Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation最新文献_第5页

Securing smart contract with runtime validation 通过运行时验证保护智能合约

Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2020-06-06 DOI: 10.1145/3385412.3385982

Ao Li, Jemin Andrew Choi, Fan Long

引用次数: 43

Towards an API for the real numbers 面向实数的API

Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2020-06-06 DOI: 10.1145/3385412.3386037

H. Boehm

{"title":"Towards an API for the real numbers","authors":"H. Boehm","doi":"10.1145/3385412.3386037","DOIUrl":"https://doi.org/10.1145/3385412.3386037","url":null,"abstract":"The real numbers are pervasive, both in daily life, and in mathematics. Students spend much time studying their properties. Yet computers and programming languages generally provide only an approximation geared towards performance, at the expense of many of the nice properties we were taught in high school. Although this is entirely appropriate for many applications, particularly those that are sensitive to arithmetic performance in the usual sense, we argue that there are others where it is a poor choice. If arithmetic computations and result are directly exposed to human users who are not floating point experts, floating point approximations tend to be viewed as bugs. For applications such as calculators, spreadsheets, and various verification tasks, the cost of precision sacrifices is high, and the performance benefit is often not critical. We argue that previous attempts to provide accurate and understandable results for such applications using the recursive reals were great steps in the right direction, but they do not suffice. Comparing recursive reals diverges if they are equal. In many cases, comparison of numbers, including equal ones, is both important, particularly in simple cases, and intractable in the general case. We propose an API for a real number type that explicitly provides decidable equality in the easy common cases, in which it is often unnatural not to. We describe a surprisingly compact and simple implementation in detail. The approach relies heavily on classical number theory results. We demonstrate the utility of such a facility in two applications: testing floating point functions, and to implement arithmetic in Google's Android calculator application.","PeriodicalId":20580,"journal":{"name":"Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79261607","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: 11

λPSI: exact inference for higher-order probabilistic programs λPSI:高阶概率程序的精确推理

Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2020-06-06 DOI: 10.1145/3385412.3386006

Timon Gehr, Samuel Steffen, Martin T. Vechev

引用次数: 24

Semantic code search via equational reasoning 通过等式推理进行语义代码搜索

Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2020-06-06 DOI: 10.1145/3385412.3386001

Varot Premtoon, James Koppel, Armando Solar-Lezama

引用次数: 39

CARAT: a case for virtual memory through compiler- and runtime-based address translation CARAT:通过基于编译器和运行时的地址转换实现虚拟内存的一种情况

Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2020-06-06 DOI: 10.1145/3385412.3385987

Brian Suchy, Simone Campanoni, Nikos Hardavellas, P. Dinda

{"title":"CARAT: a case for virtual memory through compiler- and runtime-based address translation","authors":"Brian Suchy, Simone Campanoni, Nikos Hardavellas, P. Dinda","doi":"10.1145/3385412.3385987","DOIUrl":"https://doi.org/10.1145/3385412.3385987","url":null,"abstract":"Virtual memory is a critical abstraction in modern computer systems. Its common model, paging, is currently seeing considerable innovation, yet its implementations continue to be co-designs between power-hungry/latency-adding hardware (e.g., TLBs, pagewalk caches, pagewalkers, etc) and software (the OS kernel). We make a case for a new model for virtual memory, compiler- and runtime-based address translation (CARAT), which instead is a co-design between the compiler and the OS kernel. CARAT can operate without any hardware support, although it could also be retrofitted into a traditional paging model, and could leverage simpler hardware support. CARAT uses compile-time transformations and optimizations combined with tightly-coupled runtime/kernel interaction to generate programs that run efficiently in a physical address space, but nonetheless allow the kernel to maintain protection and dynamically manage physical memory similar to what is possible using traditional virtual memory. We argue for the feasibility of CARAT through an empirical study of application characteristics and kernel behavior, as well as through the design, implementation, and performance evaluation of a CARAT prototype. Because our prototype works at the IR level (in particular, via LLVM bitcode), it can be applied to most C and C++ programs with minimal or no restrictions.","PeriodicalId":20580,"journal":{"name":"Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81005032","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: 11

A marriage of pointer- and epoch-based reclamation 这是指针式和时代性改造的结合

Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2020-06-06 DOI: 10.1145/3385412.3385978

Jeehoon Kang, Jaehwang Jung

{"title":"A marriage of pointer- and epoch-based reclamation","authors":"Jeehoon Kang, Jaehwang Jung","doi":"10.1145/3385412.3385978","DOIUrl":"https://doi.org/10.1145/3385412.3385978","url":null,"abstract":"All pointer-based nonblocking concurrent data structures should deal with the problem of safe memory reclamation: before reclaiming a memory block, a thread should ensure no other threads hold a local pointer to the block that may later be dereferenced. Various safe memory reclamation schemes have been proposed in the literature, but none of them satisfy the following desired properties at the same time: (i) robust: a non-cooperative thread does not prevent the other threads from reclaiming an unbounded number of blocks; (ii) fast: it does not incur significant time overhead; (iii) compact: it does not incur significant space overhead; (iv) self-contained: it neither relies on special hardware/OS supports nor intrusively affects execution environments; and (v) widely applicable: it supports many data structures. We introduce PEBR, which we believe is the first scheme that satisfies all the properties above. PEBR is inspired by Snowflake’s hybrid design of pointer- and epoch-based reclamation schemes (PBR and EBR, resp.) that is mostly robust, fast, and compact but neither self-contained nor widely applicable. To achieve self-containedness, we design algorithms using only the standard C/C++ concurrency features and process-wide memory fence. To achieve wide applicability, we characterize PEBR’s requirement for safe reclamation that is satisfied by a variety of data structures, including Harris’s and Harris-Herlihy-Shavit’s lists that are not supported by PBR. We experimentally evaluate whether PEBR is fast and robust using microbenchmarks, for which PEBR performs comparably to the state-of-the-art schemes.","PeriodicalId":20580,"journal":{"name":"Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75229442","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: 12

NV: an intermediate language for verification of network control planes 用于验证网络控制平面的中间语言

Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2020-06-06 DOI: 10.1145/3385412.3386019

Nick Giannarakis, Devon Loehr, Ryan Beckett, D. Walker

引用次数: 19

Effective function merging in the SSA form SSA形式的有效函数合并

Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2020-06-06 DOI: 10.1145/3385412.3386030

Rodrigo C. O. Rocha, Pavlos Petoumenos, Zheng Wang, M. Cole, Hugh Leather

{"title":"Effective function merging in the SSA form","authors":"Rodrigo C. O. Rocha, Pavlos Petoumenos, Zheng Wang, M. Cole, Hugh Leather","doi":"10.1145/3385412.3386030","DOIUrl":"https://doi.org/10.1145/3385412.3386030","url":null,"abstract":"Function merging is an important optimization for reducing code size. This technique eliminates redundant code across functions by merging them into a single function. While initially limited to identical or trivially similar functions, the most recent approach can identify all merging opportunities in arbitrary pairs of functions. However, this approach has a serious limitation which prevents it from reaching its full potential. Because it cannot handle phi-nodes, the state-of-the-art applies register demotion to eliminate them before applying its core algorithm. While a superficially minor workaround, this has a three-fold negative effect: by artificially lengthening the instruction sequences to be aligned, it hinders the identification of mergeable instruction; it prevents a vast number of functions from being profitably merged; it increases compilation overheads, both in terms of compile-time and memory usage. We present SalSSA, a novel approach that fully supports the SSA form, removing any need for register demotion. By doing so, we notably increase the number of profitably merged functions. We implement SalSSA in LLVM and apply it to the SPEC 2006 and 2017 suites. Experimental results show that our approach delivers on average, 7.9% to 9.7% reduction on the final size of the compiled code. This translates to around 2x more code size reduction over the state-of-the-art. Moreover, as a result of aligning shorter sequences of instructions and reducing the number of wasteful merge operations, our new approach incurs an average compile-time overhead of only 5%, 3x less than the state-of-the-art, while also reducing memory usage by over 2x.","PeriodicalId":20580,"journal":{"name":"Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85027001","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: 22

SCAF: a speculation-aware collaborative dependence analysis framework SCAF:一个推测感知的协作依赖分析框架

Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2020-06-06 DOI: 10.1145/3385412.3386028

Sotiris Apostolakis, Ziyang Xu, Zujun Tan, Greg Chan, Simone Campanoni, David I. August

{"title":"SCAF: a speculation-aware collaborative dependence analysis framework","authors":"Sotiris Apostolakis, Ziyang Xu, Zujun Tan, Greg Chan, Simone Campanoni, David I. August","doi":"10.1145/3385412.3386028","DOIUrl":"https://doi.org/10.1145/3385412.3386028","url":null,"abstract":"Program analysis determines the potential dataflow and control flow relationships among instructions so that compiler optimizations can respect these relationships to transform code correctly. Since many of these relationships rarely or never occur, speculative optimizations assert they do not exist while optimizing the code. To preserve correctness, speculative optimizations add validation checks to activate recovery code when these assertions prove untrue. This approach results in many missed opportunities because program analysis and thus other optimizations remain unaware of the full impact of these dynamically-enforced speculative assertions. To address this problem, this paper presents SCAF, a Speculation-aware Collaborative dependence Analysis Framework. SCAF learns of available speculative assertions via profiling, computes their full impact on memory dependence analysis, and makes this resulting information available for all code optimizations. SCAF is modular (adding new analysis modules is easy) and collaborative (modules cooperate to produce a result more precise than the confluence of all individual results). Relative to the best prior speculation-aware dependence analysis technique, by computing the full impact of speculation on memory dependence analysis, SCAF dramatically reduces the need for expensive-to-validate memory speculation in the hot loops of all 16 evaluated C/C++ SPEC benchmarks.","PeriodicalId":20580,"journal":{"name":"Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89929235","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: 8

Validating SMT solvers via semantic fusion 通过语义融合验证SMT求解器

Proceedings of the 41st ACM SIGPLAN Conference on Programming Language Design and Implementation Pub Date : 2020-06-06 DOI: 10.1145/3385412.3385985

Dominik Winterer, Chengyu Zhang, Z. Su

引用次数: 52