[MPlayer-dev-eng] Asm parameter constraints (was: Improved remove-logo filter)

[Trent Piepho]

On Fri, 3 Nov 2006, Uoti Urpala wrote:
> Michael's original comment which you disagreed with said that if you do
> use [out]"=m"(a):[in]"m"(a) then [out] and [in] could be the same memory
> location or different ones, and [out] might overlap some other input
> parameter. I don't see anything in your latest reply which would show
> that gcc guarantees the opposite will always be true.

You are saying that if you write [out]"=m"(a):[in]"m"(b) then out and in
could overlap?  This is what you mean when you say, "[out] might overlap
some other input parameter?"

If that is the case, what would you write so that out and in can't overlap?
Or do you think there is no way to keep [out]"=m"(a) from overlapping some
other input paramters, and it is thus impossible to have a "=m" parameter
that is used before all inputs are consumed?