2,246 papers · page 54 of 113
Smartphone apps create and handle a large variety of ``instance'' data that has to persist across runs, such as the current navigation route, workout results, antivirus settings, or game state. Due to the nature of the smartphone platform, an app can be paused, sent into backgrou…
Despite the growing popularity of GPGPU programming, there is not yet a portable and formally-specified barrier that one can use to synchronise across workgroups. Moreover, the occupancy-bound execution model of GPUs breaks assumptions inherent in traditional software execution b…
Machine-code slicing is an important primitive for building binary analysis and rewriting tools, such as taint trackers, fault localizers, and partial evaluators. However, it is not easy to create a machine-code slicer that exhibits a high level of precision. Moreover, the proble…
Machine-code synthesis is the problem of searching for an instruction sequence that implements a semantic specification, given as a formula in quantifier-free bit-vector logic (QFBV). Instruction sets like Intel's IA-32 have around 43,000 unique instruction schemas; this huge ins…
We present a language-independent verification framework that can be instantiated with an operational semantics to automatically generate a program verifier. The framework treats both the operational semantics and the program correctness specifications as reachability rules betwe…
Attribute grammars decorate the nodes of a program's parse tree with attributes whose values are defined by equations encoding the (static) semantics of a programming language. We show how replacing the equations of an attribute grammar with equivalent constraints that can be sol…
Validating optimizing compilers is challenging because it is hard to generate valid test programs (i.e., those that do not expose any undefined behavior). Equivalence Modulo Inputs (EMI) is an effective, promising methodology to tackle this problem. Given a test program with some…
We introduce a novel approach for using futures to automatically parallelize the execution of pure method calls. Our approach is built on three new techniques to address the challenge of automatic parallelization via future synthesis: candidate future synthesis, parallelism benef…
A key problem in parallel programming is how data is partitioned: divided into subsets that can be operated on in parallel and, in distributed memory machines, spread across multiple address spaces.
Data filtering in spreadsheets is a common problem faced by millions of end-users. The task of data filtering requires a computational model that can separate intended positive and negative string instances. We present a system, FIDEX, that can efficiently learn desired data filt…
Internet Service Providers (ISPs) use the Border Gateway Protocol (BGP) to announce and exchange routes for de- livering packets through the internet. ISPs must carefully configure their BGP routers to ensure traffic is routed reli- ably and securely. Correctly configuring BGP ro…
Cooperative statistical debugging is an effective approach for diagnosing production-run failures. To quickly identify failure predictors from the huge program predicate space, existing techniques rely on random or heuristics-guided predicate sampling at the user side. However, n…
The aggressive optimization of heavily used kernels is an important problem in high-performance computing. However, both general purpose compilers and highly specialized tools such as superoptimizers often do not have sufficient static knowledge of restrictions on program inputs …
We demonstrate that general-purpose memory allocation involving many threads on many cores can be done with high performance, multicore scalability, and low memory consumption. For this purpose, we have designed and implemented scalloc, a concurrent allocator that generally perfo…
We present Topaz, a new task-based language for computations that execute on approximate computing platforms that may occasionally produce arbitrarily inaccurate results. Topaz maps tasks onto the approximate hardware and integrates the generated results into the main computation…
To optimize code effectively, compilers must deal with memory dependencies. However, the state-of-the-art heuristics available in the literature to track memory dependencies are inherently imprecise and computationally expensive. Consequently, the most advanced code transformatio…
App stores are increasingly the preferred mechanism for distributing software, including mobile apps (Google Play), desktop apps (Mac App Store and Ubuntu Software Center), computer games (the Steam Store), and browser extensions (Chrome Web Store). The centralized nature of thes…
Previous work has shown how to insert fences that enforce sequential consistency. However, for many concurrent algorithms, sequential consistency is unnecessarily strong and can lead to high execution overhead. The reason is that, often, correctness relies on the execution order …
We present a complete end-to-end dynamic analysis system for finding data races in mobile Android applications. The capabilities of our system significantly exceed the state of the art: our system can analyze real-world application interactions in minutes rather than hours, finds…
Data races complicate programming language semantics, and a data race is often a bug. Existing techniques detect data races and define their semantics by detecting conflicts between synchronization-free regions (SFRs). However, such techniques either modify hardware or slow progr…