/// 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())
// Second step: find subscript sizes.
SmallVector<const SCEV *, 4> Sizes;
- SE->findArrayDimensions(Terms, Sizes);
+ SE->findArrayDimensions(Terms, Sizes, ElementSize);
// Third step: compute the access functions for each subscript.
SmallVector<const SCEV *, 4> SrcSubscripts, DstSubscripts;
- const SCEV *RemainderS = SrcAR->computeAccessFunctions(*SE, SrcSubscripts, Sizes);
- const SCEV *RemainderD = DstAR->computeAccessFunctions(*SE, DstSubscripts, Sizes);
+ SrcAR->computeAccessFunctions(*SE, SrcSubscripts, Sizes);
+ DstAR->computeAccessFunctions(*SE, DstSubscripts, Sizes);
// 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;
- // 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))
- return false;
-
int size = SrcSubscripts.size();
DEBUG({
}
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();
}
}
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();
}