Software trace cache

We explore the use of compiler optimizations, which optimize the layout of instructions in memory. The target is to enable the code to make better use of the underlying hardware resources regardless of the specific details of the processor/architecture in order to increase fetch performance. The Software Trace Cache (STC) is a code layout algorithm with a broader target than previous layout optimizations. We target not only an improvement in the instruction cache hit rate, but also an increase in the effective fetch width of the fetch engine. The STC algorithm organizes basic blocks into chains trying to make sequentially executed basic blocks reside in consecutive memory positions, then maps the basic block chains in memory to minimize conflict misses in the important sections of the program. We evaluate and analyze in detail the impact of the STC, and code layout optimizations in general, on the three main aspects of fetch performance; the instruction cache hit rate, the effective fetch width, and the branch prediction accuracy. Our results show that layout optimized, codes have some special characteristics that make them more amenable for high-performance instruction fetch. They have a very high rate of not-taken branches and execute long chains of sequential instructions; also, they make very effective use of instruction cache lines, mapping only useful instructions which will execute close in time, increasing both spatial and temporal locality.Peer ReviewedPostprint (published version

Ethics in a Global Society (Chapter 12 of Organizational Ethics: A Practical Approach

Globalization is having a dramatic impact on life in the 21st century. We inhabit a global society knit together by free trade, international travel, immigration, satellite communication systems, and the Internet. In this interconnected world, ethical responsibilities extend beyond national boundaries. Decisions about raw materials, manufacturing, outsourcing, farm subsidies, investments, marketing strategies, suppliers, safety standards, and energy use made in one country have ramifications for residents of other parts of the world. Organizational citizenship is now played out on a global stage. Businesses, in particular, are being urged to take on a larger role in solving the world\u27s social problems

Professional Ethics and Social Responsibility: Military Work and Peacebuilding

The paper considers a number of important questions related to the involvement of engineers in peacebuilding and military work, including the preference of many countries for high tech weapons based security over peacebuilding, whether and in what circumstances, if any, it is justified for engineers to be involved in military work; and how engineers can persuade their colleagues to apply their skills to support peacebuilding. It is introduced by an overview of what is meant by the term military work and the extent and consequences of the use of military technology worldwide. This is followed by the applications of different approaches and theories of ethics to discuss the questions presented in the introduction. The approaches and theories applied include considerations of micro-and macro-ethics, codes of ethics, virtue ethics, considerations of gender and paradigms and the ethical imperative. Initial insights include the importance of considering the associated context and the need to avoid othering, which can make different treatment of minority groups, including the use of high tech weapons against them, seem acceptable

The Peahen’s Tale, or Dressing Our Parts at Work

However, there may ultimately be no logical way to reconcile decisions that prohibit employers from requiring women to wear revealing outfits and others that permit employers to require them to wear makeup,20 or decisions that prohibit penalizing a woman for being insufficiently feminine and others that permit penalizing a man for being insufficiently masculine.21 In addition, the increasing judicial acceptance of the sex stereotyping theory of sex discrimination under Title VII is in substantial tension with recent cases that insist that sex-differentiated dress and grooming requirements that merely 22 conform to existing social gender norms do not amount to impermissible sex discrimination. Because dress is so crucial a characteristic in sexually dimorphic species, and because it is so closely tied to sexual attractiveness, choice, and power dynamics, employers should be prohibited from requiring women to dress in gender normative ways that reflect those traits even if they believe that such dress codes do not amount to intentional sex stereotyping.223 Where, as here, so many threads come together to demonstrate that sex differences in dress are likely to affect the way that individuals are treated by others, employers should not be permitted to mandate differences that implicate notions of attractiveness or power

The Peahen’s Tale, or Dressing Our Parts at Work

However, there may ultimately be no logical way to reconcile decisions that prohibit employers from requiring women to wear revealing outfits and others that permit employers to require them to wear makeup,20 or decisions that prohibit penalizing a woman for being insufficiently feminine and others that permit penalizing a man for being insufficiently masculine.21 In addition, the increasing judicial acceptance of the sex stereotyping theory of sex discrimination under Title VII is in substantial tension with recent cases that insist that sex-differentiated dress and grooming requirements that merely 22 conform to existing social gender norms do not amount to impermissible sex discrimination. Because dress is so crucial a characteristic in sexually dimorphic species, and because it is so closely tied to sexual attractiveness, choice, and power dynamics, employers should be prohibited from requiring women to dress in gender normative ways that reflect those traits even if they believe that such dress codes do not amount to intentional sex stereotyping.223 Where, as here, so many threads come together to demonstrate that sex differences in dress are likely to affect the way that individuals are treated by others, employers should not be permitted to mandate differences that implicate notions of attractiveness or power

Virtual cluster scheduling through the scheduling graph

This paper presents an instruction scheduling and cluster assignment approach for clustered processors. The proposed technique makes use of a novel representation named the scheduling graph which describes all possible schedules. A powerful deduction process is applied to this graph, reducing at each step the set of possible schedules. In contrast to traditional list scheduling techniques, the proposed scheme tries to establish relations among instructions rather than assigning each instruction to a particular cycle. The main advantage is that wrong or poor schedules can be anticipated and discarded earlier. In addition, cluster assignment of instructions is performed using another novel concept called virtual clusters, which define sets of instructions that must execute in the same cluster. These clusters are managed during the deduction process to identify incompatibilities among instructions. The mapping of virtual to physical clusters is postponed until the scheduling of the instructions has finalized. The advantages this novel approach features include: (1) accurate scheduling information when assigning, and, (2) accurate information of the cluster assignment constraints imposed by scheduling decisions. We have implemented and evaluated the proposed scheme with superblocks extracted from Speclnt95 and MediaBench. The results show that this approach produces better schedules than the previous state-of-the-art. Speed-ups are up to 15%, with average speed-ups ranging from 2.5% (2-Clusters) to 9.5% (4-Clusters).Peer ReviewedPostprint (published version