1. Welcome to the 1st Championship Value Prediction (CVP) Workshop
Mikko Lipasti, Program Chair
Los Angeles, CA
June 3rd, 2018

2. Value Prediction What is value prediction?B C
ILP = 1.3 D A B C
Predict D
Verify
ILP = 4
What is value prediction?
Generate a speculative value (predict)
Consume speculative value (execute)
Verify speculative value (compare/recover)
Goal: performance, i.e. expose more ILP
3rd point is key in my mind: must verify value, not some attribute of the value.
Branch outcome is not an operand, it is an attribute of the branch instruction!
CVP-1

3. Some History “Classical” value prediction
Independently invented by 4 groups in
AMD (Nexgen): L. Widigen and E. Sowadsky, patent filed March 1996, inv. March 1995
Technion: F. Gabbay and A. Mendelson, inv. sometime 1995, TR 11/96, US patent Sep 1997
CMU: M. Lipasti, C. Wilkerson, J. Shen, inv. Oct. 1995, ASPLOS paper submitted March 1996, MICRO June 1996
Wisconsin: Y. Sazeides, J. Smith, Summer 1996
NOTE: ASPLOS paper submitted as 9 paper copies using FedEx!
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4. CVP-1 Objectives Objectives
Stimulate interest in value prediction specifically, and microarchitectural optimizations more generally
Advance the state of the art in prediction and confidence estimation
Relied heavily on past experience with JWAC
Consistency: agreed on metrics, methodology
Low barrier to entry: developed and released toolkit and traces
Competitive: evaluated with both public and hidden traces
Diverse: defined multiple contest categories:
8KB, 32KB, unlimited
“The Journal of Instruction-Level Parallelism” JILP Workshop on Computer Architecture Competitions (JWAC-1)
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5. Thanks and acknowledgments
Steering committee
Alaa R. Alameldeen (Intel)
Chris Wilkerson (Nvidia)
Organizing committee
Arthur Perais (Qualcomm) (co-chair)
Rami Sheikh (Qualcomm) (co- chair)
Eric Rotenberg (NCSU)
Vinesh Srinivasan (NCSU)
Program committee
Joshua San Miguel (Wisconsin- Madison)
Lixin Su (ARM)
Eric Rotenberg (NCSU)
Rangeen Basu Roy Chowdhury (Intel)
Huiyang Zhou (NCSU)
Alaa Alameldeen (Intel)
Freddy Gabbay (Mellanox Technologies)
Yiannakis Sazeides (University of Cyprus)
Vinesh Srinivasan (NCSU)
Chris Wilkerson (Nvidia)
Manjunath Shevgoor (Intel)
Rami Sheikh (Qualcomm)
Arthur Perais (Qualcomm)
Bob Rychlik (Qualcomm)
Jeff Rupley (Samsung)
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6. Toolkit and traces Special thanks to NCSU and Qualcomm team THANK YOU!
Toolkit implements abstract performance model, aka. limit study of performance potential
Debated reporting accuracy/coverage vs. performance
Performance not necessarily correlated with hit rates
Debated realistic machine model vs. limit study
Converged on limit study to maximize interest, excitement
Substantial number of traces
Plenty of interest, downloads, users
THANK YOU!
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7. Review Process Large PC, hence light workload
Disappointing number of submissions (6) given initial level of interest, number of toolkit downloads, etc.
All papers reviewed by at least 4 (nearly all 5) PC members
Conflicts managed manually
Single-blind review
Reviews were discussed online (no PC meeting)
Consensus on which papers to accept emerged quickly
Authors were allowed to fine-tune results until final version deadline
For disappointing number of submissions, we can say that :
1 – We had some trouble with an external dependency (boost)
2 – The example predictor actually yielded a slowdown, and this was not fixed.
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8. Program 8:30-8:40 Introduction and Welcome 8:40-8:50
CVP1 Infrastructure & Traces  Arthur Perais (Qualcomm)
8:50-9:15
Exploring Value Prediction with the EVES predictor André Seznec (INRIA/IRISA, France) 
9:15-9:40
H3VP: History-based High-reliable Hybrid Value Predictor Kenichi Koizumi, Kei Hiraki and Mary Inaba (The University of Tokyo, Japan) 
9:40-10:05
Context-Base Computational Value Predictor with Value Compression Yasuo Ishii (ARM) 
10:05-10:30
Break
10:30-10:55
DFCM++: Augmenting DFCM with Early Update and Data Dependency-driven Value Estimation  Nayan Deshmukh, Snehil Verma, Prakhar Agrawal, Biswabandan Panda, Mainak Chaudhuri (Indian Institute of Technology Kanpur)
10:55-11:50
Panel Discussion: "Speculation: Past, Present and Future" Gurindar S. Sohi (Wisconsin-Madison), Avi Mendelson (Technion)  Chris Wilkerson (Nvidia), Andreas Moshovos (Toronto), Daniel Jiménez (Texas A&M) Moderator: Rami Sheikh (Qualcomm)
11:50-12:00
Announcement of results and awards Arthur Perais and Rami Sheikh (Qualcomm)
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