Paper Info
Title
Using speculative functional units in high level synthesis
Abstract
Speculative Functional Units (SFUs) enable a new execution paradigm for High Level Synthesis (HLS). SFUs are arithmetic functional units that operate using a predictor for the carry signal, which reduces the critical path delay. The performance of these units is determined by the success in the prediction of the carry value, i.e. the hit rate of the prediction. Hence SFUs reduce critical path at a low cost, but they cannot be used in HLS with the current techniques. In order to use them, it is necessary to include hardware support to recover from mispredictions of the carry signals. In this paper, we present techniques for designing a datapath controller for seamless deployment of SFUs in HLS. We have developed two techniques for this goal. The first approach stops the execution of the entire datapath for each misprediction and resumes execution once the correct value of the carry is known. The second approach decouples the functional unit suffering from the misprediction from the rest of the datapath. Hence, it allows the rest of the SFUs to carry on execution and be at different scheduling states at different times. Experiments show that it is possible to reduce execution time by as much as 38% and by 33% on average.
Year
DOI
Venue
2010
10.1109/DATE.2010.5457102
DATE
Keywords
Field
DocType
registers,parallel programming,hardware,adders,correlation,circuits,functional unit,dynamic scheduling,speculation,arithmetic function,critical path,high level synthesis,design optimization,arithmetic
Hit rate,Control theory,Datapath,Adder,Computer science,Scheduling (computing),Parallel computing,High-level synthesis,Real-time computing,Critical path method,Dynamic priority scheduling,Embedded system
Conference
ISSN
Citations 
PageRank 
1530-1591
5
0.47
References 
Authors
11
5
Name
Order
Citations
PageRank
Alberto A. Del Barrio17814.49
María C. Molina2101.25
José M. Mendías327319.60
Roman Hermida41048.19
Seda Öǧrenci Memik548842.57