1 files changed, 121 insertions, 0 deletions
diff --git a/llvm/lib/Target/DirectX/DXILTranslateMetadata.cpp b/llvm/lib/Target/DirectX/DXILTranslateMetadata.cpp
new file mode 100644
index 000000000000..634ead98a6ae
--- /dev/null
+++ b/llvm/lib/Target/DirectX/DXILTranslateMetadata.cpp
@@ -0,0 +1,121 @@
+//===- DXILTranslateMetadata.cpp - Pass to emit DXIL metadata ---*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+//===----------------------------------------------------------------------===//
+
+#include "DirectX.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.h"
+
+using namespace llvm;
+
+static uint32_t ConstMDToUint32(const MDOperand &MDO) {
+  ConstantInt *pConst = mdconst::extract<ConstantInt>(MDO);
+  return (uint32_t)pConst->getZExtValue();
+}
+
+static ConstantAsMetadata *Uint32ToConstMD(unsigned v, LLVMContext &Ctx) {
+  return ConstantAsMetadata::get(
+      Constant::getIntegerValue(IntegerType::get(Ctx, 32), APInt(32, v)));
+}
+
+constexpr StringLiteral ValVerKey = "dx.valver";
+constexpr unsigned DXILVersionNumFields = 2;
+
+static void emitDXILValidatorVersion(Module &M, VersionTuple &ValidatorVer) {
+  NamedMDNode *DXILValidatorVersionMD = M.getNamedMetadata(ValVerKey);
+
+  // Allow re-writing the validator version, since this can be changed at
+  // later points.
+  if (DXILValidatorVersionMD)
+    M.eraseNamedMetadata(DXILValidatorVersionMD);
+
+  DXILValidatorVersionMD = M.getOrInsertNamedMetadata(ValVerKey);
+
+  auto &Ctx = M.getContext();
+  Metadata *MDVals[DXILVersionNumFields];
+  MDVals[0] = Uint32ToConstMD(ValidatorVer.getMajor(), Ctx);
+  MDVals[1] = Uint32ToConstMD(ValidatorVer.getMinor().value_or(0), Ctx);
+
+  DXILValidatorVersionMD->addOperand(MDNode::get(Ctx, MDVals));
+}
+
+static VersionTuple loadDXILValidatorVersion(MDNode *ValVerMD) {
+  if (ValVerMD->getNumOperands() != DXILVersionNumFields)
+    return VersionTuple();
+
+  unsigned Major = ConstMDToUint32(ValVerMD->getOperand(0));
+  unsigned Minor = ConstMDToUint32(ValVerMD->getOperand(1));
+  return VersionTuple(Major, Minor);
+}
+
+static void cleanModuleFlags(Module &M) {
+  constexpr StringLiteral DeadKeys[] = {ValVerKey};
+  // Collect DeadKeys in ModuleFlags.
+  StringSet<> DeadKeySet;
+  for (auto &Key : DeadKeys) {
+    if (M.getModuleFlag(Key))
+      DeadKeySet.insert(Key);
+  }
+  if (DeadKeySet.empty())
+    return;
+
+  SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
+  M.getModuleFlagsMetadata(ModuleFlags);
+  NamedMDNode *MDFlags = M.getModuleFlagsMetadata();
+  MDFlags->eraseFromParent();
+  // Add ModuleFlag which not dead.
+  for (auto &Flag : ModuleFlags) {
+    StringRef Key = Flag.Key->getString();
+    if (DeadKeySet.contains(Key))
+      continue;
+    M.addModuleFlag(Flag.Behavior, Key, Flag.Val);
+  }
+}
+
+static void cleanModule(Module &M) { cleanModuleFlags(M); }
+
+namespace {
+class DXILTranslateMetadata : public ModulePass {
+public:
+  static char ID; // Pass identification, replacement for typeid
+  explicit DXILTranslateMetadata() : ModulePass(ID), ValidatorVer(1, 0) {}
+
+  StringRef getPassName() const override { return "DXIL Metadata Emit"; }
+
+  bool runOnModule(Module &M) override;
+
+private:
+  VersionTuple ValidatorVer;
+};
+
+} // namespace
+
+bool DXILTranslateMetadata::runOnModule(Module &M) {
+  if (MDNode *ValVerMD = cast_or_null<MDNode>(M.getModuleFlag(ValVerKey))) {
+    auto ValVer = loadDXILValidatorVersion(ValVerMD);
+    if (!ValVer.empty())
+      ValidatorVer = ValVer;
+  }
+  emitDXILValidatorVersion(M, ValidatorVer);
+  cleanModule(M);
+  return false;
+}
+
+char DXILTranslateMetadata::ID = 0;
+
+ModulePass *llvm::createDXILTranslateMetadataPass() {
+  return new DXILTranslateMetadata();
+}
+
+INITIALIZE_PASS(DXILTranslateMetadata, "dxil-metadata-emit",
+                "DXIL Metadata Emit", false, false)