On Wed, Sep 24, 2014 at 10:04 AM, Steven Bosscher <stevenb....@gmail.com> wrote: > On Wed, Sep 24, 2014 at 6:32 PM, Jan Hubicka <hubi...@ucw.cz> wrote: >> Libreoffice shows that GCC needs about twice as much of system time. >> According >> to profiles, good part is the ugly way we pass stuff down to assembler and >> other part is memory use during the copmilation stage. > > Are you using -pipe? AFAIR this still isn't the default, even on > GNU/Linux, but it is typically a lot faster than without.
Is that true even when TMPDIR is on a ram disk? There's no obvious reason that it should be true in a parallel build. Using -pipe effectively constrains communication between the compiler and the assembler to work in PIPE_BUF blocks. Using TMPDIR introduces no such constraints, and in a big program a parallel build should obscure the fact that the compiler and assembler are serialized for each individual compilation unit. Ian
