Implementing a macro-expansion inside gas?

[Alan Lehotsky]

I've been asked to add the simulation of PUSH/POP multiple  
instructions following the model of the ARM push/pop; e.g.

	push { reglist }

where reglist is a comma-separated set of register names.

This would expand to a variable number of instructions of the form

	move Ri,-(SP)
         move Rj,-(SP)
         ....

with a corresponding expansion of pop { reglist } into

          move (SP)+,Ri

etc.

I don't see any way to make CGEN handle this - it can only handle  
fixed size expansions, and I don't want to add hundreds
of macros for each possible sequence of push or pop.

It would seem straightforward (if tedious) to add code to the  
md_assemble() main loop that recognizes, parses
and (probably recursively calls md_assemble() with the specific  
expansion.  I can't use the .macro support in GAS
because of the need to handle curly braces.

Anyone else have a clever alternative?

-- Al