Merge pull request 'dead_code_removing' (#36) from dead_code_removing into master

This commit was merged in pull request #36.
This commit is contained in:
2024-04-05 17:39:56 +00:00
5 changed files with 125 additions and 61 deletions

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@@ -10,7 +10,8 @@
#include "../IR.h"
template <class NodeType>
class BackwardDataFlowAnalysis : public DataFlowAnalysis<NodeType> {
class BackwardDataFlowAnalysis : public DataFlowAnalysis<NodeType>
{
std::vector<SAPFOR::BasicBlock*> reorderSequence(const std::vector<SAPFOR::BasicBlock*>& blocks,
const std::set<SAPFOR::BasicBlock*> back_edge_sources);
public:

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@@ -29,6 +29,7 @@ public:
virtual bool addIn(const DataType& data) = 0;
virtual bool addOut(const DataType& data) = 0;
virtual bool updateState() { return false; }
virtual bool forwardData(const DataType& data) = 0;
bool newerThan(const DataFlowAnalysisNode<DataType>* block) const { return out_cnt > block->in_cnt; }

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@@ -27,6 +27,8 @@ template <class DataType>
void DataFlowAnalysisNode<DataType>::doStep()
{
int in_max_cnt = CNT_NOTINIT, out_max_cnt = CNT_NOTINIT;
bool uniq_change = updateState();
for (auto next : prev_blocks)
{
if (in_cnt < next->out_cnt)
@@ -49,7 +51,7 @@ void DataFlowAnalysisNode<DataType>::doStep()
}
}
bool was_notinit = (out_cnt == CNT_NOTINIT);
uniq_change |= (out_cnt == CNT_NOTINIT);
if (out_max_cnt != CNT_NOTINIT)
out_cnt = out_max_cnt;
@@ -58,7 +60,7 @@ void DataFlowAnalysisNode<DataType>::doStep()
in_cnt = in_max_cnt;
// TODO: fix counter overflow
if (was_notinit)
if (uniq_change)
{
out_cnt++;
in_cnt++;
@@ -68,7 +70,8 @@ void DataFlowAnalysisNode<DataType>::doStep()
/* definitions for DataFlowAnalysis class */
template <class NodeType>
void DataFlowAnalysis<NodeType>::analyze() {
void DataFlowAnalysis<NodeType>::analyze()
{
auto curr = 0;
auto stop = nodes.size();

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@@ -14,6 +14,40 @@ using std::set;
using std::remove_if;
#define PRINT_USELESS_STATEMENTS 1
#define DEBUG_IR 0
// detect wich registers are used at more than one block
// such registers should participate in live analysis to spread information about useful instructions
// such registers appears at loops
static void fillSharedRegs(const map<FuncInfo*, vector<SAPFOR::BasicBlock*>>& cfg, set<SAPFOR::Argument*>& shared_regs)
{
map<SAPFOR::Argument*, SAPFOR::BasicBlock*> used_at;
for (const auto& byFunc : cfg)
{
for (const auto& byBlock : byFunc.second)
{
for (const auto& byIrBlock : byBlock->getInstructions())
{
auto instr = byIrBlock->getInstruction();
set<SAPFOR::Argument*> used = { instr->getResult(), instr->getArg1(), instr->getArg2() };
for (auto arg : used)
{
if(arg && arg->getType() == SAPFOR::CFG_ARG_TYPE::REG)
{
auto it = used_at.find(arg);
if (it == used_at.end())
used_at[arg] = byBlock;
else if(it->second != byBlock)
shared_regs.insert(arg);
}
}
}
}
}
}
static void updateUseDefForInstruction(SAPFOR::BasicBlock* block, SAPFOR::Instruction* instr,
set<SAPFOR::Argument*>& use, set<SAPFOR::Argument*>& def,
@@ -39,7 +73,9 @@ static void updateUseDefForInstruction(SAPFOR::BasicBlock* block, SAPFOR::Instru
{
for (SAPFOR::Argument* r : res)
{
if (use.find(r) != use.end() || r->getMemType() != SAPFOR::CFG_MEM_TYPE::LOCAL_)
if (use.find(r) != use.end() ||
r->getMemType() != SAPFOR::CFG_MEM_TYPE::LOCAL_ ||
!(r->getType() == SAPFOR::CFG_ARG_TYPE::VAR || r->getType() == SAPFOR::CFG_ARG_TYPE::REG))
{
useful = true;
break;
@@ -88,8 +124,8 @@ static void updateUseDefForInstruction(SAPFOR::BasicBlock* block, SAPFOR::Instru
use.insert(e);
def.erase(e);
}
insertIfVar(args.begin(), args.end(), usedByThisBlock);
usedByThisBlock.insert(args.begin(), args.end());
}
if ((instr->getOperation() == SAPFOR::CFG_OP::F_CALL || instr->getOperation() == SAPFOR::CFG_OP::PARAM) && fName == "")
@@ -128,12 +164,13 @@ static void buildUseDef(SAPFOR::BasicBlock* block, set<SAPFOR::Argument*>& use,
useful[i] = u;
}
insertIfVar(use_with_regs.begin(), use_with_regs.end(), use);
insertIfVar(def_with_regs.begin(), def_with_regs.end(), def);
use.insert(use_with_regs.begin(), use_with_regs.end());
def.insert(def_with_regs.begin(), def_with_regs.end());
}
class DeadCodeAnalysisNode : public DataFlowAnalysisNode<map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>>> {
class DeadCodeAnalysisNode : public DataFlowAnalysisNode<map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>>>
{
private:
vector<bool> useful;
bool useful_block = false;
@@ -142,6 +179,7 @@ private:
vector<SAPFOR::Argument*>& formal_parameters;
const map<string, FuncInfo*>& funcByName;
const set<SAPFOR::Argument*>& shared_regs;
public:
bool updateJumpStatus()
{
@@ -196,30 +234,41 @@ public:
return updated;
}
map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>> getIn() {
map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>> getIn()
{
return getBlock()->getLiveOut();
}
map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>> getOut() {
map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>> getOut()
{
return getBlock()->getLiveIn();
}
bool addIn(const map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>>& data) {
bool inserted = getBlock()->addLiveOut(data);
if (!useful_block)
inserted |= updateNextNotEmpty();
inserted |= updateJumpStatus();
return inserted;
bool addIn(const map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>>& data)
{
return getBlock()->addLiveOut(data);
}
bool addOut(const map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>>& data) {
bool addOut(const map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>>& data)
{
return getBlock()->addLiveIn(data);
}
bool forwardData(const map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>>& data) {
bool updateState()
{
bool updated = false;
if (!useful_block)
updated |= updateNextNotEmpty();
updated |= updateJumpStatus();
updated |= this->forwardData({ });
return updated;
}
bool forwardData(const map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>>& data)
{
bool inserted = false;
SAPFOR::BasicBlock* bb= getBlock();
@@ -235,30 +284,34 @@ public:
for (SAPFOR::Argument* arg : use)
{
bool this_block = usedByThisBlock.find(arg) != usedByThisBlock.end();
if (!this_block)
if(arg && (arg->getType() == SAPFOR::CFG_ARG_TYPE::VAR ||
(arg->getType() == SAPFOR::CFG_ARG_TYPE::REG && shared_regs.find(arg) != shared_regs.end())))
{
auto data_it = data.find(arg);
bool this_block = usedByThisBlock.find(arg) != usedByThisBlock.end();
if (data_it == data.end())
printInternalError(convertFileName(__FILE__).c_str(), __LINE__);
inserted |= bb->addLiveIn({ *data_it });
}
else
{
auto in_it = in.find(arg);
bool skip = false;
if (in_it != in.end())
if (!this_block)
{
if (in_it->second.size() == 1 && *(in_it->second.begin()) == bb)
skip = true; // nothing to do, inserted = false
else
bb->removeLiveIn(arg);
auto data_it = data.find(arg);
if (data_it == data.end())
printInternalError(convertFileName(__FILE__).c_str(), __LINE__);
inserted |= bb->addLiveIn({ *data_it });
}
else
{
auto in_it = in.find(arg);
bool skip = false;
if (in_it != in.end())
{
if (in_it->second.size() == 1 && *(in_it->second.begin()) == bb)
skip = true; // nothing to do, inserted = false
else
bb->removeLiveIn(arg);
}
if(!skip)
inserted |= bb->addLiveIn({ { arg, { bb } } });
}
if(!skip)
inserted |= bb->addLiveIn({ { arg, { bb } } });
}
}
@@ -291,38 +344,39 @@ public:
DeadCodeAnalysisNode(SAPFOR::BasicBlock* block,
vector<SAPFOR::Argument*>& formal_parameters,
const map<string, FuncInfo*>& funcByName)
const map<string, FuncInfo*>& funcByName,
const set<SAPFOR::Argument*>& shared_regs)
:
formal_parameters(formal_parameters),
funcByName(funcByName)
funcByName(funcByName),
shared_regs(shared_regs)
{
setBlock(block);
useful.resize(block->getInstructions().size(), false);
set<SAPFOR::Argument*> use, def;
set<SAPFOR::Argument*> usedByThisBlock;
buildUseDef(getBlock(), use, def, this->formal_parameters, useful, usedByThisBlock, funcByName);
for (SAPFOR::Argument* arg : use)
getBlock()->addLiveIn({ { arg, { getBlock() } } });
}
const vector<bool>& getResult() { return useful; }
};
class DeadCodeAnalysis : public BackwardDataFlowAnalysis<DeadCodeAnalysisNode> {
class DeadCodeAnalysis : public BackwardDataFlowAnalysis<DeadCodeAnalysisNode>
{
protected:
vector<SAPFOR::Argument*>& formal_parameters;
const map<string, FuncInfo*>& funcByName;
const set<SAPFOR::Argument*>& shared_regs;
DeadCodeAnalysisNode* createNode(SAPFOR::BasicBlock* block) override {
return new DeadCodeAnalysisNode(block, formal_parameters, funcByName);
DeadCodeAnalysisNode* createNode(SAPFOR::BasicBlock* block) override
{
return new DeadCodeAnalysisNode(block, formal_parameters, funcByName, shared_regs);
}
public:
DeadCodeAnalysis(vector<SAPFOR::Argument*>& formal_parameters, const map<string, FuncInfo*>& funcByName)
DeadCodeAnalysis(vector<SAPFOR::Argument*>& formal_parameters,
const map<string, FuncInfo*>& funcByName,
const set<SAPFOR::Argument*>& shared_regs)
:
formal_parameters(formal_parameters),
funcByName(funcByName)
funcByName(funcByName),
shared_regs(shared_regs)
{ }
};
@@ -394,8 +448,10 @@ void removeDeadCode(SgStatement* func,
cfg_pair.second.erase(remove_unreachable_it, cfg_pair.second.end());
#if DEBUG_IR
dumpCFG({ cfg_pair }, false);
#endif
// detect useless code
vector<SAPFOR::Argument*> func_parameters(cfg_pair.first->funcParams.countOfPars, NULL);
map<string, FuncInfo*> funcByName;
@@ -403,8 +459,11 @@ void removeDeadCode(SgStatement* func,
for (auto& byFile : allFuncs)
for (auto byFunc : byFile.second)
funcByName[byFunc->funcName] = byFunc;
set<SAPFOR::Argument*> shared_regs;
fillSharedRegs({ cfg_pair }, shared_regs);
DeadCodeAnalysis analysis_object(func_parameters, funcByName);
DeadCodeAnalysis analysis_object(func_parameters, funcByName, shared_regs);
analysis_object.fit(cfg_pair.second);
analysis_object.analyze();

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@@ -307,8 +307,8 @@ void InitPassesDependencies(map<passes, vector<passes>> &passDepsIn, set<passes>
Pass(REMOVE_OMP_DIRS) <= Pass(REMOVE_OMP_DIRS_TRANSFORM);
Pass(CALL_GRAPH2) <= Pass(REMOVE_DEAD_CODE);
list({ REMOVE_DEAD_CODE, REVERT_SUBST_EXPR_RD, CONVERT_LOOP_TO_ASSIGN, RESTORE_LOOP_FROM_ASSIGN }) <= Pass(REMOVE_DEAD_CODE_AND_UNPARSE);
list({ CALL_GRAPH2, REVERT_SUBST_EXPR_RD }) <= Pass(REMOVE_DEAD_CODE);
list({ REMOVE_DEAD_CODE, CONVERT_LOOP_TO_ASSIGN, RESTORE_LOOP_FROM_ASSIGN }) <= Pass(REMOVE_DEAD_CODE_AND_UNPARSE);
passesIgnoreStateDone.insert({ CREATE_PARALLEL_DIRS, INSERT_PARALLEL_DIRS, INSERT_SHADOW_DIRS, EXTRACT_PARALLEL_DIRS,
EXTRACT_SHADOW_DIRS, CREATE_REMOTES, UNPARSE_FILE, REMOVE_AND_CALC_SHADOW,