26,098 papers · page 414 of 1,305
Irregular applications that involve indirect memory accesses were traditionally considered unsuitable for SIMD processing. Though some progress has been made in recent years, the existing approaches require either expensive data reorganization or favorable input distribution to d…
Increasing data movement costs motivate the integration of polyhedral loop optimizers in the standard flow (-O3) of production compilers. While polyhedral optimizers have been shown to be effective when applied as source-to-source transformation, the single static assignment form…
Compilers perform a variety of advanced optimizations to improve the quality of the generated machine code. However, optimizations that depend on the data flow of a program are often limited by control-flow merges. Code duplication can solve this problem by hoisting, i.e. duplica…
Many applications provide inherent resilience to some amount of error and can potentially trade accuracy for performance by using approximate computing. Applications running on GPUs often use local memory to minimize the number of global memory accesses and to speed up execution.…
Auto-vectorizing compilers automatically generate vector (SIMD) instructions out of scalar code. The state-of-the-art algorithm for straight-line code vectorization is Superword-Level Parallelism (SLP). In this work we identify a major limitation at the core of the SLP algorithm,…
Task granularity, i.e., the amount of work performed by parallel tasks, is a key performance attribute of parallel applications. On the one hand, fine-grained tasks (i.e., small tasks carrying out few computations) may introduce considerable parallelization overheads. On the othe…
In memory hierarchies, caches perform an important role in reducing average memory access latency. Minimizing cache misses can yield significant performance gains. As set-associative caches are widely used in modern architectures, capacity and conflict cache misses co-exist. Thes…
General-purpose GPUs have been widely utilized to accelerate parallel applications. Given a relatively complex programming model and fast architecture evolution, producing efficient GPU code is nontrivial. A variety of simulation and profiling tools have been developed to aid GPU…
Memory-bound applications heavily depend on the bandwidth of the system in order to achieve high performance. Improving temporal and/or spatial locality through loop transformations is a common way of mitigating this dependency. However, choosing the right combination of optimiza…
In May of 2016, IBM Research has made a quantum processor available in the cloud to the general public. The possibility of programming an actual quantum device has elicited much enthusiasm. Yet, quantum programming still lacks the compiler support that modern programming language…
We present SLinGen, a program generation system for linear algebra. The input to SLinGen is an application expressed mathematically in a linear-algebra-inspired language (LA) that we define. LA provides basic scalar/vector/matrix additions/multiplications and higher level operati…
Managed language runtimes such as the Java Virtual Machine (JVM) provide adequate performance for a wide range of applications, but at the same time, they lack much of the low-level control that performance-minded programmers appreciate in languages like C/C++ . One important exa…
Software often suffers from performance bottlenecks, e.g., because some code has a higher computational complexity than expected or because a code change introduces a performance regression. Finding such bottlenecks is challenging for developers and for profiling techniques becau…
Sparse Matrix-vector Multiplication (SpMV) is an important computation kernel widely used in HPC and data centers. The irregularity of SpMV is a well-known challenge that limits SpMV’s parallelism with vectorization operations. Existing work achieves limited locality and vectoriz…
We propose POKER, a permutation-based vectorization approach for vectorizing multiple queries over B+-trees. Our key insight is to combine vector loads and path-encoding-based permutations to alleviate memory latency while keeping the number of key comparisons needed for a query …
May-Happen-in-Parallel (MHP) analysis computes whether two statements in a multi-threaded program may execute concurrently or not. It works as a basis for many analyses and optimization techniques of concurrent programs. This paper proposes a novel approach for MHP analysis, by s…
Blockchain technology has increasing attention in research and across many industries. The Ethereum blockchain offers smart contracts, which are small programs defined, executed, and recorded as transactions in the blockchain transaction history. These smart contracts run on the …
Search-based satisfiability procedures try to construct a model of the input formula by simultaneously proposing candidate models and deriving new formulae implied by the input. When the formulae are satisfiable, these procedures generate a model as a witness. Dually, it is desir…
Lambda-tree syntax (λTS), also known as higher-order abstract syntax (HOAS), is a representational technique where the pure λ-calculus in a meta-language is used to represent binding constructs in an object language. A key feature of λTS is that capture-avoiding substitution in t…
Matrix interpretations are widely used in automated complexity analysis. Certifying such analyses boils down to determining the growth rate of An for a fixed non-negative rational matrix A. A direct solution for this task involves the computation of all eigenvalues of A, which of…