Look through bitcast when finding IVs. (Chris' patch really.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35347 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dale Johannesen 2007-03-26 03:01:27 +00:00
parent 5eeb4b5bf6
commit da91f49751

View File

@ -235,6 +235,16 @@ DeleteTriviallyDeadInstructions(std::set<Instruction*> &Insts) {
/// GetExpressionSCEV - Compute and return the SCEV for the specified
/// instruction.
SCEVHandle LoopStrengthReduce::GetExpressionSCEV(Instruction *Exp, Loop *L) {
// Pointer to pointer bitcast instructions return the same value as their
// operand.
if (BitCastInst *BCI = dyn_cast<BitCastInst>(Exp)) {
if (SE->hasSCEV(BCI) || !isa<Instruction>(BCI->getOperand(0)))
return SE->getSCEV(BCI);
SCEVHandle R = GetExpressionSCEV(cast<Instruction>(BCI->getOperand(0)), L);
SE->setSCEV(BCI, R);
return R;
}
// Scalar Evolutions doesn't know how to compute SCEV's for GEP instructions.
// If this is a GEP that SE doesn't know about, compute it now and insert it.
// If this is not a GEP, or if we have already done this computation, just let