[llvm] [IR] Store Metadata attachments in vector (PR #189551)

[Alexis Engelke via llvm-commits]

================
@@ -1606,56 +1566,58 @@ MDNode *Value::getMetadata(StringRef Kind) const {
 
 MDNode *Value::getMetadataImpl(unsigned KindID) const {
   const LLVMContext &Ctx = getContext();
-  const MDAttachments &Attachements = Ctx.pImpl->ValueMetadata.at(this);
-  return Attachements.lookup(KindID);
+  unsigned Idx = getMetadataIndex();
+  while (Idx) {
+    const MDAttachment &A = Ctx.pImpl->Metadatas[Idx];
+    if (A.MDKind == KindID)
+      return A.Node;
+    Idx = A.Next;
+  }
+  return nullptr;
 }
 
 void Value::getMetadata(unsigned KindID, SmallVectorImpl<MDNode *> &MDs) const {
-  if (hasMetadata())
-    getContext().pImpl->ValueMetadata.at(this).get(KindID, MDs);
+  const LLVMContext &Ctx = getContext();
+  unsigned Idx = getMetadataIndex();
+  while (Idx) {
+    const MDAttachment &A = Ctx.pImpl->Metadatas[Idx];
+    if (A.MDKind == KindID)
+      MDs.push_back(A.Node);
+    Idx = A.Next;
+  }
+  // We store metadata in reverse order, so reverse for output.
+  std::reverse(MDs.begin(), MDs.end());
 }
 
 void Value::getMetadata(StringRef Kind, SmallVectorImpl<MDNode *> &MDs) const {
-  if (hasMetadata())
-    getMetadata(getContext().getMDKindID(Kind), MDs);
+  getMetadata(getContext().getMDKindID(Kind), MDs);
 }
 
 void Value::getAllMetadata(
     SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const {
-  if (hasMetadata()) {
-    assert(getContext().pImpl->ValueMetadata.count(this) &&
-           "bit out of sync with hash table");
-    const MDAttachments &Info = getContext().pImpl->ValueMetadata.at(this);
-    Info.getAll(MDs);
+  const LLVMContext &Ctx = getContext();
+  unsigned Idx = getMetadataIndex();
+  while (Idx) {
+    const MDAttachment &A = Ctx.pImpl->Metadatas[Idx];
+    MDs.emplace_back(A.MDKind, A.Node);
+    Idx = A.Next;
+  }
+  // We store metadata in reverse order, so reverse for output in insertion
+  // order. Sort by metadata ID for stable output.
+  if (MDs.size() > 1) {
+    std::reverse(MDs.begin(), MDs.end());
+    llvm::stable_sort(MDs, less_first());
   }
 }
 
 void Value::setMetadata(unsigned KindID, MDNode *Node) {
   assert(isa<Instruction>(this) || isa<GlobalObject>(this));
 
-  // Handle the case when we're adding/updating metadata on a value.
-  if (Node) {
-    MDAttachments &Info = getContext().pImpl->ValueMetadata[this];
-    assert(!Info.empty() == HasMetadata && "bit out of sync with hash table");
-    if (Info.empty())
-      HasMetadata = true;
-    Info.set(KindID, Node);
-    return;
-  }
-
-  // Otherwise, we're removing metadata from an instruction.
-  assert((HasMetadata == (getContext().pImpl->ValueMetadata.count(this) > 0)) &&
-         "bit out of sync with hash table");
-  if (!HasMetadata)
-    return; // Nothing to remove!
-  MDAttachments &Info = getContext().pImpl->ValueMetadata.find(this)->second;
-
-  // Handle removal of an existing value.
-  Info.erase(KindID);
-  if (!Info.empty())
-    return;
-  getContext().pImpl->ValueMetadata.erase(this);
-  HasMetadata = false;
+  eraseMetadata(KindID);
+  if (Node)
+    addMetadata(KindID, *Node);
+  if (Node)
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aengelke wrote:

Removed duplicate update of HasMetadata, addMetadata does this already.

https://github.com/llvm/llvm-project/pull/189551