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LeafOS / LeafOS-Project / android_art / ef7d42fca18c16fbaf103822ad16f23246e2905d / . / compiler / dex / mir_graph.cc
blob: 10bcdb977195549762cd272175ef5728ec45bcaf [file] [log] [blame]
/*
* 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 "base/stl_util.h"
#include "compiler_internals.h"
#include "dex_file-inl.h"
#include "leb128.h"
#include "mir_graph.h"
#include "dex/quick/dex_file_to_method_inliner_map.h"
#include "dex/quick/dex_file_method_inliner.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",
"Check1",
"Check2",
"Select",
};
MIRGraph::MIRGraph(CompilationUnit* cu, ArenaAllocator* arena)
: reg_location_(NULL),
cu_(cu),
ssa_base_vregs_(NULL),
ssa_subscripts_(NULL),
vreg_to_ssa_map_(NULL),
ssa_last_defs_(NULL),
is_constant_v_(NULL),
constant_values_(NULL),
use_counts_(arena, 256, kGrowableArrayMisc),
raw_use_counts_(arena, 256, kGrowableArrayMisc),
num_reachable_blocks_(0),
dfs_order_(NULL),
dfs_post_order_(NULL),
dom_post_order_traversal_(NULL),
i_dom_list_(NULL),
def_block_matrix_(NULL),
temp_block_v_(NULL),
temp_dalvik_register_v_(NULL),
temp_ssa_register_v_(NULL),
block_list_(arena, 100, kGrowableArrayBlockList),
try_block_addr_(NULL),
entry_block_(NULL),
exit_block_(NULL),
num_blocks_(0),
current_code_item_(NULL),
dex_pc_to_block_map_(arena, 0, kGrowableArrayMisc),
current_method_(kInvalidEntry),
current_offset_(kInvalidEntry),
def_count_(0),
opcode_count_(NULL),
num_ssa_regs_(0),
method_sreg_(0),
attributes_(METHOD_IS_LEAF), // Start with leaf assumption, change on encountering invoke.
checkstats_(NULL),
arena_(arena),
backward_branches_(0),
forward_branches_(0),
compiler_temps_(arena, 6, kGrowableArrayMisc),
num_non_special_compiler_temps_(0),
max_available_non_special_compiler_temps_(0) {
try_block_addr_ = new (arena_) ArenaBitVector(arena_, 0, true /* expandable */);
max_available_special_compiler_temps_ = std::abs(static_cast<int>(kVRegNonSpecialTempBaseReg))
- std::abs(static_cast<int>(kVRegTempBaseReg));
}
MIRGraph::~MIRGraph() {
STLDeleteElements(&m_units_);
}
/*
* Parse an instruction, return the length of the instruction
*/
int MIRGraph::ParseInsn(const uint16_t* code_ptr, DecodedInstruction* decoded_instruction) {
const Instruction* instruction = Instruction::At(code_ptr);
*decoded_instruction = DecodedInstruction(instruction);
return instruction->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 = NULL;
while (insn) {
if (insn->offset == code_offset) break;
prev = insn;
insn = insn->next;
}
if (insn == NULL) {
LOG(FATAL) << "Break split failed";
}
BasicBlock *bottom_block = NewMemBB(kDalvikByteCode, num_blocks_++);
block_list_.Insert(bottom_block);
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, 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;
/* 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->predecessors->Delete(orig_block->id);
bb_taken->predecessors->Insert(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->Insert(orig_block->id);
if (bottom_block->fall_through != NullBasicBlockId) {
BasicBlock* bb_fall_through = GetBasicBlock(bottom_block->fall_through);
bb_fall_through->predecessors->Delete(orig_block->id);
bb_fall_through->predecessors->Insert(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 = orig_block->successor_blocks;
orig_block->successor_block_list_type = kNotUsed;
orig_block->successor_blocks = NULL;
GrowableArray<SuccessorBlockInfo*>::Iterator iterator(bottom_block->successor_blocks);
while (true) {
SuccessorBlockInfo *successor_block_info = iterator.Next();
if (successor_block_info == NULL) break;
BasicBlock *bb = GetBasicBlock(successor_block_info->block);
bb->predecessors->Delete(orig_block->id);
bb->predecessors->Insert(bottom_block->id);
}
}
orig_block->last_mir_insn = prev;
prev->next = NULL;
/*
* 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);
DCHECK(static_cast<int>(insn->dalvikInsn.opcode) == kMirOpCheck ||
!IsPseudoMirOp(insn->dalvikInsn.opcode));
DCHECK_EQ(dex_pc_to_block_map_.Get(insn->offset), orig_block->id);
MIR* p = insn;
dex_pc_to_block_map_.Put(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) || !IsPseudoMirOp(opcode)) {
DCHECK_EQ(dex_pc_to_block_map_.Get(p->offset), orig_block->id);
dex_pc_to_block_map_.Put(p->offset, 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 split, bool create,
BasicBlock** immed_pred_block_p) {
if (code_offset >= cu_->code_item->insns_size_in_code_units_) {
return NULL;
}
int block_id = dex_pc_to_block_map_.Get(code_offset);
BasicBlock* bb = (block_id == 0) ? NULL : block_list_.Get(block_id);
if ((bb != NULL) && (bb->start_offset == code_offset)) {
// Does this containing block start with the desired instruction?
return bb;
}
// No direct hit.
if (!create) {
return NULL;
}
if (bb != NULL) {
// The target exists somewhere in an existing block.
return SplitBlock(code_offset, bb, bb == *immed_pred_block_p ? immed_pred_block_p : NULL);
}
// Create a new block.
bb = NewMemBB(kDalvikByteCode, num_blocks_++);
block_list_.Insert(bb);
bb->start_offset = code_offset;
dex_pc_to_block_map_.Put(bb->start_offset, bb->id);
return bb;
}
/* Identify code range in try blocks and set up the empty catch blocks */
void MIRGraph::ProcessTryCatchBlocks() {
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 byte* 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, false /* split */, true /*create*/,
/* immed_pred_block_p */ NULL);
}
handlers_ptr = iterator.EndDataPointer();
}
}
/* 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) {
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, /* split */ true, /* create */ true,
/* immed_pred_block_p */ &cur_block);
cur_block->taken = taken_block->id;
taken_block->predecessors->Insert(cur_block->id);
/* Always terminate the current block for conditional branches */
if (flags & Instruction::kContinue) {
BasicBlock *fallthrough_block = FindBlock(cur_offset + width,
/*
* If the method is processed
* in sequential order from the
* beginning, we don't need to
* specify split for continue
* blocks. However, this
* routine can be called by
* compileLoop, which starts
* parsing the method from an
* arbitrary address in the
* method body.
*/
true,
/* create */
true,
/* immed_pred_block_p */
&cur_block);
cur_block->fall_through = fallthrough_block->id;
fallthrough_block->predecessors->Insert(cur_block->id);
} else if (code_ptr < code_end) {
FindBlock(cur_offset + width, /* split */ false, /* create */ true,
/* immed_pred_block_p */ NULL);
}
return cur_block;
}
/* Process instructions with the kSwitch flag */
BasicBlock* MIRGraph::ProcessCanSwitch(BasicBlock* cur_block, MIR* insn, DexOffset cur_offset,
int width, int flags) {
const uint16_t* switch_data =
reinterpret_cast<const uint16_t*>(GetCurrentInsns() + cur_offset + 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 = NULL; // 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 =
new (arena_) GrowableArray<SuccessorBlockInfo*>(arena_, size, kGrowableArraySuccessorBlocks);
for (i = 0; i < size; i++) {
BasicBlock *case_block = FindBlock(cur_offset + target_table[i], /* split */ true,
/* create */ true, /* immed_pred_block_p */ &cur_block);
SuccessorBlockInfo *successor_block_info =
static_cast<SuccessorBlockInfo*>(arena_->Alloc(sizeof(SuccessorBlockInfo),
ArenaAllocator::kAllocSuccessor));
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->Insert(successor_block_info);
case_block->predecessors->Insert(cur_block->id);
}
/* Fall-through case */
BasicBlock* fallthrough_block = FindBlock(cur_offset + width, /* split */ false,
/* create */ true, /* immed_pred_block_p */ NULL);
cur_block->fall_through = fallthrough_block->id;
fallthrough_block->predecessors->Insert(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, ArenaBitVector* try_block_addr,
const uint16_t* code_ptr, const uint16_t* code_end) {
bool in_try_block = try_block_addr->IsBitSet(cur_offset);
bool is_throw = (insn->dalvikInsn.opcode == Instruction::THROW);
bool build_all_edges =
(cu_->disable_opt & (1 << kSuppressExceptionEdges)) || is_throw || in_try_block;
/* 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);
}
cur_block->successor_block_list_type = kCatch;
cur_block->successor_blocks =
new (arena_) GrowableArray<SuccessorBlockInfo*>(arena_, 2, kGrowableArraySuccessorBlocks);
for (; iterator.HasNext(); iterator.Next()) {
BasicBlock *catch_block = FindBlock(iterator.GetHandlerAddress(), false /* split*/,
false /* creat */, NULL /* immed_pred_block_p */);
catch_block->catch_entry = true;
if (kIsDebugBuild) {
catches_.insert(catch_block->start_offset);
}
SuccessorBlockInfo *successor_block_info = reinterpret_cast<SuccessorBlockInfo*>
(arena_->Alloc(sizeof(SuccessorBlockInfo), ArenaAllocator::kAllocSuccessor));
successor_block_info->block = catch_block->id;
successor_block_info->key = iterator.GetHandlerTypeIndex();
cur_block->successor_blocks->Insert(successor_block_info);
catch_block->predecessors->Insert(cur_block->id);
}
} else if (build_all_edges) {
BasicBlock *eh_block = NewMemBB(kExceptionHandling, num_blocks_++);
cur_block->taken = eh_block->id;
block_list_.Insert(eh_block);
eh_block->start_offset = cur_offset;
eh_block->predecessors->Insert(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, /* split */ false, /* create */ true,
/* immed_pred_block_p */ NULL);
}
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 = NewMemBB(kDalvikByteCode, num_blocks_++);
block_list_.Insert(new_block);
new_block->start_offset = insn->offset;
cur_block->fall_through = new_block->id;
new_block->predecessors->Insert(cur_block->id);
MIR* new_insn = static_cast<MIR*>(arena_->Alloc(sizeof(MIR), ArenaAllocator::kAllocMIR));
*new_insn = *insn;
insn->dalvikInsn.opcode =
static_cast<Instruction::Code>(kMirOpCheck);
// Associate the two halves
insn->meta.throw_insn = new_insn;
AppendMIR(new_block, 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, uint16_t class_def_idx,
uint32_t method_idx, jobject class_loader, const DexFile& dex_file) {
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 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)));
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_.Resize(block_list_.Size() + current_code_item_->insns_size_in_code_units_);
dex_pc_to_block_map_.SetSize(dex_pc_to_block_map_.Size() + current_code_item_->insns_size_in_code_units_);
// 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_ == NULL);
DCHECK(exit_block_ == NULL);
DCHECK_EQ(num_blocks_, 0);
// Use id 0 to represent a null block.
BasicBlock* null_block = NewMemBB(kNullBlock, num_blocks_++);
DCHECK_EQ(null_block->id, NullBasicBlockId);
null_block->hidden = true;
block_list_.Insert(null_block);
entry_block_ = NewMemBB(kEntryBlock, num_blocks_++);
block_list_.Insert(entry_block_);
exit_block_ = NewMemBB(kExitBlock, num_blocks_++);
block_list_.Insert(exit_block_);
// TODO: deprecate all "cu->" fields; move what's left to wherever CompilationUnit is allocated.
cu_->dex_file = &dex_file;
cu_->class_def_idx = class_def_idx;
cu_->method_idx = method_idx;
cu_->access_flags = access_flags;
cu_->invoke_type = invoke_type;
cu_->shorty = dex_file.GetMethodShorty(dex_file.GetMethodId(method_idx));
cu_->num_ins = current_code_item_->ins_size_;
cu_->num_regs = current_code_item_->registers_size_ - cu_->num_ins;
cu_->num_outs = current_code_item_->outs_size_;
cu_->num_dalvik_registers = current_code_item_->registers_size_;
cu_->insns = current_code_item_->insns_;
cu_->code_item = current_code_item_;
} 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 = NewMemBB(kDalvikByteCode, num_blocks_++);
DCHECK_EQ(current_offset_, 0U);
cur_block->start_offset = current_offset_;
block_list_.Insert(cur_block);
// TODO: for inlining support, insert at the insert point rather than entry block.
entry_block_->fall_through = cur_block->id;
cur_block->predecessors->Insert(entry_block_->id);
/* Identify code range in try blocks and set up the empty catch blocks */
ProcessTryCatchBlocks();
/* Parse all instructions and put them into containing basic blocks */
while (code_ptr < code_end) {
MIR *insn = static_cast<MIR *>(arena_->Alloc(sizeof(MIR), ArenaAllocator::kAllocMIR));
insn->offset = current_offset_;
insn->m_unit_index = current_method_;
int width = ParseInsn(code_ptr, &insn->dalvikInsn);
insn->width = width;
Instruction::Code opcode = insn->dalvikInsn.opcode;
if (opcode_count_ != NULL) {
opcode_count_[static_cast<int>(opcode)]++;
}
int flags = Instruction::FlagsOf(insn->dalvikInsn.opcode);
uint64_t df_flags = oat_data_flow_attributes_[insn->dalvikInsn.opcode];
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.
AppendMIR(cur_block, insn);
} else {
DCHECK(cur_block->fall_through == NullBasicBlockId);
DCHECK(cur_block->taken == NullBasicBlockId);
// Unreachable instruction, mark for no continuation.
flags &= ~Instruction::kContinue;
}
} else {
AppendMIR(cur_block, insn);
}
// Associate the starting dex_pc for this opcode with its containing basic block.
dex_pc_to_block_map_.Put(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);
} else if (flags & Instruction::kReturn) {
cur_block->terminated_by_return = true;
cur_block->fall_through = exit_block_->id;
exit_block_->predecessors->Insert(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, /* split */ false, /* create */ true,
/* immed_pred_block_p */ NULL);
}
} else if (flags & Instruction::kThrow) {
cur_block = ProcessCanThrow(cur_block, insn, current_offset_, width, flags, try_block_addr_,
code_ptr, code_end);
} else if (flags & Instruction::kSwitch) {
cur_block = ProcessCanSwitch(cur_block, insn, current_offset_, width, flags);
}
current_offset_ += width;
BasicBlock *next_block = FindBlock(current_offset_, /* split */ false, /* create */
false, /* immed_pred_block_p */ NULL);
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->Insert(cur_block->id);
}
cur_block = next_block;
}
}
if (cu_->enable_debug & (1 << kDebugDumpCFG)) {
DumpCFG("/sdcard/1_post_parse_cfg/", true);
}
if (cu_->verbose) {
DumpMIRGraph();
}
}
void MIRGraph::ShowOpcodeStats() {
DCHECK(opcode_count_ != NULL);
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];
}
}
}
// 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;
std::string fname(PrettyMethod(cu_->method_idx, *cu_->dex_file));
ReplaceSpecialChars(fname);
fname = StringPrintf("%s%s%x%s.dot", dir_prefix, fname.c_str(),
GetBasicBlock(GetEntryBlock()->fall_through)->start_offset,
suffix == nullptr ? "" : suffix);
file = fopen(fname.c_str(), "w");
if (file == NULL) {
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_->Get(idx);
BasicBlock *bb = GetBasicBlock(block_idx);
if (bb == NULL) break;
if (bb->block_type == kDead) 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\\l}%s\\\n", mir->offset,
mir->ssa_rep ? GetDalvikDisassembly(mir) :
(opcode < kMirOpFirst) ? 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->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");
GrowableArray<SuccessorBlockInfo*>::Iterator iterator(bb->successor_blocks);
SuccessorBlockInfo *successor_block_info = iterator.Next();
int succ_id = 0;
while (true) {
if (successor_block_info == NULL) break;
BasicBlock *dest_block = GetBasicBlock(successor_block_info->block);
SuccessorBlockInfo *next_successor_block_info = iterator.Next();
fprintf(file, " {<f%d> %04x: %04x\\l}%s\\\n",
succ_id++,
successor_block_info->key,
dest_block->start_offset,
(next_successor_block_info != NULL) ? " | " : " ");
successor_block_info = next_successor_block_info;
}
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);
if (bb->successor_block_list_type == kPackedSwitch ||
bb->successor_block_list_type == kSparseSwitch) {
GrowableArray<SuccessorBlockInfo*>::Iterator iter(bb->successor_blocks);
succ_id = 0;
while (true) {
SuccessorBlockInfo *successor_block_info = iter.Next();
if (successor_block_info == NULL) break;
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 MIRGraph::AppendMIR(BasicBlock* bb, MIR* mir) {
if (bb->first_mir_insn == NULL) {
DCHECK(bb->last_mir_insn == NULL);
bb->last_mir_insn = bb->first_mir_insn = mir;
mir->next = NULL;
} else {
bb->last_mir_insn->next = mir;
mir->next = NULL;
bb->last_mir_insn = mir;
}
}
/* Insert an MIR instruction to the head of a basic block */
void MIRGraph::PrependMIR(BasicBlock* bb, MIR* mir) {
if (bb->first_mir_insn == NULL) {
DCHECK(bb->last_mir_insn == NULL);
bb->last_mir_insn = bb->first_mir_insn = mir;
mir->next = NULL;
} else {
mir->next = bb->first_mir_insn;
bb->first_mir_insn = mir;
}
}
/* Insert a MIR instruction after the specified MIR */
void MIRGraph::InsertMIRAfter(BasicBlock* bb, MIR* current_mir, MIR* new_mir) {
new_mir->next = current_mir->next;
current_mir->next = new_mir;
if (bb->last_mir_insn == current_mir) {
/* Is the last MIR in the block */
bb->last_mir_insn = new_mir;
}
}
char* MIRGraph::GetDalvikDisassembly(const 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
int defs = (ssa_rep != NULL) ? ssa_rep->num_defs : 0;
int uses = (ssa_rep != NULL) ? ssa_rep->num_uses : 0;
// Handle special cases.
if ((opcode == kMirOpCheck) || (opcode == kMirOpCheckPart2)) {
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;
defs = ssa_rep->num_defs;
uses = ssa_rep->num_uses;
opcode = insn.opcode;
} else if (opcode == kMirOpNop) {
str.append("[");
// Recover original opcode.
insn.opcode = Instruction::At(current_code_item_->insns_ + mir->offset)->Opcode();
opcode = insn.opcode;
nop = true;
}
if (opcode >= kMirOpFirst) {
str.append(extended_mir_op_names_[opcode - kMirOpFirst]);
} else {
dalvik_format = Instruction::FormatOf(insn.opcode);
flags = Instruction::FlagsOf(insn.opcode);
str.append(Instruction::Name(insn.opcode));
}
if (opcode == kMirOpPhi) {
BasicBlockId* incoming = mir->meta.phi_incoming;
str.append(StringPrintf(" %s = (%s",
GetSSANameWithConst(ssa_rep->defs[0], true).c_str(),
GetSSANameWithConst(ssa_rep->uses[0], true).c_str()));
str.append(StringPrintf(":%d", incoming[0]));
int i;
for (i = 1; i < uses; i++) {
str.append(StringPrintf(", %s:%d",
GetSSANameWithConst(ssa_rep->uses[i], true).c_str(),
incoming[i]));
}
str.append(")");
} else 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:
str.append(StringPrintf(" %s,", GetSSANameWithConst(ssa_rep->uses[0], false).c_str()));
offset = insn.vB;
break;
case Instruction::k22t:
str.append(StringPrintf(" %s, %s,", GetSSANameWithConst(ssa_rep->uses[0], false).c_str(),
GetSSANameWithConst(ssa_rep->uses[1], false).c_str()));
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;
}
str.append(StringPrintf(" 0x%x (%c%x)", mir->offset + offset,
offset > 0 ? '+' : '-', offset > 0 ? offset : -offset));
} else {
// 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(StringPrintf(" %s", GetSSANameWithConst(ssa_rep->defs[0], false).c_str()));
if (uses != 0) {
str.append(", ");
}
}
for (int i = 0; i < uses; i++) {
str.append(
StringPrintf(" %s", GetSSANameWithConst(ssa_rep->uses[i], show_singles).c_str()));
if (!show_singles && (reg_location_ != NULL) && 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(", #%d", 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 #%d", insn.vB));
break;
case Instruction::k22c: // Two registers, one string/type/method index
str.append(StringPrintf(", index #%d", insn.vC));
break;
case Instruction::k22s: // Add one immediate from vC
case Instruction::k22b:
str.append(StringPrintf(", #%d", insn.vC));
break;
default: {
// Nothing left to print
}
}
}
if (nop) {
str.append("]--optimized away");
}
int length = str.length() + 1;
ret = static_cast<char*>(arena_->Alloc(length, ArenaAllocator::kAllocDFInfo));
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 LLVM and 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.
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_ == NULL) {
// 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) {
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 {
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::GetShortyFromTargetIdx(int target_idx) {
// TODO: for inlining support, use current code unit.
const DexFile::MethodId& method_id = cu_->dex_file->GetMethodId(target_idx);
return cu_->dex_file->GetShorty(method_id.proto_idx_);
}
/* Debug Utility - dump a compilation unit */
void MIRGraph::DumpMIRGraph() {
BasicBlock* bb;
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) << cu_->insns << " insns";
LOG(INFO) << GetNumBlocks() << " blocks in total";
GrowableArray<BasicBlock*>::Iterator iterator(&block_list_);
while (true) {
bb = iterator.Next();
if (bb == NULL) break;
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),
ArenaAllocator::kAllocMisc));
MIR* move_result_mir = FindMoveResult(bb, mir);
if (move_result_mir == NULL) {
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) ? NULL : static_cast<RegLocation*>
(arena_->Alloc(sizeof(RegLocation) * info->num_arg_words, ArenaAllocator::kAllocMisc));
for (int 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;
info->index = mir->dalvikInsn.vB;
info->offset = mir->offset;
return info;
}
// Allocate a new basic block.
BasicBlock* MIRGraph::NewMemBB(BBType block_type, int block_id) {
BasicBlock* bb = static_cast<BasicBlock*>(arena_->Alloc(sizeof(BasicBlock),
ArenaAllocator::kAllocBB));
bb->block_type = block_type;
bb->id = block_id;
// TUNING: better estimate of the exit block predecessors?
bb->predecessors = new (arena_) GrowableArray<BasicBlockId>(arena_,
(block_type == kExitBlock) ? 2048 : 2,
kGrowableArrayPredecessors);
bb->successor_block_list_type = kNotUsed;
block_id_map_.Put(block_id, block_id);
return bb;
}
void MIRGraph::InitializeConstantPropagation() {
is_constant_v_ = new (arena_) ArenaBitVector(arena_, GetNumSSARegs(), false);
constant_values_ = static_cast<int*>(arena_->Alloc(sizeof(int) * GetNumSSARegs(), ArenaAllocator::kAllocDFInfo));
}
void MIRGraph::InitializeMethodUses() {
// The gate starts by initializing the use counts
int num_ssa_regs = GetNumSSARegs();
use_counts_.Resize(num_ssa_regs + 32);
raw_use_counts_.Resize(num_ssa_regs + 32);
// Initialize list
for (int i = 0; i < num_ssa_regs; i++) {
use_counts_.Insert(0);
raw_use_counts_.Insert(0);
}
}
void MIRGraph::InitializeSSATransformation() {
/* Compute the DFS order */
ComputeDFSOrders();
/* Compute the dominator info */
ComputeDominators();
/* Allocate data structures in preparation for SSA conversion */
CompilerInitializeSSAConversion();
/* Find out the "Dalvik reg def x block" relation */
ComputeDefBlockMatrix();
/* Insert phi nodes to dominance frontiers for all variables */
InsertPhiNodes();
/* Rename register names by local defs and phi nodes */
ClearAllVisitedFlags();
DoDFSPreOrderSSARename(GetEntryBlock());
/*
* Shared temp bit vector used by each block to count the number of defs
* from all the predecessor blocks.
*/
temp_ssa_register_v_ =
new (arena_) ArenaBitVector(arena_, GetNumSSARegs(), false, kBitMapTempSSARegisterV);
}
void MIRGraph::CheckSSARegisterVector() {
DCHECK(temp_ssa_register_v_ != nullptr);
}
} // namespace art