https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66978
--- Comment #4 from H.J. Lu <hjl.tools at gmail dot com> ---
I am testing this patch:
diff --git a/gcc/function.c b/gcc/function.c
index c3d00cd..f63c9be 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -5207,6 +5207,10 @@ expand_function_start (tree subr)
SET_DECL_RTL (parm, local);
mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
+ if (GET_MODE (local) != Pmode)
+ local = convert_to_mode (Pmode, local,
+ TYPE_UNSIGNED (TREE_TYPE (parm)));
+
insn = emit_move_insn (local, chain);
/* Mark the register as eliminable, similar to parameters. */
