[llvm] [AArch64][CostModel] Lower cost of dupq (SVE2.1) (PR #144918)

[David Green via llvm-commits]

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@@ -5583,6 +5583,26 @@ InstructionCost AArch64TTIImpl::getShuffleCost(
     Kind = TTI::SK_PermuteSingleSrc;
   }
 
+  // Segmented shuffle matching.
+  if (ST->hasSVE2p1() && CostKind == TTI::TCK_RecipThroughput &&
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davemgreen wrote:

Can it be handled for any CostKind? Often them all matching is OK (enough).

https://github.com/llvm/llvm-project/pull/144918