The 85th AICS Cafe (Progress Report*)
Date and Time: Thu. Feb. 25, 2016, 15:00-16:00
Place: Workshop room (6th floor) at AICS
(This session will be held on Thursday!)
Title: Automated GPU Kernel Transformations in Large-Scale Production Stencil Applications
Speaker: ATTIA Mohamed Wahib Mohamed (HPC Programming Framework Research Team)
Presentation Language: English
Presentation Material: English
* This AICS Cafe is a special AICS Cafe, which is an occasion for postdoctoral researchers in their 4th year to report their research activities after joining AICS. Attendance of broad audience including PI, is kindly appreciated.
This talk presents a scalable method for exposing and exploiting hidden localities in production stencil applications. An end-to-end framework automatically transforms stencil-based GPU programs to exploit inter-kernel data locality. The CUDA-to-CUDA transformation collectively replaces the user-written kernels by auto-generated kernels optimized for data reuse. The transformation is based on two basic operations, kernel fusion and fission, and relies on a series of automated steps: gathering metadata, generating graphs expressing dependencies and precedency constraints, searching for optimal kernel fissions/fusions, and generation of optimized code. We show how the automatic transformations were practical and effective in exploiting exposed data localities for a variety of real-world applications with large codebases that contain dozens of kernels and data arrays.