On Mon, 2010-02-15 at 21:28 +0100, Pavel Machek wrote: > On Tue 2010-02-16 06:59:52, Benjamin Herrenschmidt wrote: > > On Mon, 2010-02-15 at 08:34 +0100, Pavel Machek wrote: > > > > On Tue, 2010-02-09 at 16:24 +0100, Pavel Machek wrote: > > > > > ...according to gcc docs, sp should be global, or placement in > > > > > register is not guaranteed (except at asm boundaries, but there > > > are > > > > > none). > > > > > > > > Sorry I'm not sure I grok what you mean. > > > > > > Well, according to gcc doscs and my experience, local "register int > > > __asm()" variables only work by accident (or not at all). > > > > Hrm... we definitely rely on that for our thread_info() access, and so > > far it has worked well for us, but I'll poke our gcc folks just in case. > > Thanks, and let me know about any results.
All the gcc folks I talked to say something along the lines that there is no way in hell it doesn't work :-) It's true that most other use of it we have are global scope (local_paca in r13, glibc use of r2/r13, etc...) afaik, but since r1 itself is the stack pointer always, I think they pretty much guarantee it works. I'm CCing a couple of experts just to be sure. Cheers, Ben. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
