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Languages and Compilers for Writing Efficient High-Performance Computing Applications

19 Jul
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Tuesday, 07/19/2022 3:00pm to 5:00pm
PhD Thesis Defense
Speaker: Abhinav Jangda

Abstract: Many everyday applications, such as web search, speech recognition, and weather prediction, are executed on high-performance systems containing thousands of Central Processing Units (CPUs) and Graphics Processing Units (GPUs). These applications can be written in either low-level programming languages, such as NVIDIA CUDA, or domain specific languages, like Halide for image processing and PyTorch for machine learning programs.

Despite the popularity of these languages, there are several challenges that programmers face when developing efficient high-performance computing applications. First, since every hardware support a different low-level programming model, to utilize new hardware programmers need to rewrite their applications in another programming language. Second, writing efficient code involves restructuring the computation to ensure (i) regular memory access patterns, (ii) non-divergent control flow, and (iii) complete utilization of different programmer managed caches. Furthermore, since these low-level optimizations are known only to hardware experts, it is difficult for a domain expert to write optimized code for new computations. Third, existing domain specific languages suffer from optimization barriers in the language constructs that prevent new optimizations and hence, these languages provide sub- optimal performance.

To address these challenges this thesis presents the following novel abstractions and compiler techniques for writing image processing and machine learning applications that can run efficiently on a variety of high-performance systems. First, this thesis presents techniques to optimize image processing programs on GPUs using the features of modern GPUs. These techniques improve the concurrency and register usage of generated code to provide better performance than the state-of-the-art. Second, this thesis presents \nextdoor{}, which is the first system to provide an abstraction for writing graph sampling applications and efficiently executing these applications on GPUs. Third, this thesis presents \tool{}, which is a domain specific language to co-optimize communication and computation in distributed machine learning workloads. By breaking the optimization barriers in existing domain specific languages, these techniques help programmers write correct and efficient code for diverse high-performance computing workloads.


Advisor: Arjun Guha


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