add a fixme: ir isn't expressive enough.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123139 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2011-01-09 23:02:10 +00:00
parent 53e1d45adb
commit bd9d53cc65

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@ -4863,6 +4863,7 @@ ScalarEvolution::HowFarToZero(const SCEV *V, const Loop *L) {
// the stride is. As such, NUW addrec's will always become zero in
// "start / -stride" steps, and we know that the division is exact.
if (AddRec->hasNoUnsignedWrap())
// FIXME: We really want an "isexact" bit for udiv.
return getUDivExpr(Start, getNegativeSCEV(Step));
// For now we handle only constant steps.