[llvm] [SCEV] Don't use non-deterministic constant folding for trip counts (PR #90942)

[Florian Hahn via llvm-commits]

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@@ -68,9 +68,15 @@ Constant *ConstantFoldConstant(const Constant *C, const DataLayout &DL,
 /// fold instructions like loads and stores, which have no constant expression
 /// form.
 ///
+/// In some cases, constant folding may return one value chosen from a set of
+/// multiple legal return values. Using such a result is usually only valid if
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fhahn wrote:

Might be worth mentioning the NaN case as example?

https://github.com/llvm/llvm-project/pull/90942