rollback free value prediction with approximate loads n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Rollback-Free Value Prediction with Approximate Loads PowerPoint Presentation
Download Presentation
Rollback-Free Value Prediction with Approximate Loads

Loading in 2 Seconds...

play fullscreen
1 / 7
peter-mendez

Rollback-Free Value Prediction with Approximate Loads - PowerPoint PPT Presentation

107 Views
Download Presentation
Rollback-Free Value Prediction with Approximate Loads
An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Rollback-Free Value Predictionwith Approximate Loads Georgia Institute of Technology Carnegie Mellon University

  2. Mitigating Memory Wall with Approximation Rollback-Free Value Prediction • Microarchitecturally-triggered approximation • Predict the value of an approximate load when it misses in the cache • Do not checkfor mispredictions • Do not rollbackfrom mispredictions • Mitigate long latency memory accesses

  3. Rollback Free Value Prediction

  4. Design Principles Maximizeopportunities for performance and energy benefits Minimize the adverse effects of approximation on quality degradation

  5. Design Challenges and Solutions Target Performance-Critical Safe Loads • Profile-directed compilation • Usually, < 32 loads cause 80% of cache misses Utilize Fast-Learning Predictors • Two-delta stride predictor • Prediction: table lookup plus an addition Integrate RFVP with existing architecture

  6. Experimental Results with a Modern OoO Processor 1.8% 19% 0.8% 8% Average Average Maximum Maximum More CPU configurations and value predictors are in the paper

  7. Ongoing Work Mitigate both Memory Wall and Bandwidth Wall • Extend rollback-free value prediction to GPUs • Drop a fraction of the missed requests • Preliminary results: Up to 2x improvement in energy and performance with only 10% quality degradation