[LV][NFC] Fix the condition for printing debug messages

[fhahn]

Would it be possible to add a test case?

[Mel-Chen]

Add a test case

[fhahn]

Thanks for the update! Just a few comments with regard to the test.

LGTM, with the suggested cleanup for the test. It would also be good to pre-commit the test and then have the diff only show the change caused by the patch.

llvm/test/Transforms/LoopVectorize/RISCV/force-vect-msg.ll

14 ↗

(On Diff #440607)

Given that the LLVM IR is very compact I don't think the C code adds much and IMO it would be better to not include it.

27 ↗

(On Diff #440607)

Keep the comment next to the check?

34 ↗

(On Diff #440607)

this should not be needed, you can branch directly to either %for.body.preheader or %for.body.

40 ↗

(On Diff #440607)

IMO the test is easier to read if this exit block is at the end of the function

[Mel-Chen]

Update test case according to the comments.

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

 //===- LoopVectorize.cpp - A Loop Vectorizer ------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
#endif
   if (!EnableCondStoresVectorization && NumPredStores) {
     reportVectorizationFailure("There are conditional stores.",
         "store that is conditionally executed prevents vectorization",
         "ConditionalStore", ORE, TheLoop);
     ChosenFactor = ScalarCost;
   }
 
   LLVM_DEBUG(if (ForceVectorization && !ChosenFactor.Width.isScalar() &&
-                 ChosenFactor.Cost >= ScalarCost.Cost) dbgs()
+                 !isMoreProfitable(ChosenFactor, ScalarCost)) dbgs()
              << "LV: Vectorization seems to be not beneficial, "
              << "but was forced by a user.\n");
   LLVM_DEBUG(dbgs() << "LV: Selecting VF: " << ChosenFactor.Width << ".\n");
   return ChosenFactor;
 }
 
 bool LoopVectorizationCostModel::isCandidateForEpilogueVectorization(
     const Loop &L, ElementCount VF) const {