654 research outputs found
Opportunities for a Truffle-based Golo Interpreter
Golo is a simple dynamically-typed language for the Java Virtual Machine.
Initially implemented as a ahead-of-time compiler to JVM bytecode, it leverages
invokedy-namic and JSR 292 method handles to implement a reasonably efficient
runtime. Truffle is emerging as a framework for building interpreters for JVM
languages with self-specializing AST nodes. Combined with the Graal compiler,
Truffle offers a simple path towards writing efficient interpreters while
keeping the engineering efforts balanced. The Golo project is interested in
experimenting with a Truffle interpreter in the future, as it would provides
interesting comparison elements between invokedynamic versus Truffle for
building a language runtime
Virtual Machine Support for Many-Core Architectures: Decoupling Abstract from Concrete Concurrency Models
The upcoming many-core architectures require software developers to exploit
concurrency to utilize available computational power. Today's high-level
language virtual machines (VMs), which are a cornerstone of software
development, do not provide sufficient abstraction for concurrency concepts. We
analyze concrete and abstract concurrency models and identify the challenges
they impose for VMs. To provide sufficient concurrency support in VMs, we
propose to integrate concurrency operations into VM instruction sets.
Since there will always be VMs optimized for special purposes, our goal is to
develop a methodology to design instruction sets with concurrency support.
Therefore, we also propose a list of trade-offs that have to be investigated to
advise the design of such instruction sets.
As a first experiment, we implemented one instruction set extension for
shared memory and one for non-shared memory concurrency. From our experimental
results, we derived a list of requirements for a full-grown experimental
environment for further research
Solving Parity Games in Scala
Parity games are two-player games, played on directed graphs, whose nodes are labeled with priorities. Along a play, the maximal priority occurring infinitely often determines the winner. In the last two decades, a variety of algorithms and successive optimizations have been proposed. The majority of them have been implemented in PGSolver, written in OCaml, which has been elected by the community as the de facto platform to solve efficiently parity games as well as evaluate their performance in several specific cases.
PGSolver includes the Zielonka Recursive Algorithm that has been shown to perform better than the others in randomly generated games. However, even for arenas with a few thousand of nodes (especially over dense graphs), it requires minutes to solve the corresponding game.
In this paper, we deeply revisit the implementation of the recursive algorithm introducing several improvements and making use of Scala Programming Language. These choices have been proved to be very successful, gaining up to two orders of magnitude in running time
Optimizations for a Java Interpreter Using Instruction Set Enhancement
Several methods for optimizing Java interpreters have been proposed that involve augmenting the existing instruction set. In this paper we describe the design and implementation of three such optimizations for an efficient Java interpreter. Specialized instructions are new versions of existing instructions with commonly occurring operands hardwired into them, which reduces operand fetching. Superinstructions are new Java instructions which perform the work of common sequences of instructions. Finally, instruction replication is the duplication of existing instructions with a view to improving branch prediction accuracy. We describe our basic interpreter, the interpreter generator we use to automatically create optimised source code for enhanced instructions, and discuss Java specific issues relating to these optimizations. Experimental results show significant speedups (up to a factor of 3.3, and realistic average speedups of 30%-35%) are attainable using these techniques
JVM-hosted languages: They talk the talk, but do they walk the walk?
The rapid adoption of non-Java JVM languages is impressive: major international corporations are staking critical parts of their software infrastructure on components built from languages such as
Scala and Clojure. However with the possible exception of Scala,
there has been little academic consideration and characterization
of these languages to date. In this paper, we examine four nonJava JVM languages and use exploratory data analysis techniques
to investigate differences in their dynamic behavior compared to
Java. We analyse a variety of programs and levels of behavior to
draw distinctions between the different programming languages.
We brieïŹy discuss the implications of our ïŹndings for improving
the performance of JIT compilation and garbage collection on the
JVM platform
A selective dynamic compiler for embedded Java virtual machine targeting ARM processors
Tableau dâhonneur de la FacultĂ© des Ă©tudes supĂ©rieures et postdoctorales, 2004-2005Ce travail prĂ©sente une nouvelle technique de compilation dynamique sĂ©lective pour les systĂšmes embarquĂ©s avec processeurs ARM. Ce compilateur a Ă©tĂ© intĂ©grĂ© dans la plateforme J2ME/CLDC (Java 2 Micro Edition for Connected Limited Device Con- figuration). Lâobjectif principal de notre travail est dâobtenir une machine virtuelle accĂ©lĂ©rĂ©e, lĂ©gĂšre et compacte prĂȘte pour lâexĂ©cution sur les systĂšmes embarquĂ©s. Cela est atteint par lâimplĂ©mentation dâun compilateur dynamique sĂ©lectif pour lâarchitecture ARM dans la Kilo machine virtuelle de Sun (KVM). Ce compilateur est appelĂ© Armed E-Bunny. PremiĂšrement, on prĂ©sente la plateforme Java, le Java 2 Micro Edition(J2ME) pour les systĂšmes embarquĂ©s et les composants de la machine virtuelle Java. Ensuite, on discute les diffĂ©rentes techniques dâaccĂ©lĂ©ration pour la machine virtuelle Java et on dĂ©taille le principe de la compilation dynamique. Enfin, on illustre lâarchitecture, le design (la conception), lâimplĂ©mentation et les rĂ©sultats expĂ©rimentaux de notre compilateur dynamique sĂ©lective Armed E-Bunny. La version modifiĂ©e de KVM a Ă©tĂ© portĂ©e sur un ordinateur de poche (PDA) et a Ă©tĂ© testĂ©e en utilisant un benchmark standard de J2ME. Les rĂ©sultats expĂ©rimentaux de la performance montrent une accĂ©lĂ©ration de 360 % par rapport Ă la derniĂšre version de la KVM de Sun avec un espace mĂ©moire additionnel qui nâexcĂšde pas 119 kilobytes.This work presents a new selective dynamic compilation technique targeting ARM 16/32-bit embedded system processors. This compiler is built inside the J2ME/CLDC (Java 2 Micro Edition for Connected Limited Device Configuration) platform. The primary objective of our work is to come up with an efficient, lightweight and low-footprint accelerated Java virtual machine ready to be executed on embedded machines. This is achieved by implementing a selective ARM dynamic compiler called Armed E-Bunny into Sunâs Kilobyte Virtual Machine (KVM). We first present the Java platform, Java 2 Micro Edition (J2ME) for embedded systems and Java virtual machine components. Then, we discuss the different acceleration techniques for Java virtual machine and we detail the principle of dynamic compilation. After that we illustrate the architecture, design, implementation and experimental results of our selective dynamic compiler Armed E-Bunny. The modified KVM is ported on a handheld PDA and is tested using standard J2ME benchmarks. The experimental results on its performance demonstrate that a speedup of 360% over the last version of Sunâs KVM is accomplished with a footprint overhead that does not exceed 119 kilobytes
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