[llvm-branch-commits] [llvm] [LoopInterchange] Reject if inner loop IV has outer-variant step (PR #202751)

[Nikita Popov via llvm-branch-commits]

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@@ -1251,8 +1251,14 @@ bool LoopInterchangeLegality::checkInductionsAndReductions(Loop *OuterLoop) {
     for (PHINode &PHI : CurLoop->getHeader()->phis()) {
       InductionDescriptor ID;
       if (InductionDescriptor::isInductionPHI(&PHI, CurLoop, SE, ID)) {
-        if (CurLoop == InnerLoop)
+        if (CurLoop == InnerLoop) {
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nikic wrote:

Just to double check, we only care about the loop directly nested inside OuterLoop here, not any of the loops inside InnerLoop? Those don't need a loop-invariant step?

https://github.com/llvm/llvm-project/pull/202751