[llvm] [DX] Add support for program signatures (PR #67346)

[Justin Bogner via llvm-commits]

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@@ -426,6 +426,74 @@ struct ResourceBindInfo : public v0::ResourceBindInfo {
 } // namespace v2
 } // namespace PSV
 
+#define COMPONENT_PRECISION(Val, Enum) Enum = Val,
+enum class SigMinPrecision : uint32_t {
+#include "DXContainerConstants.def"
+};
+
+ArrayRef<EnumEntry<SigMinPrecision>> getSigMinPrecisions();
+
+#define D3D_SYSTEM_VALUE(Val, Enum) Enum = Val,
+enum class D3DSystemValue : uint32_t {
+#include "DXContainerConstants.def"
+};
+
+ArrayRef<EnumEntry<D3DSystemValue>> getD3DSystemValues();
+
+#define COMPONENT_TYPE(Val, Enum) Enum = Val,
+enum class SigComponentType : uint32_t {
+#include "DXContainerConstants.def"
+};
+
+ArrayRef<EnumEntry<SigComponentType>> getSigComponentTypes();
+
+struct ProgramSignatureHeader {
+  uint32_t ParamCount;
+  uint32_t FirstParamOffset;
+
+  void swapBytes() {
+    sys::swapByteOrder(ParamCount);
+    sys::swapByteOrder(ParamCount);
+  }
+};
+
+struct ProgramSignatureElement {
+  uint32_t Stream;     // Stream index (parameters must appear in non-decreasing
+                       // stream order)
+  uint32_t NameOffset; // Offset to LPCSTR from start of ProgramSignatureHeader.
+  uint32_t Index;      // Semantic Index
+  D3DSystemValue SystemValue; // Semantic type. Similar to PSV::SemanticKind.
+  SigComponentType CompType;  // Type of bits.
+  uint32_t Register;          // Register Index (row index)
+  uint8_t Mask;               // Mask (column allocation)
+
+  // The ExclusiveMask has a different meaning for input and output signatures.
+  // For an output signature, masked components of the output register are never
+  // written to.
+  // For an input signature, masked components of the input register are always
+  // read.
+  uint8_t ExclusiveMask;
+
+  uint16_t Unused;
+  SigMinPrecision MinPrecision; // Minimum precision of input/output data
+
+  void swapBytes() {
+    sys::swapByteOrder(Stream);
+    sys::swapByteOrder(NameOffset);
+    sys::swapByteOrder(Index);
+    sys::swapByteOrder(SystemValue);
+    sys::swapByteOrder(CompType);
+    sys::swapByteOrder(Register);
+    sys::swapByteOrder(Mask);
+    sys::swapByteOrder(ExclusiveMask);
+    sys::swapByteOrder(MinPrecision);
+  }
+};
+
+// Easy to get this wrong. Earlier assertions can help determine
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bogner wrote:

Incomplete comment? Probably don't really need to explain the static assert here anyway.

https://github.com/llvm/llvm-project/pull/67346