[llvm] [AArch64] Full reverse shuffles. (PR #119083)

[Matt Arsenault via llvm-commits]

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@@ -131,6 +131,13 @@ def ext: GICombineRule <
   (apply [{ applyEXT(*${root}, ${matchinfo}); }])
 >;
 
+def fullrev: GICombineRule <
+  (defs root:$root, shuffle_matchdata:$matchinfo),
+  (match (G_SHUFFLE_VECTOR $src, $src1, $src2, $mask):$root,
+         [{ return matchFullRev(*${root}, MRI); }]),
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arsenm wrote:

Predicate seems like it can go in the generic combiner 

https://github.com/llvm/llvm-project/pull/119083