[llvm-branch-commits] [clang] [llvm] [AMDGPU][Attributor] Rework update of `AAAMDWavesPerEU` (PR #123995)

[Matt Arsenault via llvm-branch-commits]

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@@ -1333,6 +1308,56 @@ static void addPreloadKernArgHint(Function &F, TargetMachine &TM) {
   }
 }
 
+/// The final check and update of the attribute 'amdgpu-waves-per-eu' based on
+/// the determined 'amdgpu-flat-work-group-size' attribute. We can't do this
+/// during attributor run because the two attributes grow in opposite direction,
+/// we should not use any intermediate value to calculate waves per eu until we
+/// have a determined flat workgroup size.
+static void updateWavesPerEU(Module &M, TargetMachine &TM) {
+  for (Function &F : M) {
+    const GCNSubtarget &ST = TM.getSubtarget<GCNSubtarget>(F);
+
+    auto FlatWgrpSizeAttr =
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arsenm wrote:

no auto 

https://github.com/llvm/llvm-project/pull/123995