ir::ControlFlowGraph::iterator
HoistParameterLoadsPass::_getTopLevelDominatingBlock(
ir::IRKernel& k, ir::ControlFlowGraph::iterator block)
{
auto loopAnalysis = static_cast<analysis::LoopAnalysis*>(
getAnalysis(Analysis::LoopAnalysis));
auto dominatorTree = static_cast<analysis::DominatorTree*>(
getAnalysis(Analysis::DominatorTreeAnalysis));
while(loopAnalysis->isContainedInLoop(block))
{
auto dominator = dominatorTree->getDominator(block);
if(dominator == block->cfg->get_entry_block())
{
block = k.cfg()->split_edge(dominator->get_fallthrough_edge(),
ir::BasicBlock(k.cfg()->newId())).first->tail;
invalidateAnalysis(analysis::Analysis::LoopAnalysis );
invalidateAnalysis(analysis::Analysis::DominatorTreeAnalysis);
break;
}
block = dominator;
}
return block;
}
DivergenceAnalysis::block_set
DivergenceAnalysis::_getDivergentBlocksInPostdominanceFrontier(
const DataflowGraph::iterator &block) {
const Analysis* dfgAnalysis = getAnalysis("DataflowGraphAnalysis");
assert(dfgAnalysis != 0);
const DataflowGraph &cdfg =
static_cast<const DataflowGraph&>(*dfgAnalysis);
DataflowGraph &dfg = const_cast<DataflowGraph&>(cdfg);
PostdominatorTree* dtree = (PostdominatorTree*)
(getAnalysis("PostDominatorTreeAnalysis"));
auto postDominator = dfg.getCFGtoDFGMap()[
dtree->getPostDominator(block->block())];
block_set divergentBlocks;
for (auto successor = block->successors().begin();
successor != block->successors().end(); ++successor) {
if (*successor == postDominator) continue;
block_set allDivergentPaths;
buildDivergentSubgraph(allDivergentPaths, *successor, postDominator);
divergentBlocks.insert(allDivergentPaths.begin(),
allDivergentPaths.end());
}
return divergentBlocks;
}
const DataflowGraph* DivergenceAnalysis::getDFG() const
{
const Analysis* dfgAnalysis = getAnalysis("DataflowGraphAnalysis");
assert(dfgAnalysis != 0);
return static_cast<const DataflowGraph*>(dfgAnalysis);
}
analysis::DataflowGraph& RemoveBarrierPass::_dfg()
{
Analysis* dfg_structure = getAnalysis(Analysis::DataflowGraphAnalysis);
assert(dfg_structure != 0);
return *static_cast<analysis::DataflowGraph*>(dfg_structure);
}
/*! \brief Analyze the control and data flow graphs searching for divergent
* variables and blocks
*
* 1) Makes data flow analysis that detects divergent variables and blocks
* based on divergent sources, such as t.id, laneId
* 2) Makes control flow analysis that detects new divergent variables based
* on the dependency of variables of variables created on divergent paths
*/
void DivergenceAnalysis::analyze(ir::IRKernel &k)
{
Analysis* dfgAnalysis = getAnalysis("DataflowGraphAnalysis");
assert(dfgAnalysis != 0);
DataflowGraph &dfg = static_cast<DataflowGraph&>(*dfgAnalysis);
dfg.convertToSSAType(DataflowGraph::Gated);
assert(dfg.ssa());
_divergGraph.clear();
_notDivergentBlocks.clear();
_kernel = &k;
report("Running Divergence analysis on kernel '" << k.name << "'")
#if REPORT_PTX > 0
k.write(std::cout);
#endif
DivergenceGraph::node_set predicates;
/* 1) Makes data flow analysis that detects divergent variables and blocks
based on divergent sources, such as t.id, laneId */
_analyzeDataFlow();
/* 2) Makes control flow analysis that detects new divergent variables
based on the dependency of variables of variables created on divergent
paths */
_analyzeControlFlow();
}
void MoveEliminationPass::runOnKernel(ir::IRKernel& k)
{
report("Eliminating moves in kernel " << k.name << "");
auto dfg = static_cast<analysis::DataflowGraph*>(
getAnalysis("DataflowGraphAnalysis"));
assert(dfg != 0);
dfg->convertToSSAType(analysis::DataflowGraph::Minimal);
auto moves = getMoves(dfg);
bool eliminatedAny = false;
report(" Eliminating moves");
for(auto move = moves.begin(); move != moves.end(); ++move)
{
if(canEliminate(*move))
{
report(" " << (*move)->i->toString());
eliminate(*move);
eliminatedAny = true;
}
}
if(eliminatedAny)
{
invalidateAnalysis("DataflowGraphAnalysis");
}
report("finished...");
}
void DeadCodeEliminationPass::runOnKernel(ir::IRKernel& k)
{
report("Running dead code elimination on kernel " << k.name);
reportE(REPORT_PTX, k);
Analysis* dfgAnalysis = getAnalysis(Analysis::DataflowGraphAnalysis);
assert(dfgAnalysis != 0);
analysis::DataflowGraph& dfg =
*static_cast<analysis::DataflowGraph*>(dfgAnalysis);
assert(dfg.ssa() != analysis::DataflowGraph::SsaType::None);
BlockSet blocks;
report(" Starting by scanning all basic blocks");
for(iterator block = dfg.begin(); block != dfg.end(); ++block)
{
report(" Queueing up BB_" << block->id());
blocks.insert(block);
}
while(!blocks.empty())
{
iterator block = *blocks.begin();
blocks.erase(blocks.begin());
eliminateDeadInstructions(dfg, blocks, block);
}
report("Finished running dead code elimination on kernel " << k.name);
reportE(REPORT_PTX, k);
}
void HoistParameterLoadsPass::_tryHoistingLoad(
ir::ControlFlowGraph::iterator block, ir::PTXInstruction* ptx,
ir::IRKernel& k)
{
report(" " << ptx->toString());
auto newBlock = _getTopLevelDominatingBlock(k, block);
if(newBlock == block) return;
report(" hoisting to " << newBlock->label());
auto dfg = static_cast<analysis::DataflowGraph*>(
getAnalysis(Analysis::DataflowGraphAnalysis));
auto load = new ir::PTXInstruction(ir::PTXInstruction::Ld);
load->addressSpace = ptx->addressSpace;
load->type = ptx->type;
load->volatility = ptx->volatility;
load->cacheOperation = ptx->cacheOperation;
load->d = ir::PTXOperand(ir::PTXOperand::Register,
ptx->d.type, dfg->newRegister());
load->a = ptx->a;
insertBeforeTerminator(newBlock, load);
ptx->opcode = ir::PTXInstruction::Mov;
ptx->a = load->d;
}
void LoopUnrollingPass::runOnKernel(ir::IRKernel& k)
{
Analysis* loopAnalysis = getAnalysis(Analysis::LoopAnalysis);
assert(loopAnalysis != 0);
// TODO actually unroll something.
}
analysis::AffineAnalysis& AffineLinearScan::_afa()
{
Analysis* aff = getAnalysis(Analysis::AffineAnalysis);
assert(aff != 0);
return *static_cast<analysis::AffineAnalysis*>(aff);
}
void DivergenceAnalysis::_convergenceAnalysis()
{
report("Running convergence analysis.");
Analysis* dfgAnalysis = getAnalysis("DataflowGraphAnalysis");
assert(dfgAnalysis != 0);
DataflowGraph &dfg = static_cast<DataflowGraph&>(*dfgAnalysis);
/* Assume all blocks are convergent */
block_set divergentBlocks;
/* 1) mark all blocks in the post-dominance frontier of divergent branches
along paths that do not encounter known convergent points
as divergent. This is an optimistic analysis. */
report(" Marking divergent blocks.");
for (auto block = dfg.begin() ; block != dfg.end(); ++block) {
if (!isDivBlock(block) || _hasTrivialPathToExit(block)) continue;
block_set divergentBlocksInPostdominanceFrontier =
_getDivergentBlocksInPostdominanceFrontier(block);
divergentBlocks.insert(divergentBlocksInPostdominanceFrontier.begin(),
divergentBlocksInPostdominanceFrontier.end());
}
report(" Marking convergent blocks.");
_notDivergentBlocks.clear();
for (auto block = dfg.begin(); block != dfg.end(); ++block) {
if (divergentBlocks.count(block) == 0) {
report(" " << block->label() << " is assumed convergent.");
_notDivergentBlocks.insert(block);
}
}
}
void DataDependenceAnalysis::analyze(ir::IRKernel& kernel)
{
auto dfg = static_cast<DataflowGraph*>(
getAnalysis("DataflowGraphAnalysis"));
report("Running data dependence analysis on kernel " << kernel.name);
for(auto block = dfg->begin(); block != dfg->end(); ++block)
{
analyzeBlock(block, dfg, _nodes, _instructionToNodes);
}
}
void DependenceAnalysis::analyze(ir::IRKernel& kernel)
{
report("Running dependence analysis on kernel " << kernel.name);
auto controlDependenceAnalysis = static_cast<ControlDependenceAnalysis*>(
getAnalysis("ControlDependenceAnalysis"));
auto dataDependenceAnalysis = static_cast<DataDependenceAnalysis*>(
getAnalysis("DataDependenceAnalysis"));
auto memoryDependenceAnalysis = static_cast<MemoryDependenceAnalysis*>(
getAnalysis("MemoryDependenceAnalysis"));
for(auto& node : *controlDependenceAnalysis)
{
auto newNode = _nodes.insert(_nodes.end(), Node(node.instruction));
_instructionToNodes.insert(std::make_pair(node.instruction, newNode));
}
for(auto& node : *this)
{
auto controlDependenceNode = controlDependenceAnalysis->getNode(
node.instruction);
addEdges(node, *controlDependenceNode, _instructionToNodes);
auto dataDependenceNode = dataDependenceAnalysis->getNode(
node.instruction);
addEdges(node, *dataDependenceNode, _instructionToNodes);
auto memoryDependenceNode = memoryDependenceAnalysis->getNode(
node.instruction);
if(memoryDependenceNode != memoryDependenceAnalysis->end())
{
addEdges(node, *memoryDependenceNode, _instructionToNodes);
}
}
}
unsigned int DivergenceAnalysis::_numberOfDivergentPathsToPostDominator(
const DataflowGraph::iterator &block) const {
const Analysis* dfgAnalysis = getAnalysis("DataflowGraphAnalysis");
assert(dfgAnalysis != 0);
const DataflowGraph &cdfg =
static_cast<const DataflowGraph&>(*dfgAnalysis);
DataflowGraph &dfg = const_cast<DataflowGraph&>(cdfg);
PostdominatorTree* dtree = (PostdominatorTree*)
(getAnalysis("PostDominatorTreeAnalysis"));
auto postDominator = dfg.getCFGtoDFGMap()[
dtree->getPostDominator(block->block())];
unsigned int divergentPaths = 0;
for (auto successor = block->successors().begin();
successor != block->successors().end(); ++successor) {
if (*successor == postDominator) {
++divergentPaths;
continue;
}
block_set allDivergentPaths;
if (doAnyDivergentPathsReachThePostDominator(allDivergentPaths,
*successor, postDominator)) {
++divergentPaths;
}
}
report(" There are " << divergentPaths << " divergent paths from "
<< block->label() << " to post-dominator " << postDominator->label());
return divergentPaths;
}
void SafeRegionAnalysis::analyze(ir::IRKernel& kernel)
{
// Get analyses
auto cycleAnalysis = static_cast<CycleAnalysis*>(
getAnalysis("CycleAnalysis"));
auto dependenceAnalysis = static_cast<DependenceAnalysis*>(
getAnalysis("DependenceAnalysis"));
auto controlDependenceAnalysis =
static_cast<ControlDependenceAnalysis*>(
getAnalysis("ControlDependenceAnalysis"));
// Find basic blocks that cannot be contained in safe regions
auto blocksThatDependOnSideEffects = getBlocksThatDependOnSideEffects(
kernel, cycleAnalysis, dependenceAnalysis, controlDependenceAnalysis);
// Find hammocks in the program
auto hammockAnalysis = static_cast<HammockGraphAnalysis*>(
getAnalysis("HammockGraphAnalysis"));
// Form safe regions around hammocks that do not contain blocks with
// side effects
formSafeRegionsAroundHammocks(_root, _regions, hammockAnalysis,
blocksThatDependOnSideEffects);
}
bool DivergenceAnalysis::_hasTrivialPathToExit(
const DataflowGraph::iterator &block) const {
// We can ignore divergent threads that immediately exit
unsigned int exitingPaths = 0;
const Analysis* dfgAnalysis = getAnalysis("DataflowGraphAnalysis");
assert(dfgAnalysis != 0);
const DataflowGraph &dfg =
static_cast<const DataflowGraph&>(*dfgAnalysis);
auto exit = --dfg.end();
for (auto successor = block->successors().begin();
successor != block->successors().end(); ++successor) {
auto path = *successor;
while (true) {
if (path == exit) {
++exitingPaths;
break;
}
if (path->successors().size() != 1) {
break;
}
if (!path->instructions().empty()) {
if (path->instructions().size() == 1) {
const ir::PTXInstruction &ptxI =
*(static_cast<ir::PTXInstruction *> (
path->instructions().back().i));
if (ptxI.isExit()) {
++exitingPaths;
}
}
break;
}
path = *path->successors().begin();
}
}
if (block->successors().size() - exitingPaths < 2) {
return true;
}
return false;
}
void DivergenceLinearScan::runOnKernel(ir::IRKernel& k)
{
auto dfg = static_cast<analysis::DataflowGraph*>(
getAnalysis("DataflowGraphAnalysis"));
dfg->convertToSSAType(analysis::DataflowGraph::Gated);
#if DIVERGENCE_REGISTER_PROFILE_H_
divergenceProfiler::resetSpillData();
#endif
_shared.clear();
LinearScanRegisterAllocationPass::runOnKernel(k);
#if DIVERGENCE_REGISTER_PROFILE_H_
if(!k.function())
divergenceProfiler::printSpillResults(k.name);
#endif
}
void HoistParameterLoadsPass::runOnKernel(ir::IRKernel& k)
{
typedef std::pair<ir::ControlFlowGraph::iterator, ir::PTXInstruction*> Load;
typedef std::vector<Load> LoadVector;
auto aliasAnalysis = static_cast<analysis::SimpleAliasAnalysis*>(
getAnalysis(Analysis::SimpleAliasAnalysis));
LoadVector candidateLoads;
report("Hoisting loads in kernel '" << k.name << "'");
report(" Identifying candidate loads");
for(auto block = k.cfg()->begin(); block != k.cfg()->end(); ++block)
{
for(auto instruction = block->instructions.begin();
instruction != block->instructions.end(); ++instruction)
{
auto ptx = static_cast<ir::PTXInstruction*>(*instruction);
if(ptx->isLoad() &&
aliasAnalysis->cannotAliasAnyStore(*instruction)
&& hasNoRegisterDependencies(*ptx))
{
report(" " << ptx->toString());
candidateLoads.push_back(std::make_pair(block, ptx));
}
}
}
report(" Attempting to hoist loads");
for(auto load = candidateLoads.begin();
load != candidateLoads.end(); ++load)
{
_tryHoistingLoad(load->first, load->second, k);
}
invalidateAnalysis(analysis::Analysis::DataflowGraphAnalysis);
invalidateAnalysis(analysis::Analysis::SimpleAliasAnalysis );
}
void FunctionInliningPass::runOnKernel(ir::IRKernel& k)
{
report("Running function inlining pass on kernel " << k.name);
auto analysis = getAnalysis(Analysis::DataflowGraphAnalysis);
assert(analysis != 0);
auto dfg = static_cast<analysis::DataflowGraph*>(analysis);
_nextRegister = dfg->maxRegister() + 1;
// Get the set of all function calls that satisfy the inlining criteria
_getFunctionsToInline(k);
// Inline all of the functions in this set
_inlineSelectedFunctions(k);
if(!_calls.empty())
{
invalidateAnalysis(Analysis::DataflowGraphAnalysis);
}
}
void ConstantPropagationPass::runOnKernel(ir::IRKernel& k)
{
report("Running constant propagation on kernel " << k.name);
Analysis* dfgAnalysis = getAnalysis("DataflowGraphAnalysis");
assert(dfgAnalysis != 0);
analysis::DataflowGraph& dfg =
*static_cast<analysis::DataflowGraph*>(dfgAnalysis);
dfg.convertToSSAType(analysis::DataflowGraph::Minimal);
assert(dfg.ssa() == analysis::DataflowGraph::Minimal);
BlockSet blocks;
report(" Starting by scanning all basic blocks");
for(iterator block = dfg.begin(); block != dfg.end(); ++block)
{
report(" Queueing up BB_" << block->id());
blocks.insert(block);
}
while(!blocks.empty())
{
iterator block = *blocks.begin();
blocks.erase(blocks.begin());
eliminateRedundantInstructions(dfg, blocks, block);
}
report("Finished running constant propagation on kernel " << k.name);
reportE(REPORT_PTX, k);
}
void terrama2::services::analysis::core::Context::loadMonitoredObject(AnalysisHashCode analysisHashCode)
{
std::lock_guard<std::recursive_mutex> lock(mutex_);
auto dataManagerPtr = dataManager_.lock();
if(!dataManagerPtr)
{
QString errMsg(QObject::tr("Invalid data manager."));
throw terrama2::core::InvalidDataManagerException() << terrama2::ErrorDescription(errMsg);
}
auto analysis = getAnalysis(analysisHashCode);
for(auto analysisDataSeries : analysis->analysisDataSeriesList)
{
auto dataSeriesPtr = dataManagerPtr->findDataSeries(analysisDataSeries.dataSeriesId);
auto datasets = dataSeriesPtr->datasetList;
if(analysisDataSeries.type == AnalysisDataSeriesType::DATASERIES_MONITORED_OBJECT_TYPE)
{
assert(datasets.size() == 1);
auto dataset = datasets[0];
auto dataProvider = dataManagerPtr->findDataProvider(dataSeriesPtr->dataProviderId);
terrama2::core::Filter filter;
//accessing data
terrama2::core::DataAccessorPtr accessor = terrama2::core::DataAccessorFactory::getInstance().make(dataProvider, dataSeriesPtr);
auto seriesMap = accessor->getSeries(filter);
auto series = seriesMap[dataset];
std::string identifier = analysisDataSeries.metadata["identifier"];
std::shared_ptr<ContextDataSeries> dataSeriesContext(new ContextDataSeries);
if(!series.syncDataSet)
{
QString errMsg(QObject::tr("No data available for DataSeries %1").arg(dataSeriesPtr->id));
throw terrama2::InvalidArgumentException() << terrama2::ErrorDescription(errMsg);
}
if(!series.syncDataSet->dataset())
{
QString errMsg(QObject::tr("Adding an invalid dataset to the analysis context: DataSeries %1").arg(dataSeriesPtr->id));
throw terrama2::InvalidArgumentException() << terrama2::ErrorDescription(errMsg);
}
std::size_t geomPropertyPosition = te::da::GetFirstPropertyPos(series.syncDataSet->dataset().get(), te::dt::GEOMETRY_TYPE);
dataSeriesContext->series = series;
dataSeriesContext->identifier = identifier;
dataSeriesContext->geometryPos = geomPropertyPosition;
ContextKey key;
key.datasetId_ = dataset->id;
key.analysisHashCode_ = analysisHashCode;
datasetMap_[key] = dataSeriesContext;
}
else if(analysisDataSeries.type == AnalysisDataSeriesType::DATASERIES_PCD_TYPE)
{
for(auto dataset : dataSeriesPtr->datasetList)
{
auto dataProvider = dataManagerPtr->findDataProvider(dataSeriesPtr->dataProviderId);
terrama2::core::Filter filter;
//accessing data
terrama2::core::DataAccessorPtr accessor = terrama2::core::DataAccessorFactory::getInstance().make(dataProvider, dataSeriesPtr);
auto seriesMap = accessor->getSeries(filter);
auto series = seriesMap[dataset];
std::string identifier = analysisDataSeries.metadata["identifier"];
std::shared_ptr<ContextDataSeries> dataSeriesContext(new ContextDataSeries);
std::size_t geomPropertyPosition = te::da::GetFirstPropertyPos(series.syncDataSet->dataset().get(), te::dt::GEOMETRY_TYPE);
dataSeriesContext->series = series;
dataSeriesContext->identifier = identifier;
dataSeriesContext->geometryPos = geomPropertyPosition;
ContextKey key;
key.datasetId_ = dataset->id;
key.analysisHashCode_ = analysisHashCode;
datasetMap_[key] = dataSeriesContext;
}
}
}
}
void ThreadFrontierReconvergencePass::runOnKernel(const ir::IRKernel& k)
{
report("Running thread frontier reconvergence pass");
typedef analysis::ThreadFrontierAnalysis::Priority Priority;
typedef std::multimap<Priority, ir::ControlFlowGraph::const_iterator,
std::greater<Priority>> ReversePriorityMap;
typedef analysis::ThreadFrontierAnalysis TFAnalysis;
typedef ir::ControlFlowGraph::const_pointer_iterator const_pointer_iterator;
Analysis* analysis = getAnalysis(Analysis::ThreadFrontierAnalysis);
assert(analysis != 0);
TFAnalysis* tfAnalysis = static_cast<TFAnalysis*>(analysis);
ReversePriorityMap priorityToBlocks;
// sort by priority (high to low)
for(ir::ControlFlowGraph::const_iterator block = k.cfg()->begin();
block != k.cfg()->end(); ++block)
{
priorityToBlocks.insert(std::make_pair(tfAnalysis->getPriority(block),
block));
}
typedef std::unordered_map<ir::BasicBlock::Id, unsigned int> IdToPCMap;
typedef std::unordered_map<unsigned int,
ir::ControlFlowGraph::const_iterator> PCToBlockMap;
IdToPCMap pcs;
PCToBlockMap branchPCs;
PCToBlockMap fallthroughPCs;
// lay the code out in priority order
report(" Packing instructions into a vector");
for(ReversePriorityMap::const_iterator
priorityAndBlock = priorityToBlocks.begin();
priorityAndBlock != priorityToBlocks.end(); ++priorityAndBlock)
{
ir::ControlFlowGraph::const_iterator block = priorityAndBlock->second;
report(" Basic Block " << block->label() << " ("
<< block->id << ")");
pcs.insert(std::make_pair(block->id, instructions.size()));
for(ir::ControlFlowGraph::InstructionList::const_iterator
instruction = block->instructions.begin();
instruction != block->instructions.end(); ++instruction)
{
const ir::PTXInstruction& ptx = static_cast<
const ir::PTXInstruction&>(**instruction);
report(" [" << instructions.size() << "] '" << ptx.toString());
instructions.push_back(ptx);
instructions.back().pc = instructions.size() - 1;
if(ptx.opcode == ir::PTXInstruction::Bra)
{
branchPCs.insert(std::make_pair(instructions.back().pc, block));
}
}
if(!_gen6)
{
// Add a branch for the fallthrough if it is in the TF
if(block->has_fallthrough_edge())
{
ir::ControlFlowGraph::const_iterator target =
block->get_fallthrough_edge()->tail;
ReversePriorityMap::const_iterator next = priorityAndBlock;
++next;
bool needsCheck = target != next->second;
TFAnalysis::BlockVector frontier =
tfAnalysis->getThreadFrontier(block);
for(TFAnalysis::BlockVector::const_iterator
stalledBlock = frontier.begin();
stalledBlock != frontier.end(); ++stalledBlock)
{
if((*stalledBlock)->id == target->id)
{
needsCheck = true;
break;
}
}
if(needsCheck)
{
fallthroughPCs.insert(std::make_pair(
instructions.size(), block));
instructions.push_back(ir::PTXInstruction(
ir::PTXInstruction::Bra,
ir::PTXOperand(target->label())));
instructions.back().needsReconvergenceCheck = true;
instructions.back().branchTargetInstruction = -1;
report(" [" << (instructions.size() - 1) << "] '"
<< instructions.back().toString());
report(" - artificial branch for check on"
" fallthrough into TF.");
}
}
}
}
report(" Updating branch targets");
for(PCToBlockMap::const_iterator pcAndBlock = branchPCs.begin();
pcAndBlock != branchPCs.end(); ++pcAndBlock)
{
ir::ControlFlowGraph::const_iterator block = pcAndBlock->second;
unsigned int pc = pcAndBlock->first;
const ir::PTXInstruction& ptx = static_cast<
const ir::PTXInstruction&>(instructions[pc]);
ir::ControlFlowGraph::const_iterator target =
block->get_branch_edge()->tail;
IdToPCMap::const_iterator targetPC = pcs.find(target->id);
assert(targetPC != pcs.end());
report(" setting branch target of '" << ptx.toString()
<< "' to " << targetPC->second);
instructions[pc].branchTargetInstruction = targetPC->second;
TFAnalysis::BlockVector frontier =
tfAnalysis->getThreadFrontier(block);
if(_gen6)
{
ir::ControlFlowGraph::const_iterator firstBlock =
k.cfg()->end();
TFAnalysis::Priority highest = 0;
frontier.push_back(block->get_branch_edge()->tail);
if(block->has_fallthrough_edge())
{
frontier.push_back(
block->get_fallthrough_edge()->tail);
}
// gen6 jumps to the block with the highest priority
for(TFAnalysis::BlockVector::const_iterator
stalledBlock = frontier.begin();
stalledBlock != frontier.end(); ++stalledBlock)
{
TFAnalysis::Priority priority =
tfAnalysis->getPriority(*stalledBlock);
if(priority >= highest)
{
highest = priority;
firstBlock = *stalledBlock;
}
}
// the reconverge point is the first block in the frontier
assert(firstBlock != k.cfg()->end());
IdToPCMap::const_iterator reconverge =
pcs.find(firstBlock->id);
assert(reconverge != pcs.end());
instructions[pc].reconvergeInstruction =
reconverge->second;
report(" re-converge point " << reconverge->second
<< ", " << firstBlock->label());
}
else
{
// Does this branch need to check for re-convergence?
// Or: are any of the target's predecessors
// in the thread frontier?
bool needsCheck = false;
for(TFAnalysis::BlockVector::const_iterator
stalledBlock = frontier.begin();
stalledBlock != frontier.end(); ++stalledBlock)
{
if((*stalledBlock)->id == target->id)
{
needsCheck = true;
report(" needs re-convergence check.");
break;
}
}
instructions[pc].needsReconvergenceCheck = needsCheck;
}
}
report(" Updating fallthrough targets");
for(PCToBlockMap::const_iterator pcAndBlock = fallthroughPCs.begin();
pcAndBlock != fallthroughPCs.end(); ++pcAndBlock)
{
ir::ControlFlowGraph::const_iterator block = pcAndBlock->second;
unsigned int pc = pcAndBlock->first;
const ir::PTXInstruction& ptx = static_cast<
const ir::PTXInstruction&>(instructions[pc]);
ir::ControlFlowGraph::const_iterator target =
block->get_fallthrough_edge()->tail;
IdToPCMap::const_iterator targetPC = pcs.find(target->id);
assert(targetPC != pcs.end());
report(" setting branch target of '" << ptx.toString()
<< "' to " << targetPC->second);
instructions[pc].branchTargetInstruction = targetPC->second;
}
}
void DivergenceAnalysis::_findBranches(branch_set& branches)
{
Analysis* dfgAnalysis = getAnalysis("DataflowGraphAnalysis");
assert(dfgAnalysis != 0);
DataflowGraph &dfg = static_cast<DataflowGraph&>(*dfgAnalysis);
/* Create a list of branches that can be divergent, that is,
they are not bra.uni and have a predicate */
DataflowGraph::iterator block = dfg.begin();
DataflowGraph::iterator endBlock = dfg.end();
/* Post-dominator tree */
PostdominatorTree *dtree;
dtree = (PostdominatorTree*) (getAnalysis("PostDominatorTreeAnalysis"));
report(" Finding branches");
for (; block != endBlock; ++block) {
ir::PTXInstruction *ptxInstruction = NULL;
if (block->instructions().size() > 0) {
/* Branch instructions can only be the last
instruction of a basic block */
DataflowGraph::Instruction& lastInstruction =
*(--block->instructions().end());
if (typeid(ir::PTXInstruction) == typeid(*(lastInstruction.i))) {
ptxInstruction =
static_cast<ir::PTXInstruction*>(lastInstruction.i);
if ((ptxInstruction->opcode == ir::PTXInstruction::Bra)) {
report(" examining " << ptxInstruction->toString());
if(ptxInstruction->uni == true) {
report(" eliminated, uniform...");
continue;
}
if(lastInstruction.s.size() == 0) {
report(" eliminated, wrong source count ("
<< lastInstruction.s.size() << ")...");
continue;
}
assert(lastInstruction.s.size() == 1);
DataflowGraph::iterator postDomBlock =
dfg.getCFGtoDFGMap()[
dtree->getPostDominator(block->block())];
if (postDomBlock != dfg.end()) {
BranchInfo newBranch(&(*block), &(*postDomBlock),
lastInstruction, _divergGraph);
branches.insert(newBranch);
report(" is potentially divergent...");
}
else {
report(" eliminated, no post-dominator...");
}
}
}
}
}
}
void ReversePostOrderTraversal::analyze(Function& function)
{
typedef util::LargeSet<BasicBlock*> BlockSet;
typedef std::stack<BasicBlock*> BlockStack;
order.clear();
BlockSet visited;
BlockStack stack;
auto cfgAnalysis = getAnalysis("ControlFlowGraph");
auto cfg = static_cast<ControlFlowGraph*>(cfgAnalysis);
report("Creating reverse post order traversal over function '" +
function.name() + "'");
// reverse post order is reversed topological order
stack.push(&*function.entry_block());
while(order.size() != function.size())
{
if(stack.empty())
{
for(auto block : order)
{
auto successors = cfg->getSuccessors(*block);
for(auto successor : successors)
{
if(visited.insert(successor).second)
{
stack.push(successor);
break;
}
}
if(!stack.empty()) break;
}
}
assertM(!stack.empty(), (function.size() - order.size())
<< " blocks are not connected.");
while(!stack.empty())
{
BasicBlock* top = stack.top();
stack.pop();
auto successors = cfg->getSuccessors(*top);
for(auto successor : successors)
{
assert(successor != nullptr);
auto predecessors = cfg->getPredecessors(*successor);
bool allPredecessorsVisited = true;
for(auto predecessor : predecessors)
{
if(visited.count(predecessor) == 0)
{
allPredecessorsVisited = false;
break;
}
}
if(!allPredecessorsVisited) continue;
if(visited.insert(successor).second)
{
stack.push(successor);
}
}
order.push_back(top);
report(" " << top->name());
}
}
// reverse the order
std::reverse(order.begin(), order.end());
}
analysis::DivergenceAnalysis& DivergenceLinearScan::_diva()
{
Analysis* divA = getAnalysis("DivergenceAnalysis");
assertM(divA != NULL, "Got null divergence analysis");
return *static_cast<analysis::DivergenceAnalysis*>(divA);
}
void DivergenceAnalysis::_analyzeDataFlow()
{
Analysis* dfg = getAnalysis("DataflowGraphAnalysis");
assert(dfg != 0);
DataflowGraph &nonConstGraph = static_cast<DataflowGraph&>(*dfg);
DataflowGraph::const_iterator block = nonConstGraph.begin();
DataflowGraph::const_iterator endBlock = nonConstGraph.end();
report("Analyzing data flow");
/* 1) Analyze the data flow adding divergence sources */
for (; block != endBlock; ++block) {
report(" for block " << block->label());
DataflowGraph::PhiInstructionVector::const_iterator
phiInstruction = block->phis().begin();
DataflowGraph::PhiInstructionVector::const_iterator
endPhiInstruction = block->phis().end();
/* Go over the phi functions and add their dependences to the
* dependence graph. */
for (; phiInstruction != endPhiInstruction; phiInstruction++) {
for (DataflowGraph::RegisterVector::const_iterator
si = phiInstruction->s.begin();
si != phiInstruction->s.end(); ++si) {
_divergGraph.insertEdge(si->id, phiInstruction->d.id);
report(" phi r" << phiInstruction->d.id << " <- r" << si->id);
}
}
DataflowGraph::InstructionVector::const_iterator
ii = block->instructions().begin();
DataflowGraph::InstructionVector::const_iterator
iiEnd = block->instructions().end();
for (; ii != iiEnd; ++ii) {
ir::PTXInstruction *ptxInstruction = NULL;
bool atom = false;
bool functionStackArgument = false;
bool localMemoryOperand = false;
bool isCall = false;
std::set<const ir::PTXOperand*> divergenceSources;
/* First we populate divergenceSources with all the
* source operands that might diverge.
*/
if (typeid(ir::PTXInstruction) == typeid(*(ii->i))) {
ptxInstruction = static_cast<ir::PTXInstruction*> (ii->i);
if (isDivergenceSource(ptxInstruction->a)) {
divergenceSources.insert(&ptxInstruction->a);
}
if (isDivergenceSource(ptxInstruction->b)) {
divergenceSources.insert(&ptxInstruction->b);
}
if (isDivergenceSource(ptxInstruction->c)) {
divergenceSources.insert(&ptxInstruction->c);
}
if (ptxInstruction->opcode == ir::PTXInstruction::Atom){
atom = true;
}
if (ptxInstruction->mayHaveAddressableOperand()) {
if (_doesOperandUseLocalMemory(ptxInstruction->a)) {
localMemoryOperand = true;
}
}
if (ptxInstruction->opcode == ir::PTXInstruction::Call){
isCall = true;
}
}
/* Second, if this is a function call, we populate divergenceSources
* with all the source operands that might diverge in a call.
*/
if (_kernel->function()) {
if (typeid(ir::PTXInstruction) == typeid(*(ii->i))) {
ptxInstruction = static_cast<ir::PTXInstruction*> (ii->i);
if (ptxInstruction->mayHaveAddressableOperand()) {
if (_isOperandAnArgument(ptxInstruction->a)) {
functionStackArgument = true;
report(" operand '" << ptxInstruction->a.toString()
<< "' is a function call argument.");
}
}
}
}
/* Third, we link the source operands to the
* destination operands, and check if the destination
* can diverge. This will only happen in case the
* instruction is atomic. */
DataflowGraph::RegisterPointerVector::const_iterator
destinationReg = ii->d.begin();
DataflowGraph::RegisterPointerVector::const_iterator
destinationEndReg = ii->d.end();
for (; destinationReg != destinationEndReg; destinationReg++) {
if (divergenceSources.size() != 0) {
std::set<const ir::PTXOperand*>::iterator
divergenceSource = divergenceSources.begin();
std::set<const ir::PTXOperand*>::iterator
divergenceSourceEnd = divergenceSources.end();
for (; divergenceSource != divergenceSourceEnd;
divergenceSource++) {
report(" destination register r"
<< *destinationReg->pointer
<< " is derived from a divergence source r"
<< *divergenceSource);
_divergGraph.insertEdge(*divergenceSource,
*destinationReg->pointer);
}
}
DataflowGraph::RegisterPointerVector::const_iterator
sourceReg = ii->s.begin();
DataflowGraph::RegisterPointerVector::const_iterator
sourceRegEnd = ii->s.end();
for (; sourceReg != sourceRegEnd; sourceReg++) {
_divergGraph.insertEdge(*sourceReg->pointer,
*destinationReg->pointer);
reportE(REPORT_ALL_DEPENDENCES,
" r" << *destinationReg->pointer
<< " <- r" << *sourceReg->pointer);
}
if (atom || functionStackArgument ||
localMemoryOperand || isCall) {
report(" destination register r"
<< *destinationReg->pointer
<< " is a divergence source.");
_divergGraph.insertNode(*destinationReg->pointer);
_divergGraph.setAsDiv(*destinationReg->pointer);
}
}
}
}
/* 2) Computes the divergence propagation */
_divergGraph.computeDivergence();
}
