http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55561
--- Comment #28 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch>
2013-01-01 17:13:39 UTC ---
(In reply to comment #26)
> For config/linux/ptrlock the changes are:
> [...]
Following your suggestions, I applied the following patch (mistakes are mine),
which allows me to run without warnings from libgomp:
Index: config/linux/wait.h
===================================================================
--- config/linux/wait.h (revision 194730)
+++ config/linux/wait.h (working copy)
@@ -51,7 +51,7 @@
if (__builtin_expect (gomp_managed_threads > gomp_available_cpus, 0))
count = gomp_throttled_spin_count_var;
for (i = 0; i < count; i++)
- if (__builtin_expect (*addr != val, 0))
+ if (__builtin_expect (__atomic_load_n(addr,MEMMODEL_RELAXED) != val, 0))
return 0;
else
cpu_relax ();
Index: config/linux/ptrlock.c
===================================================================
--- config/linux/ptrlock.c (revision 194730)
+++ config/linux/ptrlock.c (working copy)
@@ -50,9 +50,9 @@
#endif
do
do_wait (intptr, 2);
- while (*intptr == 2);
+ while (__atomic_load_n(intptr, MEMMODEL_RELAXED) == 2);
__asm volatile ("" : : : "memory");
- return *ptrlock;
+ return (void*)__atomic_load_n(ptrlock, MEMMODEL_ACQUIRE);
}
void
Index: config/linux/ptrlock.h
===================================================================
--- config/linux/ptrlock.h (revision 194730)
+++ config/linux/ptrlock.h (working copy)
@@ -48,8 +48,9 @@
{
uintptr_t oldval;
- if ((uintptr_t) *ptrlock > 2)
- return *ptrlock;
+ uintptr_t v = (uintptr_t)__atomic_load_n(ptrlock, MEMMODEL_ACQUIRE);
+ if (v > 2)
+ return (void*)v;
oldval = 0;
if (__atomic_compare_exchange_n (ptrlock, &oldval, 1, false,
