fixes #9403

compiler/ccgexprs.nim

@@ -1912,7 +1912,7 @@ proc genOrd(p: BProc, e: PNode, d: var TLoc) =
 
 proc genSomeCast(p: BProc, e: PNode, d: var TLoc) =
   const
-    ValueTypes = {tyTuple, tyObject, tyArray, tyOpenArray, tyVarargs}
+    ValueTypes = {tyTuple, tyObject, tyArray, tyOpenArray, tyVarargs, tyUncheckedArray}
   # we use whatever C gives us. Except if we have a value-type, we need to go
   # through its address:
   var a: TLoc

tests/ccgbugs/tunsafeaddr.nim

@@ -1,5 +1,6 @@
 discard """
-  output: '''12'''
+  output: '''12
+4'''
 """
 
 {.emit: """
@@ -26,3 +27,21 @@ p(@[1])
 q(@[1])
 
 main()
+
+# bug #9403
+
+type
+  MyObj = ref object
+    len: int
+    val: UncheckedArray[uint64]
+
+proc spot(x: MyObj): int64 =
+  result = cast[UncheckedArray[int64]](x.val)[0]
+
+proc newMyObj(len: int): MyObj =
+  unsafeNew(result, sizeof(result[]) + len * sizeof(uint64))
+  result.len = len
+  result.val[0] = 4u64
+  result.val[1] = 8u64
+
+echo spot(newMyObj(2))