[clang] [llvm] [DirectX] Validate registers are bound to root signature (PR #146785)

[Chris B via llvm-commits]

================
@@ -136,6 +136,51 @@ struct OverlappingRanges {
 llvm::SmallVector<OverlappingRanges>
 findOverlappingRanges(llvm::SmallVector<RangeInfo> &Infos);
 
+class RootSignatureBindingValidation {
+private:
+  llvm::SmallVector<RangeInfo, 16> Bindings;
+  struct TypeRange {
+    uint32_t Start;
+    uint32_t End;
+  };
+  std::unordered_map<dxil::ResourceClass, TypeRange> Ranges;
+
+public:
+  void addBinding(dxil::ResourceClass Type, const RangeInfo &Binding) {
+    auto It = Ranges.find(Type);
+
+    if (It == Ranges.end()) {
+      uint32_t InsertPos = Bindings.size();
+      Bindings.push_back(Binding);
+      Ranges[Type] = {InsertPos, InsertPos + 1};
+    } else {
----------------
llvm-beanz wrote:

nit: Instead of an `else` you could have an early return to avoid nesting.

https://llvm.org/docs/CodingStandards.html#use-early-exits-and-continue-to-simplify-code

https://github.com/llvm/llvm-project/pull/146785