[llvm] [polly] [SCEV] Introduce SCEVUse, use it instead of const SCEV * (NFCI) (WIP). (PR #91961)

[Ramkumar Ramachandra via llvm-commits]

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@@ -65,6 +65,117 @@ enum SCEVTypes : unsigned short;
 
 extern bool VerifySCEV;
 
+class SCEV;
+
+class SCEVUse : public PointerIntPair<const SCEV *, 3> {
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artagnon wrote:

I think you need two bits: one for NUW and one for NSW. The canonical bit can be dropped, if you can canonicalize on construction.

https://github.com/llvm/llvm-project/pull/91961