[llvm] [IR] Initial introduction of memset_pattern (PR #97583)

[Alex Bradbury via llvm-commits]

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@@ -456,6 +456,48 @@ static void createMemMoveLoop(Instruction *InsertBefore, Value *SrcAddr,
   ElseTerm->eraseFromParent();
 }
 
+static void createMemSetPatternLoop(Instruction *InsertBefore, Value *DstAddr,
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asb wrote:

Thanks for noting - it started somewhat different due to different semantics, but at this point it is indeed equivalent. I've updated.

https://github.com/llvm/llvm-project/pull/97583