* Ian Lance Taylor wrote on Sun, Jun 22, 2008 at 04:42:19PM CEST: > > First I'll note that insn-attrtab.c is particularly slow for > x86/x86_64, presumably due to the many processor varieties and complex > scheduling. It is much faster for other targets. > > Compiling it earlier than it would otherwise be does work. The > problem is that insn-attrtab.o depends on the generated file > insn-attr.h. GNU make works by making a pass over the targets, and it > builds all the ones whose dependencies are already built. Then it > makes another pass. The effect is that all the objects which do not > depend upon insn-attr.h wind up getting built before insn-attrtab.o. > > We could game the system to force insn-attrtab.o to be compiler even > earlier by adding false dependencies in the Makefile.
I would be surprised if just dependency ordering could improve things for insn-attrtab on trunk further than this patch (a variant of which was committed to trunk on 2008-04-03): <http://gcc.gnu.org/ml/gcc-patches/2008-03/msg01888.html> > A cleaner approach would be to somehow change genattrtab.c [...] That sounds like the next logical step to me. Cheers, Ralf
