unsigned PreheaderIdx = PN->getBasicBlockIndex(Preheader);
unsigned BackedgeIdx = PreheaderIdx^1;
if (GetElementPtrInst *GEPI =
- dyn_cast<GetElementPtrInst>(PN->getIncomingValue(BackedgeIdx)))
+ dyn_cast<GetElementPtrInst>(PN->getIncomingValue(BackedgeIdx)))
if (GEPI->getOperand(0) == PN) {
- assert(GEPI->getNumOperands() == 2 && "GEP types must mismatch!");
+ assert(GEPI->getNumOperands() == 2 && "GEP types must match!");
// Okay, we found a pointer recurrence. Transform this pointer
// recurrence into an integer recurrence. Compute the value that gets
if (PN->getType()->isInteger()) { // FIXME: when we have fast-math, enable!
SCEVHandle SCEV = SE->getSCEV(PN);
if (SCEV->hasComputableLoopEvolution(L))
- // FIXME: Without a strength reduction pass, it is an extremely bad idea
- // to indvar substitute anything more complex than a linear induction
- // variable. Doing so will put expensive multiply instructions inside
- // of the loop. For now just disable indvar subst on anything more
- // complex than a linear addrec.
+ // FIXME: It is an extremely bad idea to indvar substitute anything more
+ // complex than affine induction variables. Doing so will put expensive
+ // polynomial evaluations inside of the loop, and the str reduction pass
+ // currently can only reduce affine polynomials. For now just disable
+ // indvar subst on anything more complex than an affine addrec.
if (SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(SCEV))
- if (AR->getNumOperands() == 2 && isa<SCEVConstant>(AR->getOperand(1)))
+ if (AR->isAffine())
IndVars.push_back(std::make_pair(PN, SCEV));
}
}