[llvm] [AArch64] SVE Shuffleopt: merge reduction reverse into tbl (PR #206047)

[Gaëtan Bossu via llvm-commits]

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@@ -155,10 +155,130 @@ static void evaluateDeinterleave(IntrinsicInst *I, DeinterleaveMap &Candidates,
   Candidates.try_emplace(I, Extends);
 }
 
+/// Evaluate a reverse intrinsic to see what uses it. We want to find a reverse
+/// that pairs with an extract from a deinterleave, so that we can move the
+/// reverse into the tbl as well as deinterleave and extend. We also need to
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gbossu wrote:

How do you predict that the deinterleaving will be done with a tbl and won't be folded into a structured load? 

https://github.com/llvm/llvm-project/pull/206047