Add __sync_synchronize().

This function can easily be implemented on top of the mb() macro
provided by <machine/atomic.h>.

2 files changed, 48 insertions, 0 deletions

diff --git a/lib/libcompiler_rt/Makefile b/lib/libcompiler_rt/Makefile
index c75ae07..83c4ea3 100644
--- a/lib/libcompiler_rt/Makefile
+++ b/lib/libcompiler_rt/Makefile
@@ -164,6 +164,7 @@ SRCF+=	__sync_fetch_and_add_4 \
 	__sync_fetch_and_sub_4 \
 	__sync_fetch_and_xor_4 \
 	__sync_lock_test_and_set_4 \
+	__sync_synchronize \
 	__sync_val_compare_and_swap_4
 .endif
 .if ${MACHINE_ARCH:Mmips64*} != ""
diff --git a/lib/libcompiler_rt/__sync_synchronize.c b/lib/libcompiler_rt/__sync_synchronize.c
new file mode 100644
index 0000000..51e08db
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_synchronize.c
@@ -0,0 +1,47 @@
+/*-
+ * Copyright (c) 2013 Ed Schouten <ed@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <machine/atomic.h>
+
+#ifdef __clang__
+static void
+atomic_func(void)
+#else
+void
+__sync_synchronize(void)
+#endif
+{
+
+	mb();
+}
+
+#ifdef __clang__
+__strong_reference(atomic_func, __sync_synchronize);
+#endif