search for: scevanalysis

....i was computed before it: > > %idxprom.i, the zext? I'm not sure how you're getting that particular effect. ScalarEvolution::getSCEV for a zext immediately calls getSCEV on its operand. Here is an abridged record of the getSCEV results as seen by each pass with/without preserving SCEVAnalysis. In the first case, when the SCEV is invalidated, the SCEV for %i.07.i is computed in LSR as {0,+,1}<%for.body.i>. In the second case, the SCEV for %i.07.i is computed in LSR the same way, but because the SCEV for %idxprom.i from FalkorHWPFFix unique's to the same value but has the nuw f...

Hi all, I'm looking into resolving a FIXME in the LoopDataPrefetch (and FalkorMarkStridedAccesses) pass by marking both of these passes as preserving the ScalarEvolution analysis. Unfortunately, when this change is made, LSR will generate different code. One of the root causes seems to be that SCEV will return different nsw/nuw flags for the same Value, depending on what order the