diff --git a/lib/libcompiler_rt/Makefile b/lib/libcompiler_rt/Makefile
index 3a501f5771b2..ce091da77bf7 100644
--- a/lib/libcompiler_rt/Makefile
+++ b/lib/libcompiler_rt/Makefile
@@ -144,6 +144,26 @@ SRCF+=	adddf3 \
 	umodsi3
 .endif
 
+# FreeBSD-specific atomic intrinsics.
+.if ${MACHINE_CPUARCH} == "arm" || ${MACHINE_CPUARCH} == "mips"
+SRCF+=	__sync_fetch_and_add_4 \
+	__sync_fetch_and_and_4 \
+	__sync_fetch_and_or_4 \
+	__sync_fetch_and_sub_4 \
+	__sync_fetch_and_xor_4 \
+	__sync_lock_test_and_set_4 \
+	__sync_val_compare_and_swap_4
+.endif
+.if ${MACHINE_ARCH:Mmips64*} != ""
+SRCF+=	__sync_fetch_and_add_8 \
+	__sync_fetch_and_and_8 \
+	__sync_fetch_and_or_8 \
+	__sync_fetch_and_sub_8 \
+	__sync_fetch_and_xor_8 \
+	__sync_lock_test_and_set_8 \
+	__sync_val_compare_and_swap_8
+.endif
+
 .for file in ${SRCF}
 . if ${MACHINE_CPUARCH} != "arm" && exists(${CRTSRC}/${CRTARCH}/${file}.S)
 SRCS+=	${file}.S
diff --git a/lib/libcompiler_rt/__sync_fetch_and_add_4.c b/lib/libcompiler_rt/__sync_fetch_and_add_4.c
new file mode 100644
index 000000000000..3c11a3b87dd1
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_fetch_and_add_4.c
@@ -0,0 +1,6 @@
+/* $FreeBSD$ */
+#define	NAME		__sync_fetch_and_add_4
+#define	TYPE		uint32_t
+#define	FETCHADD(x, y)	atomic_fetchadd_32(x, y)
+
+#include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_fetch_and_add_8.c b/lib/libcompiler_rt/__sync_fetch_and_add_8.c
new file mode 100644
index 000000000000..6157c151767a
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_fetch_and_add_8.c
@@ -0,0 +1,6 @@
+/* $FreeBSD$ */
+#define	NAME		__sync_fetch_and_add_8
+#define	TYPE		uint64_t
+#define	FETCHADD(x, y)	atomic_fetchadd_64(x, y)
+
+#include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_fetch_and_and_4.c b/lib/libcompiler_rt/__sync_fetch_and_and_4.c
new file mode 100644
index 000000000000..1a488ec27887
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_fetch_and_and_4.c
@@ -0,0 +1,7 @@
+/* $FreeBSD$ */
+#define	NAME		__sync_fetch_and_and_4
+#define	TYPE		uint32_t
+#define	CMPSET		atomic_cmpset_32
+#define	EXPRESSION	t & value
+
+#include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_fetch_and_and_8.c b/lib/libcompiler_rt/__sync_fetch_and_and_8.c
new file mode 100644
index 000000000000..9923e31158bd
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_fetch_and_and_8.c
@@ -0,0 +1,7 @@
+/* $FreeBSD$ */
+#define	NAME		__sync_fetch_and_and_8
+#define	TYPE		uint64_t
+#define	CMPSET		atomic_cmpset_64
+#define	EXPRESSION	t & value
+
+#include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_fetch_and_op_n.h b/lib/libcompiler_rt/__sync_fetch_and_op_n.h
new file mode 100644
index 000000000000..f7f0e06e83a0
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_fetch_and_op_n.h
@@ -0,0 +1,47 @@
+/*-
+ * Copyright (c) 2011 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>
+
+TYPE
+NAME(volatile TYPE *ptr, TYPE value)
+{
+	TYPE t;
+
+#ifdef FETCHADD
+	t = FETCHADD(ptr, value);
+#else
+	do {
+		t = *ptr;
+	} while (!CMPSET(ptr, t, EXPRESSION));
+#endif
+
+	return (t);
+}
diff --git a/lib/libcompiler_rt/__sync_fetch_and_or_4.c b/lib/libcompiler_rt/__sync_fetch_and_or_4.c
new file mode 100644
index 000000000000..1feeeb17a1d6
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_fetch_and_or_4.c
@@ -0,0 +1,7 @@
+/* $FreeBSD$ */
+#define	NAME		__sync_fetch_and_or_4
+#define	TYPE		uint32_t
+#define	CMPSET		atomic_cmpset_32
+#define	EXPRESSION	t | value
+
+#include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_fetch_and_or_8.c b/lib/libcompiler_rt/__sync_fetch_and_or_8.c
new file mode 100644
index 000000000000..7cb9403bed17
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_fetch_and_or_8.c
@@ -0,0 +1,7 @@
+/* $FreeBSD$ */
+#define	NAME		__sync_fetch_and_or_8
+#define	TYPE		uint64_t
+#define	CMPSET		atomic_cmpset_64
+#define	EXPRESSION	t | value
+
+#include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_fetch_and_sub_4.c b/lib/libcompiler_rt/__sync_fetch_and_sub_4.c
new file mode 100644
index 000000000000..a251adde54f0
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_fetch_and_sub_4.c
@@ -0,0 +1,6 @@
+/* $FreeBSD$ */
+#define	NAME		__sync_fetch_and_sub_4
+#define	TYPE		uint32_t
+#define	FETCHADD(x, y)	atomic_fetchadd_32(x, -(y))
+
+#include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_fetch_and_sub_8.c b/lib/libcompiler_rt/__sync_fetch_and_sub_8.c
new file mode 100644
index 000000000000..5a93f977ec89
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_fetch_and_sub_8.c
@@ -0,0 +1,6 @@
+/* $FreeBSD$ */
+#define	NAME		__sync_fetch_and_sub_8
+#define	TYPE		uint64_t
+#define	FETCHADD(x, y)	atomic_fetchadd_64(x, -(y))
+
+#include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_fetch_and_xor_4.c b/lib/libcompiler_rt/__sync_fetch_and_xor_4.c
new file mode 100644
index 000000000000..d5f732d65f6b
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_fetch_and_xor_4.c
@@ -0,0 +1,7 @@
+/* $FreeBSD$ */
+#define	NAME		__sync_fetch_and_xor_4
+#define	TYPE		uint32_t
+#define	CMPSET		atomic_cmpset_32
+#define	EXPRESSION	t ^ value
+
+#include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_fetch_and_xor_8.c b/lib/libcompiler_rt/__sync_fetch_and_xor_8.c
new file mode 100644
index 000000000000..610037ef28bc
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_fetch_and_xor_8.c
@@ -0,0 +1,7 @@
+/* $FreeBSD$ */
+#define	NAME		__sync_fetch_and_xor_8
+#define	TYPE		uint64_t
+#define	CMPSET		atomic_cmpset_64
+#define	EXPRESSION	t ^ value
+
+#include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_lock_test_and_set_4.c b/lib/libcompiler_rt/__sync_lock_test_and_set_4.c
new file mode 100644
index 000000000000..d4965f96484f
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_lock_test_and_set_4.c
@@ -0,0 +1,7 @@
+/* $FreeBSD$ */
+#define	NAME		__sync_lock_test_and_set_4
+#define	TYPE		uint32_t
+#define	CMPSET		atomic_cmpset_32
+#define	EXPRESSION	value
+
+#include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_lock_test_and_set_8.c b/lib/libcompiler_rt/__sync_lock_test_and_set_8.c
new file mode 100644
index 000000000000..1e02203d2be5
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_lock_test_and_set_8.c
@@ -0,0 +1,7 @@
+/* $FreeBSD$ */
+#define	NAME		__sync_lock_test_and_set_8
+#define	TYPE		uint64_t
+#define	CMPSET		atomic_cmpset_64
+#define	EXPRESSION	value
+
+#include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_val_compare_and_swap_4.c b/lib/libcompiler_rt/__sync_val_compare_and_swap_4.c
new file mode 100644
index 000000000000..e0ab11515efd
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_val_compare_and_swap_4.c
@@ -0,0 +1,6 @@
+/* $FreeBSD$ */
+#define	NAME		__sync_val_compare_and_swap_4
+#define	TYPE		uint32_t
+#define	CMPSET		atomic_cmpset_32
+
+#include "__sync_val_compare_and_swap_n.h"
diff --git a/lib/libcompiler_rt/__sync_val_compare_and_swap_8.c b/lib/libcompiler_rt/__sync_val_compare_and_swap_8.c
new file mode 100644
index 000000000000..c6f1101a72c0
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_val_compare_and_swap_8.c
@@ -0,0 +1,6 @@
+/* $FreeBSD$ */
+#define	NAME		__sync_val_compare_and_swap_8
+#define	TYPE		uint64_t
+#define	CMPSET		atomic_cmpset_64
+
+#include "__sync_val_compare_and_swap_n.h"
diff --git a/lib/libcompiler_rt/__sync_val_compare_and_swap_n.h b/lib/libcompiler_rt/__sync_val_compare_and_swap_n.h
new file mode 100644
index 000000000000..cd4c9a3d1663
--- /dev/null
+++ b/lib/libcompiler_rt/__sync_val_compare_and_swap_n.h
@@ -0,0 +1,45 @@
+/*-
+ * Copyright (c) 2011 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>
+
+TYPE
+NAME(volatile TYPE *ptr, TYPE oldval, TYPE newval)
+{
+	TYPE t;
+
+	while (!CMPSET(ptr, oldval, newval)) {
+		t = *ptr;
+		if (t != oldval)
+			return (t);
+	}
+
+	return (oldval);
+}