[llvm] [DX] Support pipeline state masks (PR #66425)

[Xiang Li via llvm-commits]

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@@ -140,6 +159,22 @@ class PSVRuntimeInfo {
 
   const InfoStruct &getInfo() const { return BasicInfo; }
 
+  template <typename T> const T *getInfoAs() const {
+    if (const auto *P = std::get_if<dxbc::PSV::v2::RuntimeInfo>(&BasicInfo))
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python3kgae wrote:

Why do we want to get a v0::RuntimeInfo ptr from a v2 object?
Because v0::RuntimeInfo::swapBytes() is not included in v2::RuntimeInfo::swapBytes()?

https://github.com/llvm/llvm-project/pull/66425