[llvm] [HLSL] Analyze update counter usage (PR #130356)

[Ashley Coleman via llvm-commits]

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@@ -407,6 +411,77 @@ class DXILResourceTypeMap {
   }
 };
 
+enum ResourceCounterDirection {
+  Increment,
+  Decrement,
+  Unknown,
+};
+
+class DXILResourceCounterDirectionMap {
+  std::vector<std::pair<dxil::ResourceBindingInfo, ResourceCounterDirection>>
+      CounterDirections;
+
+public:
+  bool invalidate(Module &M, const PreservedAnalyses &PA,
+                  ModuleAnalysisManager::Invalidator &Inv);
+
+  void populate(Module &M, ModuleAnalysisManager &AM);
+
+  ResourceCounterDirection
+  operator[](const dxil::ResourceBindingInfo &Info) const {
+    auto Lower = std::lower_bound(
+        CounterDirections.begin(), CounterDirections.end(),
+        std::pair{Info, ResourceCounterDirection::Unknown},
+        [](auto lhs, auto rhs) { return lhs.first < rhs.first; });
+
+    if (Lower == CounterDirections.end()) {
+      return ResourceCounterDirection::Unknown;
+    }
+
+    if (Lower->first != Info) {
+      return ResourceCounterDirection::Unknown;
+    }
+
+    return Lower->second;
+  }
+};
+
+class DXILResourceCounterDirectionAnalysis
+    : public AnalysisInfoMixin<DXILResourceCounterDirectionAnalysis> {
+  friend AnalysisInfoMixin<DXILResourceCounterDirectionAnalysis>;
+
+  static AnalysisKey Key;
+
+public:
+  using Result = DXILResourceCounterDirectionMap;
+
+  DXILResourceCounterDirectionMap run(Module &M, ModuleAnalysisManager &AM) {
+    DXILResourceCounterDirectionMap DRCDM{};
+    DRCDM.populate(M, AM);
+    return DRCDM;
+  }
+};
+
+class DXILResourceCounterDirectionWrapperPass : public ImmutablePass {
+  DXILResourceCounterDirectionMap DRCDM;
+
+  virtual void anchor();
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V-FEXrt wrote:

I have no idea what anchor does, nor if its needed

https://github.com/llvm/llvm-project/pull/130356