http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50091
--- Comment #6 from Andreas Schwab <sch...@linux-m68k.org> 2011-08-20 14:49:14 UTC --- "st 0,%0" stores the contents of register 0 at the address pointed to by operand 0. The st insn always operates on registers and cannot take immediate data. There is no modifier that expands to the register prefix. Currently the only way to produce the correct register name is to substitute a suitable register operand.
