Re: [PATCH] MIPS gas: Fix macro expansions for .set noat

[Thiemo Seufer <ica2_ts at csv dot ica dot uni-stuttgart dot de>]

Maciej W. Rozycki wrote:
> Thiemo,
> 
>  More comments about that change -- as I understand our policy wrt $at 
> being used with ".set noat" in effect is to go for it regardless and only 
> issue a warning (that can be converted to an error with --fatal-warnings).  
> Therefore we shouldn't use as_bad() in this case.

IMHO it should be an error if the result can't work at all. I don't
see a case where overwriting the base register before its use could
be the programmers intention.

> Moreover, the situation 
> is actually already handled in general -- see the bottom exit point from 
> macro() -- so we should really only track down the failing execution path 
> within that function and check whether its epilogue correctly executes a 
> functional equivalent of this code:
> 
> if (used_at)
> 	break;
> else
> 	return;

This causes "used $at in .set noat" warnings. That's a rather confusing
message, given that no use of $at was specified in the source.


Thiemo