[llvm-branch-commits] [llvm] [llvm][GlobalOpt] Preserve COMDAT during SRA splitting (PR #220721)

[Miguel A. Arroyo via llvm-branch-commits]

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@@ -656,7 +657,22 @@ static GlobalVariable *SRAGlobal(GlobalVariable *GV, const DataLayout &DL) {
   ++NumSRA;
 
   assert(NewGlobals.size() > 0);
-  return NewGlobals.begin()->second;
+
+  auto *FirstNewGV = NewGlobals.begin()->second;
+
+  // For COFF, the comdat must contain a member which has the
+  // same name as the group.
+  if (auto *C = FirstNewGV->getComdat()) {
+    auto *DummyGV = new GlobalVariable(
+        *FirstNewGV->getParent(), Type::getInt1Ty(FirstNewGV->getContext()),
+        false, FirstNewGV->getLinkage(),
+        ConstantInt::getFalse(FirstNewGV->getContext()), C->getName(),
+        FirstNewGV, FirstNewGV->getThreadLocalMode(),
+        FirstNewGV->getAddressSpace());
+    DummyGV->setComdat(C);
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mayanez wrote:

Done. 

https://github.com/llvm/llvm-project/pull/220721