[llvm] [AArch64][GlobalISel] Add legalization for G_VECREDUCE_MUL (PR #68398)

[David Green via llvm-commits]

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@@ -885,6 +885,14 @@ AArch64LegalizerInfo::AArch64LegalizerInfo(const AArch64Subtarget &ST)
       .clampMaxNumElements(1, s16, 8)
       .lower();
 
+  getActionDefinitionsBuilder(G_VECREDUCE_MUL)
+      .clampMaxNumElements(1, s64, 1)
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davemgreen wrote:

For i64 a max clamp of 1 is the same as scalarizing, and this line could be omitted.

https://github.com/llvm/llvm-project/pull/68398