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

Ryotaro Kasuga via llvm-branch-commits llvm-branch-commits at lists.llvm.org
Thu Jun 11 04:29:54 PDT 2026


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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) {
+          const SCEV *Step = ID.getStep();
+          if (!SE->isLoopInvariant(Step, OuterLoop)) {
+            InnerLoopInductions.clear();
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kasuga-fj wrote:

Should be unnecessary. Removed, thanks.

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


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