[llvm] [SCEVExpander] Add SCEVUseVisitor and use it in SCEVExpander (NFC) (PR #188863)

[Florian Hahn via llvm-commits]

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@@ -68,21 +68,26 @@ LLVM_ABI extern bool VerifySCEV;
 
 class SCEV;
 
-struct SCEVUse : PointerIntPair<const SCEV *, 2> {
-  SCEVUse() : PointerIntPair() { setFromOpaqueValue(nullptr); }
-  SCEVUse(const SCEV *S) : PointerIntPair() {
-    setFromOpaqueValue(reinterpret_cast<void *>(const_cast<SCEV *>(S)));
-  }
-  SCEVUse(const SCEV *S, unsigned Flags) : PointerIntPair(S, Flags) {}
+template <typename SCEVPtrT = const SCEV *>
+struct SCEVUseT : PointerIntPair<SCEVPtrT, 2> {
+  using Base = PointerIntPair<SCEVPtrT, 2>;
+
+  SCEVUseT() : Base() { Base::setFromOpaqueValue(nullptr); }
+  SCEVUseT(SCEVPtrT S) : SCEVUseT(S, 0) {}
+  SCEVUseT(SCEVPtrT S, unsigned Flags) : Base(S, Flags) {}
+  template <typename OtherPtrT, typename = std::enable_if_t<
+                                    std::is_convertible_v<OtherPtrT, SCEVPtrT>>>
+  SCEVUseT(const SCEVUseT<OtherPtrT> &Other)
+      : Base(Other.getPointer(), Other.getInt()) {}
 
-  operator const SCEV *() const { return getPointer(); }
-  const SCEV *operator->() const { return getPointer(); }
+  operator const SCEV *() const { return Base::getPointer(); }
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fhahn wrote:

done thanks

https://github.com/llvm/llvm-project/pull/188863