[llvm] [DirectX] Add Range Overlap validation (PR #152229)

[Finn Plummer via llvm-commits]

================
@@ -84,8 +114,122 @@ static void reportOverlappingBinding(Module &M, DXILResourceMap &DRM) {
   }
 }
 
+static void reportOverlappingRegisters(
+    Module &M, const llvm::hlsl::BindingInfoBuilder::Binding &Reported,
+    const llvm::hlsl::BindingInfoBuilder::Binding &Overlaping) {
+  SmallString<128> Message;
+  raw_svector_ostream OS(Message);
+  OS << "register " << getResourceClassName(Reported.RC)
+     << " (space=" << Reported.Space << ", register=" << Reported.LowerBound
+     << ")" << " is overlapping with" << " register "
+     << getResourceClassName(Overlaping.RC) << " (space=" << Overlaping.Space
+     << ", register=" << Overlaping.LowerBound << ")"
+     << ", verify your root signature definition.";
+
+  M.getContext().diagnose(DiagnosticInfoGeneric(Message));
+}
+
+static dxbc::ShaderVisibility
+tripleToVisibility(llvm::Triple::EnvironmentType ET) {
+  assert((ET == Triple::Pixel || ET == Triple::Vertex ||
+          ET == Triple::Geometry || ET == Triple::Hull ||
+          ET == Triple::Domain || ET == Triple::Mesh ||
+          ET == Triple::Compute) &&
+         "Invalid Triple to shader stage conversion");
+
+  switch (ET) {
+  case Triple::Pixel:
+    return dxbc::ShaderVisibility::Pixel;
+  case Triple::Vertex:
+    return dxbc::ShaderVisibility::Vertex;
+  case Triple::Geometry:
+    return dxbc::ShaderVisibility::Geometry;
+  case Triple::Hull:
+    return dxbc::ShaderVisibility::Hull;
+  case Triple::Domain:
+    return dxbc::ShaderVisibility::Domain;
+  case Triple::Mesh:
+    return dxbc::ShaderVisibility::Mesh;
+  case Triple::Compute:
+    return dxbc::ShaderVisibility::All;
+  default:
+    llvm_unreachable("Invalid triple to shader stage conversion");
+  }
+}
+
+static void trackRootSigDescBinding(hlsl::BindingInfoBuilder &Builder,
+                                    const mcdxbc::RootSignatureDesc &RSD,
+                                    dxbc::ShaderVisibility Visibility) {
+  for (size_t I = 0; I < RSD.ParametersContainer.size(); I++) {
+    const auto &[Type, Loc] =
+        RSD.ParametersContainer.getTypeAndLocForParameter(I);
+
+    const auto &Header = RSD.ParametersContainer.getHeader(I);
+    if (Header.ShaderVisibility !=
+            llvm::to_underlying(dxbc::ShaderVisibility::All) &&
+        Header.ShaderVisibility != llvm::to_underlying(Visibility))
+      continue;
+
+    switch (Type) {
+    case llvm::to_underlying(dxbc::RootParameterType::Constants32Bit): {
+      dxbc::RTS0::v1::RootConstants Const =
+          RSD.ParametersContainer.getConstant(Loc);
+      Builder.trackBinding(dxil::ResourceClass::CBuffer, Const.RegisterSpace,
+                           Const.ShaderRegister,
+                           Const.ShaderRegister + Const.Num32BitValues, &Const);
----------------
inbelic wrote:

```suggestion
                           Const.ShaderRegister, &Const);
```
This is what we do in the frontend, and iirc, I did check the behaviour with DXC. In either case, can you double-check what the correct behaviour is. But I believe it will always have a size of 1.

https://github.com/llvm/llvm-project/pull/152229