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

[Matt Arsenault via llvm-branch-commits]

================
@@ -1336,6 +1311,59 @@ static void addPreloadKernArgHint(Function &F, TargetMachine &TM) {
   }
 }
 
+static void checkWavesPerEU(Module &M, TargetMachine &TM) {
+  for (Function &F : M) {
+    const GCNSubtarget &ST = TM.getSubtarget<GCNSubtarget>(F);
+
+    auto FlatWgrpSizeAttr =
+        AMDGPU::getIntegerPairAttribute(F, "amdgpu-flat-work-group-size");
+    auto WavesPerEUAttr = AMDGPU::getIntegerPairAttribute(
+        F, "amdgpu-waves-per-eu", /*OnlyFirstRequired=*/true);
+
+    unsigned MinWavesPerEU = ST.getMinWavesPerEU();
+    unsigned MaxWavesPerEU = ST.getMaxWavesPerEU();
+
+    unsigned MinFlatWgrpSize = 1U;
+    unsigned MaxFlatWgrpSize = 1024U;
+    if (FlatWgrpSizeAttr.has_value()) {
+      MinFlatWgrpSize = FlatWgrpSizeAttr->first;
+      MaxFlatWgrpSize = *(FlatWgrpSizeAttr->second);
+    }
----------------
arsenm wrote:

```suggestion
    if (FlatWgrpSizeAttr)
      std::tie(MinFlatWgrpSize, MaxFlatWgrpSize) = *FlatWgrpSizeAttr;
```

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