On 5/2/19 9:04 PM, Richard Biener wrote: > On May 2, 2019 8:14:46 PM GMT+02:00, Segher Boessenkool > <seg...@kernel.crashing.org> wrote: >> On Thu, May 02, 2019 at 07:41:18PM +0200, Richard Biener wrote: >>> On May 2, 2019 7:00:16 PM GMT+02:00, Segher Boessenkool >> <seg...@kernel.crashing.org> wrote: >>>> On Thu, May 02, 2019 at 03:18:00PM +0200, Richard Biener wrote: >>>>> Somewhen earlier this year I've done the experiment with using >>>>> a compile with -flto -fno-fat-lto-objects and a link >>>>> via -flto -r -flinker-output=rel into the object file. This cut >>>>> compile-time more than in half with less maintainance overhead. >>>>> >>>>> Adding other files to this handling looks trivial as well, as well >>>>> as conditionalizing it (I'd probably not want this for devel >> builds). >>>> >>>> But we want devel builds to be a lot faster than they are now :-/ >>> >>> My devel build is -O0 non-bootstrapped and building the files after >> dependency changes is fast enough. It's the bootstraps that matter, no? >> >> >> Yes, I bootstrap most of the time. For development. It catches a >> *lot* >> of problems progressive builds do not. (Those are plenty fast already >> of >> course, -O0 or not). > > So we'd catch it there but disable by default for stage 1 since we probably > do not want to rely on the host compiler. > > Richard. > >> >> Segher >
I'm interested in 2 scenarios: 1) fast non-bootstrap development build with -O2; typically I want to run a fraction of test-suite or I want to install the compiler and run-time binaries; building the compiler with -O0 will result in terribly slow build of run-time libraries 2) faster bootstrap on a massively parallel machine (64+ cores) Martin
