gcc 4.1不同的编译参数怎么会给出不同的结果？

2eye

在http://www.linuxsir.org/bbs/showthread.php?t=255844一个朋友这样解释：

If optimization level is >= 2 in gcc-4.1, strict-aliasing is used, and this could cause probelms when a pointer is referencing to a different type of object and the object is refered thereafter by using this pointer. That is the case in this example. So you should force the compiler to not use strict-aliasing by a argument "-fno-strict-aliasing" if you want to use "-O2" or "-O3".