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

[via cfe-commits]

================
@@ -14,10 +14,129 @@
 #ifndef LLVM_LIB_TARGET_DIRECTX_DXILPOSTOPTIMIZATIONVALIDATION_H
 #define LLVM_LIB_TARGET_DIRECTX_DXILPOSTOPTIMIZATIONVALIDATION_H
 
+#include "DXILRootSignature.h"
+#include "llvm/ADT/IntervalMap.h"
+#include "llvm/Analysis/DXILResource.h"
 #include "llvm/IR/PassManager.h"
 
 namespace llvm {
 
+static uint64_t combineUint32ToUint64(uint32_t High, uint32_t Low) {
+  return (static_cast<uint64_t>(High) << 32) | Low;
+}
+
+class RootSignatureBindingValidation {
+  using MapT =
+      llvm::IntervalMap<uint64_t, dxil::ResourceInfo::ResourceBinding,
+                        sizeof(llvm::dxil::ResourceInfo::ResourceBinding),
+                        llvm::IntervalMapInfo<uint64_t>>;
+
+private:
+  MapT::Allocator Allocator;
+  MapT CRegBindingsMap;
+  MapT TRegBindingsMap;
+  MapT URegBindingsMap;
+  MapT SamplersBindingsMap;
+
+  void addRange(const dxbc::RTS0::v2::RootDescriptor &Desc, uint32_t Type) {
+    assert((Type == llvm::to_underlying(dxbc::RootParameterType::CBV) ||
+            Type == llvm::to_underlying(dxbc::RootParameterType::SRV) ||
+            Type == llvm::to_underlying(dxbc::RootParameterType::UAV)) &&
+           "Invalid Type in add Range Method");
+
+    llvm::dxil::ResourceInfo::ResourceBinding Binding;
+    Binding.LowerBound = Desc.ShaderRegister;
+    Binding.Space = Desc.RegisterSpace;
+    Binding.Size = 1;
+
+    uint64_t LowRange =
+        combineUint32ToUint64(Binding.Space, Binding.LowerBound);
+    uint64_t HighRange = combineUint32ToUint64(
+        Binding.Space, Binding.LowerBound + Binding.Size - 1);
+
+    assert(LowRange <= HighRange && "Invalid range configuration");
+
+    switch (Type) {
+
+    case llvm::to_underlying(dxbc::RootParameterType::CBV):
+      CRegBindingsMap.insert(LowRange, HighRange, Binding);
+      break;
+    case llvm::to_underlying(dxbc::RootParameterType::SRV):
+      TRegBindingsMap.insert(LowRange, HighRange, Binding);
+      break;
+    case llvm::to_underlying(dxbc::RootParameterType::UAV):
+      URegBindingsMap.insert(LowRange, HighRange, Binding);
+      break;
+    }
+  }
+
+  void addRange(const dxbc::RTS0::v2::DescriptorRange &Range) {
+
+    llvm::dxil::ResourceInfo::ResourceBinding Binding;
+    Binding.LowerBound = Range.BaseShaderRegister;
+    Binding.Space = Range.RegisterSpace;
+    Binding.Size = Range.NumDescriptors;
+
+    uint64_t LowRange =
+        combineUint32ToUint64(Binding.Space, Binding.LowerBound);
+    uint64_t HighRange = combineUint32ToUint64(
+        Binding.Space, Binding.LowerBound + Binding.Size - 1);
+
+    assert(LowRange <= HighRange && "Invalid range configuration");
+
+    switch (Range.RangeType) {
+    case llvm::to_underlying(dxbc::DescriptorRangeType::CBV):
+      CRegBindingsMap.insert(LowRange, HighRange, Binding);
+      break;
+    case llvm::to_underlying(dxbc::DescriptorRangeType::SRV):
+      TRegBindingsMap.insert(LowRange, HighRange, Binding);
+      break;
+    case llvm::to_underlying(dxbc::DescriptorRangeType::UAV):
+      URegBindingsMap.insert(LowRange, HighRange, Binding);
+      break;
+    case llvm::to_underlying(dxbc::DescriptorRangeType::Sampler):
+      SamplersBindingsMap.insert(LowRange, HighRange, Binding);
+      break;
+    }
+  }
+
+public:
+  RootSignatureBindingValidation()
+      : Allocator(), CRegBindingsMap(Allocator), TRegBindingsMap(Allocator),
+        URegBindingsMap(Allocator), SamplersBindingsMap(Allocator) {}
+
+  void addRsBindingInfo(mcdxbc::RootSignatureDesc &RSD,
+                        dxbc::ShaderVisibility Visibility);
+
+  bool checkCRegBinding(dxil::ResourceInfo::ResourceBinding Binding) {
+    return CRegBindingsMap.overlaps(
----------------
joaosaffran wrote:

Not always, the user can assign any register inside the range defined in the root signature, here is an example: https://hlsl.godbolt.org/z/qYox19jex

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