程序执行时间的长短,是评价程序质量优劣的重要指标,尤其对于实时程序而言更是如此,因为往往只有知道程序执行时间的多少才能判断该程序是否满足实时控制的要求。怎样才能获得程序的执行时间呢?用逐条统计和计算指令执行时间的办法只适用于指令数目甚少而程序结构又很简单的汇编语言(或机器语言)程序,而对于指令 The length of program execution time is an important indicator to evaluate the quality of the program, especially for real-time programs, because often only know the program execution time to determine how the program meets the requirements of real-time control. How can we get the execution time of the program? The method of counting and calculating the execution time of an instruction by the clause only applies to the assembly language (or machine language) program which has a small number of instructions and a very simple program structure,