Index: llvm/lib/Transforms/IPO/GlobalOpt.cpp
===================================================================
--- llvm/lib/Transforms/IPO/GlobalOpt.cpp
+++ llvm/lib/Transforms/IPO/GlobalOpt.cpp
@@ -2115,8 +2115,16 @@
     return;
   }
 
+  // Get address space of pointers in the array of pointers.
+  unsigned ElemAddrSpace = 0;
+  const Type *UsedArrayType = V.getValueType();
+
+  if (const auto *VAT = cast<ArrayType>(UsedArrayType))
+    if (const auto *VEPT = cast<PointerType>(VAT->getArrayElementType()))
+      ElemAddrSpace = VEPT->getAddressSpace();
+
   // Type of pointer to the array of pointers.
-  PointerType *Int8PtrTy = Type::getInt8PtrTy(V.getContext(), 0);
+  PointerType *Int8PtrTy = Type::getInt8PtrTy(V.getContext(), ElemAddrSpace);
 
   SmallVector<Constant *, 8> UsedArray;
   for (GlobalValue *GV : Init) {
@@ -2124,6 +2132,7 @@
       = ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, Int8PtrTy);
     UsedArray.push_back(Cast);
   }
+
   // Sort to get deterministic order.
   array_pod_sort(UsedArray.begin(), UsedArray.end(), compareNames);
   ArrayType *ATy = ArrayType::get(Int8PtrTy, UsedArray.size());
Index: llvm/test/Transforms/GlobalOpt/global-opt-addrspace.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/GlobalOpt/global-opt-addrspace.ll
@@ -0,0 +1,34 @@
+; RUN: opt -S -passes=globalopt < %s | FileCheck %s
+;; Check that Global Opt preserves address space of llvm.used and
+;; llvm.compiler.used variables.
+
+%struct.FakeDeviceGlobal = type { ptr addrspace(4) }
+%class.anon = type { i8 }
+
+@_ZM2C = internal addrspace(1) global %struct.FakeDeviceGlobal zeroinitializer, align 8
+@_ZL1C = internal addrspace(1) global %struct.FakeDeviceGlobal zeroinitializer, align 8
+
+@llvm.compiler.used = appending global [2 x ptr addrspace(4)] [ptr addrspace(4) addrspacecast (ptr addrspace(1) @_ZM2C to ptr addrspace(4)), ptr addrspace(4) addrspacecast (ptr addrspace(1) @_ZL1C to ptr addrspace(4))]
+
+; CHECK: @llvm.compiler.used = appending global [2 x ptr addrspace(4)] [ptr addrspace(4) addrspacecast (ptr addrspace(1) @_ZL1C to ptr addrspace(4)), ptr addrspace(4) addrspacecast (ptr addrspace(1) @_ZM2C to ptr addrspace(4))]
+
+define weak_odr dso_local void @foo() {
+entry:
+  %A = alloca %class.anon, align 1
+  %A.addrspacecast = addrspacecast ptr %A to ptr addrspace(4)
+  call void @bar(ptr addrspace(4) noundef align 1 dereferenceable_or_null(1) %A.addrspacecast)
+  ret void
+}
+
+define internal void @bar(ptr addrspace(4) noundef align 1 dereferenceable_or_null(1) %this) align 2 {
+entry:
+  %this.addr = alloca ptr addrspace(4), align 8
+  %this.addr.ascast = addrspacecast ptr %this.addr to ptr addrspace(4)
+  store ptr addrspace(4) %this, ptr addrspace(4) %this.addr.ascast, align 8
+  %v1 = load ptr addrspace(4), ptr addrspace(4) addrspacecast (ptr addrspace(1) @_ZM2C to ptr addrspace(4)), align 8
+  store i32 42, ptr addrspace(4) %v1, align 4
+  %v2 = load ptr addrspace(4), ptr addrspace(4) addrspacecast (ptr addrspace(1) @_ZL1C to ptr addrspace(4)), align 8
+  store i32 42, ptr addrspace(4) %v2, align 4
+  ret void
+}
+