[PATCH] D87344: [IndVars] Remove exiting conditions that are trivially true/false

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

This looks about reasonable to me, but i don't feel confident reviewing this.



================
Comment at: llvm/lib/Transforms/Scalar/IndVarSimplify.cpp:2348-2352
+  // Can we prove it to be trivially true?
+  if (SE->isKnownPredicate(Pred, LHSS, RHSS))
+    return true;
+
+  return false;
----------------
Should this just be `return SE->isKnownPredicate(Pred, LHSS, RHSS);`,
or are there some other changes planned?


================
Comment at: llvm/lib/Transforms/Scalar/IndVarSimplify.cpp:2376
 
-    const SCEV *ExitCount = SE->getExitCount(L, ExitingBB);
-    if (isa<SCEVCouldNotCompute>(ExitCount))
+    if (!DT->dominates(ExitingBB, L->getLoopLatch()))
       return true;
----------------
// Likewise, the loop latch must be dominated by the exiting BB.


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  https://reviews.llvm.org/D87344/new/

https://reviews.llvm.org/D87344