eliminating mpc/mpfr and reducing gmp

[Jay K]

Wow that is fast.


My fastest machine, and I have several slower:


gmp
time sh -c "CC=gcc-4.2 ./configure none-none-none -disable-shared -enable-static && make && ssh root@localhost \"cd `pwd` && make install\""
real    2m2.594s

mpfr
time sh -c "./configure -disable-shared -enable-static && make && ssh root@localhost \"cd `pwd` && make install\""
real    0m43.756s

mpc
time sh -c "./configure -disable-shared -enable-static && make && ssh root@localhost \"cd `pwd` && make install\""
real    0m15.495s


which is still a significant fraction of building cc1 (I don't have that time sorry)

I used to use Cygwin. Things add up much faster there.


> mpfr et al. If you're not, it only happens once.


Almost anything long but incremental can be justified via incrementality.
But there is also, occasionally, mass bouts of trying to get the configure switches just right and
starting over repeatedly...at least me being unsure of incrementality in the fact of rerunning configure...


Anyway, just putting it out there, probably won't happen, but  configure -without-mpc -without-mpfr might be nice
and aren't difficult, -without-gmp much better, but I can't yet claim it isn't difficult.
Maybe, something like, if gmp is "in tree", after configure, the Makefile could be hacked down
to omit mpf, mpq, and lots others, but then the linkage between gcc and gmp gets messy.
  i.e. as gmp changes.


 - Jay

----------------------------------------
> Date: Mon, 27 Sep 2010 11:37:04 +0100
> From: aph@redhat.com
> To: jay.krell@cornell.edu
> CC: gcc@gcc.gnu.org
> Subject: Re: eliminating mpc/mpfr and reducing gmp
>
> On 09/27/2010 01:23 AM, Jay K wrote:
> >
> > Hi. You know, gmp/mpfr/mpc are a significant
> > portion of building any frontend/backend.
>
> I disagree. Most of the time I don't notice them.
>
> > The result is a lot faster to build, if you are just doing a just
> > a single stage build of a compiler.
>
> Sure, but if you're working on the compiler you don't need to rebuild
> mpfr et al. If you're not, it only happens once.
>
> On my box, for mpc:
>
> real 0m2.624s
> user 0m3.336s
> sys 0m1.663s
>
> and for mpfr:
>
> real 0m4.484s
> user 0m12.006s
> sys 0m5.127s
>
> Andrew.