Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation最新文献_第4页

FlexVec: auto-vectorization for irregular loops FlexVec:不规则循环的自动矢量化

Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2016-06-02 DOI: 10.1145/2908080.2908111

Sara S. Baghsorkhi, N. Vasudevan, Youfeng Wu

{"title":"FlexVec: auto-vectorization for irregular loops","authors":"Sara S. Baghsorkhi, N. Vasudevan, Youfeng Wu","doi":"10.1145/2908080.2908111","DOIUrl":"https://doi.org/10.1145/2908080.2908111","url":null,"abstract":"Traditional vectorization techniques build a dependence graph with distance and direction information to determine whether a loop is vectorizable. Since vectorization reorders the execution of instructions across iterations, in general instructions involved in a strongly connected component (SCC) are deemed not vectorizable unless the SCC can be eliminated using techniques such as scalar expansion or privatization. Therefore, traditional vectorization techniques are limited in their ability to efficiently handle loops with dynamic cross-iteration dependencies or complex control flow interweaved within the dependence cycles. When potential dependencies do not occur very often, the end-result is under utilization of the SIMD hardware. In this paper, we propose FlexVec architecture that combines new vector instructions with novel code generation techniques to dynamically adjusts vector length for loop statements affected by cross-iteration dependencies that happen at runtime. We have designed and implemented FlexVec's new ISA as extensions to the recently released AVX-512 ISA. We have evaluated the performance improvements enabled by FlexVec vectorization for 11 C/C++ SPEC 2006 benchmarks and 7 real applications with AVX-512 vectorization as baseline. We show that FlexVec vectorization technique produces a Geomean speedup of 9% for SPEC 2006 and a Geomean speedup of 11% for 7 real applications.","PeriodicalId":178839,"journal":{"name":"Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127487618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 25

Input responsiveness: using canary inputs to dynamically steer approximation 输入响应性:使用金丝雀输入动态引导逼近

Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2016-06-02 DOI: 10.1145/2908080.2908087

M. Laurenzano, Parker Hill, M. Samadi, S. Mahlke, Jason Mars, Lingjia Tang

{"title":"Input responsiveness: using canary inputs to dynamically steer approximation","authors":"M. Laurenzano, Parker Hill, M. Samadi, S. Mahlke, Jason Mars, Lingjia Tang","doi":"10.1145/2908080.2908087","DOIUrl":"https://doi.org/10.1145/2908080.2908087","url":null,"abstract":"This paper introduces Input Responsive Approximation (IRA), an approach that uses a canary input — a small program input carefully constructed to capture the intrinsic properties of the original input — to automatically control how program approximation is applied on an input-by-input basis. Motivating this approach is the observation that many of the prior techniques focusing on choosing how to approximate arrive at conservative decisions by discounting substantial differences between inputs when applying approximation. The main challenges in overcoming this limitation lie in making the choice of how to approximate both effectively (e.g., the fastest approximation that meets a particular accuracy target) and rapidly for every input. With IRA, each time the approximate program is run, a canary input is constructed and used dynamically to quickly test a spectrum of approximation alternatives. Based on these runtime tests, the approximation that best fits the desired accuracy constraints is selected and applied to the full input to produce an approximate result. We use IRA to select and parameterize mixes of four approximation techniques from the literature for a range of 13 image processing, machine learning, and data mining applications. Our results demonstrate that IRA significantly outperforms prior approaches, delivering an average of 10.2× speedup over exact execution while minimizing accuracy losses in program outputs.","PeriodicalId":178839,"journal":{"name":"Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117025348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 67

Automatically learning shape specifications 自动学习形状规格

Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2016-06-02 DOI: 10.1145/2908080.2908125

He Zhu, G. Petri, S. Jagannathan

引用次数: 27

Transactional data structure libraries 事务性数据结构库

Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2016-06-02 DOI: 10.1145/2908080.2908112

A. Spiegelman, Guy Golan-Gueta, I. Keidar

引用次数: 51

Configuration synthesis for programmable analog devices with Arco 配置合成的可编程模拟设备与Arco

Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2016-06-01 DOI: 10.1145/2908080.2908116

Sara Achour, R. Sarpeshkar, M. Rinard

引用次数: 18

Types from data: making structured data first-class citizens in F# 数据类型:使结构化数据成为f#中的一等公民

Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2016-05-10 DOI: 10.1145/2908080.2908115

T. Petříček, Gustavo Guerra, Don Syme

引用次数: 26

Into the depths of C: elaborating the de facto standards 进入C的深处:详细说明事实上的标准

Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2016-04-27 DOI: 10.1145/2908080.2908081

Kayvan Memarian, Justus Matthiesen, J. Lingard, Kyndylan Nienhuis, D. Chisnall, R. Watson, Peter Sewell

{"title":"Into the depths of C: elaborating the de facto standards","authors":"Kayvan Memarian, Justus Matthiesen, J. Lingard, Kyndylan Nienhuis, D. Chisnall, R. Watson, Peter Sewell","doi":"10.1145/2908080.2908081","DOIUrl":"https://doi.org/10.1145/2908080.2908081","url":null,"abstract":"C remains central to our computing infrastructure. It is notionally defined by ISO standards, but in reality the properties of C assumed by systems code and those implemented by compilers have diverged, both from the ISO standards and from each other, and none of these are clearly understood. We make two contributions to help improve this error-prone situation. First, we describe an in-depth analysis of the design space for the semantics of pointers and memory in C as it is used in practice. We articulate many specific questions, build a suite of semantic test cases, gather experimental data from multiple implementations, and survey what C experts believe about the de facto standards. We identify questions where there is a consensus (either following ISO or differing) and where there are conflicts. We apply all this to an experimental C implemented above capability hardware. Second, we describe a formal model, Cerberus, for large parts of C. Cerberus is parameterised on its memory model; it is linkable either with a candidate de facto memory object model, under construction, or with an operational C11 concurrency model; it is defined by elaboration to a much simpler Core language for accessibility, and it is executable as a test oracle on small examples. This should provide a solid basis for discussion of what mainstream C is now: what programmers and analysis tools can assume and what compilers aim to implement. Ultimately we hope it will be a step towards clear, consistent, and accepted semantics for the various use-cases of C.","PeriodicalId":178839,"journal":{"name":"Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124654020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 92

On the complexity and performance of parsing with derivatives 关于导数解析的复杂性和性能

Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2016-04-16 DOI: 10.1145/2908080.2908128

Michael D. Adams, Celeste Hollenbeck, M. Might

{"title":"On the complexity and performance of parsing with derivatives","authors":"Michael D. Adams, Celeste Hollenbeck, M. Might","doi":"10.1145/2908080.2908128","DOIUrl":"https://doi.org/10.1145/2908080.2908128","url":null,"abstract":"Current algorithms for context-free parsing inflict a trade-off between ease of understanding, ease of implementation, theoretical complexity, and practical performance. No algorithm achieves all of these properties simultaneously. Might et al. introduced parsing with derivatives, which handles arbitrary context-free grammars while being both easy to understand and simple to implement. Despite much initial enthusiasm and a multitude of independent implementations, its worst-case complexity has never been proven to be better than exponential. In fact, high-level arguments claiming it is fundamentally exponential have been advanced and even accepted as part of the folklore. Performance ended up being sluggish in practice, and this sluggishness was taken as informal evidence of exponentiality. In this paper, we reexamine the performance of parsing with derivatives. We have discovered that it is not exponential but, in fact, cubic. Moreover, simple (though perhaps not obvious) modifications to the implementation by Might et al. lead to an implementation that is not only easy to understand but also highly performant in practice.","PeriodicalId":178839,"journal":{"name":"Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123151031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 24

Just-in-time static type checking for dynamic languages 动态语言的即时静态类型检查

Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2016-04-13 DOI: 10.1145/2908080.2908127

Brianna M. Ren, J. Foster

{"title":"Just-in-time static type checking for dynamic languages","authors":"Brianna M. Ren, J. Foster","doi":"10.1145/2908080.2908127","DOIUrl":"https://doi.org/10.1145/2908080.2908127","url":null,"abstract":"Dynamic languages such as Ruby, Python, and JavaScript have many compelling benefits, but the lack of static types means subtle errors can remain latent in code for a long time. While many researchers have developed various systems to bring some of the benefits of static types to dynamic languages, prior approaches have trouble dealing with metaprogramming, which generates code as the program executes. In this paper, we propose Hummingbird, a new system that uses a novel technique, just-in-time static type checking, to type check Ruby code even in the presence of metaprogramming. In Hummingbird, method type signatures are gathered dynamically at run-time, as those methods are created. When a method is called, Hummingbird statically type checks the method body against current type signatures. Thus, Hummingbird provides thorough static checks on a per-method basis, while also allowing arbitrarily complex metaprogramming. For performance, Hummingbird memoizes the static type checking pass, invalidating cached checks only if necessary. We formalize Hummingbird using a core, Ruby-like language and prove it sound. To evaluate Hummingbird, we applied it to six apps, including three that use Ruby on Rails, a powerful framework that relies heavily on metaprogramming. We found that all apps typecheck successfully using Hummingbird, and that Hummingbird's performance overhead is reasonable. We applied Hummingbird to earlier versions of one Rails app and found several type errors that had been introduced and then fixed. Lastly, we demonstrate using Hummingbird in Rails development mode to typecheck an app as live updates are applied to it.","PeriodicalId":178839,"journal":{"name":"Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation","volume":"279 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127552958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 21

Refinement types for TypeScript TypeScript的细化类型

Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2016-04-08 DOI: 10.1145/2908080.2908110

Panagiotis Vekris, B. Cosman, Ranjit Jhala

引用次数: 47