[llvm] 34d6820 - [LoopFlatten] Use Loop to identify loop induction phi. NFC

[Rosie Sumpter via llvm-commits]

Author: Rosie Sumpter
Date: 2021-07-19T09:06:57+01:00
New Revision: 34d6820551c6ee7e76199407b3c1ba6fecf4398f

URL: https://github.com/llvm/llvm-project/commit/34d6820551c6ee7e76199407b3c1ba6fecf4398f
DIFF: https://github.com/llvm/llvm-project/commit/34d6820551c6ee7e76199407b3c1ba6fecf4398f.diff

LOG: [LoopFlatten] Use Loop to identify loop induction phi. NFC

Replace code which identifies induction phi with helper function
getInductionVariable to improve robustness.

Differential Revision: https://reviews.llvm.org/D106045

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/LoopFlatten.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Scalar/LoopFlatten.cpp b/llvm/lib/Transforms/Scalar/LoopFlatten.cpp
index 37bfff4ba67f6..1cad134876a40 100644
--- a/llvm/lib/Transforms/Scalar/LoopFlatten.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopFlatten.cpp
@@ -124,19 +124,12 @@ static bool findLoopComponents(
   // Find the induction PHI. If there is no induction PHI, we can't do the
   // transformation. TODO: could other variables trigger this? Do we have to
   // search for the best one?
-  InductionPHI = nullptr;
-  for (PHINode &PHI : L->getHeader()->phis()) {
-    InductionDescriptor ID;
-    if (InductionDescriptor::isInductionPHI(&PHI, L, SE, ID)) {
-      InductionPHI = Φ
-      LLVM_DEBUG(dbgs() << "Found induction PHI: "; InductionPHI->dump());
-      break;
-    }
-  }
+  InductionPHI = L->getInductionVariable(*SE);
   if (!InductionPHI) {
     LLVM_DEBUG(dbgs() << "Could not find induction PHI\n");
     return false;
   }
+  LLVM_DEBUG(dbgs() << "Found induction PHI: "; InductionPHI->dump());
 
   auto IsValidPredicate = [&](ICmpInst::Predicate Pred) {
     if (ContinueOnTrue)