[llvm] [InstCombine] Simplify `(add/sub (sub/add) (sub/add))` irrelivant of use-count (PR #105866)

[Nikita Popov via llvm-commits]

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@@ -585,6 +585,9 @@ class LLVM_LIBRARY_VISIBILITY InstCombinerImpl final
                                FPClassTest DemandedMask, KnownFPClass &Known,
                                unsigned Depth = 0);
 
+  /// Common transforms for add / disjoint or
+  Instruction *foldAddLike(BinaryOperator &I);
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nikic wrote:

If we add this kind of API, I think it would be better to make the signature `Value *LHS, Value *RHS, bool NUW, bool NSW`.

https://github.com/llvm/llvm-project/pull/105866