Re: RFA: GCC 4.2.1: Stabalizing coalesce_list's qsort

[Mark Mitchell <mark at codesourcery dot com>]

Nick Clifton wrote:
> Hi Richard,
> 
>>> Is this patch suitable for application to the 4.2 branch ?
> 
>> No, 
> 
> OK.
> 
>> but for trunk if you bootstrapped/tested this.  That is, this patch
>> is ok for mainline if you did.

(In case anyone was wondering, I'm perfectly happy for maintainers to
make decisions like this about what shouldn't go into 4.2. :-)  Avoiding
risk of changing the performance of code by tweaking code-generation
seems like the right call to me, FWIW.)

I do think that generating the same code, independent of host system, is
a very important property of GCC's design, just like generating the same
code independent of whether or not we're compiling with -g.  So, we
should be careful about this issue.  I don't have any opinion as to
whether we should use a stable sort function or just make sure our
comparison functions are stable, but if we do want to create a stable
sort function, we could stuff it in libiberty, convert everything, and
poison qsort.

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713