[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 #4 from Airbak <airbak.li at huawei dot com> ---
When I build toolchain with GNU <gcc-4.9.2.tar.bz2>, the problem also exist.

------------------
lijianhui@key:~/hi3535/Hi3535_SDK_V2.0.3.1/osdrv/kernel/linux-3.4.y$
arm-unknown-linux-gnueabi-gcc -v
Using built-in specs.
COLLECT_GCC=arm-unknown-linux-gnueabi-gcc
COLLECT_LTO_WRAPPER=/home/os/lijianhui/linaro/new-crosstool-ng/install-org-gcc/bin/../libexec/gcc/arm-unknown-linux-gnueabi/4.9.2/lto-wrapper
Target: arm-unknown-linux-gnueabi
Configured with: 
/home/os/lijianhui/linaro/new-crosstool-ng/.build/src/gcc-4.9.2/configure 
--build=x86_64-build_unknown-linux-gnu 
--host=x86_64-build_unknown-linux-gnu --target=arm-unknown-linux-gnueabi 
--prefix=/home/os/lijianhui/linaro/new-crosstool-ng/install 
...


Any suggestions?