A new ia32 backend

[craig@jcb-sc.com]

>>Richard Henderson wrote in < 19990615224736.A29894@cygnus.com >: 
>>
>>>...
>>>	while (a--) { /* nothing dependant on a */ }
>>>    becomes
>>>	if (a) do { ... } while (--a);
>>>...
>>
>>Is it really equivalent? Even if `(a == 0)' just before
>>the two lines?
>
>No, good point, there needs to be an `else --a;' added to the
>`if' clause.  (Presumably the actual code in the compiler is
>correct, but it's always good to check, as well as make sure
>these email'ed "doclets" are correct as well!)

Sigh.  Forget the `else', what is needed is a simple `--a;' after
the entire `if'.

        tq vm, (burley)