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[LoopInterchange] Modernize loops (NFC) #146105

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Merged
merged 3 commits into from
Jun 28, 2025
Merged

[LoopInterchange] Modernize loops (NFC) #146105

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bb5a7e1
[LoopInterchange] Modernize loops (NFC)
artagnon Jun 27, 2025
9e9ce50
[LoopInterchange] Use const auto & in a couple of places
artagnon Jun 27, 2025
19a427b
[LoopInterchange] Address nit
artagnon Jun 27, 2025
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25 changes: 11 additions & 14 deletions llvm/lib/Transforms/Scalar/LoopInterchange.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -551,12 +551,10 @@ struct LoopInterchange {
//
// For the old pass manager CacheCost would be null.
DenseMap<const Loop *, unsigned> CostMap;
if (CC != nullptr) {
const auto &LoopCosts = CC->getLoopCosts();
for (unsigned i = 0; i < LoopCosts.size(); i++) {
CostMap[LoopCosts[i].first] = i;
}
}
if (CC)
for (auto [Idx, Cost] : enumerate(CC->getLoopCosts()))
CostMap[Cost.first] = Idx;

// We try to achieve the globally optimal memory access for the loopnest,
// and do interchange based on a bubble-sort fasion. We start from
// the innermost loop, move it outwards to the best possible position
Expand Down Expand Up @@ -972,8 +970,8 @@ areInnerLoopExitPHIsSupported(Loop *InnerL, Loop *OuterL,
static bool areOuterLoopExitPHIsSupported(Loop *OuterLoop, Loop *InnerLoop) {
BasicBlock *LoopNestExit = OuterLoop->getUniqueExitBlock();
for (PHINode &PHI : LoopNestExit->phis()) {
for (unsigned i = 0; i < PHI.getNumIncomingValues(); i++) {
Instruction *IncomingI = dyn_cast<Instruction>(PHI.getIncomingValue(i));
for (Value *Incoming : PHI.incoming_values()) {
Instruction *IncomingI = dyn_cast<Instruction>(Incoming);
if (!IncomingI || IncomingI->getParent() != OuterLoop->getLoopLatch())
continue;

Expand Down Expand Up @@ -1132,15 +1130,14 @@ int LoopInterchangeProfitability::getInstrOrderCost() {
for (BasicBlock *BB : InnerLoop->blocks()) {
for (Instruction &Ins : *BB) {
if (const GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(&Ins)) {
unsigned NumOp = GEP->getNumOperands();
bool FoundInnerInduction = false;
bool FoundOuterInduction = false;
for (unsigned i = 0; i < NumOp; ++i) {
for (Value *Op : GEP->operands()) {
// Skip operands that are not SCEV-able.
if (!SE->isSCEVable(GEP->getOperand(i)->getType()))
if (!SE->isSCEVable(Op->getType()))
continue;

const SCEV *OperandVal = SE->getSCEV(GEP->getOperand(i));
const SCEV *OperandVal = SE->getSCEV(Op);
const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(OperandVal);
if (!AR)
continue;
Expand Down Expand Up @@ -1220,8 +1217,8 @@ LoopInterchangeProfitability::isProfitablePerInstrOrderCost() {

/// Return true if we can vectorize the loop specified by \p LoopId.
static bool canVectorize(const CharMatrix &DepMatrix, unsigned LoopId) {
for (unsigned I = 0; I != DepMatrix.size(); I++) {
char Dir = DepMatrix[I][LoopId];
for (auto Dep : DepMatrix) {
char Dir = Dep[LoopId];
if (Dir != 'I' && Dir != '=')
return false;
}
Expand Down
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