Re: asm constraint rule change

[Andi Kleen <ak at muc dot de>]

In article <17150.908609572@hurl.cygnus.com>,
Jeffrey A Law <law@cygnus.com> writes:
>   In message <19981016193609.A4141@dot.cygnus.com>you write:
>> The recent asm checking patches have tightened the rules such that output
>> constraints like "r=" are no longer valid.  The problem is that there is
>> a largish body of code that writes things that way.  More to the point,
>> despite all the examples running about the documentation, it does not ever
>> come out and specify this as a rule.  It merely says 
>> 
>> ... all output operands' constraints must use `='.
>> 
>> So this change is gonna piss some folks off, and with reason.
>> 
>> I suggest we adopt the following patch to loosen this rule again.
>> 
>> 
>> r~
>> 
>> 
>> * stmt.c (expand_asm_operands): Accept `=' or `+' at any position.
> How about let's make it a warning instead of a hard error.

> I wouldn't be suprised if some code handles them wrong if the '=' or '+' are
> not first.  We need to get folks to fix their code.

Richard's patch moves them automagically to the beginning (with the bcopy).
Don't you think that is enough, why bother the programmer with another
warning if the compiler can fix it without problems? Also the requirement
wasn't documented.

-Andi