[llvm] [LAA] Clean up APInt-overflow related code (NFC) (PR #140048)

[Florian Hahn via llvm-commits]

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@@ -2067,14 +2064,17 @@ MemoryDepChecker::isDependent(const MemAccessInfo &A, unsigned AIdx,
     return Dependence::NoDep;
 
   // Attempt to prove strided accesses independent.
-  const APInt *ConstDist = nullptr;
-  if (match(Dist, m_scev_APInt(ConstDist))) {
-    uint64_t Distance = ConstDist->abs().getZExtValue();
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fhahn wrote:

I think the uses in `isDependent` rely on `ConstDist` being at most 64 bits, which should be checked earlier. If so, it should be safe to keep the current code using `getZExtValue`, which also has the benefit of asserting if the calling code changes, e.g. after being extended to support wider widths?

https://github.com/llvm/llvm-project/pull/140048