C代码优化

说明：   该方案主要是考虑到在嵌入式开发中对程序执行速度的要求特别高，所以该方案主要是为了优化程序的执行速度。 注意：优化是有侧重点的，优化是一门平衡的艺术，它往往要以牺牲程序的可读性或者增加代码长度为代价。
(The program is mainly on account of the embedded development process to speed implementation of the requirements is particularly high, the program is mainly aimed at improving the procedures of implementation. Note : optimization is focused, optimization is an art of balance, it is often necessary to sacrifice procedures, or increase the readability of the code length price.)