Assigning registers to variables in inlines

["Timothy J. Wood" <tjw at omnigroup dot com>]

   I'm trying to emulate the Metrowerks __lwbrx PPC intrinsic (load word 
byte reversed indexed), but not having any luck.  The problem I run into 
is that gcc decides to put the 'offset' into r0 and gas gives an error 
on this saying that you should write '0' instead (presumably this is an 
error designed to catch problems in human generated code since r0 means 
'0' in this instruction instead of the actual value of r0).

   So, I'd like some way to say "don't put offset in r0".  Any other 
register is OK.  The following fails, though:

static inline unsigned int __lwbrx(register void *addr, register int 
offset) {
     register unsigned int word;
     register unsigned int asm("r9") _offset = offset;

     asm("lwbrx %0,%2,%1" : "=r" (word) : "r" (addr), "r" (_offset));
     return word;
}


...: parse error before `asm'
...: `_offset' undeclared (first use in this function)

   Is it possible to get this to work or should I look for a different 
route?  I could add addr and offset and always pass 0, but that would 
introduce another instruction.

-tim