[Bf-blender-cvs] [e4e2e3a15db] blender-v2.79a-release: Add an 'atomic cas' wrapper for pointers.

[Bastien Montagne]

Commit: e4e2e3a15db571b97b3acb005d9fcf30261d2bf2
Author: Bastien Montagne
Date:   Mon Sep 25 10:40:50 2017 +0200
Branches: blender-v2.79a-release
https://developer.blender.org/rBe4e2e3a15db571b97b3acb005d9fcf30261d2bf2

Add an 'atomic cas' wrapper for pointers.

Avoids having to repeat obfuscating castings everywhere...

===================================================================

M	intern/atomic/atomic_ops.h
M	intern/atomic/intern/atomic_ops_ext.h

===================================================================

diff --git a/intern/atomic/atomic_ops.h b/intern/atomic/atomic_ops.h
index 1e9528f9ed9..683ced7a72f 100644
--- a/intern/atomic/atomic_ops.h
+++ b/intern/atomic/atomic_ops.h
@@ -107,6 +107,8 @@ ATOMIC_INLINE unsigned int atomic_fetch_and_add_u(unsigned int *p, unsigned int
 ATOMIC_INLINE unsigned int atomic_fetch_and_sub_u(unsigned int *p, unsigned int x);
 ATOMIC_INLINE unsigned int atomic_cas_u(unsigned int *v, unsigned int old, unsigned int _new);
 
+ATOMIC_INLINE void *atomic_cas_ptr(void **v, void *old, void *_new);
+
 /* WARNING! Float 'atomics' are really faked ones, those are actually closer to some kind of spinlock-sync'ed operation,
  *          which means they are only efficient if collisions are highly unlikely (i.e. if probability of two threads
  *          working on the same pointer at the same time is very low). */
diff --git a/intern/atomic/intern/atomic_ops_ext.h b/intern/atomic/intern/atomic_ops_ext.h
index b72c94563fc..930c961bd3d 100644
--- a/intern/atomic/intern/atomic_ops_ext.h
+++ b/intern/atomic/intern/atomic_ops_ext.h
@@ -168,6 +168,18 @@ ATOMIC_INLINE unsigned int atomic_cas_u(unsigned int *v, unsigned int old, unsig
 #endif
 }
 
+/******************************************************************************/
+/* Pointer operations. */
+
+ATOMIC_INLINE void *atomic_cas_ptr(void **v, void *old, void *_new)
+{
+#if (LG_SIZEOF_PTR == 8)
+	return (void *)atomic_cas_uint64((uint64_t *)v, *(uint64_t *)&old, *(uint64_t *)&_new);
+#elif (LG_SIZEOF_PTR == 4)
+	return (void *)atomic_cas_uint32((uint32_t *)v, *(uint32_t *)&old, *(uint32_t *)&_new);
+#endif
+}
+
 /******************************************************************************/
 /* float operations. */