http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50432
--- Comment #2 from xunxun <xunxun1982 at gmail dot com> 2011-09-19 00:46:03 UTC --- It's strange that after I update to gcc4.6.2.20110916, the issue is gone. I review my earlier build process, and I found that the issue only came out if you built your gcc with "-flto".