diff --git a/lib/libcompiler_rt/Makefile b/lib/libcompiler_rt/Makefile
index 2e869ccd19d9..c75ae07d26cd 100644
--- a/lib/libcompiler_rt/Makefile
+++ b/lib/libcompiler_rt/Makefile
@@ -156,9 +156,8 @@ SRCF+=	divsi3 \
 	umodsi3
 .endif
 
-# FreeBSD-specific atomic intrinsics. Clang provides them as a builtin.
-.if (${MACHINE_CPUARCH} == "arm" && ${COMPILER_TYPE} != "clang") || \
-    ${MACHINE_CPUARCH} == "mips"
+# 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 \
diff --git a/lib/libcompiler_rt/__sync_fetch_and_add_4.c b/lib/libcompiler_rt/__sync_fetch_and_add_4.c
index 3c11a3b87dd1..6126cfa822d1 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_add_4.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_add_4.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_add_4
-#define	TYPE		uint32_t
+#define	TYPE		int32_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
index 6157c151767a..2738d5dd82e9 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_add_8.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_add_8.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_add_8
-#define	TYPE		uint64_t
+#define	TYPE		int64_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
index 1a488ec27887..49fab808a796 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_and_4.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_and_4.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_and_4
-#define	TYPE		uint32_t
+#define	TYPE		int32_t
 #define	CMPSET		atomic_cmpset_32
 #define	EXPRESSION	t & value
 
diff --git a/lib/libcompiler_rt/__sync_fetch_and_and_8.c b/lib/libcompiler_rt/__sync_fetch_and_and_8.c
index 9923e31158bd..f681785b64ae 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_and_8.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_and_8.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_and_8
-#define	TYPE		uint64_t
+#define	TYPE		int64_t
 #define	CMPSET		atomic_cmpset_64
 #define	EXPRESSION	t & value
 
diff --git a/lib/libcompiler_rt/__sync_fetch_and_op_n.h b/lib/libcompiler_rt/__sync_fetch_and_op_n.h
index f7f0e06e83a0..994e271ed088 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_op_n.h
+++ b/lib/libcompiler_rt/__sync_fetch_and_op_n.h
@@ -30,8 +30,13 @@ __FBSDID("$FreeBSD$");
 #include <sys/types.h>
 #include <machine/atomic.h>
 
+#if defined __clang__
+static TYPE
+atomic_func(volatile TYPE *ptr, TYPE value, ...)
+#else
 TYPE
 NAME(volatile TYPE *ptr, TYPE value)
+#endif
 {
 	TYPE t;
 
@@ -45,3 +50,7 @@ NAME(volatile TYPE *ptr, TYPE value)
 
 	return (t);
 }
+
+#ifdef __clang__
+__strong_reference(atomic_func, NAME);
+#endif
diff --git a/lib/libcompiler_rt/__sync_fetch_and_or_4.c b/lib/libcompiler_rt/__sync_fetch_and_or_4.c
index 1feeeb17a1d6..879b9aece713 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_or_4.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_or_4.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_or_4
-#define	TYPE		uint32_t
+#define	TYPE		int32_t
 #define	CMPSET		atomic_cmpset_32
 #define	EXPRESSION	t | value
 
diff --git a/lib/libcompiler_rt/__sync_fetch_and_or_8.c b/lib/libcompiler_rt/__sync_fetch_and_or_8.c
index 7cb9403bed17..c88a37b7f20c 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_or_8.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_or_8.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_or_8
-#define	TYPE		uint64_t
+#define	TYPE		int64_t
 #define	CMPSET		atomic_cmpset_64
 #define	EXPRESSION	t | value
 
diff --git a/lib/libcompiler_rt/__sync_fetch_and_sub_4.c b/lib/libcompiler_rt/__sync_fetch_and_sub_4.c
index a251adde54f0..e0fe14c0ad54 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_sub_4.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_sub_4.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_sub_4
-#define	TYPE		uint32_t
+#define	TYPE		int32_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
index 5a93f977ec89..4f239b3e9209 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_sub_8.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_sub_8.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_sub_8
-#define	TYPE		uint64_t
+#define	TYPE		int64_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
index d5f732d65f6b..8a6aec67be9d 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_xor_4.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_xor_4.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_xor_4
-#define	TYPE		uint32_t
+#define	TYPE		int32_t
 #define	CMPSET		atomic_cmpset_32
 #define	EXPRESSION	t ^ value
 
diff --git a/lib/libcompiler_rt/__sync_fetch_and_xor_8.c b/lib/libcompiler_rt/__sync_fetch_and_xor_8.c
index 610037ef28bc..be677f5794c5 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_xor_8.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_xor_8.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_xor_8
-#define	TYPE		uint64_t
+#define	TYPE		int64_t
 #define	CMPSET		atomic_cmpset_64
 #define	EXPRESSION	t ^ value
 
diff --git a/lib/libcompiler_rt/__sync_lock_test_and_set_4.c b/lib/libcompiler_rt/__sync_lock_test_and_set_4.c
index d4965f96484f..73d1bab83f8c 100644
--- a/lib/libcompiler_rt/__sync_lock_test_and_set_4.c
+++ b/lib/libcompiler_rt/__sync_lock_test_and_set_4.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_lock_test_and_set_4
-#define	TYPE		uint32_t
+#define	TYPE		int32_t
 #define	CMPSET		atomic_cmpset_32
 #define	EXPRESSION	value
 
diff --git a/lib/libcompiler_rt/__sync_lock_test_and_set_8.c b/lib/libcompiler_rt/__sync_lock_test_and_set_8.c
index 1e02203d2be5..83c1a6acc6a8 100644
--- a/lib/libcompiler_rt/__sync_lock_test_and_set_8.c
+++ b/lib/libcompiler_rt/__sync_lock_test_and_set_8.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_lock_test_and_set_8
-#define	TYPE		uint64_t
+#define	TYPE		int64_t
 #define	CMPSET		atomic_cmpset_64
 #define	EXPRESSION	value
 
diff --git a/lib/libcompiler_rt/__sync_val_compare_and_swap_4.c b/lib/libcompiler_rt/__sync_val_compare_and_swap_4.c
index e0ab11515efd..d69b6f505291 100644
--- a/lib/libcompiler_rt/__sync_val_compare_and_swap_4.c
+++ b/lib/libcompiler_rt/__sync_val_compare_and_swap_4.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_val_compare_and_swap_4
-#define	TYPE		uint32_t
+#define	TYPE		int32_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
index c6f1101a72c0..6b7a17d5b3c3 100644
--- a/lib/libcompiler_rt/__sync_val_compare_and_swap_8.c
+++ b/lib/libcompiler_rt/__sync_val_compare_and_swap_8.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_val_compare_and_swap_8
-#define	TYPE		uint64_t
+#define	TYPE		int64_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
index cd4c9a3d1663..ee9d02578397 100644
--- a/lib/libcompiler_rt/__sync_val_compare_and_swap_n.h
+++ b/lib/libcompiler_rt/__sync_val_compare_and_swap_n.h
@@ -30,8 +30,13 @@ __FBSDID("$FreeBSD$");
 #include <sys/types.h>
 #include <machine/atomic.h>
 
+#if defined __clang__
+static TYPE
+atomic_func(volatile TYPE *ptr, TYPE oldval, TYPE newval, ...)
+#else
 TYPE
 NAME(volatile TYPE *ptr, TYPE oldval, TYPE newval)
+#endif
 {
 	TYPE t;
 
@@ -43,3 +48,7 @@ NAME(volatile TYPE *ptr, TYPE oldval, TYPE newval)
 
 	return (oldval);
 }
+
+#ifdef __clang__
+__strong_reference(atomic_func, NAME);
+#endif