#include "llvm/Analysis/LoopAccessAnalysis.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/LoopPass.h"
+#include "llvm/Analysis/OptimizationRemarkEmitter.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/Constants.h"
AU.addRequired<ScalarEvolutionWrapperPass>();
AU.addPreserved<AAResultsWrapperPass>();
AU.addPreserved<GlobalsAAWrapperPass>();
+ AU.addRequired<OptimizationRemarkEmitterWrapperPass>();
}
StringRef getPassName() const override { return "Loop Versioning for LICM"; }
LoadAndStoreCounter = 0;
InvariantCounter = 0;
IsReadOnlyLoop = true;
+ ORE = nullptr;
CurAST.reset();
}
Loop *CurLoop = nullptr;
// AliasSet information for the current loop.
- std::unique_ptr<AliasSetTracker> CurAST;
+ std::unique_ptr<AliasSetTracker> CurAST;
// Maximum loop nest threshold
unsigned LoopDepthThreshold;
// Read only loop marker.
bool IsReadOnlyLoop = true;
+ // OptimizationRemarkEmitter
+ OptimizationRemarkEmitter *ORE;
+
bool isLegalForVersioning();
bool legalLoopStructure();
bool legalLoopInstructions();
LoadAndStoreCounter = 0;
InvariantCounter = 0;
IsReadOnlyLoop = true;
+ using namespace ore;
// Iterate over loop blocks and instructions of each block and check
// instruction safety.
for (auto *Block : CurLoop->getBlocks())
for (auto &Inst : *Block) {
// If instruction is unsafe just return false.
- if (!instructionSafeForVersioning(&Inst))
+ if (!instructionSafeForVersioning(&Inst)) {
+ ORE->emit([&]() {
+ return OptimizationRemarkMissed(DEBUG_TYPE, "IllegalLoopInst", &Inst)
+ << " Unsafe Loop Instruction";
+ });
return false;
+ }
}
// Get LoopAccessInfo from current loop.
LAI = &LAA->getInfo(CurLoop);
if (LAI->getNumRuntimePointerChecks() >
VectorizerParams::RuntimeMemoryCheckThreshold) {
DEBUG(dbgs() << " LAA: Runtime checks are more than threshold !!\n");
+ ORE->emit([&]() {
+ return OptimizationRemarkMissed(DEBUG_TYPE, "RuntimeCheck",
+ CurLoop->getStartLoc(),
+ CurLoop->getHeader())
+ << "Number of runtime checks "
+ << NV("RuntimeChecks", LAI->getNumRuntimePointerChecks())
+ << " exceeds threshold "
+ << NV("Threshold", VectorizerParams::RuntimeMemoryCheckThreshold);
+ });
return false;
}
// Loop should have at least one invariant load or store instruction.
<< ((InvariantCounter * 100) / LoadAndStoreCounter) << "%\n");
DEBUG(dbgs() << " Invariant loads & store threshold: "
<< InvariantThreshold << "%\n");
+ ORE->emit([&]() {
+ return OptimizationRemarkMissed(DEBUG_TYPE, "InvariantThreshold",
+ CurLoop->getStartLoc(),
+ CurLoop->getHeader())
+ << "Invariant load & store "
+ << NV("LoadAndStoreCounter",
+ ((InvariantCounter * 100) / LoadAndStoreCounter))
+ << " are less then defined threshold "
+ << NV("Threshold", InvariantThreshold);
+ });
return false;
}
return true;
/// c) loop memory access legality.
/// Return true if legal else returns false.
bool LoopVersioningLICM::isLegalForVersioning() {
+ using namespace ore;
DEBUG(dbgs() << "Loop: " << *CurLoop);
// Make sure not re-visiting same loop again.
if (isLoopAlreadyVisited()) {
if (!legalLoopStructure()) {
DEBUG(
dbgs() << " Loop structure not suitable for LoopVersioningLICM\n\n");
+ ORE->emit([&]() {
+ return OptimizationRemarkMissed(DEBUG_TYPE, "IllegalLoopStruct",
+ CurLoop->getStartLoc(),
+ CurLoop->getHeader())
+ << " Unsafe Loop structure";
+ });
return false;
}
// Check loop instruction leagality.
if (!legalLoopMemoryAccesses()) {
DEBUG(dbgs()
<< " Loop memory access not suitable for LoopVersioningLICM\n\n");
+ ORE->emit([&]() {
+ return OptimizationRemarkMissed(DEBUG_TYPE, "IllegalLoopMemoryAccess",
+ CurLoop->getStartLoc(),
+ CurLoop->getHeader())
+ << " Unsafe Loop memory access";
+ });
return false;
}
// Loop versioning is feasible, return true.
DEBUG(dbgs() << " Loop Versioning found to be beneficial\n\n");
+ ORE->emit([&]() {
+ return OptimizationRemark(DEBUG_TYPE, "IsLegalForVersioning",
+ CurLoop->getStartLoc(), CurLoop->getHeader())
+ << " Versioned loop for LICM."
+ << " Number of runtime checks we had to insert "
+ << NV("RuntimeChecks", LAI->getNumRuntimePointerChecks());
+ });
return true;
}
AA = &getAnalysis<AAResultsWrapperPass>().getAAResults();
SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
LAA = &getAnalysis<LoopAccessLegacyAnalysis>();
+ ORE = &getAnalysis<OptimizationRemarkEmitterWrapperPass>().getORE();
LAI = nullptr;
// Set Current Loop
CurLoop = L;
INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(LoopSimplify)
INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(OptimizationRemarkEmitterWrapperPass)
INITIALIZE_PASS_END(LoopVersioningLICM, "loop-versioning-licm",
"Loop Versioning For LICM", false, false)