Michael H. Fischer, Giovanni Campagna, Euirim Choi, M. Lam
While Alexa can perform over 100,000 skills, its capability covers only a fraction of what is possible on the web. Individuals need and want to automate a long tail of web-based tasks which often involve visiting different websites and require programming concepts such as function composition, conditional, and iterative evaluation. This paper presents DIYA (Do-It-Yourself Assistant), a new system that empowers users to create personalized web-based virtual assistant skills that require the full generality of composable control constructs, without having to learn a formal programming language. With DIYA, the user demonstrates their task of interest in the browser and issues a few simple voice commands, such as naming the skills and adding conditions on the action. DIYA turns these multi-modal specifications into voice-invocable skills written in the ThingTalk 2.0 programming language we designed for this purpose. DIYA is a prototype that works in the Chrome browser. Our user studies show that 81% of the proposed routines can be expressed using DIYA. DIYA is easy to learn, and 80% of users surveyed find DIYA useful.
{"title":"DIY assistant: a multi-modal end-user programmable virtual assistant","authors":"Michael H. Fischer, Giovanni Campagna, Euirim Choi, M. Lam","doi":"10.1145/3453483.3454046","DOIUrl":"https://doi.org/10.1145/3453483.3454046","url":null,"abstract":"While Alexa can perform over 100,000 skills, its capability covers only a fraction of what is possible on the web. Individuals need and want to automate a long tail of web-based tasks which often involve visiting different websites and require programming concepts such as function composition, conditional, and iterative evaluation. This paper presents DIYA (Do-It-Yourself Assistant), a new system that empowers users to create personalized web-based virtual assistant skills that require the full generality of composable control constructs, without having to learn a formal programming language. With DIYA, the user demonstrates their task of interest in the browser and issues a few simple voice commands, such as naming the skills and adding conditions on the action. DIYA turns these multi-modal specifications into voice-invocable skills written in the ThingTalk 2.0 programming language we designed for this purpose. DIYA is a prototype that works in the Chrome browser. Our user studies show that 81% of the proposed routines can be expressed using DIYA. DIYA is easy to learn, and 80% of users surveyed find DIYA useful.","PeriodicalId":20557,"journal":{"name":"Proceedings of the 42nd ACM SIGPLAN International Conference on Programming Language Design and Implementation","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74028121","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}
We present a safe automatic memory reclamation approach for concurrent programs, and show that it is both theoretically and practically efficient. Our approach combines ideas from referencing counting and hazard pointers in a novel way to implement concurrent reference counting with wait-free, constant-time overhead. It overcomes the limitations of previous approaches by significantly reducing modifications to, and hence contention on, the reference counts. Furthermore, it is safer and easier to use than manual approaches. Our technique involves using a novel generalization of hazard pointers to defer reference-count decrements until no other process can be incrementing them, and to defer or elide reference-count increments for short-lived references. We have implemented the approach as a C++ library and compared it experimentally to several methods including existing atomic reference-counting libraries and state-of-the art manual techniques. Our results indicate that our technique is faster than existing reference-counting implementations, and competitive with manual memory reclamation techniques. More importantly, it is significantly safer than manual techniques since objects are reclaimed automatically.
{"title":"Concurrent deferred reference counting with constant-time overhead","authors":"Daniel Anderson, G. Blelloch, Yuanhao Wei","doi":"10.1145/3453483.3454060","DOIUrl":"https://doi.org/10.1145/3453483.3454060","url":null,"abstract":"We present a safe automatic memory reclamation approach for concurrent programs, and show that it is both theoretically and practically efficient. Our approach combines ideas from referencing counting and hazard pointers in a novel way to implement concurrent reference counting with wait-free, constant-time overhead. It overcomes the limitations of previous approaches by significantly reducing modifications to, and hence contention on, the reference counts. Furthermore, it is safer and easier to use than manual approaches. Our technique involves using a novel generalization of hazard pointers to defer reference-count decrements until no other process can be incrementing them, and to defer or elide reference-count increments for short-lived references. We have implemented the approach as a C++ library and compared it experimentally to several methods including existing atomic reference-counting libraries and state-of-the art manual techniques. Our results indicate that our technique is faster than existing reference-counting implementations, and competitive with manual memory reclamation techniques. More importantly, it is significantly safer than manual techniques since objects are reclaimed automatically.","PeriodicalId":20557,"journal":{"name":"Proceedings of the 42nd ACM SIGPLAN International Conference on Programming Language Design and Implementation","volume":"266 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79010550","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}
A. Donaldson, Paul Thomson, Vasyl Teliman, Stefano Milizia, André Perez Maselco, Antoni Karpiński
Recent transformation-based approaches to compiler testing look for mismatches between the results of pairs of equivalent programs, where one program is derived from the other by randomly applying semantics-preserving transformations. We present a formulation of transformation-based compiler testing that provides effective test-case reduction almost for free: if transformations are designed to be as small and independent as possible, standard delta debugging can be used to shrink a bug-inducing transformation sequence to a smaller subsequence that still triggers the bug. The bug can then be reported as a delta between an original and minimally-transformed program. Minimized transformation sequences can also be used to heuristically deduplicate a set of bug-inducing tests, recommending manual investigation of those that involve disparate types of transformations and thus may have different root causes. We demonstrate the effectiveness of our approach via a new tool, spirv-fuzz, the first compiler-testing tool for the SPIR-V intermediate representation that underpins the Vulkan GPU programming model.
{"title":"Test-case reduction and deduplication almost for free with transformation-based compiler testing","authors":"A. Donaldson, Paul Thomson, Vasyl Teliman, Stefano Milizia, André Perez Maselco, Antoni Karpiński","doi":"10.1145/3453483.3454092","DOIUrl":"https://doi.org/10.1145/3453483.3454092","url":null,"abstract":"Recent transformation-based approaches to compiler testing look for mismatches between the results of pairs of equivalent programs, where one program is derived from the other by randomly applying semantics-preserving transformations. We present a formulation of transformation-based compiler testing that provides effective test-case reduction almost for free: if transformations are designed to be as small and independent as possible, standard delta debugging can be used to shrink a bug-inducing transformation sequence to a smaller subsequence that still triggers the bug. The bug can then be reported as a delta between an original and minimally-transformed program. Minimized transformation sequences can also be used to heuristically deduplicate a set of bug-inducing tests, recommending manual investigation of those that involve disparate types of transformations and thus may have different root causes. We demonstrate the effectiveness of our approach via a new tool, spirv-fuzz, the first compiler-testing tool for the SPIR-V intermediate representation that underpins the Vulkan GPU programming model.","PeriodicalId":20557,"journal":{"name":"Proceedings of the 42nd ACM SIGPLAN International Conference on Programming Language Design and Implementation","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86666999","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}
Luis Vega, Joseph McMahan, Adrian Sampson, D. Grossman, L. Ceze
Modern field-programmable gate arrays (FPGAs) have recently powered high-profile efficiency gains in systems from datacenters to embedded devices by offering ensembles of heterogeneous, reconfigurable hardware units. Programming stacks for FPGAs, however, are stuck in the past—they are based on traditional hardware languages, which were appropriate when FPGAs were simple, homogeneous fabrics of basic programmable primitives. We describe Reticle, a new low-level abstraction for FPGA programming that, unlike existing languages, explicitly represents the special-purpose units available on a particular FPGA device. Reticle has two levels: a portable intermediate language and a target-specific assembly language. We show how to use a standard instruction selection approach to lower intermediate programs to assembly programs, which can be both faster and more effective than the complex metaheuristics that existing FPGA toolchains use. We use Reticle to implement linear algebra operators and coroutines and find that Reticle compilation runs up to 100 times faster than current approaches while producing comparable or better run-time and utilization.
{"title":"Reticle: a virtual machine for programming modern FPGAs","authors":"Luis Vega, Joseph McMahan, Adrian Sampson, D. Grossman, L. Ceze","doi":"10.1145/3453483.3454075","DOIUrl":"https://doi.org/10.1145/3453483.3454075","url":null,"abstract":"Modern field-programmable gate arrays (FPGAs) have recently powered high-profile efficiency gains in systems from datacenters to embedded devices by offering ensembles of heterogeneous, reconfigurable hardware units. Programming stacks for FPGAs, however, are stuck in the past—they are based on traditional hardware languages, which were appropriate when FPGAs were simple, homogeneous fabrics of basic programmable primitives. We describe Reticle, a new low-level abstraction for FPGA programming that, unlike existing languages, explicitly represents the special-purpose units available on a particular FPGA device. Reticle has two levels: a portable intermediate language and a target-specific assembly language. We show how to use a standard instruction selection approach to lower intermediate programs to assembly programs, which can be both faster and more effective than the complex metaheuristics that existing FPGA toolchains use. We use Reticle to implement linear algebra operators and coroutines and find that Reticle compilation runs up to 100 times faster than current approaches while producing comparable or better run-time and utilization.","PeriodicalId":20557,"journal":{"name":"Proceedings of the 42nd ACM SIGPLAN International Conference on Programming Language Design and Implementation","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82733825","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}
Nuno P. Lopes, Juneyoung Lee, C. Hur, Zhengyang Liu, J. Regehr
We designed, implemented, and deployed Alive2: a bounded translation validation tool for the LLVM compiler’s intermediate representation (IR). It limits resource consumption by, for example, unrolling loops up to some bound, which means there are circumstances in which it misses bugs. Alive2 is designed to avoid false alarms, is fully automatic through the use of an SMT solver, and requires no changes to LLVM. By running Alive2 over LLVM’s unit test suite, we discovered and reported 47 new bugs, 28 of which have been fixed already. Moreover, our work has led to eight patches to the LLVM Language Reference—the definitive description of the semantics of its IR—and we have participated in numerous discussions with the goal of clarifying ambiguities and fixing errors in these semantics. Alive2 is open source and we also made it available on the web, where it has active users from the LLVM community.
{"title":"Alive2: bounded translation validation for LLVM","authors":"Nuno P. Lopes, Juneyoung Lee, C. Hur, Zhengyang Liu, J. Regehr","doi":"10.1145/3453483.3454030","DOIUrl":"https://doi.org/10.1145/3453483.3454030","url":null,"abstract":"We designed, implemented, and deployed Alive2: a bounded translation validation tool for the LLVM compiler’s intermediate representation (IR). It limits resource consumption by, for example, unrolling loops up to some bound, which means there are circumstances in which it misses bugs. Alive2 is designed to avoid false alarms, is fully automatic through the use of an SMT solver, and requires no changes to LLVM. By running Alive2 over LLVM’s unit test suite, we discovered and reported 47 new bugs, 28 of which have been fixed already. Moreover, our work has led to eight patches to the LLVM Language Reference—the definitive description of the semantics of its IR—and we have participated in numerous discussions with the goal of clarifying ambiguities and fixing errors in these semantics. Alive2 is open source and we also made it available on the web, where it has active users from the LLVM community.","PeriodicalId":20557,"journal":{"name":"Proceedings of the 42nd ACM SIGPLAN International Conference on Programming Language Design and Implementation","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79659156","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}
Qingkai Shi, Peisen Yao, Rongxin Wu, Charles Zhang
Sparse program analysis is fast as it propagates data flow facts via data dependence, skipping unnecessary control flows. However, when path-sensitively checking millions of lines of code, it is still prohibitively expensive because a huge number of path conditions have to be computed and solved via an SMT solver. This paper presents Fusion, a fused approach to inter-procedurally path-sensitive sparse analysis. In Fusion, the SMT solver does not work as a standalone tool on path conditions but directly on the program together with the sparse analysis. Such a fused design allows us to determine the path feasibility without explicitly computing path conditions, not only saving the cost of computing path conditions but also providing an opportunity to enhance the SMT solving algorithm. To the best of our knowledge, Fusion, for the first time, enables whole program bug detection on millions of lines of code in a common personal computer, with the precision of inter-procedural path-sensitivity. Compared to two state-of-the-art tools, Fusion is 10× faster but consumes only 10% of memory on average. Fusion has detected over a hundred bugs in mature open-source software, some of which have even been assigned CVE identifiers due to their security impact.
{"title":"Path-sensitive sparse analysis without path conditions","authors":"Qingkai Shi, Peisen Yao, Rongxin Wu, Charles Zhang","doi":"10.1145/3453483.3454086","DOIUrl":"https://doi.org/10.1145/3453483.3454086","url":null,"abstract":"Sparse program analysis is fast as it propagates data flow facts via data dependence, skipping unnecessary control flows. However, when path-sensitively checking millions of lines of code, it is still prohibitively expensive because a huge number of path conditions have to be computed and solved via an SMT solver. This paper presents Fusion, a fused approach to inter-procedurally path-sensitive sparse analysis. In Fusion, the SMT solver does not work as a standalone tool on path conditions but directly on the program together with the sparse analysis. Such a fused design allows us to determine the path feasibility without explicitly computing path conditions, not only saving the cost of computing path conditions but also providing an opportunity to enhance the SMT solving algorithm. To the best of our knowledge, Fusion, for the first time, enables whole program bug detection on millions of lines of code in a common personal computer, with the precision of inter-procedural path-sensitivity. Compared to two state-of-the-art tools, Fusion is 10× faster but consumes only 10% of memory on average. Fusion has detected over a hundred bugs in mature open-source software, some of which have even been assigned CVE identifiers due to their security impact.","PeriodicalId":20557,"journal":{"name":"Proceedings of the 42nd ACM SIGPLAN International Conference on Programming Language Design and Implementation","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87115676","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}
In quantum computing, the basic unit of information is a qubit. Simulation of a general quantum program takes exponential time in the number of qubits, which makes simulation infeasible beyond 50 qubits on current supercomputers. So, for the understanding of larger programs, we turn to static techniques. In this paper, we present an abstract interpretation of quantum programs and we use it to automatically verify assertions in polynomial time. Our key insight is to let an abstract state be a tuple of projections. For such domains, we present abstraction and concretization functions that form a Galois connection and we use them to define abstract operations. Our experiments on a laptop have verified assertions about the Bernstein-Vazirani, GHZ, and Grover benchmarks with 300 qubits.
{"title":"Quantum abstract interpretation","authors":"Nengkun Yu, J. Palsberg","doi":"10.1145/3453483.3454061","DOIUrl":"https://doi.org/10.1145/3453483.3454061","url":null,"abstract":"In quantum computing, the basic unit of information is a qubit. Simulation of a general quantum program takes exponential time in the number of qubits, which makes simulation infeasible beyond 50 qubits on current supercomputers. So, for the understanding of larger programs, we turn to static techniques. In this paper, we present an abstract interpretation of quantum programs and we use it to automatically verify assertions in polynomial time. Our key insight is to let an abstract state be a tuple of projections. For such domains, we present abstraction and concretization functions that form a Galois connection and we use them to define abstract operations. Our experiments on a laptop have verified assertions about the Bernstein-Vazirani, GHZ, and Grover benchmarks with 300 qubits.","PeriodicalId":20557,"journal":{"name":"Proceedings of the 42nd ACM SIGPLAN International Conference on Programming Language Design and Implementation","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83488243","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}
Local data-race-freedom guarantees, ensuring strong semantics for locations accessed by non-racy instructions, provide a fruitful methodology for modular reasoning in relaxed memory concurrency. We observe that standard compiler optimizations are in inherent conflict with such guarantees in general fully-relaxed memory models. Nevertheless, for a certain strengthening of the promising model by Lee et al. that only excludes relaxed RMW-store reorderings, we establish multiple useful local data-racefreedom guarantees that enhance the programmability aspect of the model.We also demonstrate that the performance price of forbidding these reorderings is insignificant. To the best of our knowledge, these results are the first to identify a model that includes the standard concurrency constructs, supports the efficient mapping of relaxed reads and writes to plain hardware loads and stores, and yet validates several local data-race-freedom guarantees. To gain confidence, our results are fully mechanized in Coq.
{"title":"Modular data-race-freedom guarantees in the promising semantics","authors":"Minki Cho, Sung-Hwan Lee, C. Hur, O. Lahav","doi":"10.1145/3453483.3454082","DOIUrl":"https://doi.org/10.1145/3453483.3454082","url":null,"abstract":"Local data-race-freedom guarantees, ensuring strong semantics for locations accessed by non-racy instructions, provide a fruitful methodology for modular reasoning in relaxed memory concurrency. We observe that standard compiler optimizations are in inherent conflict with such guarantees in general fully-relaxed memory models. Nevertheless, for a certain strengthening of the promising model by Lee et al. that only excludes relaxed RMW-store reorderings, we establish multiple useful local data-racefreedom guarantees that enhance the programmability aspect of the model.We also demonstrate that the performance price of forbidding these reorderings is insignificant. To the best of our knowledge, these results are the first to identify a model that includes the standard concurrency constructs, supports the efficient mapping of relaxed reads and writes to plain hardware loads and stores, and yet validates several local data-race-freedom guarantees. To gain confidence, our results are fully mechanized in Coq.","PeriodicalId":20557,"journal":{"name":"Proceedings of the 42nd ACM SIGPLAN International Conference on Programming Language Design and Implementation","volume":"482 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76697605","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}
Reducing a failure-inducing input to a smaller one is challenging for input with internal dependencies because most sub-inputs are invalid. Kalhauge and Palsberg made progress on this problem by mapping the task to a reduction problem for dependency graphs that avoids invalid inputs entirely. Their tool J-Reduce efficiently reduces Java bytecode to 24 percent of its original size, which made it the most effective tool until now. However, the output from their tool is often too large to be helpful in a bug report. In this paper, we show that more fine-grained modeling of dependencies leads to much more reduction. Specifically, we use propositional logic for specifying dependencies and we show how this works for Java bytecode. Once we have a propositional formula that specifies all valid sub-inputs, we run an algorithm that finds a small, valid, failure-inducing input. Our algorithm interleaves runs of the buggy program and calls to a procedure that finds a minimal satisfying assignment. Our experiments show that we can reduce Java bytecode to 4.6 percent of its original size, which is 5.3 times better than the 24.3 percent achieved by J-Reduce. The much smaller output is more suitable for bug reports.
{"title":"Logical bytecode reduction","authors":"Christian Gram Kalhauge, J. Palsberg","doi":"10.1145/3453483.3454091","DOIUrl":"https://doi.org/10.1145/3453483.3454091","url":null,"abstract":"Reducing a failure-inducing input to a smaller one is challenging for input with internal dependencies because most sub-inputs are invalid. Kalhauge and Palsberg made progress on this problem by mapping the task to a reduction problem for dependency graphs that avoids invalid inputs entirely. Their tool J-Reduce efficiently reduces Java bytecode to 24 percent of its original size, which made it the most effective tool until now. However, the output from their tool is often too large to be helpful in a bug report. In this paper, we show that more fine-grained modeling of dependencies leads to much more reduction. Specifically, we use propositional logic for specifying dependencies and we show how this works for Java bytecode. Once we have a propositional formula that specifies all valid sub-inputs, we run an algorithm that finds a small, valid, failure-inducing input. Our algorithm interleaves runs of the buggy program and calls to a procedure that finds a minimal satisfying assignment. Our experiments show that we can reduce Java bytecode to 4.6 percent of its original size, which is 5.3 times better than the 24.3 percent achieved by J-Reduce. The much smaller output is more suitable for bug reports.","PeriodicalId":20557,"journal":{"name":"Proceedings of the 42nd ACM SIGPLAN International Conference on Programming Language Design and Implementation","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89772456","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}
We define a small-step semantics for the untyped λ-calculus, that traces the β-reductions that occur during evaluation. By abstracting the computation traces, we reconstruct k-CFA using abstract interpretation, and justify constraint-based k-CFA in a semantic way. The abstract interpretation of the trace semantics also paves the way for introducing widening operators in CFA that go beyond existing analyses, that are all based on exploring a finite state space. We define ∇CFA, a widening-based analysis that limits the cycles in call stacks, and can achieve better precision than k-CFA at a similar cost.
{"title":"Trace-based control-flow analysis","authors":"Benoît Montagu, T. Jensen","doi":"10.1145/3453483.3454057","DOIUrl":"https://doi.org/10.1145/3453483.3454057","url":null,"abstract":"We define a small-step semantics for the untyped λ-calculus, that traces the β-reductions that occur during evaluation. By abstracting the computation traces, we reconstruct k-CFA using abstract interpretation, and justify constraint-based k-CFA in a semantic way. The abstract interpretation of the trace semantics also paves the way for introducing widening operators in CFA that go beyond existing analyses, that are all based on exploring a finite state space. We define ∇CFA, a widening-based analysis that limits the cycles in call stacks, and can achieve better precision than k-CFA at a similar cost.","PeriodicalId":20557,"journal":{"name":"Proceedings of the 42nd ACM SIGPLAN International Conference on Programming Language Design and Implementation","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87754920","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}
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