Index: lib/Transforms/Scalar/SROA.cpp
===================================================================
--- lib/Transforms/Scalar/SROA.cpp
+++ lib/Transforms/Scalar/SROA.cpp
@@ -1613,6 +1613,13 @@
     return IRB.CreatePtrToInt(V, NewTy);
   }
 
+  // If both types are pointers in different address spaces use the pair
+  // ptrtoint+inttoptr to keep common bits of the value immutated.
+  if (OldTy->isPtrOrPtrVectorTy() && NewTy->isPtrOrPtrVectorTy() &&
+      OldTy->getPointerAddressSpace() != NewTy->getPointerAddressSpace())
+    return IRB.CreateIntToPtr(IRB.CreatePtrToInt(V, DL.getIntPtrType(OldTy)),
+                              NewTy);
+
   return IRB.CreateBitCast(V, NewTy);
 }
 
Index: test/Transforms/SROA/union_ptr_as.ll
===================================================================
--- test/Transforms/SROA/union_ptr_as.ll
+++ test/Transforms/SROA/union_ptr_as.ll
@@ -0,0 +1,32 @@
+; RUN: opt -S -sroa < %s | FileCheck %s
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @union_cvt_float2(<2 x float> addrspace(1)* %p) {
+; CHECK: @union_cvt_float2
+; CHECK: %[[int:.*]] = ptrtoint <2 x float> addrspace(1)* %p to i64
+; CHECK-NEXT: %[[nptr:.*]] = inttoptr i64 %[[int]] to <2 x float>*
+
+  %p.addr = alloca <2 x float> addrspace(1)*, align 8
+  store <2 x float> addrspace(1)* %p, <2 x float> addrspace(1)** %p.addr, align 8
+  %1 = bitcast <2 x float> addrspace(1)** %p.addr to <2 x float>**
+  %2 = load <2 x float>** %1, align 8
+  call void @ext_call_float2(<2 x float>* %2)
+  ret void
+}
+
+define void @union_cvt_v2ptr(<2 x i8 addrspace(1)*> %p) {
+; CHECK: union_cvt_v2ptr
+; CHECK: %[[int:.*]] = ptrtoint <2 x i8 addrspace(1)*> %p to <2 x i64>
+; CHECK-NEXT: %[[nptr:.*]] = inttoptr <2 x i64> %[[int]] to <2 x i8*>
+
+  %p.addr = alloca <2 x i8 addrspace(1)*>, align 8
+  store <2 x i8 addrspace(1)*> %p, <2 x i8 addrspace(1)*>* %p.addr
+  %1 = bitcast <2 x i8 addrspace(1)*>* %p.addr to <2 x i8*>*
+  %2 = load <2 x i8*>* %1, align 8
+  call void @ext_call_v2ptr(<2 x i8*> %2)
+  ret void
+}
+
+declare void @ext_call_float2(<2 x float>*)
+declare void @ext_call_v2ptr(<2 x i8*>)