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Make LSR ignore GEP's that have loop variant base values, as we currently
cannot codegen them

llvm-svn: 22576
This commit is contained in:
Chris Lattner 2005-08-02 01:32:29 +00:00
parent 564900e5e5
commit 9ef1294210
1 changed files with 10 additions and 0 deletions
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10
llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
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@ -251,6 +251,9 @@ void LoopStrengthReduce::AnalyzeGetElementPtrUsers(GetElementPtrInst *GEP,
UIntPtrTy));
} else {
SCEVHandle Idx = SE->getSCEV(GEP->getOperand(i));
// If this operand is reducible, and it's not the one we are looking at
// currently, do not process the GEP at this time.
if (CanReduceSCEV(Idx, L))
return;
Base = SCEVAddExpr::get(Base, GetAdjustedIndex(Idx,
@ -287,6 +290,13 @@ void LoopStrengthReduce::AnalyzeGetElementPtrUsers(GetElementPtrInst *GEP,
assert(CanReduceSCEV(GEPIndexExpr, L) && "Non reducible idx??");
// FIXME: If the base is not loop invariant, we currently cannot emit this.
if (!Base->isLoopInvariant(L)) {
DEBUG(std::cerr << "IGNORING GEP due to non-invaiant base: "
<< *Base << "\n");
return;
}
Base = SCEVAddExpr::get(Base, cast<SCEVAddRecExpr>(GEPIndexExpr)->getStart());
SCEVHandle Stride = cast<SCEVAddRecExpr>(GEPIndexExpr)->getOperand(1);