DstI != DstE; ++DstI) {
if (isa<StoreInst>(*DstI) || isa<LoadInst>(*DstI)) {
OS << "da analyze - ";
- if (Dependence *D = DA->depends(&*SrcI, &*DstI, true)) {
+ if (auto D = DA->depends(&*SrcI, &*DstI, true)) {
D->dump(OS);
for (unsigned Level = 1; Level <= D->getLevels(); Level++) {
if (D->isSplitable(Level)) {
OS << "da analyze - split level = " << Level;
- OS << ", iteration = " << *DA->getSplitIteration(D, Level);
+ OS << ", iteration = " << *DA->getSplitIteration(*D, Level);
OS << "!\n";
}
}
- delete D;
}
else
OS << "none!\n";
/// source and destination array references are recurrences on a nested loop,
/// this function flattens the nested recurrences into separate recurrences
/// for each loop level.
-bool
-DependenceAnalysis::tryDelinearize(const SCEV *SrcSCEV, const SCEV *DstSCEV,
- SmallVectorImpl<Subscript> &Pair) const {
+bool DependenceAnalysis::tryDelinearize(const SCEV *SrcSCEV,
+ const SCEV *DstSCEV,
+ SmallVectorImpl<Subscript> &Pair,
+ const SCEV *ElementSize) const {
+ const SCEVUnknown *SrcBase =
+ dyn_cast<SCEVUnknown>(SE->getPointerBase(SrcSCEV));
+ const SCEVUnknown *DstBase =
+ dyn_cast<SCEVUnknown>(SE->getPointerBase(DstSCEV));
+
+ if (!SrcBase || !DstBase || SrcBase != DstBase)
+ return false;
+
+ SrcSCEV = SE->getMinusSCEV(SrcSCEV, SrcBase);
+ DstSCEV = SE->getMinusSCEV(DstSCEV, DstBase);
+
const SCEVAddRecExpr *SrcAR = dyn_cast<SCEVAddRecExpr>(SrcSCEV);
const SCEVAddRecExpr *DstAR = dyn_cast<SCEVAddRecExpr>(DstSCEV);
if (!SrcAR || !DstAR || !SrcAR->isAffine() || !DstAR->isAffine())
return false;
- SmallVector<const SCEV *, 4> SrcSubscripts, DstSubscripts, SrcSizes, DstSizes;
- const SCEV *RemainderS = SrcAR->delinearize(*SE, SrcSubscripts, SrcSizes);
- const SCEV *RemainderD = DstAR->delinearize(*SE, DstSubscripts, DstSizes);
+ // First step: collect parametric terms in both array references.
+ SmallVector<const SCEV *, 4> Terms;
+ SrcAR->collectParametricTerms(*SE, Terms);
+ DstAR->collectParametricTerms(*SE, Terms);
- int size = SrcSubscripts.size();
- // Fail when there is only a subscript: that's a linearized access function.
- if (size < 2)
- return false;
+ // Second step: find subscript sizes.
+ SmallVector<const SCEV *, 4> Sizes;
+ SE->findArrayDimensions(Terms, Sizes, ElementSize);
- int dstSize = DstSubscripts.size();
- // Fail when the number of subscripts in Src and Dst differ.
- if (size != dstSize)
- return false;
+ // Third step: compute the access functions for each subscript.
+ SmallVector<const SCEV *, 4> SrcSubscripts, DstSubscripts;
+ SrcAR->computeAccessFunctions(*SE, SrcSubscripts, Sizes);
+ DstAR->computeAccessFunctions(*SE, DstSubscripts, Sizes);
- // Fail when the size of any of the subscripts in Src and Dst differs: the
- // dependence analysis assumes that elements in the same array have same size.
- // SCEV delinearization does not have a context based on which it would decide
- // globally the size of subscripts that would best fit all the array accesses.
- for (int i = 0; i < size; ++i)
- if (SrcSizes[i] != DstSizes[i])
- return false;
-
- // When the difference in remainders is different than a constant it might be
- // that the base address of the arrays is not the same.
- const SCEV *DiffRemainders = SE->getMinusSCEV(RemainderS, RemainderD);
- if (!isa<SCEVConstant>(DiffRemainders))
+ // Fail when there is only a subscript: that's a linearized access function.
+ if (SrcSubscripts.size() < 2 || DstSubscripts.size() < 2 ||
+ SrcSubscripts.size() != DstSubscripts.size())
return false;
- // Normalize the last dimension: integrate the size of the "scalar dimension"
- // and the remainder of the delinearization.
- DstSubscripts[size-1] = SE->getMulExpr(DstSubscripts[size-1],
- DstSizes[size-1]);
- SrcSubscripts[size-1] = SE->getMulExpr(SrcSubscripts[size-1],
- SrcSizes[size-1]);
- SrcSubscripts[size-1] = SE->getAddExpr(SrcSubscripts[size-1], RemainderS);
- DstSubscripts[size-1] = SE->getAddExpr(DstSubscripts[size-1], RemainderD);
+ int size = SrcSubscripts.size();
-#ifndef NDEBUG
- DEBUG(errs() << "\nSrcSubscripts: ");
- for (int i = 0; i < size; i++)
- DEBUG(errs() << *SrcSubscripts[i]);
- DEBUG(errs() << "\nDstSubscripts: ");
- for (int i = 0; i < size; i++)
- DEBUG(errs() << *DstSubscripts[i]);
-#endif
+ DEBUG({
+ dbgs() << "\nSrcSubscripts: ";
+ for (int i = 0; i < size; i++)
+ dbgs() << *SrcSubscripts[i];
+ dbgs() << "\nDstSubscripts: ";
+ for (int i = 0; i < size; i++)
+ dbgs() << *DstSubscripts[i];
+ });
// The delinearization transforms a single-subscript MIV dependence test into
// a multi-subscript SIV dependence test that is easier to compute. So we
//
// Care is required to keep the routine below, getSplitIteration(),
// up to date with respect to this routine.
-Dependence *DependenceAnalysis::depends(Instruction *Src,
- Instruction *Dst,
- bool PossiblyLoopIndependent) {
+std::unique_ptr<Dependence>
+DependenceAnalysis::depends(Instruction *Src, Instruction *Dst,
+ bool PossiblyLoopIndependent) {
if (Src == Dst)
PossiblyLoopIndependent = false;
if (!isLoadOrStore(Src) || !isLoadOrStore(Dst)) {
// can only analyze simple loads and stores, i.e., no calls, invokes, etc.
DEBUG(dbgs() << "can only handle simple loads and stores\n");
- return new Dependence(Src, Dst);
+ return make_unique<Dependence>(Src, Dst);
}
Value *SrcPtr = getPointerOperand(Src);
case AliasAnalysis::PartialAlias:
// cannot analyse objects if we don't understand their aliasing.
DEBUG(dbgs() << "can't analyze may or partial alias\n");
- return new Dependence(Src, Dst);
+ return make_unique<Dependence>(Src, Dst);
case AliasAnalysis::NoAlias:
// If the objects noalias, they are distinct, accesses are independent.
DEBUG(dbgs() << "no alias\n");
}
if (Delinearize && Pairs == 1 && CommonLevels > 1 &&
- tryDelinearize(Pair[0].Src, Pair[0].Dst, Pair)) {
+ tryDelinearize(Pair[0].Src, Pair[0].Dst, Pair, SE->getElementSize(Src))) {
DEBUG(dbgs() << " delinerized GEP\n");
Pairs = Pair.size();
}
return nullptr;
}
- FullDependence *Final = new FullDependence(Result);
+ std::unique_ptr<Dependence> Final;
+ Final.reset(new FullDependence(Result));
Result.DV = nullptr;
return Final;
}
//
// breaks the dependence and allows us to vectorize/parallelize
// both loops.
-const SCEV *DependenceAnalysis::getSplitIteration(const Dependence *Dep,
+const SCEV *DependenceAnalysis::getSplitIteration(const Dependence &Dep,
unsigned SplitLevel) {
- assert(Dep && "expected a pointer to a Dependence");
- assert(Dep->isSplitable(SplitLevel) &&
+ assert(Dep.isSplitable(SplitLevel) &&
"Dep should be splitable at SplitLevel");
- Instruction *Src = Dep->getSrc();
- Instruction *Dst = Dep->getDst();
+ Instruction *Src = Dep.getSrc();
+ Instruction *Dst = Dep.getDst();
assert(Src->mayReadFromMemory() || Src->mayWriteToMemory());
assert(Dst->mayReadFromMemory() || Dst->mayWriteToMemory());
assert(isLoadOrStore(Src));
}
if (Delinearize && Pairs == 1 && CommonLevels > 1 &&
- tryDelinearize(Pair[0].Src, Pair[0].Dst, Pair)) {
+ tryDelinearize(Pair[0].Src, Pair[0].Dst, Pair, SE->getElementSize(Src))) {
DEBUG(dbgs() << " delinerized GEP\n");
Pairs = Pair.size();
}