Add simplified sparc8 ASM for solaris_sparc.s, from Alan Stange.

This commit is contained in:
Bruce Momjian 2006-05-18 00:05:01 +00:00
parent 407885ea3b
commit 924b9d62b4
1 changed files with 6 additions and 8 deletions

View File

@ -19,21 +19,19 @@ pg_atomic_cas:
! "cas" only works on sparcv9 chips, and requies a compiler
! that is targeting sparcv9. It will fail on a compiler
! targeting sparcv8, and of course will not be understood
! by a sparcv8 CPU. If this fails on existing Solaris
! systems, we need to use a !defined(__sparcv9) test
! to fall back to the old "ldstub" call for sparcv8 compiles.
! gcc continues to use "ldstub" because there is no indication
! which sparc version it is targeting.
! by a sparcv8 CPU. gcc continues to use "ldstub" because
! there is no indication which sparc version it is targeting.
!
! There actually is a trick for embedding "cas" for a compiler
! that is targeting sparcv8:
!
! http://cvs.opensolaris.org/source/xref/on/usr/src/lib/libc/sparc/threads/sparc.il
!
! This might work for sparc8:
! ldstub [%o0],%o1 ! moves only a byte
#ifdef __sparcv9
cas [%o0],%o2,%o1
#else
ldstub [%o0],%o1
#endif
mov %o1,%o0
retl
nop