[LLVM][TableGen] Check name conflicts between target dep and independent intrinsics

llvm/test/TableGen/intrinsic-target-prefix-for-target-independent.td

@@ -0,0 +1,9 @@
+// RUN: not llvm-tblgen -gen-intrinsic-enums -I %p/../../include %s 2>&1 | FileCheck %s -DFILE=%s
+
+include "llvm/IR/Intrinsics.td"
+
+// Check that target independent intrinsics with a prefix that matches a target
+// name are flagged.
+// CHECK: [[FILE]]:[[@LINE+1]]:5: error: target independent intrinsic `llvm.aarch64.foo' has prefix `llvm.aarch64` that conflicts with intrinsics for target `aarch64`
+def int_aarch64_foo : Intrinsic<[],[]>;
+

llvm/utils/TableGen/Basic/CodeGenIntrinsics.cpp

@@ -75,6 +75,7 @@ CodeGenIntrinsicTable::CodeGenIntrinsicTable(const RecordKeeper &RC) {
   Targets.back().Count = Intrinsics.size() - Targets.back().Offset;
 
   CheckDuplicateIntrinsics();
+  CheckTargetIndependentIntrinsics();
 }
 
 // Check for duplicate intrinsic names.
@@ -101,6 +102,28 @@ void CodeGenIntrinsicTable::CheckDuplicateIntrinsics() const {
   PrintFatalNote(First.TheDef, "Previous definition here");
 }
 
+// For target independent intrinsics, check that their second dotted component
+// does not match any target name.
+void CodeGenIntrinsicTable::CheckTargetIndependentIntrinsics() const {
+  SmallDenseSet<StringRef> TargetNames;
+  for (const auto &Target : ArrayRef(Targets).drop_front())
+    TargetNames.insert(Target.Name);
+
+  // Set of target independent intrinsics.
+  const auto &Set = Targets[0];
+  for (const auto &Int : ArrayRef(&Intrinsics[Set.Offset], Set.Count)) {
+    StringRef Name = Int.Name;
+    StringRef Prefix = Name.drop_front(5).split('.').first;
+    if (!TargetNames.contains(Prefix))
+      continue;
+    PrintFatalError(Int.TheDef,
+                    "target independent intrinsic `" + Name +
+                        "' has prefix `llvm." + Prefix +
+                        "` that conflicts with intrinsics for target `" +
+                        Prefix + "`");
+  }
+}
+
 CodeGenIntrinsic &CodeGenIntrinsicMap::operator[](const Record *Record) {
   if (!Record->isSubClassOf("Intrinsic"))
     PrintFatalError("Intrinsic defs should be subclass of 'Intrinsic' class");

llvm/utils/TableGen/Basic/CodeGenIntrinsics.h

@@ -192,6 +192,7 @@ class CodeGenIntrinsicTable {
 
 private:
   void CheckDuplicateIntrinsics() const;
+  void CheckTargetIndependentIntrinsics() const;
 };
 
 // This class builds `CodeGenIntrinsic` on demand for a given Def.