diff -r 1fb6cf5a4c4d -r ab487d32ce9a targets/plc_debug.c
--- a/targets/plc_debug.c	Mon Mar 04 12:22:49 2013 +0900
+++ b/targets/plc_debug.c	Mon Mar 04 17:49:12 2013 +0900
@@ -184,6 +184,7 @@
 
 extern int TryEnterDebugSection(void);
 extern long AtomicCompareExchange(long*, long, long);
+extern long long AtomicCompareExchange64(long long* , long long , long long);
 extern void LeaveDebugSection(void);
 extern void ValidateRetainBuffer(void);
 extern void InValidateRetainBuffer(void);
@@ -376,7 +377,10 @@
             tail.msgidx = (old_cursor >> 32); 
             new_cursor = ((uint64_t)(tail.msgidx + 1)<<32) 
                          | (uint64_t)((buffpos + size + sizeof(mTail)) & LOG_BUFFER_MASK);
-        }while(!__sync_bool_compare_and_swap(&LogCursor[level],old_cursor,new_cursor));
+        }while(AtomicCompareExchange64(
+            (long long*)&LogCursor[level],
+            (long long)old_cursor,
+            (long long)new_cursor)!=old_cursor);
 
         copy_to_log(level, buffpos, buf, size);
         copy_to_log(level, (buffpos + size) & LOG_BUFFER_MASK, &tail, sizeof(mTail));