rts: Use relaxed ordering on spinlock counterswip/tsan/storage

2 files changed, 4 insertions, 2 deletions

diff --git a/includes/stg/SMP.h b/includes/stg/SMP.h
index fa52a913c4..8eff276e60 100644
--- a/includes/stg/SMP.h
+++ b/includes/stg/SMP.h
@@ -440,6 +440,7 @@ load_load_barrier(void) {
 // Relaxed atomic operations.
 #define RELAXED_LOAD(ptr) __atomic_load_n(ptr, __ATOMIC_RELAXED)
 #define RELAXED_STORE(ptr,val) __atomic_store_n(ptr, val, __ATOMIC_RELAXED)
+#define RELAXED_ADD(ptr,val) __atomic_add_fetch(ptr, val, __ATOMIC_RELAXED)
 
 // Acquire/release atomic operations
 #define ACQUIRE_LOAD(ptr) __atomic_load_n(ptr, __ATOMIC_ACQUIRE)
@@ -466,6 +467,7 @@ EXTERN_INLINE void load_load_barrier () {} /* nothing */
 // Relaxed atomic operations
 #define RELAXED_LOAD(ptr) *ptr
 #define RELAXED_STORE(ptr,val) *ptr = val
+#define RELAXED_ADD(ptr,val) *ptr += val
 
 // Acquire/release atomic operations
 #define ACQUIRE_LOAD(ptr) *ptr
diff --git a/rts/SpinLock.c b/rts/SpinLock.c
index 314918257f..5289694aa7 100644
--- a/rts/SpinLock.c
+++ b/rts/SpinLock.c
@@ -30,10 +30,10 @@ void acquire_spin_lock_slow_path(SpinLock * p)
         for (uint32_t i = 0; i < SPIN_COUNT; i++) {
             StgWord32 r = cas((StgVolatilePtr)&(p->lock), 1, 0);
             if (r != 0) return;
-            IF_PROF_SPIN(__atomic_fetch_add(&p->spin, 1, __ATOMIC_RELAXED));
+            IF_PROF_SPIN(RELAXED_ADD(&p->spin, 1));
             busy_wait_nop();
         }
-        IF_PROF_SPIN(__atomic_fetch_add(&p->yield, 1, __ATOMIC_RELAXED));
+        IF_PROF_SPIN(RELAXED_ADD(&p->yield, 1));
         yieldThread();
     } while (1);
 }