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

[Finn Plummer via llvm-commits]

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@@ -241,6 +329,57 @@ 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));
+
+  // The data-specific flags are mutually exclusive.
+  FlagT DataFlags = FlagT::DATA_VOLATILE | FlagT::DATA_STATIC |
+                    FlagT::DATA_STATIC_WHILE_SET_AT_EXECUTE;
+
+  if (popcount(llvm::to_underlying(Flags & DataFlags)) > 1)
+    return false;
+
+  if (popcount(llvm::to_underlying(Flags & DataFlags)) == 1)
+    return true;
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inbelic wrote:

I don't think this is correct. It seems we would skip further validation.

If `Flags = DESCRIPTORS_VOLATILE | DATA_STATIC`, then this will return early as valid.

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