OK. I found the reason.
I compiled mysql with gcc-3.0.3, so some files use libgcc-3.0.3.
When I installed apache with PHP, I got this error.
I had to replace gcc-3.0.3 with gcc-2.95.3.
I can't start mysql because gcc-3.0.3 had removed.
I installed libgcc-3.0.3 because it included libgcc_s.so.1.
I compiled apache and php with gcc-2.95.3,
but I got the error again!
Finally, I removed libgcc 3.0.3 and reinstall mysql, apache and php.
What's wrong with libgcc_s.so.1 in libgcc-3.0.3?!