diff --git a/include/dxc/Support/HLSLOptions.h b/include/dxc/Support/HLSLOptions.h
index 31ca3d1c14..4a6868956a 100644
--- a/include/dxc/Support/HLSLOptions.h
+++ b/include/dxc/Support/HLSLOptions.h
@@ -36,7 +36,7 @@ class raw_ostream;
 } // namespace llvm
 
 namespace dxc {
-class DxcDllSupport;
+class SpecificDllLoader;
 }
 
 namespace hlsl {
@@ -304,9 +304,10 @@ int ReadDxcOpts(const llvm::opt::OptTable *optionTable, unsigned flagsToInclude,
                 const MainArgs &argStrings, DxcOpts &opts,
                 llvm::raw_ostream &errors);
 
-/// Sets up the specified DxcDllSupport instance as per the given options.
-int SetupDxcDllSupport(const DxcOpts &opts, dxc::DxcDllSupport &dxcSupport,
-                       llvm::raw_ostream &errors);
+/// Sets up a SpecificDllLoader instance as per the given options.
+int SetupSpecificDllLoader(const DxcOpts &opts,
+                           dxc::SpecificDllLoader &dxcSupport,
+                           llvm::raw_ostream &errors);
 
 void CopyArgsToWStrings(const llvm::opt::InputArgList &inArgs,
                         unsigned flagsToInclude,
diff --git a/include/dxc/Support/dxcapi.extval.h b/include/dxc/Support/dxcapi.extval.h
new file mode 100644
index 0000000000..e479c9cce1
--- /dev/null
+++ b/include/dxc/Support/dxcapi.extval.h
@@ -0,0 +1,29 @@
+#include "dxc/Support/dxcapi.use.h"
+#include <cassert>
+#include <string>
+
+namespace dxc {
+class DxcDllExtValidationLoader : public DllLoader {
+  // DxCompilerSupport manages the
+  // lifetime of dxcompiler.dll, while DxilExtValSupport
+  // manages the lifetime of dxil.dll
+  dxc::SpecificDllLoader DxCompilerSupport;
+  dxc::SpecificDllLoader DxilExtValSupport;
+  std::string DxilDllPath;
+
+public:
+  std::string GetDxilDllPath() { return DxilDllPath; }
+  bool DxilDllFailedToLoad() {
+    return !DxilDllPath.empty() && !DxilExtValSupport.IsEnabled();
+  }
+
+  HRESULT CreateInstanceImpl(REFCLSID clsid, REFIID riid,
+                             IUnknown **pResult) override;
+  HRESULT CreateInstance2Impl(IMalloc *pMalloc, REFCLSID clsid, REFIID riid,
+                              IUnknown **pResult) override;
+
+  HRESULT Initialize();
+
+  bool IsEnabled() const override { return DxCompilerSupport.IsEnabled(); }
+};
+} // namespace dxc
diff --git a/include/dxc/Support/dxcapi.use.h b/include/dxc/Support/dxcapi.use.h
index 44fe23bad6..2a3c350dd8 100644
--- a/include/dxc/Support/dxcapi.use.h
+++ b/include/dxc/Support/dxcapi.use.h
@@ -19,9 +19,47 @@ namespace dxc {
 extern const char *kDxCompilerLib;
 extern const char *kDxilLib;
 
-// Helper class to dynamically load the dxcompiler or a compatible libraries.
-class DxcDllSupport {
+// Interface for common dll operations
+class DllLoader {
+
 protected:
+  virtual HRESULT CreateInstanceImpl(REFCLSID clsid, REFIID riid,
+                                     IUnknown **pResult) = 0;
+  virtual HRESULT CreateInstance2Impl(IMalloc *pMalloc, REFCLSID clsid,
+                                      REFIID riid, IUnknown **pResult) = 0;
+  virtual ~DllLoader() {}
+
+public:
+  DllLoader() = default;
+  DllLoader(const DllLoader &) = delete;
+  DllLoader(DllLoader &&) = delete;
+
+  template <typename TInterface>
+  HRESULT CreateInstance(REFCLSID clsid, TInterface **pResult) {
+    return CreateInstanceImpl(clsid, __uuidof(TInterface),
+                              (IUnknown **)pResult);
+  }
+  HRESULT CreateInstance(REFCLSID clsid, REFIID riid, IUnknown **pResult) {
+    return CreateInstanceImpl(clsid, riid, (IUnknown **)pResult);
+  }
+
+  template <typename TInterface>
+  HRESULT CreateInstance2(IMalloc *pMalloc, REFCLSID clsid,
+                          TInterface **pResult) {
+    return CreateInstance2Impl(pMalloc, clsid, __uuidof(TInterface),
+                               (IUnknown **)pResult);
+  }
+  HRESULT CreateInstance2(IMalloc *pMalloc, REFCLSID clsid, REFIID riid,
+                          IUnknown **pResult) {
+    return CreateInstance2Impl(pMalloc, clsid, riid, (IUnknown **)pResult);
+  }
+
+  virtual bool IsEnabled() const = 0;
+};
+
+// Helper class to dynamically load the dxcompiler or a compatible libraries.
+class SpecificDllLoader : public DllLoader {
+
   HMODULE m_dll;
   DxcCreateInstanceProc m_createFn;
   DxcCreateInstance2Proc m_createFn2;
@@ -74,33 +112,19 @@ class DxcDllSupport {
   }
 
 public:
-  DxcDllSupport() : m_dll(nullptr), m_createFn(nullptr), m_createFn2(nullptr) {}
-
-  DxcDllSupport(DxcDllSupport &&other) {
-    m_dll = other.m_dll;
-    other.m_dll = nullptr;
-    m_createFn = other.m_createFn;
-    other.m_createFn = nullptr;
-    m_createFn2 = other.m_createFn2;
-    other.m_createFn2 = nullptr;
-  }
+  SpecificDllLoader()
+      : m_dll(nullptr), m_createFn(nullptr), m_createFn2(nullptr) {}
 
-  ~DxcDllSupport() { Cleanup(); }
-
-  HRESULT Initialize() {
-    return InitializeInternal(kDxCompilerLib, "DxcCreateInstance");
-  }
+  ~SpecificDllLoader() override { Cleanup(); }
 
   HRESULT InitializeForDll(LPCSTR dll, LPCSTR entryPoint) {
     return InitializeInternal(dll, entryPoint);
   }
 
-  template <typename TInterface>
-  HRESULT CreateInstance(REFCLSID clsid, TInterface **pResult) {
-    return CreateInstance(clsid, __uuidof(TInterface), (IUnknown **)pResult);
-  }
-
-  HRESULT CreateInstance(REFCLSID clsid, REFIID riid, IUnknown **pResult) {
+  // Also bring visibility into the interface definition of this function
+  // which takes 2 args
+  HRESULT CreateInstanceImpl(REFCLSID clsid, REFIID riid,
+                             IUnknown **pResult) override {
     if (pResult == nullptr)
       return E_POINTER;
     if (m_dll == nullptr)
@@ -109,15 +133,10 @@ class DxcDllSupport {
     return hr;
   }
 
-  template <typename TInterface>
-  HRESULT CreateInstance2(IMalloc *pMalloc, REFCLSID clsid,
-                          TInterface **pResult) {
-    return CreateInstance2(pMalloc, clsid, __uuidof(TInterface),
-                           (IUnknown **)pResult);
-  }
-
-  HRESULT CreateInstance2(IMalloc *pMalloc, REFCLSID clsid, REFIID riid,
-                          IUnknown **pResult) {
+  // Also bring visibility into the interface definition of this function
+  // which takes 3 args
+  HRESULT CreateInstance2Impl(IMalloc *pMalloc, REFCLSID clsid, REFIID riid,
+                              IUnknown **pResult) override {
     if (pResult == nullptr)
       return E_POINTER;
     if (m_dll == nullptr)
@@ -130,7 +149,16 @@ class DxcDllSupport {
 
   bool HasCreateWithMalloc() const { return m_createFn2 != nullptr; }
 
-  bool IsEnabled() const { return m_dll != nullptr; }
+  bool IsEnabled() const override { return m_dll != nullptr; }
+
+  bool GetCreateInstanceProcs(DxcCreateInstanceProc *pCreateFn,
+                              DxcCreateInstance2Proc *pCreateFn2) const {
+    if (pCreateFn == nullptr || pCreateFn2 == nullptr || m_createFn == nullptr)
+      return false;
+    *pCreateFn = m_createFn;
+    *pCreateFn2 = m_createFn2;
+    return true;
+  }
 
   void Cleanup() {
     if (m_dll != nullptr) {
@@ -152,6 +180,26 @@ class DxcDllSupport {
   }
 };
 
+// This class is for instances where we *only* expect
+// to load dxcompiler.dll, and nothing else
+class DxCompilerDllLoader : public SpecificDllLoader {
+public:
+  HRESULT Initialize() {
+    return InitializeForDll(kDxCompilerLib, "DxcCreateInstance");
+  }
+};
+
+// This class is for instances where we want to load a
+// subset of any dlls that would give DxcLibrary functionality.
+// e.g, load a IDxcLibrary object.
+// Includes but isn't limited to dxcompiler.dll and dxil.dll
+class LibraryDllLoader : public SpecificDllLoader {
+public:
+  HRESULT Initialize() {
+    return InitializeForDll(kDxCompilerLib, "DxcCreateInstance");
+  }
+};
+
 inline DxcDefine GetDefine(LPCWSTR name, LPCWSTR value) {
   DxcDefine result;
   result.Name = name;
@@ -162,8 +210,8 @@ inline DxcDefine GetDefine(LPCWSTR name, LPCWSTR value) {
 // Checks an HRESULT and formats an error message with the appended data.
 void IFT_Data(HRESULT hr, LPCWSTR data);
 
-void EnsureEnabled(DxcDllSupport &dxcSupport);
-void ReadFileIntoBlob(DxcDllSupport &dxcSupport, LPCWSTR pFileName,
+void EnsureEnabled(LibraryDllLoader &dxcSupport);
+void ReadFileIntoBlob(DllLoader &dxcSupport, LPCWSTR pFileName,
                       IDxcBlobEncoding **ppBlobEncoding);
 void WriteBlobToConsole(IDxcBlob *pBlob, DWORD streamType = STD_OUTPUT_HANDLE);
 void WriteBlobToFile(IDxcBlob *pBlob, LPCWSTR pFileName, UINT32 textCodePage);
diff --git a/include/dxc/Test/CompilationResult.h b/include/dxc/Test/CompilationResult.h
index 1d1272b379..03a2a14bc4 100644
--- a/include/dxc/Test/CompilationResult.h
+++ b/include/dxc/Test/CompilationResult.h
@@ -101,11 +101,9 @@ class TrivialDxcUnsavedFile : public IDxcUnsavedFile {
   }
 };
 
-class HlslIntellisenseSupport : public dxc::DxcDllSupport {
+class HlslIntellisenseSupport : public dxc::DxCompilerDllLoader {
 public:
   HlslIntellisenseSupport() {}
-  HlslIntellisenseSupport(HlslIntellisenseSupport &&other)
-      : dxc::DxcDllSupport(std::move(other)) {}
 
   HRESULT CreateIntellisense(IDxcIntelliSense **pResult) {
     return CreateInstance(CLSID_DxcIntelliSense, pResult);
diff --git a/include/dxc/Test/DxcTestUtils.h b/include/dxc/Test/DxcTestUtils.h
index 79ab49ee9a..f1face7194 100644
--- a/include/dxc/Test/DxcTestUtils.h
+++ b/include/dxc/Test/DxcTestUtils.h
@@ -109,11 +109,11 @@ class FileRunCommandPart {
   FileRunCommandPart(const FileRunCommandPart &) = default;
   FileRunCommandPart(FileRunCommandPart &&) = default;
 
-  FileRunCommandResult Run(dxc::DxcDllSupport &DllSupport,
+  FileRunCommandResult Run(dxc::DllLoader &DllSupport,
                            const FileRunCommandResult *Prior,
                            PluginToolsPaths *pPluginToolsPaths = nullptr,
                            LPCWSTR dumpName = nullptr);
-  FileRunCommandResult RunHashTests(dxc::DxcDllSupport &DllSupport);
+  FileRunCommandResult RunHashTests(dxc::DllLoader &DllSupport);
 
   FileRunCommandResult ReadOptsForDxc(hlsl::options::MainArgs &argStrings,
                                       hlsl::options::DxcOpts &Opts,
@@ -127,30 +127,30 @@ class FileRunCommandPart {
 private:
   FileRunCommandResult RunFileChecker(const FileRunCommandResult *Prior,
                                       LPCWSTR dumpName = nullptr);
-  FileRunCommandResult RunDxc(dxc::DxcDllSupport &DllSupport,
+  FileRunCommandResult RunDxc(dxc::DllLoader &DllSupport,
                               const FileRunCommandResult *Prior);
-  FileRunCommandResult RunDxv(dxc::DxcDllSupport &DllSupport,
+  FileRunCommandResult RunDxv(dxc::DllLoader &DllSupport,
                               const FileRunCommandResult *Prior);
-  FileRunCommandResult RunOpt(dxc::DxcDllSupport &DllSupport,
+  FileRunCommandResult RunOpt(dxc::DllLoader &DllSupport,
                               const FileRunCommandResult *Prior);
-  FileRunCommandResult RunListParts(dxc::DxcDllSupport &DllSupport,
+  FileRunCommandResult RunListParts(dxc::DllLoader &DllSupport,
                                     const FileRunCommandResult *Prior);
-  FileRunCommandResult RunD3DReflect(dxc::DxcDllSupport &DllSupport,
+  FileRunCommandResult RunD3DReflect(dxc::DllLoader &DllSupport,
                                      const FileRunCommandResult *Prior);
-  FileRunCommandResult RunDxr(dxc::DxcDllSupport &DllSupport,
+  FileRunCommandResult RunDxr(dxc::DllLoader &DllSupport,
                               const FileRunCommandResult *Prior);
-  FileRunCommandResult RunLink(dxc::DxcDllSupport &DllSupport,
+  FileRunCommandResult RunLink(dxc::DllLoader &DllSupport,
                                const FileRunCommandResult *Prior);
   FileRunCommandResult RunTee(const FileRunCommandResult *Prior);
   FileRunCommandResult RunXFail(const FileRunCommandResult *Prior);
-  FileRunCommandResult RunDxilVer(dxc::DxcDllSupport &DllSupport,
+  FileRunCommandResult RunDxilVer(dxc::DllLoader &DllSupport,
                                   const FileRunCommandResult *Prior);
-  FileRunCommandResult RunDxcHashTest(dxc::DxcDllSupport &DllSupport);
+  FileRunCommandResult RunDxcHashTest(dxc::DllLoader &DllSupport);
   FileRunCommandResult RunFromPath(const std::string &path,
                                    const FileRunCommandResult *Prior);
   FileRunCommandResult RunFileCompareText(const FileRunCommandResult *Prior);
 #ifdef _WIN32
-  FileRunCommandResult RunFxc(dxc::DxcDllSupport &DllSupport,
+  FileRunCommandResult RunFxc(dxc::DllLoader &DllSupport,
                               const FileRunCommandResult *Prior);
 #endif
 
@@ -175,12 +175,12 @@ class FileRunTestResult {
                       PluginToolsPaths *pPluginToolsPaths = nullptr,
                       LPCWSTR dumpName = nullptr);
   static FileRunTestResult
-  RunFromFileCommands(LPCWSTR fileName, dxc::DxcDllSupport &dllSupport,
+  RunFromFileCommands(LPCWSTR fileName, dxc::DxCompilerDllLoader &dllSupport,
                       PluginToolsPaths *pPluginToolsPaths = nullptr,
                       LPCWSTR dumpName = nullptr);
 };
 
-void AssembleToContainer(dxc::DxcDllSupport &dllSupport, IDxcBlob *pModule,
+void AssembleToContainer(dxc::DllLoader &dllSupport, IDxcBlob *pModule,
                          IDxcBlob **pContainer);
 std::string BlobToUtf8(IDxcBlob *pBlob);
 std::wstring BlobToWide(IDxcBlob *pBlob);
@@ -195,36 +195,34 @@ bool CheckMsgs(const LPCSTR pText, size_t TextCount, const LPCSTR *pErrorMsgs,
                size_t errorMsgCount, bool bRegex);
 bool CheckNotMsgs(const LPCSTR pText, size_t TextCount,
                   const LPCSTR *pErrorMsgs, size_t errorMsgCount, bool bRegex);
-void GetDxilPart(dxc::DxcDllSupport &dllSupport, IDxcBlob *pProgram,
+void GetDxilPart(dxc::DllLoader &dllSupport, IDxcBlob *pProgram,
                  IDxcBlob **pDxilPart);
-std::string DisassembleProgram(dxc::DxcDllSupport &dllSupport,
+std::string DisassembleProgram(dxc::DxCompilerDllLoader &dllSupport,
                                IDxcBlob *pProgram);
 void SplitPassList(LPWSTR pPassesBuffer, std::vector<LPCWSTR> &passes);
-void MultiByteStringToBlob(dxc::DxcDllSupport &dllSupport,
-                           const std::string &val, UINT32 codePoint,
-                           IDxcBlob **ppBlob);
-void MultiByteStringToBlob(dxc::DxcDllSupport &dllSupport,
-                           const std::string &val, UINT32 codePoint,
-                           IDxcBlobEncoding **ppBlob);
-void Utf8ToBlob(dxc::DxcDllSupport &dllSupport, const std::string &val,
+void MultiByteStringToBlob(dxc::DllLoader &dllSupport, const std::string &val,
+                           UINT32 codePoint, IDxcBlob **ppBlob);
+void MultiByteStringToBlob(dxc::DllLoader &dllSupport, const std::string &val,
+                           UINT32 codePoint, IDxcBlobEncoding **ppBlob);
+void Utf8ToBlob(dxc::DllLoader &dllSupport, const std::string &val,
                 IDxcBlob **ppBlob);
-void Utf8ToBlob(dxc::DxcDllSupport &dllSupport, const std::string &val,
+void Utf8ToBlob(dxc::DllLoader &dllSupport, const std::string &val,
                 IDxcBlobEncoding **ppBlob);
-void Utf8ToBlob(dxc::DxcDllSupport &dllSupport, const char *pVal,
+void Utf8ToBlob(dxc::DllLoader &dllSupport, const char *pVal,
                 IDxcBlobEncoding **ppBlob);
-void WideToBlob(dxc::DxcDllSupport &dllSupport, const std::wstring &val,
+void WideToBlob(dxc::DllLoader &dllSupport, const std::wstring &val,
                 IDxcBlob **ppBlob);
-void WideToBlob(dxc::DxcDllSupport &dllSupport, const std::wstring &val,
+void WideToBlob(dxc::DllLoader &dllSupport, const std::wstring &val,
                 IDxcBlobEncoding **ppBlob);
-void VerifyCompileOK(dxc::DxcDllSupport &dllSupport, LPCSTR pText,
+void VerifyCompileOK(dxc::DllLoader &dllSupport, LPCSTR pText,
                      LPCWSTR pTargetProfile, LPCWSTR pArgs,
                      IDxcBlob **ppResult);
-void VerifyCompileOK(dxc::DxcDllSupport &dllSupport, LPCSTR pText,
+void VerifyCompileOK(dxc::DllLoader &dllSupport, LPCSTR pText,
                      LPCWSTR pTargetProfile, std::vector<LPCWSTR> &args,
                      IDxcBlob **ppResult);
 
-HRESULT GetVersion(dxc::DxcDllSupport &DllSupport, REFCLSID clsid,
-                   unsigned &Major, unsigned &Minor);
+HRESULT GetVersion(dxc::DllLoader &DllSupport, REFCLSID clsid, unsigned &Major,
+                   unsigned &Minor);
 bool ParseTargetProfile(llvm::StringRef targetProfile,
                         llvm::StringRef &outStage, unsigned &outMajor,
                         unsigned &outMinor);
@@ -240,7 +238,7 @@ class VersionSupportInfo {
 
   VersionSupportInfo();
   // Initialize version info structure.  TODO: add device shader model support
-  void Initialize(dxc::DxcDllSupport &dllSupport);
+  void Initialize(dxc::DllLoader &dllSupport);
   // Return true if IR sensitive test should be skipped, and log comment
   bool SkipIRSensitiveTest();
   // Return true if test requiring DXIL of given version should be skipped, and
diff --git a/lib/DxcSupport/CMakeLists.txt b/lib/DxcSupport/CMakeLists.txt
index dbc8ef0c26..96474bd620 100644
--- a/lib/DxcSupport/CMakeLists.txt
+++ b/lib/DxcSupport/CMakeLists.txt
@@ -10,6 +10,7 @@ add_llvm_library(LLVMDxcSupport
   WinAdapter.cpp
   WinIncludes.cpp
   WinFunctions.cpp
+  dxcapi.extval.cpp
   )
 
 #generate header with platform-specific library name
diff --git a/lib/DxcSupport/HLSLOptions.cpp b/lib/DxcSupport/HLSLOptions.cpp
index b3eb422eb9..06e6a1bed6 100644
--- a/lib/DxcSupport/HLSLOptions.cpp
+++ b/lib/DxcSupport/HLSLOptions.cpp
@@ -1383,9 +1383,10 @@ int ReadDxcOpts(const OptTable *optionTable, unsigned flagsToInclude,
   return 0;
 }
 
-/// Sets up the specified DxcDllSupport instance as per the given options.
-int SetupDxcDllSupport(const DxcOpts &opts, dxc::DxcDllSupport &dxcSupport,
-                       llvm::raw_ostream &errors) {
+/// Sets up a SpecificDllLoader instance as per the given options.
+int SetupSpecificDllLoader(const DxcOpts &opts,
+                           dxc::SpecificDllLoader &dxcSupport,
+                           llvm::raw_ostream &errors) {
   if (!opts.ExternalLib.empty()) {
     DXASSERT(!opts.ExternalFn.empty(), "else ReadDxcOpts should have failed");
     HRESULT hrLoad = dxcSupport.InitializeForDll(opts.ExternalLib.data(),
diff --git a/lib/DxcSupport/dxcapi.extval.cpp b/lib/DxcSupport/dxcapi.extval.cpp
new file mode 100644
index 0000000000..699873cc3d
--- /dev/null
+++ b/lib/DxcSupport/dxcapi.extval.cpp
@@ -0,0 +1,54 @@
+#include "dxc/Support/WinIncludes.h"
+#include <dxc/Support/Global.h> // for hresult handling with DXC_FAILED
+#include <filesystem>           // C++17 and later
+// WinIncludes must come before dxcapi.extval.h
+#include "dxc/Support/dxcapi.extval.h"
+
+namespace dxc {
+
+HRESULT DxcDllExtValidationLoader::CreateInstanceImpl(REFCLSID clsid,
+                                                      REFIID riid,
+                                                      IUnknown **pResult) {
+  if (DxilExtValSupport.IsEnabled() && clsid == CLSID_DxcValidator)
+    return DxilExtValSupport.CreateInstance(clsid, riid, pResult);
+
+  return DxCompilerSupport.CreateInstance(clsid, riid, pResult);
+}
+
+HRESULT DxcDllExtValidationLoader::CreateInstance2Impl(IMalloc *pMalloc,
+                                                       REFCLSID clsid,
+                                                       REFIID riid,
+                                                       IUnknown **pResult) {
+  if (DxilExtValSupport.IsEnabled() && clsid == CLSID_DxcValidator)
+    return DxilExtValSupport.CreateInstance2(pMalloc, clsid, riid, pResult);
+
+  return DxCompilerSupport.CreateInstance2(pMalloc, clsid, riid, pResult);
+}
+
+HRESULT DxcDllExtValidationLoader::Initialize() {
+  // Load dxcompiler.dll
+  HRESULT Result =
+      DxCompilerSupport.InitializeForDll(kDxCompilerLib, "DxcCreateInstance");
+  // if dxcompiler.dll fails to load, return the failed HRESULT
+  if (DXC_FAILED(Result)) {
+    return Result;
+  }
+
+  // now handle external dxil.dll
+  const char *EnvVarVal = std::getenv("DXC_DXIL_DLL_PATH");
+  if (!EnvVarVal || std::string(EnvVarVal).empty()) {
+    return S_OK;
+  }
+
+  DxilDllPath = std::string(EnvVarVal);
+  std::filesystem::path DllPath(DxilDllPath);
+
+  // Check if path is absolute and exists
+  if (!DllPath.is_absolute() || !std::filesystem::exists(DllPath)) {
+    return E_INVALIDARG;
+  }
+
+  return DxilExtValSupport.InitializeForDll(DxilDllPath.c_str(),
+                                            "DxcCreateInstance");
+}
+} // namespace dxc
diff --git a/lib/DxcSupport/dxcapi.use.cpp b/lib/DxcSupport/dxcapi.use.cpp
index 399259ef87..d6084f2334 100644
--- a/lib/DxcSupport/dxcapi.use.cpp
+++ b/lib/DxcSupport/dxcapi.use.cpp
@@ -73,13 +73,13 @@ void IFT_Data(HRESULT hr, LPCWSTR data) {
   throw ::hlsl::Exception(hr, errMsg);
 }
 
-void EnsureEnabled(DxcDllSupport &dxcSupport) {
+void EnsureEnabled(LibraryDllLoader &dxcSupport) {
   if (!dxcSupport.IsEnabled()) {
-    IFT(dxcSupport.Initialize());
+    IFT(dxcSupport.InitializeForDll(kDxCompilerLib, "DxcCreateInstance"));
   }
 }
 
-void ReadFileIntoBlob(DxcDllSupport &dxcSupport, LPCWSTR pFileName,
+void ReadFileIntoBlob(DllLoader &dxcSupport, LPCWSTR pFileName,
                       IDxcBlobEncoding **ppBlobEncoding) {
   CComPtr<IDxcLibrary> library;
   IFT(dxcSupport.CreateInstance(CLSID_DxcLibrary, &library));
diff --git a/projects/dxilconv/unittests/DxilConvTests.cpp b/projects/dxilconv/unittests/DxilConvTests.cpp
index 6589647f73..c166abb7c8 100644
--- a/projects/dxilconv/unittests/DxilConvTests.cpp
+++ b/projects/dxilconv/unittests/DxilConvTests.cpp
@@ -67,7 +67,7 @@ class DxilConvTest {
   END_TEST_METHOD()
 
 private:
-  dxc::DxcDllSupport m_dllSupport;
+  dxc::DxCompilerDllLoader m_dllSupport;
   PluginToolsPaths m_TestToolPaths;
 
   void DxilConvTestCheckFile(LPCWSTR path) {
diff --git a/tools/clang/lib/SPIRV/EmitVisitor.cpp b/tools/clang/lib/SPIRV/EmitVisitor.cpp
index bf802ad208..1f7a9c5d3c 100644
--- a/tools/clang/lib/SPIRV/EmitVisitor.cpp
+++ b/tools/clang/lib/SPIRV/EmitVisitor.cpp
@@ -139,7 +139,7 @@ ReadSourceCode(llvm::StringRef filePath,
 
   std::string localFilePath(filePath.begin(), filePath.end());
   try {
-    dxc::DxcDllSupport dllSupport;
+    dxc::DxCompilerDllLoader dllSupport;
     IFT(dllSupport.Initialize());
 
     CComPtr<IDxcLibrary> pLibrary;
diff --git a/tools/clang/tools/dxa/dxa.cpp b/tools/clang/tools/dxa/dxa.cpp
index 11d9d642e5..7e391c3d0d 100644
--- a/tools/clang/tools/dxa/dxa.cpp
+++ b/tools/clang/tools/dxa/dxa.cpp
@@ -79,14 +79,14 @@ static cl::opt<bool> DumpPSV("dumppsv",
 class DxaContext {
 
 private:
-  DxcDllSupport &m_dxcSupport;
+  SpecificDllLoader &m_dxcSupport;
   HRESULT FindModule(hlsl::DxilFourCC fourCC, IDxcBlob *pSource,
                      IDxcLibrary *pLibrary, IDxcBlob **ppTarget);
   bool ExtractPart(uint32_t Part, IDxcBlob **ppTargetBlob);
   bool ExtractPart(IDxcBlob *pSource, uint32_t Part, IDxcBlob **ppTargetBlob);
 
 public:
-  DxaContext(DxcDllSupport &dxcSupport) : m_dxcSupport(dxcSupport) {}
+  DxaContext(SpecificDllLoader &dxcSupport) : m_dxcSupport(dxcSupport) {}
 
   void Assemble();
   bool ExtractFile(const char *pName);
@@ -546,7 +546,7 @@ int main(int argc, const char **argv) {
       return 2;
     }
 
-    DxcDllSupport dxcSupport;
+    LibraryDllLoader dxcSupport;
     dxc::EnsureEnabled(dxcSupport);
     DxaContext context(dxcSupport);
     if (ListParts) {
diff --git a/tools/clang/tools/dxclib/dxc.cpp b/tools/clang/tools/dxclib/dxc.cpp
index cdcfe2b3f6..8fbe55af0a 100644
--- a/tools/clang/tools/dxclib/dxc.cpp
+++ b/tools/clang/tools/dxclib/dxc.cpp
@@ -125,7 +125,7 @@ class DxcContext {
 
 private:
   DxcOpts &m_Opts;
-  DxcDllSupport &m_dxcSupport;
+  SpecificDllLoader &m_dxcSupport;
 
   int ActOnBlob(IDxcBlob *pBlob);
   int ActOnBlob(IDxcBlob *pBlob, IDxcBlob *pDebugBlob, LPCWSTR pDebugBlobName);
@@ -155,7 +155,7 @@ class DxcContext {
   }
 
 public:
-  DxcContext(DxcOpts &Opts, DxcDllSupport &dxcSupport)
+  DxcContext(DxcOpts &Opts, SpecificDllLoader &dxcSupport)
       : m_Opts(Opts), m_dxcSupport(dxcSupport) {}
 
   int Compile();
@@ -1234,8 +1234,7 @@ namespace dxc {
 
 // Writes compiler version info to stream
 void WriteDxCompilerVersionInfo(llvm::raw_ostream &OS, const char *ExternalLib,
-                                const char *ExternalFn,
-                                DxcDllSupport &DxcSupport) {
+                                const char *ExternalFn, DllLoader &DxcSupport) {
   if (DxcSupport.IsEnabled()) {
     UINT32 compilerMajor = 1;
     UINT32 compilerMinor = 0;
@@ -1294,7 +1293,7 @@ void WriteDxCompilerVersionInfo(llvm::raw_ostream &OS, const char *ExternalLib,
 }
 
 // Writes compiler version info to stream
-void WriteDXILVersionInfo(llvm::raw_ostream &OS, DxcDllSupport &DxilSupport) {
+void WriteDXILVersionInfo(llvm::raw_ostream &OS, DllLoader &DxilSupport) {
   if (DxilSupport.IsEnabled()) {
     CComPtr<IDxcVersionInfo> VerInfo;
     if (SUCCEEDED(DxilSupport.CreateInstance(CLSID_DxcValidator, &VerInfo))) {
@@ -1325,7 +1324,7 @@ void DxcContext::GetCompilerVersionInfo(llvm::raw_string_ostream &OS) {
       m_dxcSupport);
 
   // Print validator if exists
-  DxcDllSupport DxilSupport;
+  SpecificDllLoader DxilSupport;
   DxilSupport.InitializeForDll(kDxilLib, "DxcCreateInstance");
   WriteDXILVersionInfo(OS, DxilSupport);
 }
@@ -1417,7 +1416,7 @@ int dxc::main(int argc, const char **argv_) {
     const OptTable *optionTable = getHlslOptTable();
     MainArgs argStrings(argc, argv_);
     DxcOpts dxcOpts;
-    DxcDllSupport dxcSupport;
+    LibraryDllLoader dxcSupport;
 
     // Read options and check errors.
     {
@@ -1452,7 +1451,8 @@ int dxc::main(int argc, const char **argv_) {
     {
       std::string dllErrorString;
       llvm::raw_string_ostream dllErrorStream(dllErrorString);
-      int dllResult = SetupDxcDllSupport(dxcOpts, dxcSupport, dllErrorStream);
+      int dllResult =
+          SetupSpecificDllLoader(dxcOpts, dxcSupport, dllErrorStream);
       dllErrorStream.flush();
       if (dllErrorString.size()) {
         fprintf(stderr, "%s\n", dllErrorString.data());
diff --git a/tools/clang/tools/dxclib/dxc.h b/tools/clang/tools/dxclib/dxc.h
index 9ae7a06ffb..387c97cab0 100644
--- a/tools/clang/tools/dxclib/dxc.h
+++ b/tools/clang/tools/dxclib/dxc.h
@@ -18,14 +18,12 @@ class raw_ostream;
 }
 
 namespace dxc {
-class DxcDllSupport;
+class DllLoader;
 
 // Writes compiler version info to stream
 void WriteDxCompilerVersionInfo(llvm::raw_ostream &OS, const char *ExternalLib,
-                                const char *ExternalFn,
-                                dxc::DxcDllSupport &DxcSupport);
-void WriteDXILVersionInfo(llvm::raw_ostream &OS,
-                          dxc::DxcDllSupport &DxilSupport);
+                                const char *ExternalFn, DllLoader &DxcSupport);
+void WriteDXILVersionInfo(llvm::raw_ostream &OS, DllLoader &DxilSupport);
 
 #ifdef _WIN32
 int main(int argc, const wchar_t **argv_);
diff --git a/tools/clang/tools/dxlib-sample/lib_cache_manager.cpp b/tools/clang/tools/dxlib-sample/lib_cache_manager.cpp
index e6379415af..f8a93a59f9 100644
--- a/tools/clang/tools/dxlib-sample/lib_cache_manager.cpp
+++ b/tools/clang/tools/dxlib-sample/lib_cache_manager.cpp
@@ -40,7 +40,7 @@ class NoFuncBodyRewriter {
 
 private:
   CComPtr<IDxcRewriter> m_pRewriter;
-  dxc::DxcDllSupport m_dllSupport;
+  dxc::DxCompilerDllLoader m_dllSupport;
 };
 
 HRESULT NoFuncBodyRewriter::RewriteToNoFuncBody(
diff --git a/tools/clang/tools/dxopt/CMakeLists.txt b/tools/clang/tools/dxopt/CMakeLists.txt
index 1d41efc0d2..090ce21d87 100644
--- a/tools/clang/tools/dxopt/CMakeLists.txt
+++ b/tools/clang/tools/dxopt/CMakeLists.txt
@@ -8,8 +8,11 @@ set( LLVM_LINK_COMPONENTS
   Support    # just for assert and raw streams
   )
 
+set(DXCSUPPORT_DIR "${CMAKE_SOURCE_DIR}/lib/DxcSupport")
+
 add_clang_executable(dxopt
   dxopt.cpp
+  ${DXCSUPPORT_DIR}/dxcapi.use.cpp
   )
 
 target_link_libraries(dxopt
diff --git a/tools/clang/tools/dxopt/dxopt.cpp b/tools/clang/tools/dxopt/dxopt.cpp
index 29e3876e7d..e03c11ccc7 100644
--- a/tools/clang/tools/dxopt/dxopt.cpp
+++ b/tools/clang/tools/dxopt/dxopt.cpp
@@ -12,6 +12,7 @@
 #include "dxc/Support/Global.h"
 #include "dxc/Support/Unicode.h"
 #include "dxc/Support/WinIncludes.h"
+#include "dxc/Support/dxcapi.use.h"
 #include <string>
 #include <vector>
 
@@ -30,6 +31,8 @@
 
 #include "llvm/Support/FileSystem.h"
 
+extern const char *kDxCompilerLib;
+
 inline bool wcseq(LPCWSTR a, LPCWSTR b) {
   return (a == nullptr && b == nullptr) ||
          (a != nullptr && b != nullptr && wcscmp(a, b) == 0);
@@ -43,7 +46,7 @@ inline bool wcsieqopt(LPCWSTR text, LPCWSTR opt) {
   return (text[0] == L'-' || text[0] == L'/') && wcsieq(text + 1, opt);
 }
 
-static dxc::DxcDllSupport g_DxcSupport;
+static dxc::SpecificDllLoader g_DxcSupport;
 
 enum class ProgramAction {
   PrintHelp,
@@ -319,7 +322,8 @@ int main(int argc, const char **argv) {
       CW2A externalLibA(externalLib);
       IFT(g_DxcSupport.InitializeForDll(externalLibA, externalFnA));
     } else {
-      IFT(g_DxcSupport.Initialize());
+      IFT(g_DxcSupport.InitializeForDll(dxc::kDxCompilerLib,
+                                        "DxcCreateInstance"));
     }
 
     CComPtr<IDxcBlob> pBlob;
diff --git a/tools/clang/tools/dxr/dxr.cpp b/tools/clang/tools/dxr/dxr.cpp
index e64a050ffc..e88865694e 100644
--- a/tools/clang/tools/dxr/dxr.cpp
+++ b/tools/clang/tools/dxr/dxr.cpp
@@ -50,7 +50,7 @@ int main(int argc, const char **argv) {
     const OptTable *optionTable = getHlslOptTable();
     MainArgs argStrings(argc, argv_);
     DxcOpts dxcOpts;
-    DxcDllSupport dxcSupport;
+    LibraryDllLoader dxcSupport;
 
     // Read options and check errors.
     {
@@ -76,7 +76,8 @@ int main(int argc, const char **argv) {
     {
       std::string dllErrorString;
       llvm::raw_string_ostream dllErrorStream(dllErrorString);
-      int dllResult = SetupDxcDllSupport(dxcOpts, dxcSupport, dllErrorStream);
+      int dllResult =
+          SetupSpecificDllLoader(dxcOpts, dxcSupport, dllErrorStream);
       dllErrorStream.flush();
       if (dllErrorString.size()) {
         fprintf(stderr, "%s\n", dllErrorString.data());
@@ -92,7 +93,7 @@ int main(int argc, const char **argv) {
       llvm::raw_string_ostream helpStream(helpString);
       std::string version;
       llvm::raw_string_ostream versionStream(version);
-      WriteDxCompilerVersionInfo(
+      dxc::WriteDxCompilerVersionInfo(
           versionStream,
           dxcOpts.ExternalLib.empty() ? (LPCSTR) nullptr
                                       : dxcOpts.ExternalLib.data(),
@@ -111,7 +112,7 @@ int main(int argc, const char **argv) {
     if (dxcOpts.ShowVersion) {
       std::string version;
       llvm::raw_string_ostream versionStream(version);
-      WriteDxCompilerVersionInfo(
+      dxc::WriteDxCompilerVersionInfo(
           versionStream,
           dxcOpts.ExternalLib.empty() ? (LPCSTR) nullptr
                                       : dxcOpts.ExternalLib.data(),
diff --git a/tools/clang/tools/dxrfallbackcompiler/dxillib.cpp b/tools/clang/tools/dxrfallbackcompiler/dxillib.cpp
index 1c54ea6fa3..e12a7412da 100644
--- a/tools/clang/tools/dxrfallbackcompiler/dxillib.cpp
+++ b/tools/clang/tools/dxrfallbackcompiler/dxillib.cpp
@@ -15,7 +15,7 @@
 
 using namespace dxc;
 
-static DxcDllSupport g_DllSupport;
+static SpecificDllLoader g_DllSupport;
 static HRESULT g_DllLibResult = S_OK;
 static CRITICAL_SECTION cs;
 
diff --git a/tools/clang/tools/dxv/dxv.cpp b/tools/clang/tools/dxv/dxv.cpp
index 6e1ea8013e..eabae86a75 100644
--- a/tools/clang/tools/dxv/dxv.cpp
+++ b/tools/clang/tools/dxv/dxv.cpp
@@ -42,10 +42,10 @@ static cl::opt<std::string>
 
 class DxvContext {
 private:
-  DxcDllSupport &m_dxcSupport;
+  SpecificDllLoader &m_dxcSupport;
 
 public:
-  DxvContext(DxcDllSupport &dxcSupport) : m_dxcSupport(dxcSupport) {}
+  DxvContext(SpecificDllLoader &dxcSupport) : m_dxcSupport(dxcSupport) {}
 
   void Validate();
 };
@@ -160,7 +160,7 @@ int main(int argc, const char **argv) {
       return 2;
     }
 
-    DxcDllSupport dxcSupport;
+    LibraryDllLoader dxcSupport;
     dxc::EnsureEnabled(dxcSupport);
 
     DxvContext context(dxcSupport);
diff --git a/tools/clang/unittests/DxrFallback/ShaderTesterImpl.cpp b/tools/clang/unittests/DxrFallback/ShaderTesterImpl.cpp
index 08ae2c3c75..ad37f5fe18 100644
--- a/tools/clang/unittests/DxrFallback/ShaderTesterImpl.cpp
+++ b/tools/clang/unittests/DxrFallback/ShaderTesterImpl.cpp
@@ -32,7 +32,7 @@ using Microsoft::WRL::ComPtr;
 #include "dxc/dxcapi.h"
 #include <atlbase.h>
 
-static dxc::DxcDllSupport g_DxcDllHelper;
+static dxc::DxCompilerDllLoader g_DxcDllHelper;
 
 #define VERIFY_SUCCEEDED(expr)                                                 \
   {                                                                            \
diff --git a/tools/clang/unittests/DxrFallback/test_DxrFallback.cpp b/tools/clang/unittests/DxrFallback/test_DxrFallback.cpp
index d8352ae1c1..85d4c33255 100644
--- a/tools/clang/unittests/DxrFallback/test_DxrFallback.cpp
+++ b/tools/clang/unittests/DxrFallback/test_DxrFallback.cpp
@@ -49,11 +49,11 @@ void printErrors(CComPtr<IDxcOperationResult> pResult) {
   // IFTMSG(status, msg);
 }
 
-void CompileToDxilFromFile(DxcDllSupport &dxcSupport,
-                           LPCWSTR pShaderTextFilePath, LPCWSTR pEntryPoint,
-                           LPCWSTR pTargetProfile, LPCWSTR *pArgs,
-                           UINT32 argCount, const DxcDefine *pDefines,
-                           UINT32 defineCount, IDxcBlob **ppBlob) {
+void CompileToDxilFromFile(DllLoader &dxcSupport, LPCWSTR pShaderTextFilePath,
+                           LPCWSTR pEntryPoint, LPCWSTR pTargetProfile,
+                           LPCWSTR *pArgs, UINT32 argCount,
+                           const DxcDefine *pDefines, UINT32 defineCount,
+                           IDxcBlob **ppBlob) {
   CComPtr<IDxcLibrary> pLibrary;
   IFT(dxcSupport.CreateInstance(CLSID_DxcLibrary, &pLibrary));
 
@@ -83,7 +83,7 @@ void CompileToDxilFromFile(DxcDllSupport &dxcSupport,
   }
 }
 
-bool DxrCompile(DxcDllSupport &dxrFallbackSupport, const std::string &entryName,
+bool DxrCompile(DllLoader &dxrFallbackSupport, const std::string &entryName,
                 std::vector<IDxcBlob *> &libs,
                 const std::vector<std::string> &shaderNames,
                 std::vector<DxcShaderInfo> &shaderIds, bool findCalledShaders,
@@ -161,8 +161,8 @@ class Tester {
   }
 
 protected:
-  DxcDllSupport m_dxcSupport;
-  DxcDllSupport m_dxrFallbackSupport;
+  LibraryDllLoader m_dxcSupport;
+  SpecificDllLoader m_dxrFallbackSupport;
   std::wstring m_deviceName;
   std::vector<CComPtr<IDxcBlob>> m_inputBlobs;
   std::vector<IDxcBlob *> m_inputBlobPtrs;
diff --git a/tools/clang/unittests/HLSL/CompilerTest.cpp b/tools/clang/unittests/HLSL/CompilerTest.cpp
index 3f4fb30d58..02b8652ad5 100644
--- a/tools/clang/unittests/HLSL/CompilerTest.cpp
+++ b/tools/clang/unittests/HLSL/CompilerTest.cpp
@@ -80,9 +80,9 @@ class TestIncludeHandler : public IDxcIncludeHandler {
   DXC_MICROCOM_REF_FIELD(m_dwRef)
 public:
   DXC_MICROCOM_ADDREF_RELEASE_IMPL(m_dwRef)
-  dxc::DxcDllSupport &m_dllSupport;
+  dxc::DxCompilerDllLoader &m_dllSupport;
   HRESULT m_defaultErrorCode = E_FAIL;
-  TestIncludeHandler(dxc::DxcDllSupport &dllSupport)
+  TestIncludeHandler(dxc::DxCompilerDllLoader &dllSupport)
       : m_dwRef(0), m_dllSupport(dllSupport), callIndex(0) {}
   HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid,
                                            void **ppvObject) override {
@@ -285,7 +285,7 @@ class CompilerTest : public ::testing::Test {
   TEST_METHOD_PROPERTY(L"Ignore", L"true")
   END_TEST_METHOD()
 
-  dxc::DxcDllSupport m_dllSupport;
+  dxc::DxCompilerDllLoader m_dllSupport;
   VersionSupportInfo m_ver;
 
   void CreateBlobPinned(LPCVOID data, SIZE_T size, UINT32 codePage,
@@ -1264,7 +1264,7 @@ TEST_F(CompilerTest, CompileThenTestReflectionThreadSizeMS) {
 }
 
 static void VerifyPdbUtil(
-    dxc::DxcDllSupport &dllSupport, IDxcBlob *pBlob, IDxcPdbUtils *pPdbUtils,
+    dxc::DllLoader &dllSupport, IDxcBlob *pBlob, IDxcPdbUtils *pPdbUtils,
     const WCHAR *pMainFileName,
     llvm::ArrayRef<std::pair<const WCHAR *, const WCHAR *>> ExpectedArgs,
     llvm::ArrayRef<std::pair<const WCHAR *, const WCHAR *>> ExpectedFlags,
@@ -2902,9 +2902,9 @@ class SimpleIncludeHanlder : public IDxcIncludeHandler {
   DXC_MICROCOM_REF_FIELD(m_dwRef)
 public:
   DXC_MICROCOM_ADDREF_RELEASE_IMPL(m_dwRef)
-  dxc::DxcDllSupport &m_dllSupport;
+  dxc::DxCompilerDllLoader &m_dllSupport;
   HRESULT m_defaultErrorCode = E_FAIL;
-  SimpleIncludeHanlder(dxc::DxcDllSupport &dllSupport)
+  SimpleIncludeHanlder(dxc::DxCompilerDllLoader &dllSupport)
       : m_dwRef(0), m_dllSupport(dllSupport) {}
   HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid,
                                            void **ppvObject) override {
diff --git a/tools/clang/unittests/HLSL/DxilContainerTest.cpp b/tools/clang/unittests/HLSL/DxilContainerTest.cpp
index 34b4d338fe..5869923802 100644
--- a/tools/clang/unittests/HLSL/DxilContainerTest.cpp
+++ b/tools/clang/unittests/HLSL/DxilContainerTest.cpp
@@ -124,7 +124,7 @@ class DxilContainerTest : public ::testing::Test {
   TEST_METHOD_PROPERTY(L"Priority", L"1")
   END_TEST_METHOD()
 
-  dxc::DxcDllSupport m_dllSupport;
+  dxc::DxCompilerDllLoader m_dllSupport;
   VersionSupportInfo m_ver;
 
   void CreateBlobPinned(LPCVOID data, SIZE_T size, UINT32 codePage,
diff --git a/tools/clang/unittests/HLSL/DxilModuleTest.cpp b/tools/clang/unittests/HLSL/DxilModuleTest.cpp
index 9893127809..51ff34c07c 100644
--- a/tools/clang/unittests/HLSL/DxilModuleTest.cpp
+++ b/tools/clang/unittests/HLSL/DxilModuleTest.cpp
@@ -46,7 +46,7 @@ class DxilModuleTest : public ::testing::Test {
 
   TEST_CLASS_SETUP(InitSupport);
 
-  dxc::DxcDllSupport m_dllSupport;
+  dxc::DxCompilerDllLoader m_dllSupport;
   VersionSupportInfo m_ver;
 
   // Basic loading tests.
@@ -96,7 +96,7 @@ bool DxilModuleTest::InitSupport() {
 namespace {
 class Compiler {
 public:
-  Compiler(dxc::DxcDllSupport &dll)
+  Compiler(dxc::DxCompilerDllLoader &dll)
       : m_dllSupport(dll), m_msf(CreateMSFileSystem()), m_pts(m_msf.get()) {
     m_ver.Initialize(m_dllSupport);
     VERIFY_SUCCEEDED(
@@ -179,7 +179,7 @@ class Compiler {
     return msfPtr;
   }
 
-  dxc::DxcDllSupport &m_dllSupport;
+  dxc::DxCompilerDllLoader &m_dllSupport;
   VersionSupportInfo m_ver;
   CComPtr<IDxcCompiler> pCompiler;
   CComPtr<IDxcBlobEncoding> pCodeBlob;
diff --git a/tools/clang/unittests/HLSL/ExtensionTest.cpp b/tools/clang/unittests/HLSL/ExtensionTest.cpp
index 74acdd6f6f..47d19a3e0d 100644
--- a/tools/clang/unittests/HLSL/ExtensionTest.cpp
+++ b/tools/clang/unittests/HLSL/ExtensionTest.cpp
@@ -572,7 +572,7 @@ class TestSemanticDefineValidator : public IDxcSemanticDefineValidator {
     auto Check = [pName](const std::vector<std::string> &errors,
                          IDxcBlobEncoding **blob) {
       if (std::find(errors.begin(), errors.end(), pName) != errors.end()) {
-        dxc::DxcDllSupport dllSupport;
+        dxc::DxCompilerDllLoader dllSupport;
         VERIFY_SUCCEEDED(dllSupport.Initialize());
         std::string error("bad define: ");
         error.append(pName);
@@ -601,7 +601,7 @@ static std::string GetCompileErrors(IDxcOperationResult *pResult) {
 
 class Compiler {
 public:
-  Compiler(dxc::DxcDllSupport &dll) : m_dllSupport(dll) {
+  Compiler(dxc::DxCompilerDllLoader &dll) : m_dllSupport(dll) {
     VERIFY_SUCCEEDED(m_dllSupport.Initialize());
     VERIFY_SUCCEEDED(
         m_dllSupport.CreateInstance(CLSID_DxcCompiler, &pCompiler));
@@ -654,7 +654,7 @@ class Compiler {
     return DisassembleProgram(m_dllSupport, pBlob);
   }
 
-  dxc::DxcDllSupport &m_dllSupport;
+  dxc::DxCompilerDllLoader &m_dllSupport;
   CComPtr<IDxcCompiler> pCompiler;
   CComPtr<IDxcLangExtensions3> pLangExtensions;
   CComPtr<IDxcBlobEncoding> pCodeBlob;
@@ -677,7 +677,7 @@ class ExtensionTest : public ::testing::Test {
   TEST_METHOD_PROPERTY(L"Priority", L"0")
   END_TEST_CLASS()
 
-  dxc::DxcDllSupport m_dllSupport;
+  dxc::DxCompilerDllLoader m_dllSupport;
 
   TEST_METHOD(EvalAttributeCollision)
   TEST_METHOD(NoUnwind)
diff --git a/tools/clang/unittests/HLSL/FunctionTest.cpp b/tools/clang/unittests/HLSL/FunctionTest.cpp
index e8b087a369..5234b4f1f0 100644
--- a/tools/clang/unittests/HLSL/FunctionTest.cpp
+++ b/tools/clang/unittests/HLSL/FunctionTest.cpp
@@ -36,7 +36,7 @@ class FunctionTest : public ::testing::Test {
   TEST_METHOD(AllowedInParamUsesClass)
   TEST_METHOD(ParseRootSignature)
 
-  dxc::DxcDllSupport m_support;
+  dxc::DxCompilerDllLoader m_support;
   std::vector<char> rootSigText;
 
   std::string BuildSampleFunction(const char *StorageClassKeyword) {
diff --git a/tools/clang/unittests/HLSL/LinkerTest.cpp b/tools/clang/unittests/HLSL/LinkerTest.cpp
index df8bb644e1..2eddcc7f6f 100644
--- a/tools/clang/unittests/HLSL/LinkerTest.cpp
+++ b/tools/clang/unittests/HLSL/LinkerTest.cpp
@@ -80,7 +80,7 @@ class LinkerTest : public ::testing::Test {
   TEST_METHOD(RunLinkWithDxcResultRdat)
   TEST_METHOD(RunLinkWithDxcResultErrors)
 
-  dxc::DxcDllSupport m_dllSupport;
+  dxc::DxCompilerDllLoader m_dllSupport;
   VersionSupportInfo m_ver;
 
   void CreateLinker(IDxcLinker **pResultLinker) {
diff --git a/tools/clang/unittests/HLSL/OptimizerTest.cpp b/tools/clang/unittests/HLSL/OptimizerTest.cpp
index 42eff4b1a7..1294a41434 100644
--- a/tools/clang/unittests/HLSL/OptimizerTest.cpp
+++ b/tools/clang/unittests/HLSL/OptimizerTest.cpp
@@ -117,7 +117,7 @@ class OptimizerTest : public ::testing::Test {
                                              const wchar_t *profile,
                                              bool usesViewId,
                                              int streamCount = 1);
-  dxc::DxcDllSupport m_dllSupport;
+  dxc::DxCompilerDllLoader m_dllSupport;
   VersionSupportInfo m_ver;
 
   HRESULT CreateCompiler(IDxcCompiler **ppResult) {
diff --git a/tools/clang/unittests/HLSL/PixDiaTest.cpp b/tools/clang/unittests/HLSL/PixDiaTest.cpp
index d36e762762..8890a0082c 100644
--- a/tools/clang/unittests/HLSL/PixDiaTest.cpp
+++ b/tools/clang/unittests/HLSL/PixDiaTest.cpp
@@ -85,7 +85,7 @@ const char *DataKindText[] = {
     "FileStatic", "Global", "Member",      "StaticMember", "Constant",
 };
 
-static void CompileAndGetDebugPart(dxc::DxcDllSupport &dllSupport,
+static void CompileAndGetDebugPart(dxc::DllLoader &dllSupport,
                                    const char *source, const wchar_t *profile,
                                    IDxcBlob **ppDebugPart) {
   CComPtr<IDxcBlob> pContainer;
@@ -201,7 +201,7 @@ class PixDiaTest {
   TEST_METHOD(DxcPixDxilDebugInfo_VariableScopes_Function)
   TEST_METHOD(DxcPixDxilDebugInfo_VariableScopes_Member)
 
-  dxc::DxcDllSupport m_dllSupport;
+  dxc::DxCompilerDllLoader m_dllSupport;
   VersionSupportInfo m_ver;
 
   void RunSubProgramsCase(const char *hlsl);
@@ -641,14 +641,12 @@ class PixDiaTest {
   }
 
   void CompileAndRunAnnotationAndGetDebugPart(
-      dxc::DxcDllSupport &dllSupport, const char *source,
-      const wchar_t *profile, IDxcIncludeHandler *includer,
-      IDxcBlob **ppDebugPart,
+      dxc::DllLoader &dllSupport, const char *source, const wchar_t *profile,
+      IDxcIncludeHandler *includer, IDxcBlob **ppDebugPart,
       std::vector<const wchar_t *> extraArgs = {L"-Od"});
   void CompileAndRunAnnotationAndLoadDiaSource(
-      dxc::DxcDllSupport &dllSupport, const char *source,
-      const wchar_t *profile, IDxcIncludeHandler *includer,
-      IDiaDataSource **ppDataSource,
+      dxc::DllLoader &dllSupport, const char *source, const wchar_t *profile,
+      IDxcIncludeHandler *includer, IDiaDataSource **ppDataSource,
       std::vector<const wchar_t *> extraArgs = {L"-Od"});
 
   struct VariableComponentInfo {
@@ -781,7 +779,7 @@ bool PixDiaTest::InitSupport() {
 }
 
 void PixDiaTest::CompileAndRunAnnotationAndGetDebugPart(
-    dxc::DxcDllSupport &dllSupport, const char *source, const wchar_t *profile,
+    dxc::DllLoader &dllSupport, const char *source, const wchar_t *profile,
     IDxcIncludeHandler *includer, IDxcBlob **ppDebugPart,
     std::vector<const wchar_t *> extraArgs) {
 
@@ -1022,7 +1020,7 @@ TEST_F(PixDiaTest, DiaLoadBadBitcodeThenFail) {
   VERIFY_FAILED(pDiaSource->loadDataFromIStream(pStream));
 }
 
-static void CompileTestAndLoadDiaSource(dxc::DxcDllSupport &dllSupport,
+static void CompileTestAndLoadDiaSource(dxc::DllLoader &dllSupport,
                                         const char *source,
                                         const wchar_t *profile,
                                         IDiaDataSource **ppDataSource) {
@@ -1042,7 +1040,7 @@ static void CompileTestAndLoadDiaSource(dxc::DxcDllSupport &dllSupport,
   }
 }
 
-static void CompileTestAndLoadDia(dxc::DxcDllSupport &dllSupport,
+static void CompileTestAndLoadDia(dxc::DllLoader &dllSupport,
                                   IDiaDataSource **ppDataSource) {
   CompileTestAndLoadDiaSource(dllSupport, "[numthreads(8,8,1)] void main() { }",
                               L"cs_6_0", ppDataSource);
@@ -1204,7 +1202,7 @@ TEST_F(PixDiaTest, DiaCompileArgs) {
     args.push_back(L"/D");
     args.push_back(DefineList[i]);
   }
-  auto CompileAndGetDebugPart = [&args](dxc::DxcDllSupport &dllSupport,
+  auto CompileAndGetDebugPart = [&args](dxc::DllLoader &dllSupport,
                                         const char *source,
                                         const wchar_t *profile,
                                         IDxcBlob **ppDebugPart) {
@@ -1464,7 +1462,7 @@ TEST_F(PixDiaTest, PixDebugCompileInfo) {
     args.push_back(DefineList[i]);
   }
 
-  auto CompileAndGetDebugPart = [&args](dxc::DxcDllSupport &dllSupport,
+  auto CompileAndGetDebugPart = [&args](dxc::DllLoader &dllSupport,
                                         const char *source,
                                         const wchar_t *profile,
                                         IDxcBlob **ppDebugPart) {
@@ -1532,7 +1530,7 @@ TEST_F(PixDiaTest, PixDebugCompileInfo) {
 }
 
 void PixDiaTest::CompileAndRunAnnotationAndLoadDiaSource(
-    dxc::DxcDllSupport &dllSupport, const char *source, const wchar_t *profile,
+    dxc::DllLoader &dllSupport, const char *source, const wchar_t *profile,
     IDxcIncludeHandler *includer, IDiaDataSource **ppDataSource,
     std::vector<const wchar_t *> extraArgs) {
   CComPtr<IDxcBlob> pDebugContent;
diff --git a/tools/clang/unittests/HLSL/PixTest.cpp b/tools/clang/unittests/HLSL/PixTest.cpp
index c032e9e872..991c4f38fc 100644
--- a/tools/clang/unittests/HLSL/PixTest.cpp
+++ b/tools/clang/unittests/HLSL/PixTest.cpp
@@ -156,7 +156,7 @@ class PixTest : public ::testing::Test {
   TEST_METHOD(NonUniformResourceIndex_DescriptorHeap)
   TEST_METHOD(NonUniformResourceIndex_Raytracing)
 
-  dxc::DxcDllSupport m_dllSupport;
+  dxc::DxCompilerDllLoader m_dllSupport;
   VersionSupportInfo m_ver;
 
   HRESULT CreateContainerBuilder(IDxcContainerBuilder **ppResult) {
diff --git a/tools/clang/unittests/HLSL/PixTestUtils.cpp b/tools/clang/unittests/HLSL/PixTestUtils.cpp
index 61647ff5fa..4707ca9f7f 100644
--- a/tools/clang/unittests/HLSL/PixTestUtils.cpp
+++ b/tools/clang/unittests/HLSL/PixTestUtils.cpp
@@ -166,7 +166,7 @@ DxilRegisterToNameMap BuildDxilRegisterToNameMap(char const *disassembly) {
   return ret;
 }
 
-std::wstring Disassemble(dxc::DxcDllSupport &dllSupport, IDxcBlob *pProgram) {
+std::wstring Disassemble(dxc::DllLoader &dllSupport, IDxcBlob *pProgram) {
   CComPtr<IDxcCompiler> pCompiler;
   VERIFY_SUCCEEDED(pix_test::CreateCompiler(dllSupport, &pCompiler));
 
@@ -182,7 +182,7 @@ std::wstring Disassemble(dxc::DxcDllSupport &dllSupport, IDxcBlob *pProgram) {
 // For CreateBlobFromText
 namespace {
 
-void CreateBlobPinned(dxc::DxcDllSupport &dllSupport,
+void CreateBlobPinned(dxc::DllLoader &dllSupport,
                       _In_bytecount_(size) LPCVOID data, SIZE_T size,
                       UINT32 codePage, IDxcBlobEncoding **ppBlob) {
   CComPtr<IDxcLibrary> library;
@@ -215,7 +215,7 @@ std::vector<std::string> SplitAndPreserveEmptyLines(std::string const &str,
   return lines;
 }
 
-void CompileAndLogErrors(dxc::DxcDllSupport &dllSupport, LPCSTR pText,
+void CompileAndLogErrors(dxc::DllLoader &dllSupport, LPCSTR pText,
                          LPCWSTR pTargetProfile, std::vector<LPCWSTR> &args,
                          IDxcIncludeHandler *includer,
                          _Outptr_ IDxcBlob **ppResult) {
@@ -241,7 +241,7 @@ void CompileAndLogErrors(dxc::DxcDllSupport &dllSupport, LPCSTR pText,
   VERIFY_SUCCEEDED(pResult->GetResult(ppResult));
 }
 
-PassOutput RunAnnotationPasses(dxc::DxcDllSupport &dllSupport, IDxcBlob *dxil,
+PassOutput RunAnnotationPasses(dxc::DllLoader &dllSupport, IDxcBlob *dxil,
                                int startingLineNumber) {
   CComPtr<IDxcOptimizer> pOptimizer;
   VERIFY_SUCCEEDED(dllSupport.CreateInstance(CLSID_DxcOptimizer, &pOptimizer));
@@ -334,7 +334,7 @@ GatherDebugLocLabelsFromDxcUtils(DebuggerInterfaces &debuggerInterfaces) {
   return std::make_unique<InstructionOffsetSeekerImpl>(debuggerInterfaces);
 }
 
-CComPtr<IDxcBlob> GetDebugPart(dxc::DxcDllSupport &dllSupport,
+CComPtr<IDxcBlob> GetDebugPart(dxc::DllLoader &dllSupport,
                                IDxcBlob *container) {
 
   CComPtr<IDxcLibrary> pLib;
@@ -355,17 +355,16 @@ CComPtr<IDxcBlob> GetDebugPart(dxc::DxcDllSupport &dllSupport,
   return debugPart;
 }
 
-void CreateBlobFromText(dxc::DxcDllSupport &dllSupport, const char *pText,
+void CreateBlobFromText(dxc::DllLoader &dllSupport, const char *pText,
                         IDxcBlobEncoding **ppBlob) {
   CreateBlobPinned(dllSupport, pText, strlen(pText) + 1, CP_UTF8, ppBlob);
 }
 
-HRESULT CreateCompiler(dxc::DxcDllSupport &dllSupport,
-                       IDxcCompiler **ppResult) {
+HRESULT CreateCompiler(dxc::DllLoader &dllSupport, IDxcCompiler **ppResult) {
   return dllSupport.CreateInstance(CLSID_DxcCompiler, ppResult);
 }
 
-CComPtr<IDxcBlob> Compile(dxc::DxcDllSupport &dllSupport, const char *hlsl,
+CComPtr<IDxcBlob> Compile(dxc::DllLoader &dllSupport, const char *hlsl,
                           const wchar_t *target,
                           std::vector<const wchar_t *> extraArgs,
                           const wchar_t *entry) {
@@ -428,7 +427,7 @@ CComPtr<IDxcBlob> Compile(dxc::DxcDllSupport &dllSupport, const char *hlsl,
   return pProgram;
 }
 
-CComPtr<IDxcBlob> WrapInNewContainer(dxc::DxcDllSupport &dllSupport,
+CComPtr<IDxcBlob> WrapInNewContainer(dxc::DllLoader &dllSupport,
                                      IDxcBlob *part) {
   CComPtr<IDxcAssembler> pAssembler;
   IFT(dllSupport.CreateInstance(CLSID_DxcAssembler, &pAssembler));
diff --git a/tools/clang/unittests/HLSL/PixTestUtils.h b/tools/clang/unittests/HLSL/PixTestUtils.h
index 8f7d0cdf45..d55868e75c 100644
--- a/tools/clang/unittests/HLSL/PixTestUtils.h
+++ b/tools/clang/unittests/HLSL/PixTestUtils.h
@@ -19,7 +19,7 @@
 #include <vector>
 
 namespace dxc {
-class DxcDllSupport;
+class DllLoader;
 }
 
 namespace pix_test {
@@ -27,23 +27,22 @@ namespace pix_test {
 std::vector<std::string> SplitAndPreserveEmptyLines(std::string const &str,
                                                     char delimeter);
 
-CComPtr<IDxcBlob> GetDebugPart(dxc::DxcDllSupport &dllSupport,
-                               IDxcBlob *container);
-void CreateBlobFromText(dxc::DxcDllSupport &dllSupport, const char *pText,
+CComPtr<IDxcBlob> GetDebugPart(dxc::DllLoader &dllSupport, IDxcBlob *container);
+void CreateBlobFromText(dxc::DllLoader &dllSupport, const char *pText,
                         IDxcBlobEncoding **ppBlob);
 
-HRESULT CreateCompiler(dxc::DxcDllSupport &dllSupport, IDxcCompiler **ppResult);
-CComPtr<IDxcBlob> Compile(dxc::DxcDllSupport &dllSupport, const char *hlsl,
+HRESULT CreateCompiler(dxc::DllLoader &dllSupport, IDxcCompiler **ppResult);
+CComPtr<IDxcBlob> Compile(dxc::DllLoader &dllSupport, const char *hlsl,
                           const wchar_t *target,
                           std::vector<const wchar_t *> extraArgs = {},
                           const wchar_t *entry = L"main");
 
-void CompileAndLogErrors(dxc::DxcDllSupport &dllSupport, LPCSTR pText,
+void CompileAndLogErrors(dxc::DllLoader &dllSupport, LPCSTR pText,
                          LPCWSTR pTargetProfile, std::vector<LPCWSTR> &args,
                          IDxcIncludeHandler *includer,
                          _Outptr_ IDxcBlob **ppResult);
 
-CComPtr<IDxcBlob> WrapInNewContainer(dxc::DxcDllSupport &dllSupport,
+CComPtr<IDxcBlob> WrapInNewContainer(dxc::DllLoader &dllSupport,
                                      IDxcBlob *part);
 
 struct ValueLocation {
@@ -56,7 +55,7 @@ struct PassOutput {
   std::vector<std::string> lines;
 };
 
-PassOutput RunAnnotationPasses(dxc::DxcDllSupport &dllSupport, IDxcBlob *dxil,
+PassOutput RunAnnotationPasses(dxc::DllLoader &dllSupport, IDxcBlob *dxil,
                                int startingLineNumber = 0);
 
 struct DebuggerInterfaces {
diff --git a/tools/clang/unittests/HLSL/RewriterTest.cpp b/tools/clang/unittests/HLSL/RewriterTest.cpp
index 613c8561a3..1d53a733ef 100644
--- a/tools/clang/unittests/HLSL/RewriterTest.cpp
+++ b/tools/clang/unittests/HLSL/RewriterTest.cpp
@@ -103,7 +103,7 @@ class RewriterTest : public ::testing::Test {
   TEST_METHOD(RunGlobalsUsedInMethod)
   TEST_METHOD(RunRewriterFails)
 
-  dxc::DxcDllSupport m_dllSupport;
+  dxc::DxCompilerDllLoader m_dllSupport;
   CComPtr<IDxcIncludeHandler> m_pIncludeHandler;
 
   struct VerifyResult {
@@ -173,7 +173,7 @@ class RewriterTest : public ::testing::Test {
   struct FileWithBlob {
     CComPtr<IDxcBlobEncoding> BlobEncoding;
 
-    FileWithBlob(dxc::DxcDllSupport &support, LPCWSTR path) {
+    FileWithBlob(dxc::DllLoader &support, LPCWSTR path) {
       CComPtr<IDxcLibrary> library;
       IFT(support.CreateInstance(CLSID_DxcLibrary, &library));
       UINT32 codePage = CP_UTF8;
diff --git a/tools/clang/unittests/HLSL/SystemValueTest.cpp b/tools/clang/unittests/HLSL/SystemValueTest.cpp
index be29612890..91d6cf1215 100644
--- a/tools/clang/unittests/HLSL/SystemValueTest.cpp
+++ b/tools/clang/unittests/HLSL/SystemValueTest.cpp
@@ -198,7 +198,7 @@ class SystemValueTest : public ::testing::Test {
     VERIFY_IS_TRUE(bMessageFound);
   }
 
-  dxc::DxcDllSupport m_dllSupport;
+  dxc::DxCompilerDllLoader m_dllSupport;
   VersionSupportInfo m_ver;
   unsigned m_HighestMajor, m_HighestMinor; // Shader Model Supported
 
diff --git a/tools/clang/unittests/HLSL/ValidationTest.cpp b/tools/clang/unittests/HLSL/ValidationTest.cpp
index 980bf6c7c2..1c64caf7aa 100644
--- a/tools/clang/unittests/HLSL/ValidationTest.cpp
+++ b/tools/clang/unittests/HLSL/ValidationTest.cpp
@@ -20,10 +20,12 @@
 #include "dxc/DxilContainer/DxilContainerAssembler.h"
 #include "dxc/DxilContainer/DxilPipelineStateValidation.h"
 #include "dxc/DxilHash/DxilHash.h"
+#include "dxc/Support/Unicode.h" // for wstring conversions like WideToUtf8String
 #include "dxc/Support/WinIncludes.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Regex.h"
+#include <wchar.h>
 
 #ifdef _WIN32
 #include <atlbase.h>
@@ -32,6 +34,7 @@
 #include "dxc/Support/Global.h"
 
 #include "dxc/DXIL/DxilShaderModel.h"
+#include "dxc/Support/dxcapi.extval.h"
 #include "dxc/Test/DxcTestUtils.h"
 #include "dxc/Test/HlslTestUtils.h"
 
@@ -323,11 +326,12 @@ class ValidationTest : public ::testing::Test {
   TEST_METHOD(PSVContentValidationCS)
   TEST_METHOD(PSVContentValidationMS)
   TEST_METHOD(PSVContentValidationAS)
+  TEST_METHOD(UnitTestExtValidationSupport)
   TEST_METHOD(WrongPSVSize)
   TEST_METHOD(WrongPSVSizeOnZeros)
   TEST_METHOD(WrongPSVVersion)
 
-  dxc::DxcDllSupport m_dllSupport;
+  dxc::DxCompilerDllLoader m_dllSupport;
   VersionSupportInfo m_ver;
 
   void TestCheck(LPCWSTR name) {
@@ -4207,6 +4211,97 @@ TEST_F(ValidationTest, ValidateWithHash) {
   VERIFY_ARE_EQUAL(memcmp(Result, pHeader->Hash.Digest, sizeof(Result)), 0);
 }
 
+#ifdef _WIN32
+std::wstring GetEnvVarW(const std::wstring &VarName) {
+  if (const wchar_t *Result = _wgetenv(VarName.c_str()))
+    return std::wstring(Result);
+  return std::wstring();
+}
+
+void SetEnvVarW(const std::wstring &VarName, const std::wstring &VarValue) {
+  _wputenv_s(VarName.c_str(), VarValue.c_str());
+}
+
+// For now, 3 things are tested:
+// 1. The environment variable is not set. GetDxilDllPath() is empty and
+// DxilDllFailedToLoad() returns false
+// 2. Given a bogus path in the environment variable, and an initialized
+// DxcDllExtValidationSupport object, GetDxilDllPath()
+// retrieves the bogus path despite DxcDllExtValidationSupport failing to load
+// it as a dll, and DxilDllFailedToLoad() returns true.
+// 3. CLSID_DxcCompiler, CLSID_DxcLinker, CLSID_DxcValidator
+// may be created through DxcDllExtValidationSupport.
+// This is all to simply test that the new class, DxcDllExtValidationSupport,
+// works as intended.
+
+TEST_F(ValidationTest, UnitTestExtValidationSupport) {
+  dxc::DxcDllExtValidationLoader ExtSupportEmpty;
+  dxc::DxcDllExtValidationLoader ExtSupportBogus;
+
+  // capture any existing value in the environment variable,
+  // so that it can be restored after the test
+  std::wstring OldEnvVal = GetEnvVarW(L"DXC_DXIL_DLL_PATH");
+
+  // 1. with no env var set, test GetDxilDllPath() and DxilDllFailedToLoad()
+
+  // make sure the variable is cleared, in case other tests may have set it
+  SetEnvVarW(L"DXC_DXIL_DLL_PATH", L"");
+
+  // empty initialization should succeed
+  VERIFY_SUCCEEDED(ExtSupportEmpty.Initialize());
+
+  VERIFY_IS_FALSE(ExtSupportEmpty.DxilDllFailedToLoad());
+  std::string EmptyPath = ExtSupportBogus.GetDxilDllPath();
+  VERIFY_ARE_EQUAL_STR(EmptyPath.c_str(), "");
+
+  // 2. Test with a bogus path in the environment variable
+  SetEnvVarW(L"DXC_DXIL_DLL_PATH", L"bogus");
+
+  if (!ExtSupportBogus.IsEnabled()) {
+    VERIFY_FAILED(ExtSupportBogus.Initialize());
+  }
+
+  // validate that m_dllExtSupport2 was able to capture the environment
+  // variable's value, and that loading the bogus path was unsuccessful
+  std::string BogusPath = ExtSupportBogus.GetDxilDllPath();
+  VERIFY_ARE_EQUAL_STR(BogusPath.c_str(), "bogus");
+  VERIFY_IS_TRUE(ExtSupportBogus.DxilDllFailedToLoad());
+
+  // 3. Test production of class IDs CLSID_DxcCompiler, CLSID_DxcLinker,
+  // and CLSID_DxcValidator through DxcDllExtValidationSupport.
+  CComPtr<IDxcCompiler> Compiler;
+  CComPtr<IDxcLinker> Linker;
+  CComPtr<IDxcValidator> Validator;
+
+  VERIFY_SUCCEEDED(ExtSupportBogus.CreateInstance(
+      CLSID_DxcCompiler, __uuidof(IDxcCompiler), (IUnknown **)&Compiler));
+  VERIFY_SUCCEEDED(ExtSupportBogus.CreateInstance(
+      CLSID_DxcLinker, __uuidof(IDxcLinker), (IUnknown **)&Linker));
+  VERIFY_SUCCEEDED(ExtSupportBogus.CreateInstance(
+      CLSID_DxcValidator, __uuidof(IDxcValidator), (IUnknown **)&Validator));
+
+  Linker.Release();
+  Validator.Release();
+  Compiler.Release();
+
+  CComPtr<IMalloc> Malloc;
+  CComPtr<IDxcCompiler2> Compiler2;
+  VERIFY_SUCCEEDED(DxcCoGetMalloc(1, &Malloc));
+  VERIFY_SUCCEEDED(ExtSupportBogus.CreateInstance2(Malloc, CLSID_DxcCompiler,
+                                                   __uuidof(IDxcCompiler),
+                                                   (IUnknown **)&Compiler2));
+  VERIFY_SUCCEEDED(ExtSupportBogus.CreateInstance2(
+      Malloc, CLSID_DxcLinker, __uuidof(IDxcLinker), (IUnknown **)&Linker));
+  VERIFY_SUCCEEDED(ExtSupportBogus.CreateInstance2(Malloc, CLSID_DxcValidator,
+                                                   __uuidof(IDxcValidator),
+                                                   (IUnknown **)&Validator));
+
+  // reset the environment variable to its previous value,
+  // or the empty string if there was no previous value
+  SetEnvVarW(L"DXC_DXIL_DLL_PATH", OldEnvVal);
+}
+#endif
+
 TEST_F(ValidationTest, ValidatePreviewBypassHash) {
   if (m_ver.SkipDxilVersion(1, ShaderModel::kHighestMinor))
     return;
diff --git a/tools/clang/unittests/HLSLExec/CMakeLists.txt b/tools/clang/unittests/HLSLExec/CMakeLists.txt
index b490ac94e9..ac305a31a1 100644
--- a/tools/clang/unittests/HLSLExec/CMakeLists.txt
+++ b/tools/clang/unittests/HLSLExec/CMakeLists.txt
@@ -5,6 +5,8 @@ find_package(D3D12 REQUIRED) # Used for ExecutionTest.cpp.
 
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /bigobj")
 
+set(DXCSUPPORT_DIR "${CMAKE_SOURCE_DIR}/lib/DxcSupport")
+
 add_clang_library(ExecHLSLTests SHARED
   ExecutionTest.cpp
   ShaderOpTest.cpp
diff --git a/tools/clang/unittests/HLSLExec/ExecutionTest.cpp b/tools/clang/unittests/HLSLExec/ExecutionTest.cpp
index 586c55328d..68e94794cc 100644
--- a/tools/clang/unittests/HLSLExec/ExecutionTest.cpp
+++ b/tools/clang/unittests/HLSLExec/ExecutionTest.cpp
@@ -459,7 +459,7 @@ class ExecutionTest {
                        L"Table:ShaderOpArithTable.xml#PackUnpackOpTable")
   END_TEST_METHOD()
 
-  dxc::DxcDllSupport m_support;
+  dxc::DxCompilerDllLoader m_support;
 
   bool m_D3DInitCompleted = false;
   bool m_ExperimentalModeEnabled = false;
@@ -3568,13 +3568,13 @@ struct Dispatch {
 };
 
 std::shared_ptr<st::ShaderOpTest> RunDispatch(ID3D12Device *pDevice,
-                                              dxc::DxcDllSupport &support,
+                                              dxc::SpecificDllLoader &support,
                                               st::ShaderOp *pShaderOp,
                                               const Dispatch D) {
   char compilerOptions[256];
 
   std::shared_ptr<st::ShaderOpTest> test = std::make_shared<st::ShaderOpTest>();
-  test->SetDxcSupport(&support);
+  test->SetSpecificDllLoader(&support);
   test->SetInitCallback(nullptr);
   test->SetDevice(pDevice);
 
@@ -10765,7 +10765,7 @@ TEST_F(ExecutionTest, DynamicResourcesDynamicIndexingTest) {
 void RunWaveSizeTest(UINT minWaveSize, UINT maxWaveSize,
                      std::shared_ptr<st::ShaderOpSet> ShaderOpSet,
                      CComPtr<ID3D12Device> pDevice,
-                     dxc::DxcDllSupport &m_support) {
+                     dxc::SpecificDllLoader &m_support) {
   // format shader source
   const char waveSizeTestShader[] =
       R"(struct TestData { 
@@ -10835,7 +10835,7 @@ bool TestShaderRangeAgainstRequirements(UINT shaderminws, UINT shadermaxws,
 void ExecuteWaveSizeRangeInstance(UINT minWaveSize, UINT maxWaveSize,
                                   std::shared_ptr<st::ShaderOpSet> ShaderOpSet,
                                   CComPtr<ID3D12Device> pDevice,
-                                  dxc::DxcDllSupport &m_support,
+                                  dxc::SpecificDllLoader &m_support,
                                   UINT minShaderWaveSize,
                                   UINT maxShaderWaveSize,
                                   UINT prefShaderWaveSize, bool usePreferred) {
@@ -10918,7 +10918,7 @@ void ExecuteWaveSizeRangeInstance(UINT minWaveSize, UINT maxWaveSize,
 void RunWaveSizeRangeTest(UINT minWaveSize, UINT maxWaveSize,
                           std::shared_ptr<st::ShaderOpSet> ShaderOpSet,
                           CComPtr<ID3D12Device> pDevice,
-                          dxc::DxcDllSupport &m_support) {
+                          dxc::SpecificDllLoader &m_support) {
 
   for (UINT minShaderWaveSize = 4; minShaderWaveSize <= maxWaveSize;
        minShaderWaveSize *= 2) {
@@ -12427,7 +12427,7 @@ TEST_F(ExecutionTest, QuadAnyAll) {
 // input string pointers.
 st::ShaderOpTest::TShaderCallbackFn MakeShaderReplacementCallback(
     std::vector<std::wstring> dxcArgs, std::vector<std::string> lookFors,
-    std::vector<std::string> replacements, dxc::DxcDllSupport &dllSupport) {
+    std::vector<std::string> replacements, dxc::DllLoader &dllSupport) {
 
   auto ShaderInitFn = [dxcArgs, lookFors, replacements, &dllSupport](
                           LPCSTR Name, LPCSTR pText, IDxcBlob **ppShaderBlob,
@@ -12743,7 +12743,7 @@ __declspec(dllexport) HRESULT WINAPI
     pOutputStrFn(pStrCtx, L"Unable to enable info queue for D3D.\r\n.");
   }
   try {
-    dxc::DxcDllSupport m_support;
+    dxc::DxCompilerDllLoader m_support;
     m_support.Initialize();
 
     const char *pName = nullptr;
@@ -12779,7 +12779,7 @@ __declspec(dllexport) HRESULT WINAPI
     std::shared_ptr<st::ShaderOpTest> test =
         std::make_shared<st::ShaderOpTest>();
     test->SetupRenderTarget(pShaderOp, pDevice, pCommandQueue, pRenderTarget);
-    test->SetDxcSupport(&m_support);
+    test->SetSpecificDllLoader(&m_support);
     test->RunShaderOp(pShaderOp);
     test->PresentRenderTarget(pShaderOp, pCommandQueue, pRenderTarget);
 
diff --git a/tools/clang/unittests/HLSLExec/HlslExecTestUtils.h b/tools/clang/unittests/HLSLExec/HlslExecTestUtils.h
index 3822ef02ad..96b756f535 100644
--- a/tools/clang/unittests/HLSLExec/HlslExecTestUtils.h
+++ b/tools/clang/unittests/HLSLExec/HlslExecTestUtils.h
@@ -228,8 +228,9 @@ static bool createDevice(ID3D12Device **D3DDevice,
 }
 
 inline void readHlslDataIntoNewStream(LPCWSTR RelativePath, IStream **Stream,
-                                      dxc::DxcDllSupport &Support) {
-  VERIFY_SUCCEEDED(Support.Initialize());
+                                      dxc::SpecificDllLoader &Support) {
+  VERIFY_SUCCEEDED(
+      Support.InitializeForDll(dxc::kDxCompilerLib, "DxcCreateInstance"));
   CComPtr<IDxcLibrary> Library;
   CComPtr<IDxcBlobEncoding> Blob;
   CComPtr<IStream> StreamCom;
diff --git a/tools/clang/unittests/HLSLExec/LongVectors.cpp b/tools/clang/unittests/HLSLExec/LongVectors.cpp
index a3c2c94d00..7de0b1b1a1 100644
--- a/tools/clang/unittests/HLSLExec/LongVectors.cpp
+++ b/tools/clang/unittests/HLSLExec/LongVectors.cpp
@@ -547,14 +547,14 @@ void OpTest::testBaseMethod(
   LPCSTR ShaderName = "LongVectorOp";
   // ShaderOpArith.xml defines the input/output resources and the shader source.
   CComPtr<IStream> TestXML;
-  readHlslDataIntoNewStream(L"ShaderOpArith.xml", &TestXML, DxcDllSupport);
+  readHlslDataIntoNewStream(L"ShaderOpArith.xml", &TestXML, DxilDllLoader);
 
   // RunShaderOpTest is a helper function that handles resource creation
   // and setup. It also handles the shader compilation and execution. It takes a
   // callback that is called when the shader is compiled, but before it is
   // executed.
   std::shared_ptr<st::ShaderOpTestResult> TestResult = st::RunShaderOpTest(
-      D3DDevice, DxcDllSupport, TestXML, ShaderName,
+      D3DDevice, DxilDllLoader, TestXML, ShaderName,
       [&](LPCSTR Name, std::vector<BYTE> &ShaderData, st::ShaderOp *ShaderOp) {
         hlsl_test::LogCommentFmt(L"RunShaderOpTest CallBack. Resource Name: %S",
                                  Name);
diff --git a/tools/clang/unittests/HLSLExec/LongVectors.h b/tools/clang/unittests/HLSLExec/LongVectors.h
index b7a37d09c1..38edc02341 100644
--- a/tools/clang/unittests/HLSLExec/LongVectors.h
+++ b/tools/clang/unittests/HLSLExec/LongVectors.h
@@ -299,7 +299,7 @@ class OpTest {
   void testBaseMethod(std::unique_ptr<TestConfig<DataTypeT>> &TestConfig);
 
 private:
-  dxc::DxcDllSupport DxcDllSupport;
+  dxc::SpecificDllLoader DxilDllLoader;
   bool Initialized = false;
 };
 
diff --git a/tools/clang/unittests/HLSLExec/ShaderOpTest.cpp b/tools/clang/unittests/HLSLExec/ShaderOpTest.cpp
index 60ce3a9241..5ef2068165 100644
--- a/tools/clang/unittests/HLSLExec/ShaderOpTest.cpp
+++ b/tools/clang/unittests/HLSLExec/ShaderOpTest.cpp
@@ -25,7 +25,7 @@
 #include "HlslTestUtils.h"          // LogCommentFmt
 #include "dxc/DXIL/DxilConstants.h" // ComponentType
 #include "dxc/Support/Global.h"     // OutputDebugBytes
-#include "dxc/Support/dxcapi.use.h" // DxcDllSupport
+#include "dxc/Support/dxcapi.use.h" // *DllLoader
 #include "dxc/dxcapi.h"             // IDxcCompiler
 
 #include <DirectXMath.h>
@@ -1148,7 +1148,7 @@ void ShaderOpTest::SetRootValues(ID3D12GraphicsCommandList *pList,
 
 void ShaderOpTest::SetDevice(ID3D12Device *pDevice) { m_pDevice = pDevice; }
 
-void ShaderOpTest::SetDxcSupport(dxc::DxcDllSupport *pDxcSupport) {
+void ShaderOpTest::SetSpecificDllLoader(dxc::SpecificDllLoader *pDxcSupport) {
   m_pDxcSupport = pDxcSupport;
 }
 
@@ -2758,8 +2758,8 @@ bool ShaderOpParser::ReadAtElementName(IXmlReader *pReader, LPCWSTR pName) {
 }
 
 std::shared_ptr<ShaderOpTestResult>
-RunShaderOpTestAfterParse(ID3D12Device *pDevice, dxc::DxcDllSupport &support,
-                          LPCSTR pName,
+RunShaderOpTestAfterParse(ID3D12Device *pDevice,
+                          dxc::SpecificDllLoader &support, LPCSTR pName,
                           st::ShaderOpTest::TInitCallbackFn pInitCallback,
                           st::ShaderOpTest::TShaderCallbackFn pShaderCallback,
                           std::shared_ptr<st::ShaderOpSet> ShaderOpSet) {
@@ -2790,7 +2790,7 @@ RunShaderOpTestAfterParse(ID3D12Device *pDevice, dxc::DxcDllSupport &support,
   pShaderOp->UseWarpDevice = hlsl_test::GetTestParamUseWARP(true);
 
   std::shared_ptr<st::ShaderOpTest> test = std::make_shared<st::ShaderOpTest>();
-  test->SetDxcSupport(&support);
+  test->SetSpecificDllLoader(&support);
   test->SetInitCallback(pInitCallback);
   test->SetShaderCallback(pShaderCallback);
   test->SetDevice(pDevice);
@@ -2805,8 +2805,8 @@ RunShaderOpTestAfterParse(ID3D12Device *pDevice, dxc::DxcDllSupport &support,
 }
 
 std::shared_ptr<ShaderOpTestResult>
-RunShaderOpTestAfterParse(ID3D12Device *pDevice, dxc::DxcDllSupport &support,
-                          LPCSTR pName,
+RunShaderOpTestAfterParse(ID3D12Device *pDevice,
+                          dxc::SpecificDllLoader &support, LPCSTR pName,
                           st::ShaderOpTest::TInitCallbackFn pInitCallback,
                           std::shared_ptr<st::ShaderOpSet> ShaderOpSet) {
   return RunShaderOpTestAfterParse(pDevice, support, pName, pInitCallback,
@@ -2814,7 +2814,7 @@ RunShaderOpTestAfterParse(ID3D12Device *pDevice, dxc::DxcDllSupport &support,
 }
 
 std::shared_ptr<ShaderOpTestResult>
-RunShaderOpTest(ID3D12Device *pDevice, dxc::DxcDllSupport &support,
+RunShaderOpTest(ID3D12Device *pDevice, dxc::SpecificDllLoader &support,
                 IStream *pStream, LPCSTR pName,
                 st::ShaderOpTest::TInitCallbackFn pInitCallback) {
   DXASSERT_NOMSG(pStream != nullptr);
diff --git a/tools/clang/unittests/HLSLExec/ShaderOpTest.h b/tools/clang/unittests/HLSLExec/ShaderOpTest.h
index 76983aa48f..23078f5303 100644
--- a/tools/clang/unittests/HLSLExec/ShaderOpTest.h
+++ b/tools/clang/unittests/HLSLExec/ShaderOpTest.h
@@ -31,7 +31,7 @@
 ///////////////////////////////////////////////////////////////////////////////
 // Forward declarations.
 namespace dxc {
-class DxcDllSupport;
+class SpecificDllLoader;
 }
 struct IStream;
 struct IXmlReader;
@@ -284,7 +284,7 @@ class ShaderOpTest {
   void RunShaderOp(ShaderOp *pShaderOp);
   void RunShaderOp(std::shared_ptr<ShaderOp> pShaderOp);
   void SetDevice(ID3D12Device *pDevice);
-  void SetDxcSupport(dxc::DxcDllSupport *pDxcSupport);
+  void SetSpecificDllLoader(dxc::SpecificDllLoader *pDxcSupport);
   void SetInitCallback(TInitCallbackFn InitCallbackFn);
   void SetShaderCallback(TShaderCallbackFn ShaderCallbackFn);
   void SetupRenderTarget(ShaderOp *pShaderOp, ID3D12Device *pDevice,
@@ -314,7 +314,7 @@ class ShaderOpTest {
   CComPtr<ID3D12RootSignature> m_pRootSignature;
   CComPtr<ID3D12QueryHeap> m_pQueryHeap;
   CComPtr<ID3D12Resource> m_pQueryBuffer;
-  dxc::DxcDllSupport *m_pDxcSupport = nullptr;
+  dxc::SpecificDllLoader *m_pDxcSupport = nullptr;
   CommandListRefs m_CommandList;
   HANDLE m_hFence;
   ShaderOp *m_pShaderOp;
@@ -354,20 +354,20 @@ struct ShaderOpTestResult {
 };
 
 std::shared_ptr<ShaderOpTestResult>
-RunShaderOpTestAfterParse(ID3D12Device *pDevice, dxc::DxcDllSupport &support,
-                          LPCSTR pName,
+RunShaderOpTestAfterParse(ID3D12Device *pDevice,
+                          dxc::SpecificDllLoader &support, LPCSTR pName,
                           st::ShaderOpTest::TInitCallbackFn pInitCallback,
                           st::ShaderOpTest::TShaderCallbackFn pShaderCallback,
                           std::shared_ptr<st::ShaderOpSet> ShaderOpSet);
 
 std::shared_ptr<ShaderOpTestResult>
-RunShaderOpTestAfterParse(ID3D12Device *pDevice, dxc::DxcDllSupport &support,
-                          LPCSTR pName,
+RunShaderOpTestAfterParse(ID3D12Device *pDevice,
+                          dxc::SpecificDllLoader &support, LPCSTR pName,
                           st::ShaderOpTest::TInitCallbackFn pInitCallback,
                           std::shared_ptr<st::ShaderOpSet> ShaderOpSet);
 
 std::shared_ptr<ShaderOpTestResult>
-RunShaderOpTest(ID3D12Device *pDevice, dxc::DxcDllSupport &support,
+RunShaderOpTest(ID3D12Device *pDevice, dxc::SpecificDllLoader &support,
                 IStream *pStream, LPCSTR pName,
                 st::ShaderOpTest::TInitCallbackFn pInitCallback);
 
diff --git a/tools/clang/unittests/HLSLTestLib/DxcTestUtils.cpp b/tools/clang/unittests/HLSLTestLib/DxcTestUtils.cpp
index 7e59b8f10f..207a77e1ea 100644
--- a/tools/clang/unittests/HLSLTestLib/DxcTestUtils.cpp
+++ b/tools/clang/unittests/HLSLTestLib/DxcTestUtils.cpp
@@ -13,6 +13,7 @@
 #include "dxc/Support/Global.h"
 #include "dxc/Support/HLSLOptions.h"
 #include "dxc/Support/Unicode.h"
+#include "dxc/Support/dxcapi.use.h"
 #include "dxc/Test/CompilationResult.h"
 #include "dxc/Test/HlslTestUtils.h"
 #include "llvm/ADT/APInt.h"
@@ -24,6 +25,13 @@
 using namespace std;
 using namespace hlsl_test;
 
+namespace dxc {
+
+extern const char *kDxCompilerLib;
+extern const char *kDxilLib;
+
+} // namespace dxc
+
 MODULE_SETUP(TestModuleSetup)
 MODULE_CLEANUP(TestModuleCleanup)
 
@@ -173,13 +181,14 @@ bool CheckOperationResultMsgs(IDxcOperationResult *pResult,
       maySucceedAnyway, bRegex);
 }
 
-std::string DisassembleProgram(dxc::DxcDllSupport &dllSupport,
+std::string DisassembleProgram(dxc::DxCompilerDllLoader &dllSupport,
                                IDxcBlob *pProgram) {
   CComPtr<IDxcCompiler> pCompiler;
   CComPtr<IDxcBlobEncoding> pDisassembly;
 
   if (!dllSupport.IsEnabled()) {
-    VERIFY_SUCCEEDED(dllSupport.Initialize());
+    VERIFY_SUCCEEDED(
+        dllSupport.InitializeForDll(dxc::kDxCompilerLib, "DxcCreateInstance"));
   }
 
   VERIFY_SUCCEEDED(dllSupport.CreateInstance(CLSID_DxcCompiler, &pCompiler));
@@ -187,7 +196,7 @@ std::string DisassembleProgram(dxc::DxcDllSupport &dllSupport,
   return BlobToUtf8(pDisassembly);
 }
 
-void AssembleToContainer(dxc::DxcDllSupport &dllSupport, IDxcBlob *pModule,
+void AssembleToContainer(dxc::DllLoader &dllSupport, IDxcBlob *pModule,
                          IDxcBlob **pContainer) {
   CComPtr<IDxcAssembler> pAssembler;
   CComPtr<IDxcOperationResult> pResult;
@@ -302,7 +311,7 @@ std::wstring BlobToWide(IDxcBlob *pBlob) {
   }
 }
 
-void Utf8ToBlob(dxc::DxcDllSupport &dllSupport, const char *pVal,
+void Utf8ToBlob(dxc::DllLoader &dllSupport, const char *pVal,
                 IDxcBlobEncoding **ppBlob) {
   CComPtr<IDxcLibrary> library;
   IFT(dllSupport.CreateInstance(CLSID_DxcLibrary, &library));
@@ -310,32 +319,30 @@ void Utf8ToBlob(dxc::DxcDllSupport &dllSupport, const char *pVal,
                                                 ppBlob));
 }
 
-void MultiByteStringToBlob(dxc::DxcDllSupport &dllSupport,
-                           const std::string &val, UINT32 codePage,
-                           IDxcBlobEncoding **ppBlob) {
+void MultiByteStringToBlob(dxc::DllLoader &dllSupport, const std::string &val,
+                           UINT32 codePage, IDxcBlobEncoding **ppBlob) {
   CComPtr<IDxcLibrary> library;
   IFT(dllSupport.CreateInstance(CLSID_DxcLibrary, &library));
   IFT(library->CreateBlobWithEncodingOnHeapCopy(val.data(), val.size(),
                                                 codePage, ppBlob));
 }
 
-void MultiByteStringToBlob(dxc::DxcDllSupport &dllSupport,
-                           const std::string &val, UINT32 codePage,
-                           IDxcBlob **ppBlob) {
+void MultiByteStringToBlob(dxc::DllLoader &dllSupport, const std::string &val,
+                           UINT32 codePage, IDxcBlob **ppBlob) {
   MultiByteStringToBlob(dllSupport, val, codePage, (IDxcBlobEncoding **)ppBlob);
 }
 
-void Utf8ToBlob(dxc::DxcDllSupport &dllSupport, const std::string &val,
+void Utf8ToBlob(dxc::DllLoader &dllSupport, const std::string &val,
                 IDxcBlobEncoding **ppBlob) {
   MultiByteStringToBlob(dllSupport, val, CP_UTF8, ppBlob);
 }
 
-void Utf8ToBlob(dxc::DxcDllSupport &dllSupport, const std::string &val,
+void Utf8ToBlob(dxc::DllLoader &dllSupport, const std::string &val,
                 IDxcBlob **ppBlob) {
   Utf8ToBlob(dllSupport, val, (IDxcBlobEncoding **)ppBlob);
 }
 
-void WideToBlob(dxc::DxcDllSupport &dllSupport, const std::wstring &val,
+void WideToBlob(dxc::DllLoader &dllSupport, const std::wstring &val,
                 IDxcBlobEncoding **ppBlob) {
   CComPtr<IDxcLibrary> library;
   IFT(dllSupport.CreateInstance(CLSID_DxcLibrary, &library));
@@ -343,12 +350,12 @@ void WideToBlob(dxc::DxcDllSupport &dllSupport, const std::wstring &val,
       val.data(), val.size() * sizeof(wchar_t), DXC_CP_WIDE, ppBlob));
 }
 
-void WideToBlob(dxc::DxcDllSupport &dllSupport, const std::wstring &val,
+void WideToBlob(dxc::DllLoader &dllSupport, const std::wstring &val,
                 IDxcBlob **ppBlob) {
   WideToBlob(dllSupport, val, (IDxcBlobEncoding **)ppBlob);
 }
 
-void VerifyCompileOK(dxc::DxcDllSupport &dllSupport, LPCSTR pText,
+void VerifyCompileOK(dxc::DllLoader &dllSupport, LPCSTR pText,
                      LPCWSTR pTargetProfile, LPCWSTR pArgs,
                      IDxcBlob **ppResult) {
   std::vector<std::wstring> argsW;
@@ -363,7 +370,7 @@ void VerifyCompileOK(dxc::DxcDllSupport &dllSupport, LPCSTR pText,
   VerifyCompileOK(dllSupport, pText, pTargetProfile, args, ppResult);
 }
 
-void VerifyCompileOK(dxc::DxcDllSupport &dllSupport, LPCSTR pText,
+void VerifyCompileOK(dxc::DllLoader &dllSupport, LPCSTR pText,
                      LPCWSTR pTargetProfile, std::vector<LPCWSTR> &args,
                      IDxcBlob **ppResult) {
   CComPtr<IDxcCompiler> pCompiler;
@@ -381,8 +388,8 @@ void VerifyCompileOK(dxc::DxcDllSupport &dllSupport, LPCSTR pText,
   VERIFY_SUCCEEDED(pResult->GetResult(ppResult));
 }
 
-HRESULT GetVersion(dxc::DxcDllSupport &DllSupport, REFCLSID clsid,
-                   unsigned &Major, unsigned &Minor) {
+HRESULT GetVersion(dxc::DllLoader &DllSupport, REFCLSID clsid, unsigned &Major,
+                   unsigned &Minor) {
   CComPtr<IUnknown> pUnk;
   if (SUCCEEDED(DllSupport.CreateInstance(clsid, &pUnk))) {
     CComPtr<IDxcVersionInfo> pVersionInfo;
@@ -418,7 +425,7 @@ VersionSupportInfo::VersionSupportInfo()
     : m_CompilerIsDebugBuild(false), m_InternalValidator(false), m_DxilMajor(0),
       m_DxilMinor(0), m_ValMajor(0), m_ValMinor(0) {}
 
-void VersionSupportInfo::Initialize(dxc::DxcDllSupport &dllSupport) {
+void VersionSupportInfo::Initialize(dxc::DllLoader &dllSupport) {
   VERIFY_IS_TRUE(dllSupport.IsEnabled());
 
   // Default to Dxil 1.0 and internal Val 1.0
diff --git a/tools/clang/unittests/HLSLTestLib/FileCheckerTest.cpp b/tools/clang/unittests/HLSLTestLib/FileCheckerTest.cpp
index 2d9ee7315d..1fc0664fa9 100644
--- a/tools/clang/unittests/HLSLTestLib/FileCheckerTest.cpp
+++ b/tools/clang/unittests/HLSLTestLib/FileCheckerTest.cpp
@@ -59,7 +59,7 @@ FileRunCommandPart::FileRunCommandPart(const std::string &command,
 }
 
 FileRunCommandResult
-FileRunCommandPart::RunHashTests(dxc::DxcDllSupport &DllSupport) {
+FileRunCommandPart::RunHashTests(dxc::DllLoader &DllSupport) {
   if (0 == _stricmp(Command.c_str(), "%dxc")) {
     return RunDxcHashTest(DllSupport);
   } else {
@@ -68,7 +68,7 @@ FileRunCommandPart::RunHashTests(dxc::DxcDllSupport &DllSupport) {
 }
 
 FileRunCommandResult
-FileRunCommandPart::Run(dxc::DxcDllSupport &DllSupport,
+FileRunCommandPart::Run(dxc::DllLoader &DllSupport,
                         const FileRunCommandResult *Prior,
                         PluginToolsPaths *pPluginToolsPaths /*=nullptr*/,
                         LPCWSTR dumpName /*=nullptr*/) {
@@ -302,7 +302,7 @@ static void AddOutputsToFileMap(IUnknown *pUnkResult, FileMap *pVFS) {
 
 static HRESULT CompileForHash(hlsl::options::DxcOpts &opts,
                               LPCWSTR CommandFileName,
-                              dxc::DxcDllSupport &DllSupport,
+                              dxc::DllLoader &DllSupport,
                               std::vector<LPCWSTR> &flags,
                               IDxcBlob **ppHashBlob, std::string &output) {
   CComPtr<IDxcLibrary> pLibrary;
@@ -375,7 +375,7 @@ static HRESULT CompileForHash(hlsl::options::DxcOpts &opts,
 }
 
 FileRunCommandResult
-FileRunCommandPart::RunDxcHashTest(dxc::DxcDllSupport &DllSupport) {
+FileRunCommandPart::RunDxcHashTest(dxc::DllLoader &DllSupport) {
   hlsl::options::MainArgs args;
   hlsl::options::DxcOpts opts;
   ReadOptsForDxc(args, opts);
@@ -453,7 +453,7 @@ FileRunCommandPart::RunDxcHashTest(dxc::DxcDllSupport &DllSupport) {
   return FileRunCommandResult::Success();
 }
 
-static FileRunCommandResult CheckDxilVer(dxc::DxcDllSupport &DllSupport,
+static FileRunCommandResult CheckDxilVer(dxc::DllLoader &DllSupport,
                                          unsigned RequiredDxilMajor,
                                          unsigned RequiredDxilMinor,
                                          bool bCheckValidator = true) {
@@ -487,7 +487,7 @@ static FileRunCommandResult CheckDxilVer(dxc::DxcDllSupport &DllSupport,
 }
 
 FileRunCommandResult
-FileRunCommandPart::RunDxc(dxc::DxcDllSupport &DllSupport,
+FileRunCommandPart::RunDxc(dxc::DllLoader &DllSupport,
                            const FileRunCommandResult *Prior) {
   // Support piping stdin from prior if needed.
   UNREFERENCED_PARAMETER(Prior);
@@ -597,7 +597,7 @@ FileRunCommandPart::RunDxc(dxc::DxcDllSupport &DllSupport,
 }
 
 FileRunCommandResult
-FileRunCommandPart::RunDxv(dxc::DxcDllSupport &DllSupport,
+FileRunCommandPart::RunDxv(dxc::DllLoader &DllSupport,
                            const FileRunCommandResult *Prior) {
   std::string args(strtrim(Arguments));
   const char *inputPos = strstr(args.c_str(), "%s");
@@ -650,7 +650,7 @@ FileRunCommandPart::RunDxv(dxc::DxcDllSupport &DllSupport,
 }
 
 FileRunCommandResult
-FileRunCommandPart::RunOpt(dxc::DxcDllSupport &DllSupport,
+FileRunCommandPart::RunOpt(dxc::DllLoader &DllSupport,
                            const FileRunCommandResult *Prior) {
   std::string args(strtrim(Arguments));
   const char *inputPos = strstr(args.c_str(), "%s");
@@ -701,7 +701,7 @@ FileRunCommandPart::RunOpt(dxc::DxcDllSupport &DllSupport,
 }
 
 FileRunCommandResult
-FileRunCommandPart::RunListParts(dxc::DxcDllSupport &DllSupport,
+FileRunCommandPart::RunListParts(dxc::DllLoader &DllSupport,
                                  const FileRunCommandResult *Prior) {
   std::string args(strtrim(Arguments));
   const char *inputPos = strstr(args.c_str(), "%s");
@@ -769,7 +769,7 @@ FileRunCommandPart::RunListParts(dxc::DxcDllSupport &DllSupport,
 }
 
 FileRunCommandResult
-FileRunCommandPart::RunD3DReflect(dxc::DxcDllSupport &DllSupport,
+FileRunCommandPart::RunD3DReflect(dxc::DllLoader &DllSupport,
                                   const FileRunCommandResult *Prior) {
   std::string args(strtrim(Arguments));
   if (args != "%s")
@@ -865,7 +865,7 @@ FileRunCommandPart::RunD3DReflect(dxc::DxcDllSupport &DllSupport,
 }
 
 FileRunCommandResult
-FileRunCommandPart::RunDxr(dxc::DxcDllSupport &DllSupport,
+FileRunCommandPart::RunDxr(dxc::DllLoader &DllSupport,
                            const FileRunCommandResult *Prior) {
   // Support piping stdin from prior if needed.
   UNREFERENCED_PARAMETER(Prior);
@@ -918,7 +918,7 @@ FileRunCommandPart::RunDxr(dxc::DxcDllSupport &DllSupport,
 }
 
 FileRunCommandResult
-FileRunCommandPart::RunLink(dxc::DxcDllSupport &DllSupport,
+FileRunCommandPart::RunLink(dxc::DllLoader &DllSupport,
                             const FileRunCommandResult *Prior) {
   hlsl::options::MainArgs args;
   hlsl::options::DxcOpts opts;
@@ -1153,7 +1153,7 @@ FileRunCommandPart::RunXFail(const FileRunCommandResult *Prior) {
 }
 
 FileRunCommandResult
-FileRunCommandPart::RunDxilVer(dxc::DxcDllSupport &DllSupport,
+FileRunCommandPart::RunDxilVer(dxc::DllLoader &DllSupport,
                                const FileRunCommandResult *Prior) {
   Arguments = strtrim(Arguments);
   if (Arguments.size() != 3 || !std::isdigit(Arguments[0]) ||
@@ -1258,7 +1258,7 @@ FileRunCommandPart::RunFromPath(const std::string &toolPath,
 #endif //_WIN32
 
 class FileRunTestResultImpl : public FileRunTestResult {
-  dxc::DxcDllSupport &m_support;
+  dxc::DxCompilerDllLoader &m_support;
   PluginToolsPaths *m_pPluginToolsPaths;
   LPCWSTR m_dumpName = nullptr;
   // keep track of virtual files for duration of this test (for all RUN lines)
@@ -1332,7 +1332,7 @@ class FileRunTestResultImpl : public FileRunTestResult {
   }
 
 public:
-  FileRunTestResultImpl(dxc::DxcDllSupport &support,
+  FileRunTestResultImpl(dxc::DxCompilerDllLoader &support,
                         PluginToolsPaths *pPluginToolsPaths = nullptr,
                         LPCWSTR dumpName = nullptr)
       : m_support(support), m_pPluginToolsPaths(pPluginToolsPaths),
@@ -1371,7 +1371,7 @@ class FileRunTestResultImpl : public FileRunTestResult {
 
 FileRunTestResult
 FileRunTestResult::RunHashTestFromFileCommands(LPCWSTR fileName) {
-  dxc::DxcDllSupport dllSupport;
+  dxc::DxCompilerDllLoader dllSupport;
   IFT(dllSupport.Initialize());
   FileRunTestResultImpl result(dllSupport);
   result.RunHashTestFromFileCommands(fileName);
@@ -1381,7 +1381,7 @@ FileRunTestResult::RunHashTestFromFileCommands(LPCWSTR fileName) {
 FileRunTestResult FileRunTestResult::RunFromFileCommands(
     LPCWSTR fileName, PluginToolsPaths *pPluginToolsPaths /*=nullptr*/,
     LPCWSTR dumpName /*=nullptr*/) {
-  dxc::DxcDllSupport dllSupport;
+  dxc::DxCompilerDllLoader dllSupport;
   IFT(dllSupport.Initialize());
   FileRunTestResultImpl result(dllSupport, pPluginToolsPaths, dumpName);
   result.RunFileCheckFromFileCommands(fileName);
@@ -1389,7 +1389,7 @@ FileRunTestResult FileRunTestResult::RunFromFileCommands(
 }
 
 FileRunTestResult FileRunTestResult::RunFromFileCommands(
-    LPCWSTR fileName, dxc::DxcDllSupport &dllSupport,
+    LPCWSTR fileName, dxc::DxCompilerDllLoader &dllSupport,
     PluginToolsPaths *pPluginToolsPaths /*=nullptr*/,
     LPCWSTR dumpName /*=nullptr*/) {
   FileRunTestResultImpl result(dllSupport, pPluginToolsPaths, dumpName);
diff --git a/tools/clang/unittests/SPIRV/LibTestUtils.cpp b/tools/clang/unittests/SPIRV/LibTestUtils.cpp
index a5ec27977b..d5f5b32e5f 100644
--- a/tools/clang/unittests/SPIRV/LibTestUtils.cpp
+++ b/tools/clang/unittests/SPIRV/LibTestUtils.cpp
@@ -130,7 +130,7 @@ bool compileCodeWithSpirvGeneration(const llvm::StringRef code,
     rest.emplace_back(arg.begin(), arg.end());
 
   try {
-    dxc::DxcDllSupport dllSupport;
+    dxc::DxCompilerDllLoader dllSupport;
     IFT(dllSupport.Initialize());
 
     if (hlsl::options::initHlslOptTable())
diff --git a/tools/clang/unittests/dxc_batch/dxc_batch.cpp b/tools/clang/unittests/dxc_batch/dxc_batch.cpp
index 1c3c86b46f..a642cacf78 100644
--- a/tools/clang/unittests/dxc_batch/dxc_batch.cpp
+++ b/tools/clang/unittests/dxc_batch/dxc_batch.cpp
@@ -68,7 +68,7 @@ class DxcContext {
 
 private:
   DxcOpts &m_Opts;
-  DxcDllSupport &m_dxcSupport;
+  SpecificDllLoader &m_dxcSupport;
 
   int ActOnBlob(IDxcBlob *pBlob);
   int ActOnBlob(IDxcBlob *pBlob, IDxcBlob *pDebugBlob, LPCWSTR pDebugBlobName);
@@ -83,7 +83,7 @@ class DxcContext {
   int VerifyRootSignature();
 
 public:
-  DxcContext(DxcOpts &Opts, DxcDllSupport &dxcSupport)
+  DxcContext(DxcOpts &Opts, SpecificDllLoader &dxcSupport)
       : m_Opts(Opts), m_dxcSupport(dxcSupport) {}
 
   int Compile(llvm::StringRef path, bool bLibLink);
@@ -124,7 +124,7 @@ static void PrintHlslException(const ::hlsl::Exception &hlslException,
   }
 }
 
-static int Compile(llvm::StringRef command, DxcDllSupport &dxcSupport,
+static int Compile(llvm::StringRef command, SpecificDllLoader &dxcSupport,
                    llvm::StringRef path, bool bLinkLib,
                    std::string &errorString) {
   // llvm::raw_string_ostream &errorStream) {
@@ -756,14 +756,14 @@ void DxcContext::WriteHeader(IDxcBlobEncoding *pDisassembly, IDxcBlob *pCode,
 
 class DxcBatchContext {
 public:
-  DxcBatchContext(DxcOpts &Opts, DxcDllSupport &dxcSupport)
+  DxcBatchContext(DxcOpts &Opts, SpecificDllLoader &dxcSupport)
       : m_Opts(Opts), m_dxcSupport(dxcSupport) {}
 
   int BatchCompile(bool bMultiThread, bool bLibLink);
 
 private:
   DxcOpts &m_Opts;
-  DxcDllSupport &m_dxcSupport;
+  SpecificDllLoader &m_dxcSupport;
 };
 
 int DxcBatchContext::BatchCompile(bool bMultiThread, bool bLibLink) {
@@ -880,7 +880,7 @@ int __cdecl wmain(int argc, const wchar_t **argv_) {
     MainArgs batchArgStrings(refArgs);
 
     DxcOpts dxcOpts;
-    DxcDllSupport dxcSupport;
+    LibraryDllLoader dxcSupport;
 
     // Read options and check errors.
     {
@@ -913,7 +913,8 @@ int __cdecl wmain(int argc, const wchar_t **argv_) {
     {
       std::string dllErrorString;
       llvm::raw_string_ostream dllErrorStream(dllErrorString);
-      int dllResult = SetupDxcDllSupport(dxcOpts, dxcSupport, dllErrorStream);
+      int dllResult =
+          SetupSpecificDllLoader(dxcOpts, dxcSupport, dllErrorStream);
       dllErrorStream.flush();
       if (dllErrorString.size()) {
         fprintf(stderr, "%s", dllErrorString.data());