {
return use_counts_.Get(vreg);
int GetRawUseCount(int vreg) const {
return raw_use_counts_.Get(vreg);
int GetSSASubscript(int ssa_reg) const {
return ssa_subscripts_->Get(ssa_reg);
RegLocation GetRawSrc(MIR* mir, int num) {
DCHECK(num < mir->ssa_rep->num_uses);
RegLocation res = reg_location_[mir->ssa_rep->uses[num]];
return res;
RegLocation GetRawDest(MIR* mir) {
DCHECK_GT(mir->ssa_rep->num_defs, 0);
RegLocation res = reg_location_[mir->ssa_rep->defs[0]];
return res;
RegLocation GetDest(MIR* mir) {
RegLocation res = GetRawDest(mir);
return res;
RegLocation GetSrc(MIR* mir, int num) {
RegLocation res = GetRawSrc(mir, num);
return res;
RegLocation GetDestWide(MIR* mir) {
RegLocation res = GetRawDest(mir);
return res;
RegLocation GetSrcWide(MIR* mir, int low) {
RegLocation res = GetRawSrc(mir, low);
return res;
RegLocation GetBadLoc() {
return bad_loc;
int GetMethodSReg() const {
return method_sreg_;
* @brief Used to obtain the number of compiler temporaries being used.
* @return Returns the number of compiler temporaries.
size_t GetNumUsedCompilerTemps() const {
size_t total_num_temps = compiler_temps_.Size();
DCHECK_LE(num_non_special_compiler_temps_, total_num_temps);
return total_num_temps;
* @brief Used to obtain the number of non-special compiler temporaries being used.
* @return Returns the number of non-special compiler temporaries.
size_t GetNumNonSpecialCompilerTemps() const {
return num_non_special_compiler_temps_;
* @brief Used to set the total number of available non-special compiler temporaries.
* @details Can fail setting the new max if there are more temps being used than the new_max.
* @param new_max The new maximum number of non-special compiler temporaries.
* @return Returns true if the max was set and false if failed to set.
bool SetMaxAvailableNonSpecialCompilerTemps(size_t new_max) {
if (new_max < GetNumNonSpecialCompilerTemps()) {
return false;
} else {
max_available_non_special_compiler_temps_ = new_max;
return true;
* @brief Provides the number of non-special compiler temps available.
* @details Even if this returns zero, special compiler temps are guaranteed to be available.
* @return Returns the number of available temps.
size_t GetNumAvailableNonSpecialCompilerTemps();
* @brief Used to obtain an existing compiler temporary.
* @param index The index of the temporary which must be strictly less than the
* number of temporaries.
* @return Returns the temporary that was asked for.
CompilerTemp* GetCompilerTemp(size_t index) const {
return compiler_temps_.Get(index);
* @brief Used to obtain the maximum number of compiler temporaries that can be requested.
* @return Returns the maximum number of compiler temporaries, whether used or not.
size_t GetMaxPossibleCompilerTemps() const {
return max_available_special_compiler_temps_ + max_available_non_special_compiler_temps_;
* @brief Used to obtain a new unique compiler temporary.
* @param ct_type Type of compiler temporary requested.
* @param wide Whether we should allocate a wide temporary.
* @return Returns the newly created compiler temporary.
CompilerTemp* GetNewCompilerTemp(CompilerTempType ct_type, bool wide);
bool MethodIsLeaf() {
return attributes_ & METHOD_IS_LEAF;
RegLocation GetRegLocation(int index) {
DCHECK((index >= 0) && (index < num_ssa_regs_));
return reg_location_[index];
RegLocation GetMethodLoc() {
return reg_location_[method_sreg_];
bool IsBackedge(BasicBlock* branch_bb, BasicBlockId target_bb_id) {
return ((target_bb_id != NullBasicBlockId) &&
(GetBasicBlock(target_bb_id)->start_offset <= branch_bb->start_offset));
bool IsBackwardsBranch(BasicBlock* branch_bb) {
return IsBackedge(branch_bb, branch_bb->taken) || IsBackedge(branch_bb, branch_bb->fall_through);
void CountBranch(DexOffset target_offset) {
if (target_offset <= current_offset_) {
} else {
int GetBranchCount() {
return backward_branches_ + forward_branches_;
// Is this vreg in the in set?
bool IsInVReg(int vreg) {
return (vreg >= cu_->num_regs);
void DumpCheckStats();
MIR* FindMoveResult(BasicBlock* bb, MIR* mir);
int SRegToVReg(int ssa_reg) const;
void VerifyDataflow();
void CheckForDominanceFrontier(BasicBlock* dom_bb, const BasicBlock* succ_bb);
void EliminateNullChecksAndInferTypesStart();
bool EliminateNullChecksAndInferTypes(BasicBlock* bb);
void EliminateNullChecksAndInferTypesEnd();
bool EliminateClassInitChecksGate();
bool EliminateClassInitChecks(BasicBlock* bb);
void EliminateClassInitChecksEnd();
bool ApplyGlobalValueNumberingGate();
bool ApplyGlobalValueNumbering(BasicBlock* bb);
void ApplyGlobalValueNumberingEnd();
* Type inference handling helpers. Because Dalvik's bytecode is not fully typed,
* we have to do some work to figure out the sreg type. For some operations it is
* clear based on the opcode (i.e. ADD_FLOAT v0, v1, v2), but for others (MOVE), we
* may never know the "real" type.
* We perform the type inference operation by using an iterative walk over
* the graph, propagating types "defined" by typed opcodes to uses and defs in
* non-typed opcodes (such as MOVE). The Setxx(index) helpers are used to set defined
* types on typed opcodes (such as ADD_INT). The Setxx(index, is_xx) form is used to
* propagate types through non-typed opcodes such as PHI and MOVE. The is_xx flag
* tells whether our guess of the type is based on a previously typed definition.
* If so, the defined type takes precedence. Note that it's possible to have the same sreg
* show multiple defined types because dx treats constants as untyped bit patterns.
* The return value of the Setxx() helpers says whether or not the Setxx() action changed
* the current guess, and is used to know when to terminate the iterative walk.
bool SetFp(int index, bool is_fp);
bool SetFp(int index);
bool SetCore(int index, bool is_core);
bool SetCore(int index);
bool SetRef(int index, bool is_ref);
bool SetRef(int index);
bool SetWide(int index, bool is_wide);
bool SetWide(int index);
bool SetHigh(int index, bool is_high);
bool SetHigh(int index);
bool PuntToInterpreter() {
return punt_to_interpreter_;
void SetPuntToInterpreter(bool val) {
punt_to_interpreter_ = val;
char* GetDalvikDisassembly(const MIR* mir);
void ReplaceSpecialChars(std::string& str);
std::string GetSSAName(int ssa_reg);
std::string GetSSANameWithConst(int ssa_reg, bool singles_only);
void GetBlockName(BasicBlock* bb, char* name);
const char* GetShortyFromTargetIdx(int);
void DumpMIRGraph();
CallInfo* NewMemCallInfo(BasicBlock* bb, MIR* mir, InvokeType type, bool is_range);
BasicBlock* NewMemBB(BBType block_type, int block_id);
MIR* NewMIR();
MIR* AdvanceMIR(BasicBlock** p_bb, MIR* mir);
BasicBlock* NextDominatedBlock(BasicBlock* bb);
bool LayoutBlocks(BasicBlock* bb);
void ComputeTopologicalSortOrder();
BasicBlock* CreateNewBB(BBType block_type);
bool InlineSpecialMethodsGate();
void InlineSpecialMethodsStart();
void InlineSpecialMethods(BasicBlock* bb);
void InlineSpecialMethodsEnd();
* @brief Perform the initial preparation for the Method Uses.
void InitializeMethodUses();
* @brief Perform the initial preparation for the Constant Propagation.
void InitializeConstantPropagation();
* @brief Perform the initial preparation for the SSA Transformation.
void SSATransformationStart();
* @brief Insert a the operands for the Phi nodes.
* @param bb the considered BasicBlock.
* @return true
bool InsertPhiNodeOperands(BasicBlock* bb);
* @brief Perform the cleanup after the SSA Transformation.
void SSATransformationEnd();
* @brief Perform constant propagation on a BasicBlock.
* @param bb the considered BasicBlock.
void DoConstantPropagation(BasicBlock* bb);
* @brief Count the uses in the BasicBlock
* @param bb the BasicBlock
void CountUses(struct BasicBlock* bb);
static uint64_t GetDataFlowAttributes(Instruction::Code opcode);
static uint64_t GetDataFlowAttributes(MIR* mir);
* @brief Combine BasicBlocks
* @param the BasicBlock we are considering
void CombineBlocks(BasicBlock* bb);
void ClearAllVisitedFlags();
void AllocateSSAUseData(MIR *mir, int num_uses);
void AllocateSSADefData(MIR *mir, int num_defs);
void CalculateBasicBlockInformation();
void InitializeBasicBlockData();
void ComputeDFSOrders();
void ComputeDefBlockMatrix();
void ComputeDominators();
void CompilerInitializeSSAConversion();
void InsertPhiNodes();
void DoDFSPreOrderSSARename(BasicBlock* block);
* IsDebugBuild sanity check: keep track of the Dex PCs for catch entries so that later on
* we can verify that all catch entries have native PC entries.
std::set<uint32_t> catches_;
// TODO: make these private.
RegLocation* reg_location_; // Map SSA names to location.
SafeMap<unsigned int, unsigned int> block_id_map_; // Block collapse lookup cache.
static const char* extended_mir_op_names_[kMirOpLast - kMirOpFirst];
static const uint32_t analysis_attributes_[kMirOpLast];
void HandleSSADef(int* defs, int dalvik_reg, int reg_index);
bool InferTypeAndSize(BasicBlock* bb, MIR* mir, bool changed);
// Used for removing redudant suspend tests
void AppendGenSuspendTestList(BasicBlock* bb) {
if (gen_suspend_test_list_.Size() == 0 ||
gen_suspend_test_list_.Get(gen_suspend_test_list_.Size() - 1) != bb) {
/* This is used to check if there is already a method call dominating the
* source basic block of a backedge and being dominated by the target basic
* block of the backedge.
bool HasSuspendTestBetween(BasicBlock* source, BasicBlockId target_id);
int FindCommonParent(int block1, int block2);
void ComputeSuccLineIn(ArenaBitVector* dest, const ArenaBitVector* src1,
const ArenaBitVector* src2);
void HandleLiveInUse(ArenaBitVector* use_v, ArenaBitVector* def_v,
ArenaBitVector* live_in_v, int dalvik_reg_id);
void HandleDef(ArenaBitVector* def_v, int dalvik_reg_id);
void HandleExtended(ArenaBitVector* use_v, ArenaBitVector* def_v,
ArenaBitVector* live_in_v,
const MIR::DecodedInstruction& d_insn);
bool DoSSAConversion(BasicBlock* bb);
bool InvokeUsesMethodStar(MIR* mir);
int ParseInsn(const uint16_t* code_ptr, MIR::DecodedInstruction* decoded_instruction);
bool ContentIsInsn(const uint16_t* code_ptr);
BasicBlock* SplitBlock(DexOffset code_offset, BasicBlock* orig_block,
BasicBlock** immed_pred_block_p);
BasicBlock* FindBlock(DexOffset code_offset, bool split, bool create,
BasicBlock** immed_pred_block_p);
void ProcessTryCatchBlocks();
bool IsBadMonitorExitCatch(NarrowDexOffset monitor_exit_offset, NarrowDexOffset catch_offset);
BasicBlock* ProcessCanBranch(BasicBlock* cur_block, MIR* insn, DexOffset cur_offset, int width,
int flags, const uint16_t* code_ptr, const uint16_t* code_end);
BasicBlock* ProcessCanSwitch(BasicBlock* cur_block, MIR* insn, DexOffset cur_offset, int width,
int flags);
BasicBlock* ProcessCanThrow(BasicBlock* cur_block, MIR* insn, DexOffset cur_offset, int width,
int flags, ArenaBitVector* try_block_addr, const uint16_t* code_ptr,
const uint16_t* code_end);
int AddNewSReg(int v_reg);
void HandleSSAUse(int* uses, int dalvik_reg, int reg_index);
void DataFlowSSAFormat35C(MIR* mir);
void DataFlowSSAFormat3RC(MIR* mir);
void DataFlowSSAFormatExtended(MIR* mir);
bool FindLocalLiveIn(BasicBlock* bb);
bool VerifyPredInfo(BasicBlock* bb);
BasicBlock* NeedsVisit(BasicBlock* bb);
BasicBlock* NextUnvisitedSuccessor(BasicBlock* bb);
void MarkPreOrder(BasicBlock* bb);
void RecordDFSOrders(BasicBlock* bb);
void ComputeDomPostOrderTraversal(BasicBlock* bb);
void SetConstant(int32_t ssa_reg, int value);
void SetConstantWide(int ssa_reg, int64_t value);
int GetSSAUseCount(int s_reg);
bool BasicBlockOpt(BasicBlock* bb);
bool BuildExtendedBBList(struct BasicBlock* bb);
bool FillDefBlockMatrix(BasicBlock* bb);
void InitializeDominationInfo(BasicBlock* bb);
bool ComputeblockIDom(BasicBlock* bb);
bool ComputeBlockDominators(BasicBlock* bb);
bool SetDominators(BasicBlock* bb);
bool ComputeBlockLiveIns(BasicBlock* bb);
bool ComputeDominanceFrontier(BasicBlock* bb);
void CountChecks(BasicBlock* bb);
void AnalyzeBlock(BasicBlock* bb, struct MethodStats* stats);
bool ComputeSkipCompilation(struct MethodStats* stats, bool skip_default,
std::string* skip_message);
CompilationUnit* const cu_;
GrowableArray<int>* ssa_base_vregs_;
GrowableArray<int>* ssa_subscripts_;
// Map original Dalvik virtual reg i to the current SSA name.
int* vreg_to_ssa_map_; // length == method->registers_size
int* ssa_last_defs_; // length == method->registers_size
ArenaBitVector* is_constant_v_; // length == num_ssa_reg
int* constant_values_; // length == num_ssa_reg
// Use counts of ssa names.
GrowableArray<uint32_t> use_counts_; // Weighted by nesting depth
GrowableArray<uint32_t> raw_use_counts_; // Not weighted
unsigned int num_reachable_blocks_;
unsigned int max_num_reachable_blocks_;
GrowableArray<BasicBlockId>* dfs_order_;
GrowableArray<BasicBlockId>* dfs_post_order_;
GrowableArray<BasicBlockId>* dom_post_order_traversal_;
GrowableArray<BasicBlockId>* topological_order_;
int* i_dom_list_;
ArenaBitVector** def_block_matrix_; // num_dalvik_register x num_blocks.
std::unique_ptr<ScopedArenaAllocator> temp_scoped_alloc_;
uint16_t* temp_insn_data_;
uint32_t temp_bit_vector_size_;
ArenaBitVector* temp_bit_vector_;
std::unique_ptr<GlobalValueNumbering> temp_gvn_;
static const int kInvalidEntry = -1;
GrowableArray<BasicBlock*> block_list_;
ArenaBitVector* try_block_addr_;
BasicBlock* entry_block_;
BasicBlock* exit_block_;
unsigned int num_blocks_;
const DexFile::CodeItem* current_code_item_;
GrowableArray<uint16_t> dex_pc_to_block_map_; // FindBlock lookup cache.
std::vector<DexCompilationUnit*> m_units_; // List of methods included in this graph
typedef std::pair<int, int> MIRLocation; // Insert point, (m_unit_ index, offset)
std::vector<MIRLocation> method_stack_; // Include stack
int current_method_;
DexOffset current_offset_; // Offset in code units
int def_count_; // Used to estimate size of ssa name storage.
int* opcode_count_; // Dex opcode coverage stats.
int num_ssa_regs_; // Number of names following SSA transformation.
std::vector<BasicBlockId> extended_basic_blocks_; // Heads of block "traces".
int method_sreg_;
unsigned int attributes_;
Checkstats* checkstats_;
ArenaAllocator* arena_;
int backward_branches_;
int forward_branches_;
GrowableArray<CompilerTemp*> compiler_temps_;
size_t num_non_special_compiler_temps_;
size_t max_available_non_special_compiler_temps_;
size_t max_available_special_compiler_temps_;
bool punt_to_interpreter_; // Difficult or not worthwhile - just interpret.
uint64_t merged_df_flags_;
GrowableArray<MirIFieldLoweringInfo> ifield_lowering_infos_;
GrowableArray<MirSFieldLoweringInfo> sfield_lowering_infos_;
GrowableArray<MirMethodLoweringInfo> method_lowering_infos_;
static const uint64_t oat_data_flow_attributes_[kMirOpLast];
GrowableArray<BasicBlock*> gen_suspend_test_list_; // List of blocks containing suspend tests
friend class ClassInitCheckEliminationTest;
friend class GlobalValueNumberingTest;
friend class LocalValueNumberingTest;
} // namespace art