Re: new module for async-safe spin locks

[Bruno Haible]

>   - Solaris cc: are handled through inline asm, based on the code that
>     GCC would generate.

Sun Studio 11 cc (__SUNPRO_C == 0x580) does not support GCC extended asm syntax,
but Sun Studio 12 cc (__SUNPRO_C >= 0x590) does.


2020-07-03  Bruno Haible  <bruno@clisp.org>

        asyncsafe-spin: Use GCC extended asm syntax for SunStudio 12 compiler.
        * lib/asyncsafe-spin.c (memory_barrier, atomic_compare_and_swap): Use
        the GCC extended asm syntax also for the Sun Studio 12 compilers.

diff --git a/lib/asyncsafe-spin.c b/lib/asyncsafe-spin.c
index 81e48ad..6ea5781 100644
--- a/lib/asyncsafe-spin.c
+++ b/lib/asyncsafe-spin.c
@@ -186,14 +186,14 @@ do_unlock (asyncsafe_spinlock_t *lock)
 
 #  elif (defined __GNUC__ || defined __SUNPRO_C) && (defined __sparc || 
defined __i386 || defined __x86_64__)
 /* For older versions of GCC, use inline assembly.
-   GCC and the Oracle Studio C compiler understand GCC's extended asm syntax,
-   but the plain Solaris cc understands only simple asm.  */
+   GCC and the Oracle Studio C 12 compiler understand GCC's extended asm 
syntax,
+   but the plain Oracle Studio C 11 compiler understands only simple asm.  */
 /* An implementation that verifies the unlocks.  */
 
 static void
 memory_barrier (void)
 {
-#   if defined __GNUC__
+#   if defined __GNUC__ || __SUNPRO_C >= 0x590
 #    if defined __i386 || defined __x86_64__
   asm volatile ("mfence");
 #    endif
@@ -216,7 +216,7 @@ static unsigned int
 atomic_compare_and_swap (volatile unsigned int *vp, unsigned int cmp,
                          unsigned int newval)
 {
-#   if defined __GNUC__
+#   if defined __GNUC__ || __SUNPRO_C >= 0x590
   unsigned int oldval;
 #    if defined __i386 || defined __x86_64__
   asm volatile (" lock\n cmpxchgl %3,(%1)"