WORST-CASE EXECUTION TIME ANALYSIS ON MODERN PROCESSORS

Many of the trends that have dominated recent evolution and advancemen t within the computer architecture community have complicated the anal ysis of task execution times. Most of the difficulties result from two particular emphases: (1) Instruction-level parallelism, mid (2) Optim ization of average-case behavior rather than worst-case latencies. Bot h of these trends have resulted in increased nondeterminism in the tim e required to execute particular code sequences. And since the analysi s required to determine worst-case task execution times on modern proc essors is so complicated, it is not practical for programmers to perfo rm all of the necessary analyses by hand. Tools must aid them. This pa per describes ongoing research on a collection of tools intended to au tomate the analyses that must be performed in order to build reliable real-rime software for modern computing environments. Emphasis is give n to the interplay between components of the development environment.