[Bug middle-end/64012] GCC-4.9.2 option -fcaller-saves in -O2

[airbak.li at huawei dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64012

--- Comment #5 from Airbak <airbak.li at huawei dot com> ---
I'm sorry for my mistake. 
GCC-4.8.3 also have this phenomenon. GCC 4.4.1 is OK.