Index: lib/AST/ExprConstant.cpp
===================================================================
--- lib/AST/ExprConstant.cpp
+++ lib/AST/ExprConstant.cpp
@@ -4995,7 +4995,11 @@
       Result.Designator.setInvalid();
       return true;
     } else {
-      // Cast is of an lvalue, no need to change value.
+      // Cast is of an lvalue, no need to change value, unless they have
+      // different address spaces.
+      if (Info.Ctx.getTargetAddressSpace(getType(Value.getLValueBase())) !=
+          Info.Ctx.getTargetAddressSpace(E->getType()->getPointeeType()))
+        return false;
       Result.setFrom(Info.Ctx, Value);
       return true;
     }
Index: test/Sema/const-eval.c
===================================================================
--- test/Sema/const-eval.c
+++ test/Sema/const-eval.c
@@ -137,3 +137,6 @@
 void PR24622();
 struct PR24622 {} pr24622;
 EVAL_EXPR(52, &pr24622 == (void *)&PR24622); // expected-error {{must have a constant size}}
+
+int __attribute__((address_space(1))) addrspace1;
+int *addrspace0_ptr = (int *)(long)&addrspace1; // expected-error {{not a compile-time constant}}