Thanks pico,
if they simply compile down to the the standard single special register instructions -- CPSID I and CPSIE I --
They do, so I've added the three barrier instructions along the lines of what x893 had in one of those threads. As nobody argued his code in the last two months I'm figure it's kosher until I look into this more deeply.
As I understand it though as I'm using an M0 it's not important, but makes the macro pore portable.
Rob