[llvm] [AMDGPU][LIT] Added a MIR LIT showing the SGPR spills (PR #94584)

[Christudasan Devadasan via llvm-commits]

================
@@ -0,0 +1,231 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5
+# RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx908 -verify-machineinstrs -stress-regalloc=3 -start-before=greedy -stop-after=si-lower-sgpr-spills -o - %s | FileCheck -check-prefix=SGPR_SPILLED %s
----------------
cdevadas wrote:

I think it is reasonable to start the test from sgpr-regalloc and keep it until sgpr spill lowering to capture how the newly inserted stack slot coloring helps optimize vgpr lanes. I don't see any problem with the test.

https://github.com/llvm/llvm-project/pull/94584