Hi Alex, On Fri, 8 Feb 2019 at 01:58, Alexander Graf <ag...@suse.de> wrote: > > > > > Am 08.02.2019 um 05:11 schrieb Simon Glass <s...@chromium.org>: > > > > Hi Alex, > > > >> On Sat, 2 Feb 2019 at 09:07, Alexander Graf <ag...@suse.de> wrote: > >> > >> > >> > >>> Am 02.02.2019 um 15:13 schrieb Simon Glass <s...@chromium.org>: > >>> > >>> Hi Alex, > >>> > >>>> On Thu, 31 Jan 2019 at 08:06, Alexander Graf <ag...@suse.de> wrote: > >>>> > >>>> The board_r init function was complaining that we are looping through > >>>> an array, calling all our tiny init stubs sequentially via indirect > >>>> function calls (which can't be speculated, so they are slow). > >>> > >>> Is this a compiler warning? Could you let me know what this is? > >> > >> It's the code comment I'm removing with this patch :). > >> > >>> > >>>> > >>>> The solution to that is pretty easy though. All we need to do is inline > >>>> the function that loops through the functions and the compiler will > >>>> automatically convert almost all indirect calls into direct inlined code. > >>> > >>> You mean it calls the functions one after the other without a > >>> function-table array? > >> > >> Exactly. Magical, eh? It even inlines them! > > > > Yes it is surprising. I am also surprised that it reduces code size, > > but I suppose that is why it does it. Presumably the inlining is what > > does that. > > Yes, of course. With separate object files, the compiler can not inline > anything at all, because it does not know how the function pointers get used. > > The alternative to this *might* be LTO, which we could think about as well. > It should help reduce indirection and code size overall. But I don't know how > well gold works with the linker scripts we have.
Hmm don't we have that? We should. > > > But what happens if we #define DEBUG? > > Define it where? ;) Yes exactly. At present you can turn this on globally by putting it at the top of initcall.c. I think it is worth a comment on how to enable debugging. Does the code size blow out horribly if debugging is enabled? (and hello from Munich!) Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
