[clang][CodeGen] Put constant initializer globals into constant addrspace (#90048)

Place constant initializer globals into the constant address space.
Clang generates such globals for e.g. larger array member initializers
of classes and then emits copy operations from the global to the
object(s). The globals are never written so they ought to be in the
constant address space.

1 files changed, 7 insertions, 4 deletions

diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index 44d476976a55..cd9936a6dc0b 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -537,9 +537,12 @@ void AggExprEmitter::EmitArrayInit(Address DestPtr, llvm::ArrayType *AType,
       elementType.isTriviallyCopyableType(CGF.getContext())) {
     CodeGen::CodeGenModule &CGM = CGF.CGM;
     ConstantEmitter Emitter(CGF);
-    LangAS AS = ArrayQTy.getAddressSpace();
+    QualType GVArrayQTy = CGM.getContext().getAddrSpaceQualType(
+        CGM.getContext().removeAddrSpaceQualType(ArrayQTy),
+        CGM.GetGlobalConstantAddressSpace());
+    LangAS AS = GVArrayQTy.getAddressSpace();
     if (llvm::Constant *C =
-            Emitter.tryEmitForInitializer(ExprToVisit, AS, ArrayQTy)) {
+            Emitter.tryEmitForInitializer(ExprToVisit, AS, GVArrayQTy)) {
       auto GV = new llvm::GlobalVariable(
           CGM.getModule(), C->getType(),
           /* isConstant= */ true, llvm::GlobalValue::PrivateLinkage, C,
@@ -547,10 +550,10 @@ void AggExprEmitter::EmitArrayInit(Address DestPtr, llvm::ArrayType *AType,
           /* InsertBefore= */ nullptr, llvm::GlobalVariable::NotThreadLocal,
           CGM.getContext().getTargetAddressSpace(AS));
       Emitter.finalize(GV);
-      CharUnits Align = CGM.getContext().getTypeAlignInChars(ArrayQTy);
+      CharUnits Align = CGM.getContext().getTypeAlignInChars(GVArrayQTy);
       GV->setAlignment(Align.getAsAlign());
       Address GVAddr(GV, GV->getValueType(), Align);
-      EmitFinalDestCopy(ArrayQTy, CGF.MakeAddrLValue(GVAddr, ArrayQTy));
+      EmitFinalDestCopy(ArrayQTy, CGF.MakeAddrLValue(GVAddr, GVArrayQTy));
       return;
     }
   }