[llvm] [AArch64] Adjust costs for masked CompressStore and ExpandLoad (PR #226950)

[Benjamin Maxwell via llvm-commits]

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@@ -5582,7 +5581,7 @@ AArch64TTIImpl::getMaskedMemoryOpCost(const MemIntrinsicCostAttributes &MICA,
     //  cntp     x8, p1, p0.s
     //  whilelo  p0.s, xzr, x8
     //  st1w     { z0.s }, p0, [x0]
-    MemOpCost *= 4;
+    MemOpCost += 4;
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MacDue wrote:

Same here, the `ptrue` normally won't occur as we can do `cntp x0, p0, p0.s`.

https://github.com/llvm/llvm-project/pull/226950