[llvm-branch-commits] [clang] [lld] [llvm] Reland "Compute GUIDs once and store in metadata" (#184065) (PR #201849)

[Maksim Sabianin via llvm-branch-commits]

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@@ -141,17 +141,21 @@ std::unique_ptr<Module> llvm::CloneModule(
   for (const Function &I : M) {
     Function *F = cast<Function>(VMap[&I]);
 
-    if (I.isDeclaration()) {
+    auto CopyMD = [&]() {
       // Copy over metadata for declarations since we're not doing it below in
       // CloneFunctionInto().
       SmallVector<std::pair<unsigned, MDNode *>, 1> MDs;
       I.getAllMetadata(MDs);
       for (auto MD : MDs)
         F->addMetadata(MD.first, *MapMetadata(MD.second, VMap));
+    };
+    if (I.isDeclaration()) {
+      CopyMD();
       continue;
     }
 
     if (!ShouldCloneDefinition(&I)) {
+      CopyMD();
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maksimsab wrote:

Doesn't this line create a blowup of unnecessary copies?

https://github.com/llvm/llvm-project/pull/201849