A formal model of software pipelining loops with conditions

Abstract

This paper addresses the problem of parallelizing loops with conditional branches in the context of software pipelining. A new formal approach to this problem is proposed in the form of Predicated Software Pipelining (PSP) model. The PSP model represents execution of a loop with conditional branches as transitions of a finite state machine. Each node of the state machine is composed of operations of one parallelized loop iteration. The rules for operation movements between nodes in the PSP model are described. The model represents a new theoretical framework for further investigation of inherent properties of these loops.