Application of compiler-assisted multiple instruction rollback recovery to speculative execution

Speculative execution is a method to increase instruction level parallelism which can be exploited by both super-scalar and VLIW architectures. The key to a successful general speculation strategy is a repair mechanism to handle mispredicted branches and accurate reporting of exceptions for speculated instructions. Multiple instruction rollback is a technique developed for recovery from transient processor failure. Many of the difficulties encountered during recovery from branch misprediction or from instruction re-execution due to exception in a speculative execution architecture are similar to those encountered during multiple instruction rollback. The applicability of a recently developed compiler-assisted multiple instruction rollback scheme to aid in speculative execution repair is investigated. Extensions to the compiler-assisted scheme to support branch and exception repair are presented along with performance measurements across ten application programs

Thermodynamic Investigations of Alcohol-Hydrocarbon Systems by Frontal Analysis

[No abstract provided.

The synthesis and adenosine deaminase activity of two analogues of ganciclovir

In an attempt to produce a prodrug which is effectively transported across the blood-brain barrier, two analogues of ganciclovir were synthesized and their adenosine deaminase (ADA) activity was determined. 2-Amino-6-chloro-9-[(1,3- dihydroxy-2-propoxy)methyl] purine (6-Cl-DHPG) and 2-amino-6-methoxy-9- [(1,3-dihydroxy-2-propoxy)methyl] purine (6-MeO-DHPG) were synthesized from guanine. An alternate route for the synthesis of an intermediate was investigated in an attempt to improve the yield; however, ambiguous results were obtained. Both substrates were shown to be enzymatically converted to ganciclovir. The Michaelis-Menten parameters for the hydrolysis of 6-CI-DHPG (ΚΜ = 313 µΜ, Vmax = 1.27 × 10-6) and 6-MeO-DHPG (KM = 345 µM, Vmax = 5.05 × 10-5) were determined by continuous spectrophotometric (CS) assay

Simulation and analysis of support hardware for multiple instruction rollback

Recently, a compiler-assisted approach to multiple instruction retry was developed. In this scheme, a read buffer of size 2N, where N represents the maximum instruction rollback distance, is used to resolve one type of data hazard. This hardware support helps to reduce code growth, compilation time, and some of the performance impacts associated with hazard resolution. The 2N read buffer size requirement of the compiler-assisted approach is worst case, assuring data redundancy for all data required but also providing some unnecessary redundancy. By adding extra bits in the operand field for source 1 and source 2 it becomes possible to design the read buffer to save only those values required, thus reducing the read buffer size requirement. This study measures the effect on performance of a DECstation 3100 running 10 application programs using 6 read buffer configurations at varying read buffer sizes

Compiler-Assisted Multiple Instruction Rollback Recovery Using a Read Buffer

Multiple instruction rollback (MIR) is a technique to provide rapid recovery from transient processor failures and was implemented in hardware by researchers and slow in mainframe computers. Hardware-based MIR designs eliminate rollback data hazards by providing data redundancy implemented in hardware. Compiler-based MIR designs were also developed which remove rollback data hazards directly with data flow manipulations, thus eliminating the need for most data redundancy hardware. Compiler-assisted techniques to achieve multiple instruction rollback recovery are addressed. It is observed that data some hazards resulting from instruction rollback can be resolved more efficiently by providing hardware redundancy while others are resolved more efficiently with compiler transformations. A compiler-assisted multiple instruction rollback scheme is developed which combines hardware-implemented data redundancy with compiler-driven hazard removal transformations. Experimental performance evaluations were conducted which indicate improved efficiency over previous hardware-based and compiler-based schemes. Various enhancements to the compiler transformations and to the data redundancy hardware developed for the compiler-assisted MIR scheme are described and evaluated. The final topic deals with the application of compiler-assisted MIR techniques to aid in exception repair and branch repair in a speculative execution architecture

It's not rocket science: Humanities, arts and social sciences in the space sector

The space industry is traditionally associated with STEM disciplines, but humanities, arts and social sciences have plenty to offer to the modern space sector. Space accounting scholars Dr Basil Tucker and Dr Hank Alewine investigate the potential of HASS to address the unique and unprecedented challenges of the New Space Age

Landscape of the Past: The 1815 Log House at Western Kentucky University

The 1815 Log House is located on the campus of Western Kentucky University. Built in the early 1800\u27s by Archibald Felts, the house was occupied by his descendants until 1968. The dogtrot floor plan, V-notched logs, and stone chimneys are some of the historical architectural features that can be viewed. It was donated to the Kentucky Library & Museum at WKU in 1980, and now serves as an on-site exhibit of early frontier life in Kentucky. The new landscape design for the log house includes a kitchen garden with period-appropriate plants and outdoor demonstration areas. The inventories and journals of the Shaker community at South Union, KY provided the basis for the vegetables used in the kitchen garden, including \u27Late Flat Dutch\u27 cabbage and \u27Long Scarlet\u27 radish. Dye plants, such as bloodroot {Sanguinaria canadensis) and Virginia creeper (Parthenocissus quinquefolia). are included in the kitchen garden; the front of the house will be used to display examples of field crops, including \u27Stowell\u27s Evergreen corn. An area close to the house has been designed for a native plants display. Construction of these gardens in the spring of 2008 involved the removal of grass around the house in keeping with historical accuracy. Combined with the house\u27s location on campus, this will increase the potential for soil erosion. A fence and plants that are intended to act as vegetative filters are included in the design to help slow water runoff, and the use of raised planting beds and mulch to cover the bare soil will minimize soil loss. The native plant garden is intended to act as an introduction to the larger house exhibit, and provides a selection of plants native to Kentucky. Many plants are not typically seen outside of wild woodland settings, such as strawberry bush (Euonymus americana), bird\u27s foot violet {Violapedala), and rattlesnake plantain {Goodyera pubescens), and should increase visitors\u27 enjoyment of the entire display. A path connects the native garden to the house exhibit

Optimizing transition services programs : development of effective program models

The provision of transition services to students with disabilities is a collaborative effort among school districts, vocational rehabilitation agencies and other service agencies. The South Carolina Vocational Rehabilitation Department has placed an emphasis on transition services for students with disabilities in recent years. Implementing effective programs is not a "one size fits all" approach, as there are currently 86 school districts in the state, each with differing levels of resources, differences in programmatic focus, and different approaches to decision-making. This requires a site-by-site approach to relationship building and program implementation

Library Keeping Pace: Online, Media-Rich, and Interactive!

Have you had a look around the Library's website lately? If so, you will have noticed some really cool resources that we have created to help people learn about the Library and what it has to offer. Included are podcasts, online tutorials, interactive maps, and video tours