[llvm] [AArch64] Extend performActiveLaneMaskCombine for more than two extracts (PR #146725)

[Kerry McLaughlin via llvm-commits]

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@@ -167,6 +225,35 @@ define void @test_fixed_extract(i64 %i, i64 %n) #0 {
     ret void
 }
 
+; Negative test where the number of extracts is right, but they cannot be combined because
+; there is not an extract for each part
+define void @test_2x2bit_2x4bit_mask(i64 %i, i64 %n) #0 {
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kmclaughlin-arm wrote:

I've replaced the `@test_2x2bit_2x4bit_mask` test that I added with your suggestion as I think it's a more useful test.

https://github.com/llvm/llvm-project/pull/146725