[llvm] [LoopUnroll] Remove redundant llvm.dbg instructions after blocks (PR #89069)

[via llvm-commits]

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@@ -333,6 +333,9 @@ bool llvm::MergeBlockIntoPredecessor(BasicBlock *BB, DomTreeUpdater *DTU,
   // Finally, erase the old block and update dominator info.
   DeleteDeadBlock(BB, DTU);
 
+  // Remove redundant "llvm.dbg" instrunctions after blocks merged.
+  RemoveRedundantDbgInstrs(PredBB);
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coderchenlin wrote:

@fhahn, I added a condition to control it (only execute with the "-g" flag ). Could you please review it again?

https://github.com/llvm/llvm-project/pull/89069