Theo Schlossnagle wrote:
>
> On May 18, 2006, at 11:56 AM, Bruce Momjian wrote:
>
> > Theo Schlossnagle wrote:
> >>
> >> On May 17, 2006, at 8:30 PM, Bruce Momjian wrote:
> >>
>
> [ snip ]
>
> >>> OK, so what do you suggest? Remove that URL from the comments?
> >>> Anything else?
> >>
> >> If you compile with -xarch=v8plus you should be able to omit the
> >> #ifdef's entirely. The sparcv8plus and sparcv9 cas instruction are
> >> identical. Is the goal here to support Sparc chips that do not
> >> support the v8plus instruction set? I'm not on the ports list, so
> >> maybe I missed the original problem report.
> >
> > We don't actually know all the Solaris versions/hardware we should
> > support, so it is hard to say if we currently have running sparcv8
> > CPUs.
> > The best solution is to use separate entries for v8 and v9. Is
> > there a
> > unique preprocessor symbol when a sparcv8plus binary is being
> > generated?
>
> Heh.. you could likely guess it:
> #if defined(__sparcv8plus)
Nice, comments and macro tests updated. New version of file attached.
--
Bruce Momjian http://candle.pha.pa.us
EnterpriseDB http://www.enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +
!=======================================================================
! solaris_sparc.s -- compare and swap for solaris_sparc
!=======================================================================
! Fortunately the Sun compiler can process cpp conditionals with -P
! '/' is the comment for x86, while '!' is the comment for Sparc
#if defined(__sparcv9) || defined(__sparc)
.section ".text"
.align 8
.skip 24
.align 4
.global pg_atomic_cas
pg_atomic_cas:
! "cas" only works on sparcv9 and sparcv8plus chips, and
! requies a compiler targeting these CPUs. It will fail
! on a compiler targeting sparcv8, and of course will not
! be understood by a sparcv8 CPU. gcc continues to use
! "ldstub" because it targets sparcv7.
!
! There is actually a trick for embedding "cas" in a
! sparcv8-targeted compiler, but it can only be run
! on a sparcv8plus/v9 cpus:
!
! http://cvs.opensolaris.org/source/xref/on/usr/src/lib/libc/sparc/threads/sparc.il
!
#if defined(__sparcv9) || defined(__sparcv8plus)
cas [%o0],%o2,%o1
#else
ldstub [%o0],%o1
#endif
mov %o1,%o0
retl
nop
.type pg_atomic_cas,2
.size pg_atomic_cas,(.-pg_atomic_cas)
#endif
