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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
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "mir_graph.h"
#include <inttypes.h>
#include <queue>
#include <unistd.h>
#include "base/bit_vector-inl.h"
#include "base/logging.h"
#include "base/stl_util.h"
#include "base/stringprintf.h"
#include "base/scoped_arena_containers.h"
#include "compiler_ir.h"
#include "dex_file-inl.h"
#include "dex_flags.h"
#include "dex_instruction-inl.h"
#include "driver/compiler_driver.h"
#include "driver/dex_compilation_unit.h"
#include "dex/quick/quick_compiler.h"
#include "leb128.h"
#include "pass_driver_me_post_opt.h"
#include "stack.h"
#include "utils.h"
namespace art {
#define MAX_PATTERN_LEN 5
const char* MIRGraph::extended_mir_op_names_[kMirOpLast - kMirOpFirst] = {
"Phi",
"Copy",
"FusedCmplFloat",
"FusedCmpgFloat",
"FusedCmplDouble",
"FusedCmpgDouble",
"FusedCmpLong",
"Nop",
"OpNullCheck",
"OpRangeCheck",
"OpDivZeroCheck",
"Check",
"Select",
"ConstVector",
"MoveVector",
"PackedMultiply",
"PackedAddition",
"PackedSubtract",
"PackedShiftLeft",
"PackedSignedShiftRight",
"PackedUnsignedShiftRight",
"PackedAnd",
"PackedOr",
"PackedXor",
"PackedAddReduce",
"PackedReduce",
"PackedSet",
"ReserveVectorRegisters",
"ReturnVectorRegisters",
"MemBarrier",
"PackedArrayGet",
"PackedArrayPut",
"MaddInt",
"MsubInt",
"MaddLong",
"MsubLong",
};
MIRGraph::MIRGraph(CompilationUnit* cu, ArenaAllocator* arena)
: reg_location_(nullptr),
block_id_map_(std::less<unsigned int>(), arena->Adapter()),
cu_(cu),
ssa_base_vregs_(arena->Adapter(kArenaAllocSSAToDalvikMap)),
ssa_subscripts_(arena->Adapter(kArenaAllocSSAToDalvikMap)),
vreg_to_ssa_map_(nullptr),
ssa_last_defs_(nullptr),
is_constant_v_(nullptr),
constant_values_(nullptr),
use_counts_(arena->Adapter()),
raw_use_counts_(arena->Adapter()),
num_reachable_blocks_(0),
max_num_reachable_blocks_(0),
dfs_orders_up_to_date_(false),
domination_up_to_date_(false),
mir_ssa_rep_up_to_date_(false),
topological_order_up_to_date_(false),
dfs_order_(arena->Adapter(kArenaAllocDfsPreOrder)),
dfs_post_order_(arena->Adapter(kArenaAllocDfsPostOrder)),
dom_post_order_traversal_(arena->Adapter(kArenaAllocDomPostOrder)),
topological_order_(arena->Adapter(kArenaAllocTopologicalSortOrder)),
topological_order_loop_ends_(arena->Adapter(kArenaAllocTopologicalSortOrder)),
topological_order_indexes_(arena->Adapter(kArenaAllocTopologicalSortOrder)),
topological_order_loop_head_stack_(arena->Adapter(kArenaAllocTopologicalSortOrder)),
max_nested_loops_(0u),
i_dom_list_(nullptr),
temp_scoped_alloc_(),
block_list_(arena->Adapter(kArenaAllocBBList)),
try_block_addr_(nullptr),
entry_block_(nullptr),
exit_block_(nullptr),
current_code_item_(nullptr),
m_units_(arena->Adapter()),
method_stack_(arena->Adapter()),
current_method_(kInvalidEntry),
current_offset_(kInvalidEntry),
def_count_(0),
opcode_count_(nullptr),
num_ssa_regs_(0),
extended_basic_blocks_(arena->Adapter()),
method_sreg_(0),
attributes_(METHOD_IS_LEAF), // Start with leaf assumption, change on encountering invoke.
checkstats_(nullptr),
arena_(arena),
backward_branches_(0),
forward_branches_(0),
num_non_special_compiler_temps_(0),
max_available_special_compiler_temps_(1), // We only need the method ptr as a special temp for now.
requested_backend_temp_(false),
compiler_temps_committed_(false),
punt_to_interpreter_(false),
merged_df_flags_(0u),
ifield_lowering_infos_(arena->Adapter(kArenaAllocLoweringInfo)),
sfield_lowering_infos_(arena->Adapter(kArenaAllocLoweringInfo)),
method_lowering_infos_(arena->Adapter(kArenaAllocLoweringInfo)),
suspend_checks_in_loops_(nullptr) {
memset(&temp_, 0, sizeof(temp_));
use_counts_.reserve(256);
raw_use_counts_.reserve(256);
block_list_.reserve(100);
try_block_addr_ = new (arena_) ArenaBitVector(arena_, 0, true /* expandable */);
if (cu_->instruction_set == kX86 || cu_->instruction_set == kX86_64) {
// X86 requires a temp to keep track of the method address.
// TODO For x86_64, addressing can be done with RIP. When that is implemented,
// this needs to be updated to reserve 0 temps for BE.
max_available_non_special_compiler_temps_ = cu_->target64 ? 2 : 1;
reserved_temps_for_backend_ = max_available_non_special_compiler_temps_;
} else {
// Other architectures do not have a known lower bound for non-special temps.
// We allow the update of the max to happen at BE initialization stage and simply set 0 for now.
max_available_non_special_compiler_temps_ = 0;
reserved_temps_for_backend_ = 0;
}
}
MIRGraph::~MIRGraph() {
STLDeleteElements(&block_list_);
STLDeleteElements(&m_units_);
}
/*
* Parse an instruction, return the length of the instruction
*/
int MIRGraph::ParseInsn(const uint16_t* code_ptr, MIR::DecodedInstruction* decoded_instruction) {
const Instruction* inst = Instruction::At(code_ptr);
decoded_instruction->opcode = inst->Opcode();
decoded_instruction->vA = inst->HasVRegA() ? inst->VRegA() : 0;
decoded_instruction->vB = inst->HasVRegB() ? inst->VRegB() : 0;
decoded_instruction->vB_wide = inst->HasWideVRegB() ? inst->WideVRegB() : 0;
decoded_instruction->vC = inst->HasVRegC() ? inst->VRegC() : 0;
if (inst->HasVarArgs35c()) {
inst->GetVarArgs(decoded_instruction->arg);
}
return inst->SizeInCodeUnits();
}
/* Split an existing block from the specified code offset into two */
BasicBlock* MIRGraph::SplitBlock(DexOffset code_offset,
BasicBlock* orig_block, BasicBlock** immed_pred_block_p) {
DCHECK_GT(code_offset, orig_block->start_offset);
MIR* insn = orig_block->first_mir_insn;
MIR* prev = nullptr; // Will be set to instruction before split.
while (insn) {
if (insn->offset == code_offset) break;
prev = insn;
insn = insn->next;
}
if (insn == nullptr) {
LOG(FATAL) << "Break split failed";
}
// Now insn is at the instruction where we want to split, namely
// insn will be the first instruction of the "bottom" block.
// Similarly, prev will be the last instruction of the "top" block
BasicBlock* bottom_block = CreateNewBB(kDalvikByteCode);
bottom_block->start_offset = code_offset;
bottom_block->first_mir_insn = insn;
bottom_block->last_mir_insn = orig_block->last_mir_insn;
/* If this block was terminated by a return, conditional branch or throw,
* the flag needs to go with the bottom block
*/
bottom_block->terminated_by_return = orig_block->terminated_by_return;
orig_block->terminated_by_return = false;
bottom_block->conditional_branch = orig_block->conditional_branch;
orig_block->conditional_branch = false;
bottom_block->explicit_throw = orig_block->explicit_throw;
orig_block->explicit_throw = false;
/* Handle the taken path */
bottom_block->taken = orig_block->taken;
if (bottom_block->taken != NullBasicBlockId) {
orig_block->taken = NullBasicBlockId;
BasicBlock* bb_taken = GetBasicBlock(bottom_block->taken);
bb_taken->ErasePredecessor(orig_block->id);
bb_taken->predecessors.push_back(bottom_block->id);
}
/* Handle the fallthrough path */
bottom_block->fall_through = orig_block->fall_through;
orig_block->fall_through = bottom_block->id;
bottom_block->predecessors.push_back(orig_block->id);
if (bottom_block->fall_through != NullBasicBlockId) {
BasicBlock* bb_fall_through = GetBasicBlock(bottom_block->fall_through);
bb_fall_through->ErasePredecessor(orig_block->id);
bb_fall_through->predecessors.push_back(bottom_block->id);
}
/* Handle the successor list */
if (orig_block->successor_block_list_type != kNotUsed) {
bottom_block->successor_block_list_type = orig_block->successor_block_list_type;
bottom_block->successor_blocks.swap(orig_block->successor_blocks);
orig_block->successor_block_list_type = kNotUsed;
DCHECK(orig_block->successor_blocks.empty()); // Empty after the swap() above.
for (SuccessorBlockInfo* successor_block_info : bottom_block->successor_blocks) {
BasicBlock* bb = GetBasicBlock(successor_block_info->block);
if (bb != nullptr) {
bb->ErasePredecessor(orig_block->id);
bb->predecessors.push_back(bottom_block->id);
}
}
}
orig_block->last_mir_insn = prev;
prev->next = nullptr;
/*
* Update the immediate predecessor block pointer so that outgoing edges
* can be applied to the proper block.
*/
if (immed_pred_block_p) {
DCHECK_EQ(*immed_pred_block_p, orig_block);
*immed_pred_block_p = bottom_block;
}
// Associate dex instructions in the bottom block with the new container.
DCHECK(insn != nullptr);
DCHECK(insn != orig_block->first_mir_insn);
DCHECK(insn == bottom_block->first_mir_insn);
DCHECK_EQ(insn->offset, bottom_block->start_offset);
// Scan the "bottom" instructions, remapping them to the
// newly created "bottom" block.
MIR* p = insn;
p->bb = bottom_block->id;
while (p != bottom_block->last_mir_insn) {
p = p->next;
DCHECK(p != nullptr);
p->bb = bottom_block->id;
}
return bottom_block;
}
/*
* Given a code offset, find out the block that starts with it. If the offset
* is in the middle of an existing block, split it into two. If immed_pred_block_p
* is not non-null and is the block being split, update *immed_pred_block_p to
* point to the bottom block so that outgoing edges can be set up properly
* (by the caller)
* Utilizes a map for fast lookup of the typical cases.
*/
BasicBlock* MIRGraph::FindBlock(DexOffset code_offset, bool create,
BasicBlock** immed_pred_block_p,
ScopedArenaVector<uint16_t>* dex_pc_to_block_map) {
if (UNLIKELY(code_offset >= current_code_item_->insns_size_in_code_units_)) {
// There can be a fall-through out of the method code. We shall record such a block
// here (assuming create==true) and check that it's dead at the end of InlineMethod().
// Though we're only aware of the cases where code_offset is exactly the same as
// insns_size_in_code_units_, treat greater code_offset the same just in case.
code_offset = current_code_item_->insns_size_in_code_units_;
}
int block_id = (*dex_pc_to_block_map)[code_offset];
BasicBlock* bb = GetBasicBlock(block_id);
if ((bb != nullptr) && (bb->start_offset == code_offset)) {
// Does this containing block start with the desired instruction?
return bb;
}
// No direct hit.
if (!create) {
return nullptr;
}
if (bb != nullptr) {
// The target exists somewhere in an existing block.
BasicBlock* bottom_block = SplitBlock(code_offset, bb, bb == *immed_pred_block_p ? immed_pred_block_p : nullptr);
DCHECK(bottom_block != nullptr);
MIR* p = bottom_block->first_mir_insn;
BasicBlock* orig_block = bb;
DCHECK_EQ((*dex_pc_to_block_map)[p->offset], orig_block->id);
// Scan the "bottom" instructions, remapping them to the
// newly created "bottom" block.
(*dex_pc_to_block_map)[p->offset] = bottom_block->id;
while (p != bottom_block->last_mir_insn) {
p = p->next;
DCHECK(p != nullptr);
int opcode = p->dalvikInsn.opcode;
/*
* Some messiness here to ensure that we only enter real opcodes and only the
* first half of a potentially throwing instruction that has been split into
* CHECK and work portions. Since the 2nd half of a split operation is always
* the first in a BasicBlock, we can't hit it here.
*/
if ((opcode == kMirOpCheck) || !MIR::DecodedInstruction::IsPseudoMirOp(opcode)) {
BasicBlockId mapped_id = (*dex_pc_to_block_map)[p->offset];
// At first glance the instructions should all be mapped to orig_block.
// However, multiple instructions may correspond to the same dex, hence an earlier
// instruction may have already moved the mapping for dex to bottom_block.
DCHECK((mapped_id == orig_block->id) || (mapped_id == bottom_block->id));
(*dex_pc_to_block_map)[p->offset] = bottom_block->id;
}
}
return bottom_block;
}
// Create a new block.
bb = CreateNewBB(kDalvikByteCode);
bb->start_offset = code_offset;
(*dex_pc_to_block_map)[bb->start_offset] = bb->id;
return bb;
}
/* Identify code range in try blocks and set up the empty catch blocks */
void MIRGraph::ProcessTryCatchBlocks(ScopedArenaVector<uint16_t>* dex_pc_to_block_map) {
int tries_size = current_code_item_->tries_size_;
DexOffset offset;
if (tries_size == 0) {
return;
}
for (int i = 0; i < tries_size; i++) {
const DexFile::TryItem* pTry =
DexFile::GetTryItems(*current_code_item_, i);
DexOffset start_offset = pTry->start_addr_;
DexOffset end_offset = start_offset + pTry->insn_count_;
for (offset = start_offset; offset < end_offset; offset++) {
try_block_addr_->SetBit(offset);
}
}
// Iterate over each of the handlers to enqueue the empty Catch blocks.
const uint8_t* handlers_ptr = DexFile::GetCatchHandlerData(*current_code_item_, 0);
uint32_t handlers_size = DecodeUnsignedLeb128(&handlers_ptr);
for (uint32_t idx = 0; idx < handlers_size; idx++) {
CatchHandlerIterator iterator(handlers_ptr);
for (; iterator.HasNext(); iterator.Next()) {
uint32_t address = iterator.GetHandlerAddress();
FindBlock(address, true /*create*/, /* immed_pred_block_p */ nullptr, dex_pc_to_block_map);
}
handlers_ptr = iterator.EndDataPointer();
}
}
bool MIRGraph::IsBadMonitorExitCatch(NarrowDexOffset monitor_exit_offset,
NarrowDexOffset catch_offset) {
// Catches for monitor-exit during stack unwinding have the pattern
// move-exception (move)* (goto)? monitor-exit throw
// In the currently generated dex bytecode we see these catching a bytecode range including
// either its own or an identical monitor-exit, http://b/15745363 . This function checks if
// it's the case for a given monitor-exit and catch block so that we can ignore it.
// (We don't want to ignore all monitor-exit catches since one could enclose a synchronized
// block in a try-block and catch the NPE, Error or Throwable and we should let it through;
// even though a throwing monitor-exit certainly indicates a bytecode error.)
const Instruction* monitor_exit = Instruction::At(current_code_item_->insns_ + monitor_exit_offset);
DCHECK(monitor_exit->Opcode() == Instruction::MONITOR_EXIT);
int monitor_reg = monitor_exit->VRegA_11x();
const Instruction* check_insn = Instruction::At(current_code_item_->insns_ + catch_offset);
if (check_insn->Opcode() == Instruction::MOVE_EXCEPTION) {
if (check_insn->VRegA_11x() == monitor_reg) {
// Unexpected move-exception to the same register. Probably not the pattern we're looking for.
return false;
}
check_insn = check_insn->Next();
}
while (true) {
int dest = -1;
bool wide = false;
switch (check_insn->Opcode()) {
case Instruction::MOVE_WIDE:
wide = true;
FALLTHROUGH_INTENDED;
case Instruction::MOVE_OBJECT:
case Instruction::MOVE:
dest = check_insn->VRegA_12x();
break;
case Instruction::MOVE_WIDE_FROM16:
wide = true;
FALLTHROUGH_INTENDED;
case Instruction::MOVE_OBJECT_FROM16:
case Instruction::MOVE_FROM16:
dest = check_insn->VRegA_22x();
break;
case Instruction::MOVE_WIDE_16:
wide = true;
FALLTHROUGH_INTENDED;
case Instruction::MOVE_OBJECT_16:
case Instruction::MOVE_16:
dest = check_insn->VRegA_32x();
break;
case Instruction::GOTO:
case Instruction::GOTO_16:
case Instruction::GOTO_32:
check_insn = check_insn->RelativeAt(check_insn->GetTargetOffset());
FALLTHROUGH_INTENDED;
default:
return check_insn->Opcode() == Instruction::MONITOR_EXIT &&
check_insn->VRegA_11x() == monitor_reg;
}
if (dest == monitor_reg || (wide && dest + 1 == monitor_reg)) {
return false;
}
check_insn = check_insn->Next();
}
}
/* Process instructions with the kBranch flag */
BasicBlock* MIRGraph::ProcessCanBranch(BasicBlock* cur_block, MIR* insn, DexOffset cur_offset,
int width, int flags, const uint16_t* code_ptr,
const uint16_t* code_end,
ScopedArenaVector<uint16_t>* dex_pc_to_block_map) {
DexOffset target = cur_offset;
switch (insn->dalvikInsn.opcode) {
case Instruction::GOTO:
case Instruction::GOTO_16:
case Instruction::GOTO_32:
target += insn->dalvikInsn.vA;
break;
case Instruction::IF_EQ:
case Instruction::IF_NE:
case Instruction::IF_LT:
case Instruction::IF_GE:
case Instruction::IF_GT:
case Instruction::IF_LE:
cur_block->conditional_branch = true;
target += insn->dalvikInsn.vC;
break;
case Instruction::IF_EQZ:
case Instruction::IF_NEZ:
case Instruction::IF_LTZ:
case Instruction::IF_GEZ:
case Instruction::IF_GTZ:
case Instruction::IF_LEZ:
cur_block->conditional_branch = true;
target += insn->dalvikInsn.vB;
break;
default:
LOG(FATAL) << "Unexpected opcode(" << insn->dalvikInsn.opcode << ") with kBranch set";
}
CountBranch(target);
BasicBlock* taken_block = FindBlock(target, /* create */ true,
/* immed_pred_block_p */ &cur_block,
dex_pc_to_block_map);
DCHECK(taken_block != nullptr);
cur_block->taken = taken_block->id;
taken_block->predecessors.push_back(cur_block->id);
/* Always terminate the current block for conditional branches */
if (flags & Instruction::kContinue) {
BasicBlock* fallthrough_block = FindBlock(cur_offset + width,
/* create */
true,
/* immed_pred_block_p */
&cur_block,
dex_pc_to_block_map);
DCHECK(fallthrough_block != nullptr);
cur_block->fall_through = fallthrough_block->id;
fallthrough_block->predecessors.push_back(cur_block->id);
} else if (code_ptr < code_end) {
FindBlock(cur_offset + width, /* create */ true, /* immed_pred_block_p */ nullptr, dex_pc_to_block_map);
}
return cur_block;
}
/* Process instructions with the kSwitch flag */
BasicBlock* MIRGraph::ProcessCanSwitch(BasicBlock* cur_block, MIR* insn, DexOffset cur_offset,
int width, int flags ATTRIBUTE_UNUSED,
ScopedArenaVector<uint16_t>* dex_pc_to_block_map) {
const uint16_t* switch_data =
reinterpret_cast<const uint16_t*>(GetCurrentInsns() + cur_offset +
static_cast<int32_t>(insn->dalvikInsn.vB));
int size;
const int* keyTable;
const int* target_table;
int i;
int first_key;
/*
* Packed switch data format:
* ushort ident = 0x0100 magic value
* ushort size number of entries in the table
* int first_key first (and lowest) switch case value
* int targets[size] branch targets, relative to switch opcode
*
* Total size is (4+size*2) 16-bit code units.
*/
if (insn->dalvikInsn.opcode == Instruction::PACKED_SWITCH) {
DCHECK_EQ(static_cast<int>(switch_data[0]),
static_cast<int>(Instruction::kPackedSwitchSignature));
size = switch_data[1];
first_key = switch_data[2] | (switch_data[3] << 16);
target_table = reinterpret_cast<const int*>(&switch_data[4]);
keyTable = nullptr; // Make the compiler happy.
/*
* Sparse switch data format:
* ushort ident = 0x0200 magic value
* ushort size number of entries in the table; > 0
* int keys[size] keys, sorted low-to-high; 32-bit aligned
* int targets[size] branch targets, relative to switch opcode
*
* Total size is (2+size*4) 16-bit code units.
*/
} else {
DCHECK_EQ(static_cast<int>(switch_data[0]),
static_cast<int>(Instruction::kSparseSwitchSignature));
size = switch_data[1];
keyTable = reinterpret_cast<const int*>(&switch_data[2]);
target_table = reinterpret_cast<const int*>(&switch_data[2 + size*2]);
first_key = 0; // To make the compiler happy.
}
if (cur_block->successor_block_list_type != kNotUsed) {
LOG(FATAL) << "Successor block list already in use: "
<< static_cast<int>(cur_block->successor_block_list_type);
}
cur_block->successor_block_list_type =
(insn->dalvikInsn.opcode == Instruction::PACKED_SWITCH) ? kPackedSwitch : kSparseSwitch;
cur_block->successor_blocks.reserve(size);
for (i = 0; i < size; i++) {
BasicBlock* case_block = FindBlock(cur_offset + target_table[i], /* create */ true,
/* immed_pred_block_p */ &cur_block,
dex_pc_to_block_map);
DCHECK(case_block != nullptr);
SuccessorBlockInfo* successor_block_info =
static_cast<SuccessorBlockInfo*>(arena_->Alloc(sizeof(SuccessorBlockInfo),
kArenaAllocSuccessors));
successor_block_info->block = case_block->id;
successor_block_info->key =
(insn->dalvikInsn.opcode == Instruction::PACKED_SWITCH) ?
first_key + i : keyTable[i];
cur_block->successor_blocks.push_back(successor_block_info);
case_block->predecessors.push_back(cur_block->id);
}
/* Fall-through case */
BasicBlock* fallthrough_block = FindBlock(cur_offset + width, /* create */ true,
/* immed_pred_block_p */ nullptr,
dex_pc_to_block_map);
DCHECK(fallthrough_block != nullptr);
cur_block->fall_through = fallthrough_block->id;
fallthrough_block->predecessors.push_back(cur_block->id);
return cur_block;
}
/* Process instructions with the kThrow flag */
BasicBlock* MIRGraph::ProcessCanThrow(BasicBlock* cur_block,
MIR* insn,
DexOffset cur_offset,
int width,
int flags ATTRIBUTE_UNUSED,
ArenaBitVector* try_block_addr,
const uint16_t* code_ptr,
const uint16_t* code_end,
ScopedArenaVector<uint16_t>* dex_pc_to_block_map) {
bool in_try_block = try_block_addr->IsBitSet(cur_offset);
bool is_throw = (insn->dalvikInsn.opcode == Instruction::THROW);
/* In try block */
if (in_try_block) {
CatchHandlerIterator iterator(*current_code_item_, cur_offset);
if (cur_block->successor_block_list_type != kNotUsed) {
LOG(INFO) << PrettyMethod(cu_->method_idx, *cu_->dex_file);
LOG(FATAL) << "Successor block list already in use: "
<< static_cast<int>(cur_block->successor_block_list_type);
}
for (; iterator.HasNext(); iterator.Next()) {
BasicBlock* catch_block = FindBlock(iterator.GetHandlerAddress(), false /* create */,
nullptr /* immed_pred_block_p */,
dex_pc_to_block_map);
if (insn->dalvikInsn.opcode == Instruction::MONITOR_EXIT &&
IsBadMonitorExitCatch(insn->offset, catch_block->start_offset)) {
// Don't allow monitor-exit to catch its own exception, http://b/15745363 .
continue;
}
if (cur_block->successor_block_list_type == kNotUsed) {
cur_block->successor_block_list_type = kCatch;
}
catch_block->catch_entry = true;
if (kIsDebugBuild) {
catches_.insert(catch_block->start_offset);
}
SuccessorBlockInfo* successor_block_info = reinterpret_cast<SuccessorBlockInfo*>
(arena_->Alloc(sizeof(SuccessorBlockInfo), kArenaAllocSuccessors));
successor_block_info->block = catch_block->id;
successor_block_info->key = iterator.GetHandlerTypeIndex();
cur_block->successor_blocks.push_back(successor_block_info);
catch_block->predecessors.push_back(cur_block->id);
}
in_try_block = (cur_block->successor_block_list_type != kNotUsed);
}
bool build_all_edges =
(cu_->disable_opt & (1 << kSuppressExceptionEdges)) || is_throw || in_try_block;
if (!in_try_block && build_all_edges) {
BasicBlock* eh_block = CreateNewBB(kExceptionHandling);
cur_block->taken = eh_block->id;
eh_block->start_offset = cur_offset;
eh_block->predecessors.push_back(cur_block->id);
}
if (is_throw) {
cur_block->explicit_throw = true;
if (code_ptr < code_end) {
// Force creation of new block following THROW via side-effect.
FindBlock(cur_offset + width, /* create */ true, /* immed_pred_block_p */ nullptr, dex_pc_to_block_map);
}
if (!in_try_block) {
// Don't split a THROW that can't rethrow - we're done.
return cur_block;
}
}
if (!build_all_edges) {
/*
* Even though there is an exception edge here, control cannot return to this
* method. Thus, for the purposes of dataflow analysis and optimization, we can
* ignore the edge. Doing this reduces compile time, and increases the scope
* of the basic-block level optimization pass.
*/
return cur_block;
}
/*
* Split the potentially-throwing instruction into two parts.
* The first half will be a pseudo-op that captures the exception
* edges and terminates the basic block. It always falls through.
* Then, create a new basic block that begins with the throwing instruction
* (minus exceptions). Note: this new basic block must NOT be entered into
* the block_map. If the potentially-throwing instruction is the target of a
* future branch, we need to find the check psuedo half. The new
* basic block containing the work portion of the instruction should
* only be entered via fallthrough from the block containing the
* pseudo exception edge MIR. Note also that this new block is
* not automatically terminated after the work portion, and may
* contain following instructions.
*
* Note also that the dex_pc_to_block_map entry for the potentially
* throwing instruction will refer to the original basic block.
*/
BasicBlock* new_block = CreateNewBB(kDalvikByteCode);
new_block->start_offset = insn->offset;
cur_block->fall_through = new_block->id;
new_block->predecessors.push_back(cur_block->id);
MIR* new_insn = NewMIR();
*new_insn = *insn;
insn->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpCheck);
// Associate the two halves.
insn->meta.throw_insn = new_insn;
new_block->AppendMIR(new_insn);
return new_block;
}
/* Parse a Dex method and insert it into the MIRGraph at the current insert point. */
void MIRGraph::InlineMethod(const DexFile::CodeItem* code_item, uint32_t access_flags,
InvokeType invoke_type ATTRIBUTE_UNUSED, uint16_t class_def_idx,
uint32_t method_idx, jobject class_loader, const DexFile& dex_file,
Handle<mirror::DexCache> dex_cache) {
current_code_item_ = code_item;
method_stack_.push_back(std::make_pair(current_method_, current_offset_));
current_method_ = m_units_.size();
current_offset_ = 0;
// TODO: will need to snapshot stack image and use that as the mir context identification.
m_units_.push_back(new (arena_) DexCompilationUnit(
cu_, class_loader, Runtime::Current()->GetClassLinker(), dex_file, current_code_item_,
class_def_idx, method_idx, access_flags,
cu_->compiler_driver->GetVerifiedMethod(&dex_file, method_idx), dex_cache));
const uint16_t* code_ptr = current_code_item_->insns_;
const uint16_t* code_end =
current_code_item_->insns_ + current_code_item_->insns_size_in_code_units_;
// TODO: need to rework expansion of block list & try_block_addr when inlining activated.
// TUNING: use better estimate of basic blocks for following resize.
block_list_.reserve(block_list_.size() + current_code_item_->insns_size_in_code_units_);
// FindBlock lookup cache.
ScopedArenaAllocator allocator(&cu_->arena_stack);
ScopedArenaVector<uint16_t> dex_pc_to_block_map(allocator.Adapter());
dex_pc_to_block_map.resize(current_code_item_->insns_size_in_code_units_ +
1 /* Fall-through on last insn; dead or punt to interpreter. */);
// TODO: replace with explicit resize routine. Using automatic extension side effect for now.
try_block_addr_->SetBit(current_code_item_->insns_size_in_code_units_);
try_block_addr_->ClearBit(current_code_item_->insns_size_in_code_units_);
// If this is the first method, set up default entry and exit blocks.
if (current_method_ == 0) {
DCHECK(entry_block_ == nullptr);
DCHECK(exit_block_ == nullptr);
DCHECK_EQ(GetNumBlocks(), 0U);
// Use id 0 to represent a null block.
BasicBlock* null_block = CreateNewBB(kNullBlock);
DCHECK_EQ(null_block->id, NullBasicBlockId);
null_block->hidden = true;
entry_block_ = CreateNewBB(kEntryBlock);
exit_block_ = CreateNewBB(kExitBlock);
} else {
UNIMPLEMENTED(FATAL) << "Nested inlining not implemented.";
/*
* Will need to manage storage for ins & outs, push prevous state and update
* insert point.
*/
}
/* Current block to record parsed instructions */
BasicBlock* cur_block = CreateNewBB(kDalvikByteCode);
DCHECK_EQ(current_offset_, 0U);
cur_block->start_offset = current_offset_;
// TODO: for inlining support, insert at the insert point rather than entry block.
entry_block_->fall_through = cur_block->id;
cur_block->predecessors.push_back(entry_block_->id);
/* Identify code range in try blocks and set up the empty catch blocks */
ProcessTryCatchBlocks(&dex_pc_to_block_map);
uint64_t merged_df_flags = 0u;
/* Parse all instructions and put them into containing basic blocks */
while (code_ptr < code_end) {
MIR *insn = NewMIR();
insn->offset = current_offset_;
insn->m_unit_index = current_method_;
int width = ParseInsn(code_ptr, &insn->dalvikInsn);
Instruction::Code opcode = insn->dalvikInsn.opcode;
if (opcode_count_ != nullptr) {
opcode_count_[static_cast<int>(opcode)]++;
}
int flags = insn->dalvikInsn.FlagsOf();
int verify_flags = Instruction::VerifyFlagsOf(insn->dalvikInsn.opcode);
uint64_t df_flags = GetDataFlowAttributes(insn);
merged_df_flags |= df_flags;
if (df_flags & DF_HAS_DEFS) {
def_count_ += (df_flags & DF_A_WIDE) ? 2 : 1;
}
if (df_flags & DF_LVN) {
cur_block->use_lvn = true; // Run local value numbering on this basic block.
}
// Check for inline data block signatures.
if (opcode == Instruction::NOP) {
// A simple NOP will have a width of 1 at this point, embedded data NOP > 1.
if ((width == 1) && ((current_offset_ & 0x1) == 0x1) && ((code_end - code_ptr) > 1)) {
// Could be an aligning nop. If an embedded data NOP follows, treat pair as single unit.
uint16_t following_raw_instruction = code_ptr[1];
if ((following_raw_instruction == Instruction::kSparseSwitchSignature) ||
(following_raw_instruction == Instruction::kPackedSwitchSignature) ||
(following_raw_instruction == Instruction::kArrayDataSignature)) {
width += Instruction::At(code_ptr + 1)->SizeInCodeUnits();
}
}
if (width == 1) {
// It is a simple nop - treat normally.
cur_block->AppendMIR(insn);
} else {
DCHECK(cur_block->fall_through == NullBasicBlockId);
DCHECK(cur_block->taken == NullBasicBlockId);
// Unreachable instruction, mark for no continuation and end basic block.
flags &= ~Instruction::kContinue;
FindBlock(current_offset_ + width, /* create */ true,
/* immed_pred_block_p */ nullptr, &dex_pc_to_block_map);
}
} else {
cur_block->AppendMIR(insn);
}
// Associate the starting dex_pc for this opcode with its containing basic block.
dex_pc_to_block_map[insn->offset] = cur_block->id;
code_ptr += width;
if (flags & Instruction::kBranch) {
cur_block = ProcessCanBranch(cur_block, insn, current_offset_,
width, flags, code_ptr, code_end, &dex_pc_to_block_map);
} else if (flags & Instruction::kReturn) {
cur_block->terminated_by_return = true;
cur_block->fall_through = exit_block_->id;
exit_block_->predecessors.push_back(cur_block->id);
/*
* Terminate the current block if there are instructions
* afterwards.
*/
if (code_ptr < code_end) {
/*
* Create a fallthrough block for real instructions
* (incl. NOP).
*/
FindBlock(current_offset_ + width, /* create */ true,
/* immed_pred_block_p */ nullptr, &dex_pc_to_block_map);
}
} else if (flags & Instruction::kThrow) {
cur_block = ProcessCanThrow(cur_block, insn, current_offset_, width, flags, try_block_addr_,
code_ptr, code_end, &dex_pc_to_block_map);
} else if (flags & Instruction::kSwitch) {
cur_block = ProcessCanSwitch(cur_block, insn, current_offset_, width,
flags, &dex_pc_to_block_map);
}
if (verify_flags & Instruction::kVerifyVarArgRange ||
verify_flags & Instruction::kVerifyVarArgRangeNonZero) {
/*
* The Quick backend's runtime model includes a gap between a method's
* argument ("in") vregs and the rest of its vregs. Handling a range instruction
* which spans the gap is somewhat complicated, and should not happen
* in normal usage of dx. Punt to the interpreter.
*/
int first_reg_in_range = insn->dalvikInsn.vC;
int last_reg_in_range = first_reg_in_range + insn->dalvikInsn.vA - 1;
if (IsInVReg(first_reg_in_range) != IsInVReg(last_reg_in_range)) {
punt_to_interpreter_ = true;
}
}
current_offset_ += width;
BasicBlock* next_block = FindBlock(current_offset_, /* create */ false,
/* immed_pred_block_p */ nullptr,
&dex_pc_to_block_map);
if (next_block) {
/*
* The next instruction could be the target of a previously parsed
* forward branch so a block is already created. If the current
* instruction is not an unconditional branch, connect them through
* the fall-through link.
*/
DCHECK(cur_block->fall_through == NullBasicBlockId ||
GetBasicBlock(cur_block->fall_through) == next_block ||
GetBasicBlock(cur_block->fall_through) == exit_block_);
if ((cur_block->fall_through == NullBasicBlockId) && (flags & Instruction::kContinue)) {
cur_block->fall_through = next_block->id;
next_block->predecessors.push_back(cur_block->id);
}
cur_block = next_block;
}
}
merged_df_flags_ = merged_df_flags;
if (cu_->enable_debug & (1 << kDebugDumpCFG)) {
DumpCFG("/sdcard/1_post_parse_cfg/", true);
}
if (cu_->verbose) {
DumpMIRGraph();
}
// Check if there's been a fall-through out of the method code.
BasicBlockId out_bb_id = dex_pc_to_block_map[current_code_item_->insns_size_in_code_units_];
if (UNLIKELY(out_bb_id != NullBasicBlockId)) {
// Eagerly calculate DFS order to determine if the block is dead.
DCHECK(!DfsOrdersUpToDate());
ComputeDFSOrders();
BasicBlock* out_bb = GetBasicBlock(out_bb_id);
DCHECK(out_bb != nullptr);
if (out_bb->block_type != kDead) {
LOG(WARNING) << "Live fall-through out of method in " << PrettyMethod(method_idx, dex_file);
SetPuntToInterpreter(true);
}
}
}
void MIRGraph::ShowOpcodeStats() {
DCHECK(opcode_count_ != nullptr);
LOG(INFO) << "Opcode Count";
for (int i = 0; i < kNumPackedOpcodes; i++) {
if (opcode_count_[i] != 0) {
LOG(INFO) << "-C- " << Instruction::Name(static_cast<Instruction::Code>(i))
<< " " << opcode_count_[i];
}
}
}
uint64_t MIRGraph::GetDataFlowAttributes(Instruction::Code opcode) {
DCHECK_LT((size_t) opcode, (sizeof(oat_data_flow_attributes_) / sizeof(oat_data_flow_attributes_[0])));
return oat_data_flow_attributes_[opcode];
}
uint64_t MIRGraph::GetDataFlowAttributes(MIR* mir) {
DCHECK(mir != nullptr);
Instruction::Code opcode = mir->dalvikInsn.opcode;
return GetDataFlowAttributes(opcode);
}
// The path can easily surpass FS limits because of parameters etc. Use pathconf to get FS
// restrictions here. Note that a successful invocation will return an actual value. If the path
// is too long for some reason, the return will be ENAMETOOLONG. Then cut off part of the name.
//
// It's possible the path is not valid, or some other errors appear. In that case return false.
static bool CreateDumpFile(std::string& fname, const char* dir_prefix, NarrowDexOffset start_offset,
const char *suffix, int nr, std::string* output) {
std::string dir = StringPrintf("./%s", dir_prefix);
int64_t max_name_length = pathconf(dir.c_str(), _PC_NAME_MAX);
if (max_name_length <= 0) {
PLOG(ERROR) << "Could not get file name restrictions for " << dir;
return false;
}
std::string name = StringPrintf("%s%x%s_%d.dot", fname.c_str(), start_offset,
suffix == nullptr ? "" : suffix, nr);
std::string fpath;
if (static_cast<int64_t>(name.size()) > max_name_length) {
std::string suffix_str = StringPrintf("_%d.dot", nr);
name = name.substr(0, static_cast<size_t>(max_name_length) - suffix_str.size()) + suffix_str;
}
// Sanity check.
DCHECK_LE(name.size(), static_cast<size_t>(max_name_length));
*output = StringPrintf("%s%s", dir_prefix, name.c_str());
return true;
}
// TODO: use a configurable base prefix, and adjust callers to supply pass name.
/* Dump the CFG into a DOT graph */
void MIRGraph::DumpCFG(const char* dir_prefix, bool all_blocks, const char *suffix) {
FILE* file;
static AtomicInteger cnt(0);
// Increment counter to get a unique file number.
cnt++;
int nr = cnt.LoadRelaxed();
std::string fname(PrettyMethod(cu_->method_idx, *cu_->dex_file));
ReplaceSpecialChars(fname);
std::string fpath;
if (!CreateDumpFile(fname, dir_prefix, GetBasicBlock(GetEntryBlock()->fall_through)->start_offset,
suffix, nr, &fpath)) {
LOG(ERROR) << "Could not create dump file name for " << fname;
return;
}
file = fopen(fpath.c_str(), "w");
if (file == nullptr) {
PLOG(ERROR) << "Could not open " << fpath << " for DumpCFG.";
return;
}
fprintf(file, "digraph G {\n");
fprintf(file, " rankdir=TB\n");
int num_blocks = all_blocks ? GetNumBlocks() : num_reachable_blocks_;
int idx;
for (idx = 0; idx < num_blocks; idx++) {
int block_idx = all_blocks ? idx : dfs_order_[idx];
BasicBlock* bb = GetBasicBlock(block_idx);
if (bb == nullptr) continue;
if (bb->block_type == kDead) continue;
if (bb->hidden) continue;
if (bb->block_type == kEntryBlock) {
fprintf(file, " entry_%d [shape=Mdiamond];\n", bb->id);
} else if (bb->block_type == kExitBlock) {
fprintf(file, " exit_%d [shape=Mdiamond];\n", bb->id);
} else if (bb->block_type == kDalvikByteCode) {
fprintf(file, " block%04x_%d [shape=record,label = \"{ \\\n",
bb->start_offset, bb->id);
const MIR* mir;
fprintf(file, " {block id %d\\l}%s\\\n", bb->id,
bb->first_mir_insn ? " | " : " ");
for (mir = bb->first_mir_insn; mir; mir = mir->next) {
int opcode = mir->dalvikInsn.opcode;
fprintf(file, " {%04x %s %s %s %s %s %s %s %s %s\\l}%s\\\n", mir->offset,
mir->ssa_rep ? GetDalvikDisassembly(mir) :
!MIR::DecodedInstruction::IsPseudoMirOp(opcode) ?
Instruction::Name(mir->dalvikInsn.opcode) :
extended_mir_op_names_[opcode - kMirOpFirst],
(mir->optimization_flags & MIR_IGNORE_RANGE_CHECK) != 0 ? " no_rangecheck" : " ",
(mir->optimization_flags & MIR_IGNORE_NULL_CHECK) != 0 ? " no_nullcheck" : " ",
(mir->optimization_flags & MIR_IGNORE_SUSPEND_CHECK) != 0 ? " no_suspendcheck" : " ",
(mir->optimization_flags & MIR_STORE_NON_TEMPORAL) != 0 ? " non_temporal" : " ",
(mir->optimization_flags & MIR_CALLEE) != 0 ? " inlined" : " ",
(mir->optimization_flags & MIR_CLASS_IS_INITIALIZED) != 0 ? " cl_inited" : " ",
(mir->optimization_flags & MIR_CLASS_IS_IN_DEX_CACHE) != 0 ? " cl_in_cache" : " ",
(mir->optimization_flags & MIR_IGNORE_DIV_ZERO_CHECK) != 0 ? " no_div_check" : " ",
mir->next ? " | " : " ");
}
fprintf(file, " }\"];\n\n");
} else if (bb->block_type == kExceptionHandling) {
char block_name[BLOCK_NAME_LEN];
GetBlockName(bb, block_name);
fprintf(file, " %s [shape=invhouse];\n", block_name);
}
char block_name1[BLOCK_NAME_LEN], block_name2[BLOCK_NAME_LEN];
if (bb->taken != NullBasicBlockId) {
GetBlockName(bb, block_name1);
GetBlockName(GetBasicBlock(bb->taken), block_name2);
fprintf(file, " %s:s -> %s:n [style=dotted]\n",
block_name1, block_name2);
}
if (bb->fall_through != NullBasicBlockId) {
GetBlockName(bb, block_name1);
GetBlockName(GetBasicBlock(bb->fall_through), block_name2);
fprintf(file, " %s:s -> %s:n\n", block_name1, block_name2);
}
if (bb->successor_block_list_type != kNotUsed) {
fprintf(file, " succ%04x_%d [shape=%s,label = \"{ \\\n",
bb->start_offset, bb->id,
(bb->successor_block_list_type == kCatch) ? "Mrecord" : "record");
int last_succ_id = static_cast<int>(bb->successor_blocks.size() - 1u);
int succ_id = 0;
for (SuccessorBlockInfo* successor_block_info : bb->successor_blocks) {
BasicBlock* dest_block = GetBasicBlock(successor_block_info->block);
fprintf(file, " {<f%d> %04x: %04x\\l}%s\\\n",
succ_id,
successor_block_info->key,
dest_block->start_offset,
(succ_id != last_succ_id) ? " | " : " ");
++succ_id;
}
fprintf(file, " }\"];\n\n");
GetBlockName(bb, block_name1);
fprintf(file, " %s:s -> succ%04x_%d:n [style=dashed]\n",
block_name1, bb->start_offset, bb->id);
// Link the successor pseudo-block with all of its potential targets.
succ_id = 0;
for (SuccessorBlockInfo* successor_block_info : bb->successor_blocks) {
BasicBlock* dest_block = GetBasicBlock(successor_block_info->block);
GetBlockName(dest_block, block_name2);
fprintf(file, " succ%04x_%d:f%d:e -> %s:n\n", bb->start_offset,
bb->id, succ_id++, block_name2);
}
}
fprintf(file, "\n");
if (cu_->verbose) {
/* Display the dominator tree */
GetBlockName(bb, block_name1);
fprintf(file, " cfg%s [label=\"%s\", shape=none];\n",
block_name1, block_name1);
if (bb->i_dom) {
GetBlockName(GetBasicBlock(bb->i_dom), block_name2);
fprintf(file, " cfg%s:s -> cfg%s:n\n\n", block_name2, block_name1);
}
}
}
fprintf(file, "}\n");
fclose(file);
}
/* Insert an MIR instruction to the end of a basic block. */
void BasicBlock::AppendMIR(MIR* mir) {
// Insert it after the last MIR.
InsertMIRListAfter(last_mir_insn, mir, mir);
}
void BasicBlock::AppendMIRList(MIR* first_list_mir, MIR* last_list_mir) {
// Insert it after the last MIR.
InsertMIRListAfter(last_mir_insn, first_list_mir, last_list_mir);
}
void BasicBlock::AppendMIRList(const std::vector<MIR*>& insns) {
for (std::vector<MIR*>::const_iterator it = insns.begin(); it != insns.end(); it++) {
MIR* new_mir = *it;
// Add a copy of each MIR.
InsertMIRListAfter(last_mir_insn, new_mir, new_mir);
}
}
/* Insert a MIR instruction after the specified MIR. */
void BasicBlock::InsertMIRAfter(MIR* current_mir, MIR* new_mir) {
InsertMIRListAfter(current_mir, new_mir, new_mir);
}
void BasicBlock::InsertMIRListAfter(MIR* insert_after, MIR* first_list_mir, MIR* last_list_mir) {
// If no MIR, we are done.
if (first_list_mir == nullptr || last_list_mir == nullptr) {
return;
}
// If insert_after is null, assume BB is empty.
if (insert_after == nullptr) {
first_mir_insn = first_list_mir;
last_mir_insn = last_list_mir;
last_list_mir->next = nullptr;
} else {
MIR* after_list = insert_after->next;
insert_after->next = first_list_mir;
last_list_mir->next = after_list;
if (after_list == nullptr) {
last_mir_insn = last_list_mir;
}
}
// Set this BB to be the basic block of the MIRs.
MIR* last = last_list_mir->next;
for (MIR* mir = first_list_mir; mir != last; mir = mir->next) {
mir->bb = id;
}
}
/* Insert an MIR instruction to the head of a basic block. */
void BasicBlock::PrependMIR(MIR* mir) {
InsertMIRListBefore(first_mir_insn, mir, mir);
}
void BasicBlock::PrependMIRList(MIR* first_list_mir, MIR* last_list_mir) {
// Insert it before the first MIR.
InsertMIRListBefore(first_mir_insn, first_list_mir, last_list_mir);
}
void BasicBlock::PrependMIRList(const std::vector<MIR*>& to_add) {
for (std::vector<MIR*>::const_iterator it = to_add.begin(); it != to_add.end(); it++) {
MIR* mir = *it;
InsertMIRListBefore(first_mir_insn, mir, mir);
}
}
/* Insert a MIR instruction before the specified MIR. */
void BasicBlock::InsertMIRBefore(MIR* current_mir, MIR* new_mir) {
// Insert as a single element list.
return InsertMIRListBefore(current_mir, new_mir, new_mir);
}
MIR* BasicBlock::FindPreviousMIR(MIR* mir) {
MIR* current = first_mir_insn;
while (current != nullptr) {
MIR* next = current->next;
if (next == mir) {
return current;
}
current = next;
}
return nullptr;
}
void BasicBlock::InsertMIRListBefore(MIR* insert_before, MIR* first_list_mir, MIR* last_list_mir) {
// If no MIR, we are done.
if (first_list_mir == nullptr || last_list_mir == nullptr) {
return;
}
// If insert_before is null, assume BB is empty.
if (insert_before == nullptr) {
first_mir_insn = first_list_mir;
last_mir_insn = last_list_mir;
last_list_mir->next = nullptr;
} else {
if (first_mir_insn == insert_before) {
last_list_mir->next = first_mir_insn;
first_mir_insn = first_list_mir;
} else {
// Find the preceding MIR.
MIR* before_list = FindPreviousMIR(insert_before);
DCHECK(before_list != nullptr);
before_list->next = first_list_mir;
last_list_mir->next = insert_before;
}
}
// Set this BB to be the basic block of the MIRs.
for (MIR* mir = first_list_mir; mir != last_list_mir->next; mir = mir->next) {
mir->bb = id;
}
}
bool BasicBlock::RemoveMIR(MIR* mir) {
// Remove as a single element list.
return RemoveMIRList(mir, mir);
}
bool BasicBlock::RemoveMIRList(MIR* first_list_mir, MIR* last_list_mir) {
if (first_list_mir == nullptr) {
return false;
}
// Try to find the MIR.
MIR* before_list = nullptr;
MIR* after_list = nullptr;
// If we are removing from the beginning of the MIR list.
if (first_mir_insn == first_list_mir) {
before_list = nullptr;
} else {
before_list = FindPreviousMIR(first_list_mir);
if (before_list == nullptr) {
// We did not find the mir.
return false;
}
}
// Remove the BB information and also find the after_list.
for (MIR* mir = first_list_mir; mir != last_list_mir->next; mir = mir->next) {
mir->bb = NullBasicBlockId;
}
after_list = last_list_mir->next;
// If there is nothing before the list, after_list is the first_mir.
if (before_list == nullptr) {
first_mir_insn = after_list;
} else {
before_list->next = after_list;
}
// If there is nothing after the list, before_list is last_mir.
if (after_list == nullptr) {
last_mir_insn = before_list;
}
return true;
}
MIR* BasicBlock::GetFirstNonPhiInsn() {
MIR* mir = first_mir_insn;
while (mir != nullptr && static_cast<int>(mir->dalvikInsn.opcode) == kMirOpPhi) {
mir = mir->next;
}
return mir;
}
MIR* BasicBlock::GetNextUnconditionalMir(MIRGraph* mir_graph, MIR* current) {
MIR* next_mir = nullptr;
if (current != nullptr) {
next_mir = current->next;
}
if (next_mir == nullptr) {
// Only look for next MIR that follows unconditionally.
if ((taken == NullBasicBlockId) && (fall_through != NullBasicBlockId)) {
next_mir = mir_graph->GetBasicBlock(fall_through)->first_mir_insn;
}
}
return next_mir;
}
static void FillTypeSizeString(uint32_t type_size, std::string* decoded_mir) {
DCHECK(decoded_mir != nullptr);
OpSize type = static_cast<OpSize>(type_size >> 16);
uint16_t vect_size = (type_size & 0xFFFF);
// Now print the type and vector size.
std::stringstream ss;
ss << " (type:";
ss << type;
ss << " vectsize:";
ss << vect_size;
ss << ")";
decoded_mir->append(ss.str());
}
void MIRGraph::DisassembleExtendedInstr(const MIR* mir, std::string* decoded_mir) {
DCHECK(decoded_mir != nullptr);
int opcode = mir->dalvikInsn.opcode;
SSARepresentation* ssa_rep = mir->ssa_rep;
int defs = (ssa_rep != nullptr) ? ssa_rep->num_defs : 0;
int uses = (ssa_rep != nullptr) ? ssa_rep->num_uses : 0;
if (opcode < kMirOpFirst) {
return; // It is not an extended instruction.
}
decoded_mir->append(extended_mir_op_names_[opcode - kMirOpFirst]);
switch (opcode) {
case kMirOpPhi: {
if (defs > 0 && uses > 0) {
BasicBlockId* incoming = mir->meta.phi_incoming;
decoded_mir->append(StringPrintf(" %s = (%s",
GetSSANameWithConst(ssa_rep->defs[0], true).c_str(),
GetSSANameWithConst(ssa_rep->uses[0], true).c_str()));
decoded_mir->append(StringPrintf(":%d", incoming[0]));
for (int i = 1; i < uses; i++) {
decoded_mir->append(StringPrintf(", %s:%d", GetSSANameWithConst(ssa_rep->uses[i], true).c_str(), incoming[i]));
}
decoded_mir->append(")");
}
break;
}
case kMirOpCopy:
if (ssa_rep != nullptr) {
decoded_mir->append(" ");
decoded_mir->append(GetSSANameWithConst(ssa_rep->defs[0], false));
if (defs > 1) {
decoded_mir->append(", ");
decoded_mir->append(GetSSANameWithConst(ssa_rep->defs[1], false));
}
decoded_mir->append(" = ");
decoded_mir->append(GetSSANameWithConst(ssa_rep->uses[0], false));
if (uses > 1) {
decoded_mir->append(", ");
decoded_mir->append(GetSSANameWithConst(ssa_rep->uses[1], false));
}
} else {
decoded_mir->append(StringPrintf(" v%d = v%d", mir->dalvikInsn.vA, mir->dalvikInsn.vB));
}
break;
case kMirOpFusedCmplFloat:
case kMirOpFusedCmpgFloat:
case kMirOpFusedCmplDouble:
case kMirOpFusedCmpgDouble:
case kMirOpFusedCmpLong:
if (ssa_rep != nullptr) {
decoded_mir->append(" ");
decoded_mir->append(GetSSANameWithConst(ssa_rep->uses[0], false));
for (int i = 1; i < uses; i++) {
decoded_mir->append(", ");
decoded_mir->append(GetSSANameWithConst(ssa_rep->uses[i], false));
}
} else {
decoded_mir->append(StringPrintf(" v%d, v%d", mir->dalvikInsn.vA, mir->dalvikInsn.vB));
}
break;
case kMirOpMoveVector:
decoded_mir->append(StringPrintf(" vect%d = vect%d", mir->dalvikInsn.vA, mir->dalvikInsn.vB));
FillTypeSizeString(mir->dalvikInsn.vC, decoded_mir);
break;
case kMirOpPackedAddition:
decoded_mir->append(StringPrintf(" vect%d = vect%d + vect%d", mir->dalvikInsn.vA, mir->dalvikInsn.vA, mir->dalvikInsn.vB));
FillTypeSizeString(mir->dalvikInsn.vC, decoded_mir);
break;
case kMirOpPackedMultiply:
decoded_mir->append(StringPrintf(" vect%d = vect%d * vect%d", mir->dalvikInsn.vA, mir->dalvikInsn.vA, mir->dalvikInsn.vB));
FillTypeSizeString(mir->dalvikInsn.vC, decoded_mir);
break;
case kMirOpPackedSubtract:
decoded_mir->append(StringPrintf(" vect%d = vect%d - vect%d", mir->dalvikInsn.vA, mir->dalvikInsn.vA, mir->dalvikInsn.vB));
FillTypeSizeString(mir->dalvikInsn.vC, decoded_mir);
break;
case kMirOpPackedAnd:
decoded_mir->append(StringPrintf(" vect%d = vect%d & vect%d", mir->dalvikInsn.vA, mir->dalvikInsn.vA, mir->dalvikInsn.vB));
FillTypeSizeString(mir->dalvikInsn.vC, decoded_mir);
break;
case kMirOpPackedOr:
decoded_mir->append(StringPrintf(" vect%d = vect%d \\| vect%d", mir->dalvikInsn.vA, mir->dalvikInsn.vA, mir->dalvikInsn.vB));
FillTypeSizeString(mir->dalvikInsn.vC, decoded_mir);
break;
case kMirOpPackedXor:
decoded_mir->append(StringPrintf(" vect%d = vect%d ^ vect%d", mir->dalvikInsn.vA, mir->dalvikInsn.vA, mir->dalvikInsn.vB));
FillTypeSizeString(mir->dalvikInsn.vC, decoded_mir);
break;
case kMirOpPackedShiftLeft:
decoded_mir->append(StringPrintf(" vect%d = vect%d \\<\\< %d", mir->dalvikInsn.vA, mir->dalvikInsn.vA, mir->dalvikInsn.vB));
FillTypeSizeString(mir->dalvikInsn.vC, decoded_mir);
break;
case kMirOpPackedUnsignedShiftRight:
decoded_mir->append(StringPrintf(" vect%d = vect%d \\>\\>\\> %d", mir->dalvikInsn.vA, mir->dalvikInsn.vA, mir->dalvikInsn.vB));
FillTypeSizeString(mir->dalvikInsn.vC, decoded_mir);
break;
case kMirOpPackedSignedShiftRight:
decoded_mir->append(StringPrintf(" vect%d = vect%d \\>\\> %d", mir->dalvikInsn.vA, mir->dalvikInsn.vA, mir->dalvikInsn.vB));
FillTypeSizeString(mir->dalvikInsn.vC, decoded_mir);
break;
case kMirOpConstVector:
decoded_mir->append(StringPrintf(" vect%d = %x, %x, %x, %x", mir->dalvikInsn.vA, mir->dalvikInsn.arg[0],
mir->dalvikInsn.arg[1], mir->dalvikInsn.arg[2], mir->dalvikInsn.arg[3]));
break;
case kMirOpPackedSet:
if (ssa_rep != nullptr) {
decoded_mir->append(StringPrintf(" vect%d = %s", mir->dalvikInsn.vA,
GetSSANameWithConst(ssa_rep->uses[0], false).c_str()));
if (uses > 1) {
decoded_mir->append(", ");
decoded_mir->append(GetSSANameWithConst(ssa_rep->uses[1], false));
}
} else {
decoded_mir->append(StringPrintf(" vect%d = v%d", mir->dalvikInsn.vA, mir->dalvikInsn.vB));
}
FillTypeSizeString(mir->dalvikInsn.vC, decoded_mir);
break;
case kMirOpPackedAddReduce:
if (ssa_rep != nullptr) {
decoded_mir->append(" ");
decoded_mir->append(GetSSANameWithConst(ssa_rep->defs[0], false));
if (defs > 1) {
decoded_mir->append(", ");
decoded_mir->append(GetSSANameWithConst(ssa_rep->defs[1], false));
}
decoded_mir->append(StringPrintf(" = vect%d + %s", mir->dalvikInsn.vB,
GetSSANameWithConst(ssa_rep->uses[0], false).c_str()));
if (uses > 1) {
decoded_mir->append(", ");
decoded_mir->append(GetSSANameWithConst(ssa_rep->uses[1], false));
}
} else {
decoded_mir->append(StringPrintf("v%d = vect%d + v%d", mir->dalvikInsn.vA, mir->dalvikInsn.vB, mir->dalvikInsn.vA));
}
FillTypeSizeString(mir->dalvikInsn.vC, decoded_mir);
break;
case kMirOpPackedReduce:
if (ssa_rep != nullptr) {
decoded_mir->append(" ");
decoded_mir->append(GetSSANameWithConst(ssa_rep->defs[0], false));
if (defs > 1) {
decoded_mir->append(", ");
decoded_mir->append(GetSSANameWithConst(ssa_rep->defs[1], false));
}
decoded_mir->append(StringPrintf(" = vect%d (extr_idx:%d)", mir->dalvikInsn.vB, mir->dalvikInsn.arg[0]));
} else {
decoded_mir->append(StringPrintf(" v%d = vect%d (extr_idx:%d)", mir->dalvikInsn.vA,
mir->dalvikInsn.vB, mir->dalvikInsn.arg[0]));
}
FillTypeSizeString(mir->dalvikInsn.vC, decoded_mir);
break;
case kMirOpReserveVectorRegisters:
case kMirOpReturnVectorRegisters:
decoded_mir->append(StringPrintf(" vect%d - vect%d", mir->dalvikInsn.vA, mir->dalvikInsn.vB));
break;
case kMirOpMemBarrier: {
decoded_mir->append(" type:");
std::stringstream ss;
ss << static_cast<MemBarrierKind>(mir->dalvikInsn.vA);
decoded_mir->append(ss.str());
break;
}
case kMirOpPackedArrayGet:
case kMirOpPackedArrayPut:
decoded_mir->append(StringPrintf(" vect%d", mir->dalvikInsn.vA));
if (ssa_rep != nullptr) {
decoded_mir->append(StringPrintf(", %s[%s]",
GetSSANameWithConst(ssa_rep->uses[0], false).c_str(),
GetSSANameWithConst(ssa_rep->uses[1], false).c_str()));
} else {
decoded_mir->append(StringPrintf(", v%d[v%d]", mir->dalvikInsn.vB, mir->dalvikInsn.vC));
}
FillTypeSizeString(mir->dalvikInsn.arg[0], decoded_mir);
break;
case kMirOpMaddInt:
case kMirOpMsubInt:
case kMirOpMaddLong:
case kMirOpMsubLong:
if (ssa_rep != nullptr) {
decoded_mir->append(" ");
decoded_mir->append(GetSSANameWithConst(ssa_rep->defs[0], false));
if (defs > 1) {
decoded_mir->append(", ");
decoded_mir->append(GetSSANameWithConst(ssa_rep->defs[1], false));
}
for (int i = 0; i < uses; i++) {
decoded_mir->append(", ");
decoded_mir->append(GetSSANameWithConst(ssa_rep->uses[i], false));
}
} else {
decoded_mir->append(StringPrintf(" v%d, v%d, v%d, v%d",
mir->dalvikInsn.vA, mir->dalvikInsn.vB,
mir->dalvikInsn.vC, mir->dalvikInsn.arg[0]));
}
break;
default:
break;
}
}
char* MIRGraph::GetDalvikDisassembly(const MIR* mir) {
MIR::DecodedInstruction insn = mir->dalvikInsn;
std::string str;
int flags = 0;
int opcode = insn.opcode;
char* ret;
bool nop = false;
SSARepresentation* ssa_rep = mir->ssa_rep;
Instruction::Format dalvik_format = Instruction::k10x; // Default to no-operand format.
// Handle special cases that recover the original dalvik instruction.
if (opcode == kMirOpCheck) {
str.append(extended_mir_op_names_[opcode - kMirOpFirst]);
str.append(": ");
// Recover the original Dex instruction.
insn = mir->meta.throw_insn->dalvikInsn;
ssa_rep = mir->meta.throw_insn->ssa_rep;
opcode = insn.opcode;
} else if (opcode == kMirOpNop) {
str.append("[");
if (mir->offset < current_code_item_->insns_size_in_code_units_) {
// Recover original opcode.
insn.opcode = Instruction::At(current_code_item_->insns_ + mir->offset)->Opcode();
opcode = insn.opcode;
}
nop = true;
}
int defs = (ssa_rep != nullptr) ? ssa_rep->num_defs : 0;
int uses = (ssa_rep != nullptr) ? ssa_rep->num_uses : 0;
if (MIR::DecodedInstruction::IsPseudoMirOp(opcode)) {
// Note that this does not check the MIR's opcode in all cases. In cases where it
// recovered dalvik instruction, it uses opcode of that instead of the extended one.
DisassembleExtendedInstr(mir, &str);
} else {
dalvik_format = Instruction::FormatOf(insn.opcode);
flags = insn.FlagsOf();
str.append(Instruction::Name(insn.opcode));
// For invokes-style formats, treat wide regs as a pair of singles.
bool show_singles = ((dalvik_format == Instruction::k35c) ||
(dalvik_format == Instruction::k3rc));
if (defs != 0) {
str.append(" ");
str.append(GetSSANameWithConst(ssa_rep->defs[0], false));
if (defs > 1) {
str.append(", ");
str.append(GetSSANameWithConst(ssa_rep->defs[1], false));
}
if (uses != 0) {
str.append(", ");
}
}
for (int i = 0; i < uses; i++) {
str.append(" ");
str.append(GetSSANameWithConst(ssa_rep->uses[i], show_singles));
if (!show_singles && (reg_location_ != nullptr) && reg_location_[i].wide) {
// For the listing, skip the high sreg.
i++;
}
if (i != (uses - 1)) {
str.append(",");
}
}
switch (dalvik_format) {
case Instruction::k11n: // Add one immediate from vB.
case Instruction::k21s:
case Instruction::k31i:
case Instruction::k21h:
str.append(StringPrintf(", #0x%x", insn.vB));
break;
case Instruction::k51l: // Add one wide immediate.
str.append(StringPrintf(", #%" PRId64, insn.vB_wide));
break;
case Instruction::k21c: // One register, one string/type/method index.
case Instruction::k31c:
str.append(StringPrintf(", index #0x%x", insn.vB));
break;
case Instruction::k22c: // Two registers, one string/type/method index.
str.append(StringPrintf(", index #0x%x", insn.vC));
break;
case Instruction::k22s: // Add one immediate from vC.
case Instruction::k22b:
str.append(StringPrintf(", #0x%x", insn.vC));
break;
default:
// Nothing left to print.
break;
}
if ((flags & Instruction::kBranch) != 0) {
// For branches, decode the instructions to print out the branch targets.
int offset = 0;
switch (dalvik_format) {
case Instruction::k21t:
offset = insn.vB;
break;
case Instruction::k22t:
offset = insn.vC;
break;
case Instruction::k10t:
case Instruction::k20t:
case Instruction::k30t:
offset = insn.vA;
break;
default:
LOG(FATAL) << "Unexpected branch format " << dalvik_format << " from " << insn.opcode;
break;
}
str.append(StringPrintf(", 0x%x (%c%x)", mir->offset + offset,
offset > 0 ? '+' : '-', offset > 0 ? offset : -offset));
}
if (nop) {
str.append("]--optimized away");
}
}
int length = str.length() + 1;
ret = arena_->AllocArray<char>(length, kArenaAllocDFInfo);
strncpy(ret, str.c_str(), length);
return ret;
}
/* Turn method name into a legal Linux file name */
void MIRGraph::ReplaceSpecialChars(std::string& str) {
static const struct { const char before; const char after; } match[] = {
{'/', '-'}, {';', '#'}, {' ', '#'}, {'$', '+'},
{'(', '@'}, {')', '@'}, {'<', '='}, {'>', '='}
};
for (unsigned int i = 0; i < sizeof(match)/sizeof(match[0]); i++) {
std::replace(str.begin(), str.end(), match[i].before, match[i].after);
}
}
std::string MIRGraph::GetSSAName(int ssa_reg) {
// TODO: This value is needed for debugging. Currently, we compute this and then copy to the
// arena. We should be smarter and just place straight into the arena, or compute the
// value more lazily.
int vreg = SRegToVReg(ssa_reg);
if (vreg >= static_cast<int>(GetFirstTempVR())) {
return StringPrintf("t%d_%d", SRegToVReg(ssa_reg), GetSSASubscript(ssa_reg));
} else {
return StringPrintf("v%d_%d", SRegToVReg(ssa_reg), GetSSASubscript(ssa_reg));
}
}
// Similar to GetSSAName, but if ssa name represents an immediate show that as well.
std::string MIRGraph::GetSSANameWithConst(int ssa_reg, bool singles_only) {
if (reg_location_ == nullptr) {
// Pre-SSA - just use the standard name.
return GetSSAName(ssa_reg);
}
if (IsConst(reg_location_[ssa_reg])) {
if (!singles_only && reg_location_[ssa_reg].wide &&
!reg_location_[ssa_reg].high_word) {
return StringPrintf("v%d_%d#0x%" PRIx64, SRegToVReg(ssa_reg), GetSSASubscript(ssa_reg),
ConstantValueWide(reg_location_[ssa_reg]));
} else {
return StringPrintf("v%d_%d#0x%x", SRegToVReg(ssa_reg), GetSSASubscript(ssa_reg),
ConstantValue(reg_location_[ssa_reg]));
}
} else {
int vreg = SRegToVReg(ssa_reg);
if (vreg >= static_cast<int>(GetFirstTempVR())) {
return StringPrintf("t%d_%d", SRegToVReg(ssa_reg), GetSSASubscript(ssa_reg));
} else {
return StringPrintf("v%d_%d", SRegToVReg(ssa_reg), GetSSASubscript(ssa_reg));
}
}
}
void MIRGraph::GetBlockName(BasicBlock* bb, char* name) {
switch (bb->block_type) {
case kEntryBlock:
snprintf(name, BLOCK_NAME_LEN, "entry_%d", bb->id);
break;
case kExitBlock:
snprintf(name, BLOCK_NAME_LEN, "exit_%d", bb->id);
break;
case kDalvikByteCode:
snprintf(name, BLOCK_NAME_LEN, "block%04x_%d", bb->start_offset, bb->id);
break;
case kExceptionHandling:
snprintf(name, BLOCK_NAME_LEN, "exception%04x_%d", bb->start_offset,
bb->id);
break;
default:
snprintf(name, BLOCK_NAME_LEN, "_%d", bb->id);
break;
}
}
const char* MIRGraph::GetShortyFromMethodReference(const MethodReference& target_method) {
const DexFile::MethodId& method_id =
target_method.dex_file->GetMethodId(target_method.dex_method_index);
return target_method.dex_file->GetShorty(method_id.proto_idx_);
}
/* Debug Utility - dump a compilation unit */
void MIRGraph::DumpMIRGraph() {
const char* block_type_names[] = {
"Null Block",
"Entry Block",
"Code Block",
"Exit Block",
"Exception Handling",
"Catch Block"
};
LOG(INFO) << "Compiling " << PrettyMethod(cu_->method_idx, *cu_->dex_file);
LOG(INFO) << GetInsns(0) << " insns";
LOG(INFO) << GetNumBlocks() << " blocks in total";
for (BasicBlock* bb : block_list_) {
LOG(INFO) << StringPrintf("Block %d (%s) (insn %04x - %04x%s)",
bb->id,
block_type_names[bb->block_type],
bb->start_offset,
bb->last_mir_insn ? bb->last_mir_insn->offset : bb->start_offset,
bb->last_mir_insn ? "" : " empty");
if (bb->taken != NullBasicBlockId) {
LOG(INFO) << " Taken branch: block " << bb->taken
<< "(0x" << std::hex << GetBasicBlock(bb->taken)->start_offset << ")";
}
if (bb->fall_through != NullBasicBlockId) {
LOG(INFO) << " Fallthrough : block " << bb->fall_through
<< " (0x" << std::hex << GetBasicBlock(bb->fall_through)->start_offset << ")";
}
}
}
/*
* Build an array of location records for the incoming arguments.
* Note: one location record per word of arguments, with dummy
* high-word loc for wide arguments. Also pull up any following
* MOVE_RESULT and incorporate it into the invoke.
*/
CallInfo* MIRGraph::NewMemCallInfo(BasicBlock* bb, MIR* mir, InvokeType type, bool is_range) {
CallInfo* info = static_cast<CallInfo*>(arena_->Alloc(sizeof(CallInfo),
kArenaAllocMisc));
MIR* move_result_mir = FindMoveResult(bb, mir);
if (move_result_mir == nullptr) {
info->result.location = kLocInvalid;
} else {
info->result = GetRawDest(move_result_mir);
move_result_mir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpNop);
}
info->num_arg_words = mir->ssa_rep->num_uses;
info->args = (info->num_arg_words == 0) ? nullptr :
arena_->AllocArray<RegLocation>(info->num_arg_words, kArenaAllocMisc);
for (size_t i = 0; i < info->num_arg_words; i++) {
info->args[i] = GetRawSrc(mir, i);
}
info->opt_flags = mir->optimization_flags;
info->type = type;
info->is_range = is_range;
if (IsInstructionQuickInvoke(mir->dalvikInsn.opcode)) {
const auto& method_info = GetMethodLoweringInfo(mir);
info->method_ref = method_info.GetTargetMethod();
} else {
info->method_ref = MethodReference(GetCurrentDexCompilationUnit()->GetDexFile(),
mir->dalvikInsn.vB);
}
info->index = mir->dalvikInsn.vB;
info->offset = mir->offset;
info->mir = mir;
return info;
}
// Allocate a new MIR.
MIR* MIRGraph::NewMIR() {
MIR* mir = new (arena_) MIR();
return mir;
}
// Allocate a new basic block.
BasicBlock* MIRGraph::NewMemBB(BBType block_type, int block_id) {
BasicBlock* bb = new (arena_) BasicBlock(block_id, block_type, arena_);
// TUNING: better estimate of the exit block predecessors?
bb->predecessors.reserve((block_type == kExitBlock) ? 2048 : 2);
block_id_map_.Put(block_id, block_id);
return bb;
}
void MIRGraph::InitializeConstantPropagation() {
is_constant_v_ = new (arena_) ArenaBitVector(arena_, GetNumSSARegs(), false);
constant_values_ = arena_->AllocArray<int>(GetNumSSARegs(), kArenaAllocDFInfo);
}
void MIRGraph::InitializeMethodUses() {
// The gate starts by initializing the use counts.
int num_ssa_regs = GetNumSSARegs();
use_counts_.clear();
use_counts_.reserve(num_ssa_regs + 32);
use_counts_.resize(num_ssa_regs, 0u);
raw_use_counts_.clear();
raw_use_counts_.reserve(num_ssa_regs + 32);
raw_use_counts_.resize(num_ssa_regs, 0u);
}
void MIRGraph::SSATransformationStart() {
DCHECK(temp_scoped_alloc_.get() == nullptr);
temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack));
temp_.ssa.num_vregs = GetNumOfCodeAndTempVRs();
temp_.ssa.work_live_vregs = new (temp_scoped_alloc_.get()) ArenaBitVector(
temp_scoped_alloc_.get(), temp_.ssa.num_vregs, false, kBitMapRegisterV);
}
void MIRGraph::SSATransformationEnd() {
// Verify the dataflow information after the pass.
if (cu_->enable_debug & (1 << kDebugVerifyDataflow)) {
VerifyDataflow();
}
temp_.ssa.num_vregs = 0u;
temp_.ssa.work_live_vregs = nullptr;
DCHECK(temp_.ssa.def_block_matrix == nullptr);
temp_.ssa.phi_node_blocks = nullptr;
DCHECK(temp_scoped_alloc_.get() != nullptr);
temp_scoped_alloc_.reset();
// Update the maximum number of reachable blocks.
max_num_reachable_blocks_ = num_reachable_blocks_;
// Mark MIR SSA representations as up to date.
mir_ssa_rep_up_to_date_ = true;
}
size_t MIRGraph::GetNumDalvikInsns() const {
size_t cumulative_size = 0u;
bool counted_current_item = false;
const uint8_t size_for_null_code_item = 2u;
for (auto it : m_units_) {
const DexFile::CodeItem* code_item = it->GetCodeItem();
// Even if the code item is null, we still count non-zero value so that
// each m_unit is counted as having impact.
cumulative_size += (code_item == nullptr ?
size_for_null_code_item : code_item->insns_size_in_code_units_);
if (code_item == current_code_item_) {
counted_current_item = true;
}
}
// If the current code item was not counted yet, count it now.
// This can happen for example in unit tests where some fields like m_units_
// are not initialized.
if (counted_current_item == false) {
cumulative_size += (current_code_item_ == nullptr ?
size_for_null_code_item : current_code_item_->insns_size_in_code_units_);
}
return cumulative_size;
}
static BasicBlock* SelectTopologicalSortOrderFallBack(
MIRGraph* mir_graph, const ArenaBitVector* current_loop,
const ScopedArenaVector<size_t>* visited_cnt_values, ScopedArenaAllocator* allocator,
ScopedArenaVector<BasicBlockId>* tmp_stack) {
// No true loop head has been found but there may be true loop heads after the mess we need
// to resolve. To avoid taking one of those, pick the candidate with the highest number of
// reachable unvisited nodes. That candidate will surely be a part of a loop.
BasicBlock* fall_back = nullptr;
size_t fall_back_num_reachable = 0u;
// Reuse the same bit vector for each candidate to mark reachable unvisited blocks.
ArenaBitVector candidate_reachable(allocator, mir_graph->GetNumBlocks(), false, kBitMapMisc);
AllNodesIterator iter(mir_graph);
for (BasicBlock* candidate = iter.Next(); candidate != nullptr; candidate = iter.Next()) {
if (candidate->hidden || // Hidden, or
candidate->visited || // already processed, or
(*visited_cnt_values)[candidate->id] == 0u || // no processed predecessors, or
(current_loop != nullptr && // outside current loop.
!current_loop->IsBitSet(candidate->id))) {
continue;
}
DCHECK(tmp_stack->empty());
tmp_stack->push_back(candidate->id);
candidate_reachable.ClearAllBits();
size_t num_reachable = 0u;
while (!tmp_stack->empty()) {
BasicBlockId current_id = tmp_stack->back();
tmp_stack->pop_back();
BasicBlock* current_bb = mir_graph->GetBasicBlock(current_id);
DCHECK(current_bb != nullptr);
ChildBlockIterator child_iter(current_bb, mir_graph);
BasicBlock* child_bb = child_iter.Next();
for ( ; child_bb != nullptr; child_bb = child_iter.Next()) {
DCHECK(!child_bb->hidden);
if (child_bb->visited || // Already processed, or
(current_loop != nullptr && // outside current loop.
!current_loop->IsBitSet(child_bb->id))) {
continue;
}
if (!candidate_reachable.IsBitSet(child_bb->id)) {
candidate_reachable.SetBit(child_bb->id);
tmp_stack->push_back(child_bb->id);
num_reachable += 1u;
}
}
}
if (fall_back_num_reachable < num_reachable) {
fall_back_num_reachable = num_reachable;
fall_back = candidate;
}
}
return fall_back;
}
// Compute from which unvisited blocks is bb_id reachable through unvisited blocks.
static void ComputeUnvisitedReachableFrom(MIRGraph* mir_graph, BasicBlockId bb_id,
ArenaBitVector* reachable,
ScopedArenaVector<BasicBlockId>* tmp_stack) {
// NOTE: Loop heads indicated by the "visited" flag.
DCHECK(tmp_stack->empty());
reachable->ClearAllBits();
tmp_stack->push_back(bb_id);
while (!tmp_stack->empty()) {
BasicBlockId current_id = tmp_stack->back();
tmp_stack->pop_back();
BasicBlock* current_bb = mir_graph->GetBasicBlock(current_id);
DCHECK(current_bb != nullptr);
for (BasicBlockId pred_id : current_bb->predecessors) {
BasicBlock* pred_bb = mir_graph->GetBasicBlock(pred_id);
DCHECK(pred_bb != nullptr);
if (!pred_bb->visited && !reachable->IsBitSet(pred_bb->id)) {
reachable->SetBit(pred_bb->id);
tmp_stack->push_back(pred_bb->id);
}
}
}
}
void MIRGraph::ComputeTopologicalSortOrder() {
ScopedArenaAllocator allocator(&cu_->arena_stack);
unsigned int num_blocks = GetNumBlocks();
ScopedArenaQueue<BasicBlock*> q(allocator.Adapter());
ScopedArenaVector<size_t> visited_cnt_values(num_blocks, 0u, allocator.Adapter());
ScopedArenaVector<BasicBlockId> loop_head_stack(allocator.Adapter());
size_t max_nested_loops = 0u;
ArenaBitVector loop_exit_blocks(&allocator, num_blocks, false, kBitMapMisc);
loop_exit_blocks.ClearAllBits();
// Count the number of blocks to process and add the entry block(s).
unsigned int num_blocks_to_process = 0u;
for (BasicBlock* bb : block_list_) {
if (bb->hidden == true) {
continue;
}
num_blocks_to_process += 1u;
if (bb->predecessors.size() == 0u) {
// Add entry block to the queue.
q.push(bb);
}
}
// Clear the topological order arrays.
topological_order_.clear();
topological_order_.reserve(num_blocks);
topological_order_loop_ends_.clear();
topological_order_loop_ends_.resize(num_blocks, 0u);
topological_order_indexes_.clear();
topological_order_indexes_.resize(num_blocks, static_cast<uint16_t>(-1));
// Mark all blocks as unvisited.
ClearAllVisitedFlags();
// For loop heads, keep track from which blocks they are reachable not going through other
// loop heads. Other loop heads are excluded to detect the heads of nested loops. The children
// in this set go into the loop body, the other children are jumping over the loop.
ScopedArenaVector<ArenaBitVector*> loop_head_reachable_from(allocator.Adapter());
loop_head_reachable_from.resize(num_blocks, nullptr);
// Reuse the same temp stack whenever calculating a loop_head_reachable_from[loop_head_id].
ScopedArenaVector<BasicBlockId> tmp_stack(allocator.Adapter());
while (num_blocks_to_process != 0u) {
BasicBlock* bb = nullptr;
if (!q.empty()) {
num_blocks_to_process -= 1u;
// Get top.
bb = q.front();
q.pop();
if (bb->visited) {
// Loop head: it was already processed, mark end and copy exit blocks to the queue.
DCHECK(q.empty()) << PrettyMethod(cu_->method_idx, *cu_->dex_file);
uint16_t idx = static_cast<uint16_t>(topological_order_.size());
topological_order_loop_ends_[topological_order_indexes_[bb->id]] = idx;
DCHECK_EQ(loop_head_stack.back(), bb->id);
loop_head_stack.pop_back();
ArenaBitVector* reachable =
loop_head_stack.empty() ? nullptr : loop_head_reachable_from[loop_head_stack.back()];
for (BasicBlockId candidate_id : loop_exit_blocks.Indexes()) {
if (reachable == nullptr || reachable->IsBitSet(candidate_id)) {
q.push(GetBasicBlock(candidate_id));
// NOTE: The BitVectorSet::IndexIterator will not check the pointed-to bit again,
// so clearing the bit has no effect on the iterator.
loop_exit_blocks.ClearBit(candidate_id);
}
}
continue;
}
} else {
// Find the new loop head.
AllNodesIterator iter(this);
while (true) {
BasicBlock* candidate = iter.Next();
if (candidate == nullptr) {
// We did not find a true loop head, fall back to a reachable block in any loop.
ArenaBitVector* current_loop =
loop_head_stack.empty() ? nullptr : loop_head_reachable_from[loop_head_stack.back()];
bb = SelectTopologicalSortOrderFallBack(this, current_loop, &visited_cnt_values,
&allocator, &tmp_stack);
DCHECK(bb != nullptr) << PrettyMethod(cu_->method_idx, *cu_->dex_file);
if (kIsDebugBuild && cu_->dex_file != nullptr) {
LOG(INFO) << "Topological sort order: Using fall-back in "
<< PrettyMethod(cu_->method_idx, *cu_->dex_file) << " BB #" << bb->id
<< " @0x" << std::hex << bb->start_offset
<< ", num_blocks = " << std::dec << num_blocks;
}
break;
}
if (candidate->hidden || // Hidden, or
candidate->visited || // already processed, or
visited_cnt_values[candidate->id] == 0u || // no processed predecessors, or
(!loop_head_stack.empty() && // outside current loop.
!loop_head_reachable_from[loop_head_stack.back()]->IsBitSet(candidate->id))) {
continue;
}
for (BasicBlockId pred_id : candidate->predecessors) {
BasicBlock* pred_bb = GetBasicBlock(pred_id);
DCHECK(pred_bb != nullptr);
if (pred_bb != candidate && !pred_bb->visited &&
!pred_bb->dominators->IsBitSet(candidate->id)) {
candidate = nullptr; // Set candidate to null to indicate failure.
break;
}
}
if (candidate != nullptr) {
bb = candidate;
break;
}
}
// Compute blocks from which the loop head is reachable and process those blocks first.
ArenaBitVector* reachable =
new (&allocator) ArenaBitVector(&allocator, num_blocks, false, kBitMapMisc);
loop_head_reachable_from[bb->id] = reachable;
ComputeUnvisitedReachableFrom(this, bb->id, reachable, &tmp_stack);
// Now mark as loop head. (Even if it's only a fall back when we don't find a true loop.)
loop_head_stack.push_back(bb->id);
max_nested_loops = std::max(max_nested_loops, loop_head_stack.size());
}
DCHECK_EQ(bb->hidden, false);
DCHECK_EQ(bb->visited, false);
bb->visited = true;
bb->nesting_depth = loop_head_stack.size();
// Now add the basic block.
uint16_t idx = static_cast<uint16_t>(topological_order_.size());
topological_order_indexes_[bb->id] = idx;
topological_order_.push_back(bb->id);
// Update visited_cnt_values for children.
ChildBlockIterator succIter(bb, this);
BasicBlock* successor = succIter.Next();
for ( ; successor != nullptr; successor = succIter.Next()) {
if (successor->hidden) {
continue;
}
// One more predecessor was visited.
visited_cnt_values[successor->id] += 1u;
if (visited_cnt_values[successor->id] == successor->predecessors.size()) {
if (loop_head_stack.empty() ||
loop_head_reachable_from[loop_head_stack.back()]->IsBitSet(successor->id)) {
q.push(successor);
} else {
DCHECK(!loop_exit_blocks.IsBitSet(successor->id));
loop_exit_blocks.SetBit(successor->id);
}
}
}
}
// Prepare the loop head stack for iteration.
topological_order_loop_head_stack_.clear();
topological_order_loop_head_stack_.reserve(max_nested_loops);
max_nested_loops_ = max_nested_loops;
topological_order_up_to_date_ = true;
}
bool BasicBlock::IsExceptionBlock() const {
if (block_type == kExceptionHandling) {
return true;
}
return false;
}
ChildBlockIterator::ChildBlockIterator(BasicBlock* bb, MIRGraph* mir_graph)
: basic_block_(bb), mir_graph_(mir_graph), visited_fallthrough_(false),
visited_taken_(false), have_successors_(false) {
// Check if we actually do have successors.
if (basic_block_ != 0 && basic_block_->successor_block_list_type != kNotUsed) {
have_successors_ = true;
successor_iter_ = basic_block_->successor_blocks.cbegin();
}
}
BasicBlock* ChildBlockIterator::Next() {
// We check if we have a basic block. If we don't we cannot get next child.
if (basic_block_ == nullptr) {
return nullptr;
}
// If we haven't visited fallthrough, return that.
if (visited_fallthrough_ == false) {
visited_fallthrough_ = true;
BasicBlock* result = mir_graph_->GetBasicBlock(basic_block_->fall_through);
if (result != nullptr) {
return result;
}
}
// If we haven't visited taken, return that.
if (visited_taken_ == false) {
visited_taken_ = true;
BasicBlock* result = mir_graph_->GetBasicBlock(basic_block_->taken);
if (result != nullptr) {
return result;
}
}
// We visited both taken and fallthrough. Now check if we have successors we need to visit.
if (have_successors_ == true) {
// Get information about next successor block.
auto end = basic_block_->successor_blocks.cend();
while (successor_iter_ != end) {
SuccessorBlockInfo* successor_block_info = *successor_iter_;
++successor_iter_;
// If block was replaced by zero block, take next one.
if (successor_block_info->block != NullBasicBlockId) {
return mir_graph_->GetBasicBlock(successor_block_info->block);
}
}
}
// We do not have anything.
return nullptr;
}
BasicBlock* BasicBlock::Copy(CompilationUnit* c_unit) {
MIRGraph* mir_graph = c_unit->mir_graph.get();
return Copy(mir_graph);
}
BasicBlock* BasicBlock::Copy(MIRGraph* mir_graph) {
BasicBlock* result_bb = mir_graph->CreateNewBB(block_type);
// We don't do a memcpy style copy here because it would lead to a lot of things
// to clean up. Let us do it by hand instead.
// Copy in taken and fallthrough.
result_bb->fall_through = fall_through;
result_bb->taken = taken;
// Copy successor links if needed.
ArenaAllocator* arena = mir_graph->GetArena();
result_bb->successor_block_list_type = successor_block_list_type;
if (result_bb->successor_block_list_type != kNotUsed) {
result_bb->successor_blocks.reserve(successor_blocks.size());
for (SuccessorBlockInfo* sbi_old : successor_blocks) {
SuccessorBlockInfo* sbi_new = static_cast<SuccessorBlockInfo*>(
arena->Alloc(sizeof(SuccessorBlockInfo), kArenaAllocSuccessors));
memcpy(sbi_new, sbi_old, sizeof(SuccessorBlockInfo));
result_bb->successor_blocks.push_back(sbi_new);
}
}
// Copy offset, method.
result_bb->start_offset = start_offset;
// Now copy instructions.
for (MIR* mir = first_mir_insn; mir != 0; mir = mir->next) {
// Get a copy first.
MIR* copy = mir->Copy(mir_graph);
// Append it.
result_bb->AppendMIR(copy);
}
return result_bb;
}
MIR* MIR::Copy(MIRGraph* mir_graph) {
MIR* res = mir_graph->NewMIR();
*res = *this;
// Remove links
res->next = nullptr;
res->bb = NullBasicBlockId;
res->ssa_rep = nullptr;
return res;
}
MIR* MIR::Copy(CompilationUnit* c_unit) {
return Copy(c_unit->mir_graph.get());
}
uint32_t SSARepresentation::GetStartUseIndex(Instruction::Code opcode) {
// Default result.
int res = 0;
// We are basically setting the iputs to their igets counterparts.
switch (opcode) {
case Instruction::IPUT:
case Instruction::IPUT_OBJECT:
case Instruction::IPUT_BOOLEAN:
case Instruction::IPUT_BYTE:
case Instruction::IPUT_CHAR:
case Instruction::IPUT_SHORT:
case Instruction::IPUT_QUICK:
case Instruction::IPUT_OBJECT_QUICK:
case Instruction::IPUT_BOOLEAN_QUICK:
case Instruction::IPUT_BYTE_QUICK:
case Instruction::IPUT_CHAR_QUICK:
case Instruction::IPUT_SHORT_QUICK:
case Instruction::APUT:
case Instruction::APUT_OBJECT:
case Instruction::APUT_BOOLEAN:
case Instruction::APUT_BYTE:
case Instruction::APUT_CHAR:
case Instruction::APUT_SHORT:
case Instruction::SPUT:
case Instruction::SPUT_OBJECT:
case Instruction::SPUT_BOOLEAN:
case Instruction::SPUT_BYTE:
case Instruction::SPUT_CHAR:
case Instruction::SPUT_SHORT:
// Skip the VR containing what to store.
res = 1;
break;
case Instruction::IPUT_WIDE:
case Instruction::IPUT_WIDE_QUICK:
case Instruction::APUT_WIDE:
case Instruction::SPUT_WIDE:
// Skip the two VRs containing what to store.
res = 2;
break;
default:
// Do nothing in the general case.
break;
}
return res;
}
/**
* @brief Given a decoded instruction, it checks whether the instruction
* sets a constant and if it does, more information is provided about the
* constant being set.
* @param ptr_value pointer to a 64-bit holder for the constant.
* @param wide Updated by function whether a wide constant is being set by bytecode.
* @return Returns false if the decoded instruction does not represent a constant bytecode.
*/
bool MIR::DecodedInstruction::GetConstant(int64_t* ptr_value, bool* wide) const {
bool sets_const = true;
int64_t value = vB;
DCHECK(ptr_value != nullptr);
DCHECK(wide != nullptr);
switch (opcode) {
case Instruction::CONST_4:
case Instruction::CONST_16:
case Instruction::CONST:
*wide = false;
value <<= 32; // In order to get the sign extend.
value >>= 32;
break;
case Instruction::CONST_HIGH16:
*wide = false;
value <<= 48; // In order to get the sign extend.
value >>= 32;
break;
case Instruction::CONST_WIDE_16:
case Instruction::CONST_WIDE_32:
*wide = true;
value <<= 32; // In order to get the sign extend.
value >>= 32;
break;
case Instruction::CONST_WIDE:
*wide = true;
value = vB_wide;
break;
case Instruction::CONST_WIDE_HIGH16:
*wide = true;
value <<= 48; // In order to get the sign extend.
break;
default:
sets_const = false;
break;
}
if (sets_const) {
*ptr_value = value;
}
return sets_const;
}
void BasicBlock::ResetOptimizationFlags(uint16_t reset_flags) {
// Reset flags for all MIRs in bb.
for (MIR* mir = first_mir_insn; mir != nullptr; mir = mir->next) {
mir->optimization_flags &= (~reset_flags);
}
}
void BasicBlock::Kill(MIRGraph* mir_graph) {
for (BasicBlockId pred_id : predecessors) {
BasicBlock* pred_bb = mir_graph->GetBasicBlock(pred_id);
DCHECK(pred_bb != nullptr);
// Sadly we have to go through the children by hand here.
pred_bb->ReplaceChild(id, NullBasicBlockId);
}
predecessors.clear();
// Mark as dead and hidden.
block_type = kDead;
hidden = true;
// Detach it from its MIRs so we don't generate code for them. Also detached MIRs
// are updated to know that they no longer have a parent.
for (MIR* mir = first_mir_insn; mir != nullptr; mir = mir->next) {
mir->bb = NullBasicBlockId;
}
first_mir_insn = nullptr;
last_mir_insn = nullptr;
data_flow_info = nullptr;
// Erase this bb from all children's predecessors and kill unreachable children.
ChildBlockIterator iter(this, mir_graph);
for (BasicBlock* succ_bb = iter.Next(); succ_bb != nullptr; succ_bb = iter.Next()) {
succ_bb->ErasePredecessor(id);
}
// Remove links to children.
fall_through = NullBasicBlockId;
taken = NullBasicBlockId;
successor_block_list_type = kNotUsed;
if (kIsDebugBuild) {
if (catch_entry) {
DCHECK_EQ(mir_graph->catches_.count(start_offset), 1u);
mir_graph->catches_.erase(start_offset);
}
}
}
bool BasicBlock::IsSSALiveOut(const CompilationUnit* c_unit, int ssa_reg) {
// In order to determine if the ssa reg is live out, we scan all the MIRs. We remember
// the last SSA number of the same dalvik register. At the end, if it is different than ssa_reg,
// then it is not live out of this BB.
int dalvik_reg = c_unit->mir_graph->SRegToVReg(ssa_reg);
int last_ssa_reg = -1;
// Walk through the MIRs backwards.
for (MIR* mir = first_mir_insn; mir != nullptr; mir = mir->next) {
// Get ssa rep.
SSARepresentation *ssa_rep = mir->ssa_rep;
// Go through the defines for this MIR.
for (int i = 0; i < ssa_rep->num_defs; i++) {
DCHECK(ssa_rep->defs != nullptr);
// Get the ssa reg.
int def_ssa_reg = ssa_rep->defs[i];
// Get dalvik reg.
int def_dalvik_reg = c_unit->mir_graph->SRegToVReg(def_ssa_reg);
// Compare dalvik regs.
if (dalvik_reg == def_dalvik_reg) {
// We found a def of the register that we are being asked about.
// Remember it.
last_ssa_reg = def_ssa_reg;
}
}
}
if (last_ssa_reg == -1) {
// If we get to this point we couldn't find a define of register user asked about.
// Let's assume the user knows what he's doing so we can be safe and say that if we
// couldn't find a def, it is live out.
return true;
}
// If it is not -1, we found a match, is it ssa_reg?
return (ssa_reg == last_ssa_reg);
}
bool BasicBlock::ReplaceChild(BasicBlockId old_bb, BasicBlockId new_bb) {
// We need to check taken, fall_through, and successor_blocks to replace.
bool found = false;
if (taken == old_bb) {
taken = new_bb;
found = true;
}
if (fall_through == old_bb) {
fall_through = new_bb;
found = true;
}
if (successor_block_list_type != kNotUsed) {
for (SuccessorBlockInfo* successor_block_info : successor_blocks) {
if (successor_block_info->block == old_bb) {
successor_block_info->block = new_bb;
found = true;
}
}
}
return found;
}
void BasicBlock::ErasePredecessor(BasicBlockId old_pred) {
auto pos = std::find(predecessors.begin(), predecessors.end(), old_pred);
DCHECK(pos != predecessors.end());
// It's faster to move the back() to *pos than erase(pos).
*pos = predecessors.back();
predecessors.pop_back();
size_t idx = std::distance(predecessors.begin(), pos);
for (MIR* mir = first_mir_insn; mir != nullptr; mir = mir->next) {
if (static_cast<int>(mir->dalvikInsn.opcode) != kMirOpPhi) {
break;
}
DCHECK_EQ(mir->ssa_rep->num_uses - 1u, predecessors.size());