1 files changed, 106 insertions, 0 deletions
diff --git a/src/include/port/atomics/generic-acc.h b/src/include/port/atomics/generic-acc.h
new file mode 100644
index 0000000..3c75b6a
--- /dev/null
+++ b/src/include/port/atomics/generic-acc.h
@@ -0,0 +1,106 @@
+/*-------------------------------------------------------------------------
+ *
+ * generic-acc.h
+ *	  Atomic operations support when using HPs acc on HPUX
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * NOTES:
+ *
+ * Documentation:
+ * * inline assembly for Itanium-based HP-UX:
+ *   http://h21007.www2.hp.com/portal/download/files/unprot/Itanium/inline_assem_ERS.pdf
+ * * Implementing Spinlocks on the Intel (R) Itanium (R) Architecture and PA-RISC
+ *   http://h21007.www2.hp.com/portal/download/files/unprot/itanium/spinlocks.pdf
+ *
+ * Itanium only supports a small set of numbers (6, -8, -4, -1, 1, 4, 8, 16)
+ * for atomic add/sub, so we just implement everything but compare_exchange
+ * via the compare_exchange fallbacks in atomics/generic.h.
+ *
+ * src/include/port/atomics/generic-acc.h
+ *
+ * -------------------------------------------------------------------------
+ */
+
+#include <machine/sys/inline.h>
+
+#define pg_compiler_barrier_impl()	_Asm_sched_fence()
+
+#if defined(HAVE_ATOMICS)
+
+/* IA64 always has 32/64 bit atomics */
+
+#define PG_HAVE_ATOMIC_U32_SUPPORT
+typedef struct pg_atomic_uint32
+{
+	volatile uint32 value;
+} pg_atomic_uint32;
+
+#define PG_HAVE_ATOMIC_U64_SUPPORT
+typedef struct pg_atomic_uint64
+{
+	/*
+	 * Alignment is guaranteed to be 64bit. Search for "Well-behaved
+	 * application restrictions" => "Data alignment and data sharing" on HP's
+	 * website. Unfortunately the URL doesn't seem to stable enough to
+	 * include.
+	 */
+	volatile uint64 value;
+} pg_atomic_uint64;
+
+
+#define MINOR_FENCE (_Asm_fence) (_UP_CALL_FENCE | _UP_SYS_FENCE | \
+								 _DOWN_CALL_FENCE | _DOWN_SYS_FENCE )
+
+#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;
+	uint32	current;
+
+	_Asm_mov_to_ar(_AREG_CCV, *expected, MINOR_FENCE);
+	/*
+	 * We want a barrier, not just release/acquire semantics.
+	 */
+	_Asm_mf();
+	/*
+	 * Notes:
+	 * _DOWN_MEM_FENCE | _UP_MEM_FENCE prevents reordering by the compiler
+	 */
+	current =  _Asm_cmpxchg(_SZ_W, /* word */
+							_SEM_REL,
+							&ptr->value,
+							newval, _LDHINT_NONE,
+							_DOWN_MEM_FENCE | _UP_MEM_FENCE);
+	ret = current == *expected;
+	*expected = current;
+	return ret;
+}
+
+
+#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;
+
+	_Asm_mov_to_ar(_AREG_CCV, *expected, MINOR_FENCE);
+	_Asm_mf();
+	current =  _Asm_cmpxchg(_SZ_D, /* doubleword */
+							_SEM_REL,
+							&ptr->value,
+							newval, _LDHINT_NONE,
+							_DOWN_MEM_FENCE | _UP_MEM_FENCE);
+	ret = current == *expected;
+	*expected = current;
+	return ret;
+}
+
+#undef MINOR_FENCE
+
+#endif /* defined(HAVE_ATOMICS) */