[llvm] [AMDGPU] Fix lowering of abs for i16 vectors with more than 2 elements (PR #95413)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,1152 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=amdgcn-- -mcpu=gfx600 < %s | FileCheck -check-prefix=GFX6 %s
+; RUN: llc -mtriple=amdgcn-- -mcpu=gfx700 < %s | FileCheck -check-prefix=GFX7 %s
+; RUN: llc -mtriple=amdgcn-- -mcpu=gfx803 < %s | FileCheck -check-prefix=GFX8 %s
+; RUN: llc -mtriple=amdgcn-- -mcpu=gfx900 < %s | FileCheck -check-prefix=GFX9 %s
+; RUN: llc -mtriple=amdgcn-- -mcpu=gfx1010 < %s | FileCheck -check-prefix=GFX10 %s
+; RUN: llc -mtriple=amdgcn-- -mcpu=gfx1100 < %s | FileCheck -check-prefix=GFX11 %s
+; RUN: llc -mtriple=amdgcn-- -mcpu=gfx1200 < %s | FileCheck -check-prefix=GFX12 %s
+
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arsenm wrote:

We apparently don't have existing tests for this, so you should also test the scalar, 2 and 3 element cases, and maybe 6.

Also we should have the 32/64cases, but I guess you can just add an i16 suffix to the test and leave those for later. Also would be nice to cover the basic SALU cases 

https://github.com/llvm/llvm-project/pull/95413