1 files changed, 103 insertions, 0 deletions
diff --git a/src/include/port/atomics/generic-xlc.h b/src/include/port/atomics/generic-xlc.h
new file mode 100644
index 00000000000..579554d8a67
--- /dev/null
+++ b/src/include/port/atomics/generic-xlc.h
@@ -0,0 +1,103 @@
+/*-------------------------------------------------------------------------
+ *
+ * generic-xlc.h
+ *	  Atomic operations for IBM's CC
+ *
+ * Portions Copyright (c) 2013-2014, PostgreSQL Global Development Group
+ *
+ * NOTES:
+ *
+ * Documentation:
+ * * Synchronization and atomic built-in functions
+ *   http://publib.boulder.ibm.com/infocenter/lnxpcomp/v8v101/topic/com.ibm.xlcpp8l.doc/compiler/ref/bif_sync.htm
+ *
+ * src/include/port/atomics/generic-xlc.h
+ *
+ * -------------------------------------------------------------------------
+ */
+
+#include <atomic.h>
+
+#define PG_HAVE_ATOMIC_U32_SUPPORT
+typedef struct pg_atomic_uint32
+{
+	volatile uint32 value;
+} pg_atomic_uint32;
+
+
+/* 64bit atomics are only supported in 64bit mode */
+#ifdef __64BIT__
+#define PG_HAVE_ATOMIC_U64_SUPPORT
+typedef struct pg_atomic_uint64
+{
+	volatile uint64 value;
+} pg_atomic_uint64;
+
+#endif /* __64BIT__ */
+
+#if defined(PG_USE_INLINE) || defined(ATOMICS_INCLUDE_DEFINITIONS)
+
+#define PG_HAVE_ATOMIC_COMPARE_EXCHANGE_U32
+static inline bool
+pg_atomic_compare_exchange_u32_impl(volatile pg_atomic_uint32 *ptr,
+									uint32 *expected, uint32 newval)
+{
+	bool	ret;
+	uint64	current;
+
+	/*
+	 * xlc's documentation tells us:
+	 * "If __compare_and_swap is used as a locking primitive, insert a call to
+	 * the __isync built-in function at the start of any critical sections."
+	 */
+	__isync();
+
+	/*
+	 * XXX: __compare_and_swap is defined to take signed parameters, but that
+	 * shouldn't matter since we don't perform any arithmetic operations.
+	 */
+	current = (uint32)__compare_and_swap((volatile int*)ptr->value,
+										 (int)*expected, (int)newval);
+	ret = current == *expected;
+	*expected = current;
+	return ret;
+}
+
+#define PG_HAVE_ATOMIC_FETCH_ADD_U32
+static inline uint32
+pg_atomic_fetch_add_u32_impl(volatile pg_atomic_uint32 *ptr, int32 add_)
+{
+	return __fetch_and_add(&ptr->value, add_);
+}
+#endif
+
+#ifdef PG_HAVE_ATOMIC_U64_SUPPORT
+
+#define PG_HAVE_ATOMIC_COMPARE_EXCHANGE_U64
+static inline bool
+pg_atomic_compare_exchange_u64_impl(volatile pg_atomic_uint64 *ptr,
+									uint64 *expected, uint64 newval)
+{
+	bool	ret;
+	uint64	current;
+
+	__isync();
+
+	current = (uint64)__compare_and_swaplp((volatile long*)ptr->value,
+										   (long)*expected, (long)newval);
+	ret = current == *expected;
+	*expected = current;
+	return ret;
+}
+
+#define PG_HAVE_ATOMIC_FETCH_ADD_U64
+static inline uint64
+pg_atomic_fetch_add_u64_impl(volatile pg_atomic_uint64 *ptr, int64 add_)
+{
+	return __fetch_and_addlp(&ptr->value, add_);
+}
+#endif
+
+#endif /* PG_HAVE_ATOMIC_U64_SUPPORT */
+
+#endif /* defined(PG_USE_INLINE) || defined(ATOMICS_INCLUDE_DEFINITIONS) */