Diversity can be created in a number of ways, such as by adding nonfunctional code, reordering code or randomizing memory locations, file names or system calls. 多样性可有多种方法生成,如加入不起作用的代码、重新排序的代码或者存储位置、文件名或系统调用的随机化等。
Second, we studied and compared three main methods of code reordering, including procedure reordering, basic block reordering and procedure splitting. 从过程重排和基本块重排以及过程分裂三个方面对当前的重排算法进行了剖析,比较了各种算法的特点。
Code reordering is an important technology which can increase I-Cache hit rate and improve program's performance. 代码重排技术是提高指令Cache命中率、提升程序性能的一种重要优化方法。
Third, we analyzed in detail the implement method of code reordering in GCC and pointed out its deficiencies. 分析了GCC中代码重排的实现方法,指出了其存在的不足。