Throttle back indvar substitution from creating multiplies in loops. This is bad bad bad.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15227 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-07-26 02:47:12 +00:00
parent 8d65a06a3e
commit 595ee7ec26

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@ -607,9 +607,9 @@ void IndVarSimplify::runOnLoop(Loop *L) {
// 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.
if (!isa<SCEVAddRecExpr>(SCEV) ||
cast<SCEVAddRecExpr>(SCEV)->getNumOperands() < 3)
IndVars.push_back(std::make_pair(PN, SCEV));
if (SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(SCEV))
if (AR->getNumOperands() == 2 && isa<SCEVConstant>(AR->getOperand(1)))
IndVars.push_back(std::make_pair(PN, SCEV));
}
// If there are no induction variables in the loop, there is nothing more to