[llvm] [VPlan] Simplify Plan's entry in removeBranchOnConst. (PR #154510)

[via llvm-commits]

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@@ -2565,6 +2565,9 @@ void InnerLoopVectorizer::fixVectorizedLoop(VPTransformState &State) {
   // Remove redundant induction instructions.
   cse(HeaderBB);
 
+  if (Plan.getScalarPreheader()->getNumPredecessors() == 0)
+    return;
+
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ayalz wrote:

Early exit if remainder/default scalar loop is dead, w/o setting/updating profile weights for the vector loop? Worth a comment.

https://github.com/llvm/llvm-project/pull/154510