[llvm] [AArch64] Use indexed dup for 128b segmented splat (PR #144688)

[Sander de Smalen via llvm-commits]

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@@ -0,0 +1,142 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc -mtriple=aarch64-linux-gnu < %s | FileCheck %s
+
+;; Patterns that lower to concat_vectors where all incoming operands are the same.
+
+define void @concat_i8q_256(<16 x i8> %data, ptr %addr) #0 {
+; CHECK-LABEL: concat_i8q_256:
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sdesmalen-arm wrote:

For the tests, could you add some cases that result in an indexed dup with an index other than 0? e.g. a load of a 256bit vector (which would result in a z-register), a shuffle vector that splats the top 128-bits of that vector over the low and high parts, which should result in a indexed dup instruction with index of 1.

https://github.com/llvm/llvm-project/pull/144688