On 11/30/2015 4:01 AM, Andrew Haley wrote:
>> There is a way for people to be clear about what they want to clobber,
>> and that's to use extended asm. The way to clear up the ambiguity
is to
>> start deprecating basic asm, not to add to the confusion by changing
its
>> behavior after all these years.
>
> Well, I disagree. The warning is good, but so is the memory clobber.
> They're not exclusive.
As Richard Henderson put it: "I'd be perfectly happy to deprecate and
later completely remove basic asm within functions."
So my intent is that today's optional warning becomes tomorrow's default
warning which eventually turns into a fatal error. We could speed that
up a bit by making it a default warning now and a fatal error as soon as
we re-enter phase 1. I just thought it might be better to update the
docs now and delay the change to give more of a heads up.
Yes, we could pursue both clobbering and completely removing at the same
time, but I don't think we should. Since (currently) basic asm always
has no clobbers describing how to update basic asm to extended is fairly
simple: To get the same behavior in extended as you used to get from
basic, just add a colon. If some versions of gcc perform clobbers, then
knowing how to convert gets way harder.
dw
