[llvm-branch-commits] [llvm] [AMDGPU][Attributor] Skip update if an AA is at its initial state (PR #114726)

[Shilei Tian via llvm-branch-commits]

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@@ -1145,31 +1169,71 @@ struct AAAMDWavesPerEU : public AAAMDSizeRangeAttribute {
     auto &InfoCache = static_cast<AMDGPUInformationCache &>(A.getInfoCache());
     ChangeStatus Change = ChangeStatus::UNCHANGED;
 
+    Function *F = getAssociatedFunction();
+
+    const auto *AAFlatWorkGroupSize = A.getAAFor<AAAMDFlatWorkGroupSize>(
+        *this, IRPosition::function(*F), DepClassTy::REQUIRED);
+    if (!AAFlatWorkGroupSize || !AAFlatWorkGroupSize->isValidState()) {
+      LLVM_DEBUG(
+          dbgs() << '[' << getName()
+                 << "] AAAMDFlatWorkGroupSize is unavailable or invalid.\n");
+      return ChangeStatus::UNCHANGED;
+    }
+
+    if (AAFlatWorkGroupSize->isAtInitialState()) {
+      LLVM_DEBUG(dbgs() << '[' << getName()
+                        << "] AAAMDFlatWorkGroupSize is still at initial "
+                           "state. Skip the update.\n");
+      return ChangeStatus::UNCHANGED;
+    }
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shiltian wrote:

An initial state is always a valid state, but the reverse is not necessarily true. Once the value is updated, it is no longer in the initial state; however, it remains valid. As such, updates should continue, and the manifest function must still be invoked.

https://github.com/llvm/llvm-project/pull/114726