[llvm] [Draft][AMDGPU] Take into account amdgpu-waves-per-eu in getRegPressureLimit (PR #173992)

[Juan Manuel Martinez Caamaño via llvm-commits]

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@@ -4,12 +4,21 @@
 
 # MachineLICM shall limit hoisting of V_CVT instructions out of the loop keeping
 # register pressure within the budget. VGPR budget at occupancy 10 is 24 vgprs.
+# Respect this limit, unless the user explicitely limited the occupancy.
 
+# Both tests have the same mir, only the amdgpu-waves-per-eu attribute changes.
+
+--- |
+  define amdgpu_kernel void @test_default() { ret void }
+
+  define amdgpu_kernel void @test_eu_wave_limit() #0 { ret void }
+
+  attributes #0 = { "amdgpu-waves-per-eu"="1,1" }
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jmmartinez wrote:

Add a third case here with "amdgpu-waves-per-eu" maxed out.

https://github.com/llvm/llvm-project/pull/173992