Operation Scheduling: Algorithms and Applications

Abstract

Operation scheduling (OS) is an important task in the high-level synthesis process. An inappropriate scheduling of the operations can fail to exploit the full potential of the system. In this chapter, we try to give a comprehensive coverage on the heuristic algorithms currently available for solving both timing and resource constrained scheduling problems. Besides providing a broad survey on this topic, we focus on some of the most popularly used algorithms, such as List Scheduling, Force-Directed Scheduling and Simulated Annealing, as well as the newly introduced approach based on the Ant Colony Optimization meta-heuristics. We discuss in details on their applicability and performance by comparing them on solution quality, performance stability, scalability, extensibility, and computation cost. Moreover, as an application of operation scheduling, we introduce a novel uniformed design space exploration method that exploits the duality of the time and resource constrained scheduling problems, which automatically constructs a high quality time/area tradeoff curve in a fast, effective manner.Keywords: Design space exploration, Ant colony optimization, Instruction scheduling, MAX-MIN ant system IntroductionAs fabrication technology advances and transistors become more plentiful, modern computing systems can achieve better system performance by increasing the amount of computation units. It is estimated that we will be able to integrate more than a half billion transistors on a 468 mm 2 chip by the year of 2009 [38]. This yields tremendous potential for future computing systems, however, it imposes big challenges on how to effectively use and design such complicated systems.As computing systems become more complex, so do the applications that can run on them. Designers will increasingly rely on automated design tools in order P. Coussy and A. Morawiec (eds.) High-Level Synthesis.

A Schedule Optimization of Ant Colony Optimization to Arrange Scheduling Process at Certainty Variables

“…We have tested 10 expereiment. Experiments conducted with a number of different cycles provide a significant time estimate [11]. More cycles give longer time.…”

Domain Specific High-Level Synthesis for Cryptographic Workloads

“…These scheduling problems are NP-hard [22], consequently several Iterative Heuristic Methods are employed to solve them. Some most popularly used algorithms are List Scheduling (LS), Force-Directed Scheduling (FDS) and Simulated Annealing [218]. Fig.…”

“…The pursuit to raise the abstraction level of design modeling, optimization and implementation has been the goal of several generations of CAD researchers, both from industry and academia. Some of the earliest research efforts were launched as early as 1970's while the industry was still adapting to the CAD systems; this era is termed as the generation 0 of HLS [218]. A pioneering HLS tool was developed at Carnegie Mellon university (called CMU Design automation or CMU-DA), which accepted the behavioral description as ISPL (Instruction Set Processor Language).…”

Automatically Optimizing the Latency, Area, and Accuracy of C Programs for High-Level Synthesis

“…5, when an expression in a loop is optimized, its latency is estimated by scheduling its operations by using an As-Late-As-Possible (ALAP) [15] scheduling algorithm, where each operation is scheduled to the latest opportunity, while respecting the order of data dependences. Because the expression is eventually used in a loop, and the II of the loop is critical to how fast the loop can execute, it is necessary to start optimizing for II as soon as possible.…”

“…For straight-line code, non-pipelined loops, and consecutive loops, we use a simple ALAP scheduling [15] to estimate resource utilization.…”