[llvm-branch-commits] [clang] [llvm] [DirectX] Add Range Overlap validation to `DXILPostOptimizationValidation.cpp` (PR #148919)

[Joshua Batista via llvm-branch-commits]

================
@@ -260,6 +260,93 @@ getRootSignature(RootSignatureBindingInfo &RSBI,
   return RootSigDesc;
 }
 
+static void
+reportOverlappingRegisters(Module &M,
+                           llvm::hlsl::rootsig::OverlappingRanges Overlap) {
+  const llvm::hlsl::rootsig::RangeInfo *Info = Overlap.A;
+  const llvm::hlsl::rootsig::RangeInfo *OInfo = Overlap.B;
+  SmallString<128> Message;
+  raw_svector_ostream OS(Message);
+  OS << "register " << ResourceClassToString(Info->Class)
+     << " (space=" << Info->Space << ", register=" << Info->LowerBound << ")"
+     << " is overlapping with"
+     << " register " << ResourceClassToString(OInfo->Class)
+     << " (space=" << OInfo->Space << ", register=" << OInfo->LowerBound << ")"
+     << ", verify your root signature definition";
+
+  M.getContext().diagnose(DiagnosticInfoGeneric(Message));
+}
+
+static bool reportOverlappingRanges(Module &M,
+                                    const mcdxbc::RootSignatureDesc &RSD) {
+  using namespace llvm::hlsl::rootsig;
+
+  llvm::SmallVector<RangeInfo> Infos;
+
+  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);
+    switch (Type) {
+    case llvm::to_underlying(dxbc::RootParameterType::Constants32Bit): {
+      dxbc::RTS0::v1::RootConstants Const =
+          RSD.ParametersContainer.getConstant(Loc);
+
+      RangeInfo Info;
+      Info.Space = Const.RegisterSpace;
+      Info.LowerBound = Const.ShaderRegister;
+      Info.UpperBound = Info.LowerBound;
+      Info.Class = ParameterToResourceClass(Type);
+      Info.Visibility = (dxbc::ShaderVisibility)Header.ShaderVisibility;
+
+      Infos.push_back(Info);
+      break;
+    }
+    case llvm::to_underlying(dxbc::RootParameterType::SRV):
+    case llvm::to_underlying(dxbc::RootParameterType::UAV):
+    case llvm::to_underlying(dxbc::RootParameterType::CBV): {
+      dxbc::RTS0::v2::RootDescriptor Desc =
+          RSD.ParametersContainer.getRootDescriptor(Loc);
+
+      RangeInfo Info;
+      Info.Space = Desc.RegisterSpace;
+      Info.LowerBound = Desc.ShaderRegister;
+      Info.UpperBound = Info.LowerBound;
+      Info.Class = ParameterToResourceClass(Type);
+      Info.Visibility = (dxbc::ShaderVisibility)Header.ShaderVisibility;
+
+      Infos.push_back(Info);
+      break;
+    }
+    case llvm::to_underlying(dxbc::RootParameterType::DescriptorTable): {
+      const mcdxbc::DescriptorTable &Table =
+          RSD.ParametersContainer.getDescriptorTable(Loc);
+
+      for (const dxbc::RTS0::v2::DescriptorRange &Range : Table.Ranges) {
+        RangeInfo Info;
+        Info.Space = Range.RegisterSpace;
+        Info.LowerBound = Range.BaseShaderRegister;
+        Info.UpperBound = Info.LowerBound + ((Range.NumDescriptors == ~0U)
+                                                 ? Range.NumDescriptors
+                                                 : Range.NumDescriptors - 1);
+        Info.Visibility = (dxbc::ShaderVisibility)Header.ShaderVisibility;
+        Info.Class = RangeToResourceClass(Range.RangeType);
----------------
bob80905 wrote:

Nit: it looks like class should be assigned before visibility for consistency

https://github.com/llvm/llvm-project/pull/148919