Introduction to the 28th International Conference on Logic Programming Special Issue

We are proud to introduce this special issue of the Journal of Theory and Practice of Logic Programming (TPLP), dedicated to the full papers accepted for the 28th International Conference on Logic Programming (ICLP). The ICLP meetings started in Marseille in 1982 and since then constitute the main venue for presenting and discussing work in the area of logic programming

Symbolic and analytic techniques for resource analysis of Java bytecode

Recent work in resource analysis has translated the idea of amortised resource analysis to imperative languages using a program logic that allows mixing of assertions about heap shapes, in the tradition of separation logic, and assertions about consumable resources. Separately, polyhedral methods have been used to calculate bounds on numbers of iterations in loop-based programs. We are attempting to combine these ideas to deal with Java programs involving both data structures and loops, focusing on the bytecode level rather than on source code

Compiler analysis for trace-level speculative multithreaded architectures

Trace-level speculative multithreaded processors exploit trace-level speculation by means of two threads working cooperatively. One thread, called the speculative thread, executes instructions ahead of the other by speculating on the result of several traces. The other thread executes speculated traces and verifies the speculation made by the first thread. In this paper, we propose a static program analysis for identifying candidate traces to be speculated. This approach identifies large regions of code whose live-output values may be successfully predicted. We present several heuristics to determine the best opportunities for dynamic speculation, based on compiler analysis and program profiling information. Simulation results show that the proposed trace recognition techniques achieve on average a speed-up close to 38% for a collection of SPEC2000 benchmarks.Peer ReviewedPostprint (published version

“Please send us your money”: The BBC’s evolving relationship with charitable causes, fundraising and humanitarian appeals

Fundraising for charitable causes has had a key place in the BBC’s schedule since the earliest days of the corporation and the establishment of the weekly radio appeal. As new forms of fundraising through high-profile media events developed in the 1980s, raising unprecedentedly large sums for charity, the BBC had to adjust the way it negotiated with good causes and audiences. These changes coincided with professionalization and rapid growth of the NGO sector, which sought to elicit funds from a wider public using innovative techniques and new ways of reaching out through the media. This article uses internal BBC documents to examine how, against this rapidly changing background, the organization navigated the rules behind broadcasting of appeals. This includes the way that the BBC interacted with the Disasters Emergency Committee that had been established in the 1960s to provide an interface between broadcasters and charities to oversee exceptional fundraising for international causes. In some cases, the BBC faced difficulties in reconciling its duty to educate audiences about charitable causes with the fundraising imperative which relied on TV extravaganzas. In other cases, the BBC confronted the question of whether it was hosting a global fundraising event or simply covering an event organized by others. These kinds of emerging challenges which arose out of new innovations in fundraising via broadcasting produced interesting debates that are still evolving both within the charitable sector and in the way it relates to the media. The BBC’s role within this ecology provides some illuminating insights about the issues connected with raising funds for humanitarian causes

A Robust Class of Linear Recurrence Sequences

We introduce a subclass of linear recurrence sequences which we call poly-rational sequences because they are denoted by rational expressions closed under sum and product. We show that this class is robust by giving several characterisations: polynomially ambiguous weighted automata, copyless cost-register automata, rational formal series, and linear recurrence sequences whose eigenvalues are roots of rational numbers