[llvm] [AArch64] Align nontemporal store/load little-endian checks (PR #177468)

[Tomer Shafir via llvm-commits]

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@@ -405,17 +406,34 @@ class AArch64TTIImpl final : public BasicTTIImplBase<AArch64TTIImpl> {
       return NumElements > 1 && isPowerOf2_64(NumElements) && EltSize >= 8 &&
              EltSize <= 128 && isPowerOf2_64(EltSize);
     }
-    return BaseT::isLegalNTStore(DataType, Alignment);
+    return std::nullopt;
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tomershafir wrote:

Because we previously had wrong semantics where `BaseT::isLegalNTStore` has been called for both load and store. Now the callers call `BaseT::isLegalNTLoad` for load and `BaseT::isLegalNTStore` for store (it doesnt change functionality as both implementations are the same)

https://github.com/llvm/llvm-project/pull/177468