[llvm] [Loads] Support dereference for non-constant offset (PR #149551)

[Nikita Popov via llvm-commits]

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@@ -361,29 +361,25 @@ bool llvm::isDereferenceableAndAlignedInLoop(
     AccessSize = MaxPtrDiff;
     AccessSizeSCEV = PtrDiff;
   } else if (auto *MinAdd = dyn_cast<SCEVAddExpr>(AccessStart)) {
-    if (MinAdd->getNumOperands() != 2)
-      return false;
+    const auto *NewBase = dyn_cast<SCEVUnknown>(SE.getPointerBase(MinAdd));
+    auto *OffsetSCEV = SE.removePointerBase(MinAdd);
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nikic wrote:

Can move the removePointerBase() call below `!NewBase`.

https://github.com/llvm/llvm-project/pull/149551