[llvm] [AMDGPU] Optimize away v_readfirstlane_b32 on SGPR input (PR #151033)

[Shilei Tian via llvm-commits]

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@@ -0,0 +1,271 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5
+# RUN: llc -march=amdgcn -mcpu=gfx900 -run-pass=si-fix-sgpr-copies -o -  %s | FileCheck %s
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shiltian wrote:

use `-mtriple` pls

https://github.com/llvm/llvm-project/pull/151033