At Fri, 11 Jun 2004 19:14:11 +0000 (UTC), "Maciej W. Rozycki" wrote: > 2. Gas should definitely use the codes consistently. And it's a pity the > ABI got broken -- I think another mnemonic should have been chosen for the > correct implementation of "break", available to any ISA. in retrospect, the 'B' variation probably wasn't the greatest idea. If it were removed (leaving 'c' and 'c','q' variations), I don't know that any real harm would occur. It may be very confusing to people who expect that the break code will translate into the instruction in an obvious way, and obviously it would mess up use of 20-bit codes, but i don't know how prevalent that is. Unfortunately, at this point, Linux should probably accept the divide-by-zero code in both locations. (Really, from day one, assemblers probably should have accepted a 20-bit code. I just checked my copy of the Kane r2000/r3000 book, and it was 20-bit all the way back then. If i had to guess, i'd guess that gas was copying a non-gnu assembler's behaviour. In any case, water under the bridge.) cgd