中文摘要：

符号化WCET（worst-case execution time）分析是用符号表达式表示任务的最大执行时间：表达式中包含了参数．通过在运行时刻快速确定表达式值，符号化WCET分析可以更精确地估算WCET．提出了一种针对其分支直接依赖于输入数据的程序的符号化WCET分析方法．首先对Blieberger方法进行扩充，使得WCET符号表达式能够表达依赖输入分支，然后利用程序的控制依赖图对符号表达式进行化简，从而产生带条件的WCET符号表达式，即不同的条件对应不同的符号表达式与已有方法不同，符号化WCET公式直接依赖于输入参数，使得运行时的WCET估算更加简单直接．

英文摘要：

Symbolic WCET （worst-case execution time） analysis yields symbolic upper bound expressions for tasks that contain parameters. Quickly evaluated at run-time, such expressions can improve the accuracy of WCET estimate. This paper proposes a symbolic WCET analysis method that is especially for the input-data dependent branches. First, the formulas described by Blieberger is expanded, so that they can express the input-data dependent branches. Simplification of the formulas using control -dependent graph y ields conditional symbolic expressions that have different forms corresponding to different input value range s. Different from the existing methods, the symbolic formulas are directly dependent on input-data, so WCET estimate evaluation at run-time is more simple and straightforward.