Re: recent binutils and mips64-linux

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

Maciej W. Rozycki wrote:
> On Fri, 19 Sep 2003, Thiemo Seufer wrote:
> 
> > > > A third answer is to add a -msign-extend-addresses switch in the assembler.
> > > > Together with -mabi=64 this would produce optimized ELF64 output.
> > > 
> > >  Hmm, what do you exactly mean -- is that what I am worrying about?
> > 
> > The idea is to use the assembler's 32bit macro expansions for addresses.
> 
>  So it is...
> 
> > This reduces the .text size of a n64 kernel and improves the performance,
> > without tricks like -Wa,32.
> 
>  What if the final link leads to segments being mapped outside the 32-bit
> address range?  We won't know about it when assembling.

Then the resulting code is broken. It's the programmers responsibility
to care about it. IMHO that's not a problem, this feature is only
useful for kernels, and the tricks currently done there are worse.

>  If the idea were to be implemented, there should be a flag added to the
> header of object files that would forbid the linker to map addresses
> outside the 32-bit range.

Please don't add any header flag. An additional (.note?) section would
be nice, but is not a priority for me.


Thiemo