[PATCH] D62110: [LV] prevent potential divide by zero. NFC

[Nick Desaulniers via Phabricator via llvm-commits]

nickdesaulniers created this revision.
nickdesaulniers added a reviewer: rengolin.
Herald added subscribers: llvm-commits, rkruppe, hiraditya.
Herald added a project: LLVM.

scan-build flags a long chain where if LoopCost is 0, then a division by
zero might occur. Add a quick check after its final assignment before
use.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D62110

Files:
  llvm/lib/Transforms/Vectorize/LoopVectorize.cpp


Index: llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
===================================================================
--- llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -5000,6 +5000,8 @@
   // then we calculate the cost of VF here.
   if (LoopCost == 0)
     LoopCost = expectedCost(VF).first;
+  if (LoopCost == 0)
+    return 1;
 
   // Clamp the calculated IC to be between the 1 and the max interleave count
   // that the target allows.


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