通过查看centos的更新包，发现已经支持 gcc 32位版本了。

http://mirrors.hustunique.com/centos/7.0.1406/updates/x86_64/Packages/

对应的文件是:

libstdc++-4.8.2-16.2.el7_0.i686.rpm                18-Aug-2014 21:35    301K

libgcc-4.8.2-16.2.el7_0.i686.rpm                   18-Aug-2014 21:34     94K

使用命令查看这两个包，发现有我们需要的文件了。

# rpm -qpl libgcc-4.8.2-16.2.el7_0.i686.rpm    

warning: libgcc-4.8.2-16.2.el7_0.i686.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY

/lib/libgcc_s-4.8.2-20140120.so.1

/lib/libgcc_s.so.1

/usr/share/doc/libgcc-4.8.2

/usr/share/doc/libgcc-4.8.2/COPYING

/usr/share/doc/libgcc-4.8.2/COPYING.LIB

/usr/share/doc/libgcc-4.8.2/COPYING.RUNTIME

/usr/share/doc/libgcc-4.8.2/COPYING3

/usr/share/doc/libgcc-4.8.2/COPYING3.LIB

# rpm -qpl libstdc++-4.8.2-16.2.el7_0.i686.rpm 

warning: libstdc++-4.8.2-16.2.el7_0.i686.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY

/usr/lib/libstdc++.so.6

/usr/lib/libstdc++.so.6.0.19

/usr/share/gcc-4.8.2

/usr/share/gcc-4.8.2/python

/usr/share/gcc-4.8.2/python/libstdcxx

/usr/share/gcc-4.8.2/python/libstdcxx/__init__.py

/usr/share/gcc-4.8.2/python/libstdcxx/__init__.pyc

/usr/share/gcc-4.8.2/python/libstdcxx/__init__.pyo

/usr/share/gcc-4.8.2/python/libstdcxx/v6

/usr/share/gcc-4.8.2/python/libstdcxx/v6/__init__.py

/usr/share/gcc-4.8.2/python/libstdcxx/v6/__init__.pyc

/usr/share/gcc-4.8.2/python/libstdcxx/v6/__init__.pyo

/usr/share/gcc-4.8.2/python/libstdcxx/v6/printers.py

/usr/share/gcc-4.8.2/python/libstdcxx/v6/printers.pyc

/usr/share/gcc-4.8.2/python/libstdcxx/v6/printers.pyo

/usr/share/gdb

/usr/share/gdb/auto-load

/usr/share/gdb/auto-load/usr

/usr/share/gdb/auto-load/usr/lib

/usr/share/gdb/auto-load/usr/lib/libstdc++.so.6.0.19-gdb.py

/usr/share/gdb/auto-load/usr/lib/libstdc++.so.6.0.19-gdb.pyc

/usr/share/gdb/auto-load/usr/lib/libstdc++.so.6.0.19-gdb.pyo

centos 7 已经支持 gcc 编译32位程序