[llvm] [HLSL] Add descriptor table metadata parsing (PR #142492)

[Finn Plummer via llvm-commits]

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@@ -241,6 +332,66 @@ static bool verifyRegisterSpace(uint32_t RegisterSpace) {
 
 static bool verifyDescriptorFlag(uint32_t Flags) { return (Flags & ~0xE) == 0; }
 
+static bool verifyRangeType(uint32_t Type) {
+  switch (Type) {
+  case llvm::to_underlying(dxbc::DescriptorRangeType::CBV):
+  case llvm::to_underlying(dxbc::DescriptorRangeType::SRV):
+  case llvm::to_underlying(dxbc::DescriptorRangeType::UAV):
+  case llvm::to_underlying(dxbc::DescriptorRangeType::Sampler):
+    return true;
+  };
+
+  return false;
+}
+
+static bool verifyDescriptorRangeFlag(uint32_t Version, uint32_t Type,
+                                      uint32_t FlagsVal) {
+  using FlagT = dxbc::DescriptorRangeFlag;
+  FlagT Flags = FlagT(FlagsVal);
+
+  const bool IsSampler =
+      (Type == llvm::to_underlying(dxbc::DescriptorRangeType::Sampler));
+
+  if (Version == 1) {
+    if (IsSampler)
+      return Flags == FlagT::NONE;
+    return Flags == FlagT::DESCRIPTORS_VOLATILE;
+  }
+
+  // The data-specific flags are mutually exclusive.
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inbelic wrote:

the descriptor flags are also mutually exclusive. Do we want an explicit check for this? It seems like it is covered below. Maybe it is good for clarity?

https://github.com/llvm/llvm-project/pull/142492