http://bugs.winehq.org/show_bug.cgi?id=22316
--- Comment #9 from Dan Kegel dank@kegel.com 2010-11-07 08:05:45 CST --- Does the option -mstackrealign help? From that bug report, and from Artem's response on bug 22387, I gather that might be the thing to do when using aggressive optimizations on gcc-4.5.x.