基于VLIW体系结构的流相关分析*

流相关是影响VLIW(very long instruction word)结构上的循环调度的一个关键因素.目前的研究未利用VLIW的锁步特性.利用这一性质，围绕着包含这一概念，该文为VLIW结构上的流相关分析提出了一个完整的娄学模型，发现体间流相关集合可划分为若干不相交的线序集合,存在且仅存在一个独立的、全包含的流相关集合(基),使其他所有流相关都不必要.该模型允许多周期操作和条件分支.该结果可作为研究VLIW的数学基础,也可用于工程实践.

Flow Dependence Analysis for VLIW Architectures

Flow dependence is a key factor influencing loop scheduling on VLIW (very long instruction word) architectures. Current research has not exploited the lockstep property of VLIWs. By making using of this property and centering on the concept of inclusion, a complete mathematical model for flow dependence analysis on VLIW architectures is presented in this paper. It is found that loop-carried flow dependencies form a set of disjoint linear ordered sets, and that there is one and only one basis that is independent and inclusive, making unnecessary all the other dependencies. The model allows multi-cycled operations and conditional branches. It lays a mathematical foundation for research on VLIWs, and is applicable to engineering practice.