diff options
Diffstat (limited to 'src/backend/port/tas/sunstudio_sparc.s')
| -rw-r--r-- | src/backend/port/tas/sunstudio_sparc.s | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/src/backend/port/tas/sunstudio_sparc.s b/src/backend/port/tas/sunstudio_sparc.s new file mode 100644 index 0000000..4bebf07 --- /dev/null +++ b/src/backend/port/tas/sunstudio_sparc.s @@ -0,0 +1,53 @@ +!------------------------------------------------------------------------- +! +! sunstudio_sparc.s +! compare and swap for Sun Studio on Sparc +! +! Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group +! Portions Copyright (c) 1994, Regents of the University of California +! +! IDENTIFICATION +! src/backend/port/tas/sunstudio_sparc.s +! +!------------------------------------------------------------------------- + +! 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 + ! requires 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 + ! + ! NB: We're assuming we're running on a TSO system here - solaris + ! userland luckily always has done so. + +#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 |