[llvm] LAA: improve code in a couple of routines (NFC) (PR #108092)

[Florian Hahn via llvm-commits]

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@@ -2040,19 +2039,16 @@ MemoryDepChecker::isDependent(const MemAccessInfo &A, unsigned AIdx,
                          *Dist, MaxStride, TypeByteSize))
     return Dependence::NoDep;
 
-  const SCEVConstant *C = dyn_cast<SCEVConstant>(Dist);
+  const SCEVConstant *ConstDist = dyn_cast<SCEVConstant>(Dist);
 
   // Attempt to prove strided accesses independent.
-  if (C) {
-    const APInt &Val = C->getAPInt();
-    int64_t Distance = Val.getSExtValue();
+  if (ConstDist) {
+    int64_t Distance = std::abs(ConstDist->getAPInt().getSExtValue());
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fhahn wrote:

Also, if we take the absolute value, clearer to use uint64_t + getZExtValue?

https://github.com/llvm/llvm-project/pull/108092