Re: pa-risc/linux abi
clint,
> > > a pa-risc assembler kernel to make up for gcc's crappy single precision
> > > performance, so I can have defaults that work without HP's compiler.
> > > Can you confirm that Linux uses HP's 32 bit ABI (i.e., which registers
> > > are used in argument passing, and how the stack frame works)? My
> >
> > Debian hppa is 32 bit -- will forward the rest of this to the experts.
jda knows the cause of this, we discussed this onece, that single
prcision was slower on pa than double precision because single still has
to pass the entire parameter in the two registers, the HP compiler
doesn't have to do that and it can crank out two per set. The issues
here is that we would need more patterns in gcc and a change in the
framework. Maybe jda can make a comment here.
> Debian HPPA is 32-bit ELF.
> HPUX is 32-bit SOM. Different binary format.
> I'm pretty sure the calling convention is the same for both.
No, it is not the same. We cannot generate "pass fpregs in general
registers" as HPUX does, this would require tons of code in the linker
and stubs into/outof to move parameters around to the right places.
Aside from that major bit, we also probably differ in how we pass small
structs to functions. SOM was "ported" (and I use the word loosely) to
become ELF32 for hppa. We had to make things up as it went along.
> (But I'm not the expert, tausq is traveling, hopefully jda/willy can reply)
>
> > > assembly kernel works under HP-UX, and I'm wondering if it will under
> > > linux. The document I used to write it I found on the linux site, but
> > > it's an HP doc:
> > > http://ftp.parisc-linux.org/docs/arch/rad_11_0_32.pdf
> >
> > I can try it out if it will work with 2.6.0. I tried a build with
> > just the prefetch and -mpa-risc-2-0, and it failed. If I can't figure
> > it out I may give you a shout.
I don't clearly understand what an "assembly kernel" does? Can you
please enlighten me as to it's proper functioning within the context of
a toolchain?
> Anyone who has deamons that drive him to writing assembly for
> "dead" architectures deserves access to said architectures at least.
> If Debian or some other kind soul can't provide it, please contact
> me offline and I can arrange remote access to a crash and bash system.
Ineed.
c.
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