Speed of compiling gimple-match.c

[Segher Boessenkool]

On Tue, May 04, 2021 at 10:40:38AM +0200, Richard Biener via Gcc wrote:
> On Mon, May 3, 2021 at 11:10 PM Andrew Pinski via Gcc <gcc@gcc.gnu.org> wrote:
> >   I noticed my (highly, -j24) parallel build of GCC is serialized on
> > compiling gimple-match.c.  Has anyone looked into splitting this
> > generated file into multiple files?
> 
> There were threads about this in the past, yes.  There's the
> possibility to use LTO for this as well (also mentioned in those
> threads).  Note it's not easy to split in a meaningful way in
> genmatch.c

But it will have to be handled at least somewhat soon: on not huge
parallelism (-j120 for example) building *-match.c takes longer than
building everything else in gcc/ together (wallclock time), and it is a
huge part of regstrap time (bigger than running all of the testsuite!)


Segher