--- a/src/os/unix/ngx_atomic.h
+++ b/src/os/unix/ngx_atomic.h
@@ -87,10 +87,17 @@ ngx_atomic_cmp_set(ngx_atomic_t *lock, n
 ngx_atomic_int_t
 ngx_atomic_fetch_add(ngx_atomic_t *value, ngx_atomic_int_t add);
 
+/*
+ * Sun Studio 12 exits with segmentation fault on '__asm ("pause")',
+ * so ngx_cpu_pause is declared in src/os/unix/ngx_sunpro_x86.il
+ */
+
+void
+ngx_cpu_pause(void);
+
 /* the code in src/os/unix/ngx_sunpro_x86.il */
 
 #define ngx_memory_barrier()        __asm (".volatile"); __asm (".nonvolatile")
-#define ngx_cpu_pause()             __asm ("pause")
 
 
 #else /* ( __GNUC__ || __INTEL_COMPILER ) */
@@ -121,10 +128,17 @@ ngx_atomic_cmp_set(ngx_atomic_t *lock, n
 ngx_atomic_int_t
 ngx_atomic_fetch_add(ngx_atomic_t *value, ngx_atomic_int_t add);
 
+/*
+ * Sun Studio 12 exits with segmentation fault on '__asm ("pause")',
+ * so ngx_cpu_pause is declared in src/os/unix/ngx_sunpro_amd64.il
+ */
+
+void
+ngx_cpu_pause(void);
+
 /* the code in src/os/unix/ngx_sunpro_amd64.il */
 
 #define ngx_memory_barrier()        __asm (".volatile"); __asm (".nonvolatile")
-#define ngx_cpu_pause()             __asm ("pause")
 
 
 #else /* ( __GNUC__ || __INTEL_COMPILER ) */