On Tue, 2012-06-05 at 12:44 +0200, Gabriel Paubert wrote: > On Tue, Jun 05, 2012 at 08:00:42AM +1000, Benjamin Herrenschmidt wrote: > > On Mon, 2012-06-04 at 13:03 +0200, Gabriel Paubert wrote: > > > There is no conflict to the ABI. These functions are supposed to be > > > directly reachable from whatever code > > > section may need them. > > > > > > Now I have a question: how did you get the need for this? > > > > > > None of my kernels uses them: > > > - if I compile with -O2, the compiler simply expands epilogue and > > > prologue to series of lwz and stw > > > - if I compile with -Os, the compiler generates lmw/stmw which give > > > the smallest possible cache footprint > > > > > > Neither did I find a single reference to these functions in several > > > systems that I grepped for. > > > > Newer gcc's ... even worse, with -Os, it does it for a single register > > spill afaik. At least that's how I hit it with grub2 using whatever gcc > > is in fc17. > > Ok, it's beyond stupid, and at this point must be considered a gcc bug.
Probably, I haven't had a chance to report it... It would make more sense if the out of line functions also handled creating the stack frame & disposing of it (ie, maybe a tail call for return) but they don't even do that so yes it's quite gross. Cheers, Ben. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
