Costing JIT Traces

Tracing JIT compilation generates units of compilation that are easy to analyse and are known to execute frequently. The AJITPar project aims to investigate whether the information in JIT traces can be used to make better scheduling decisions or perform code transformations to adapt the code for a specific parallel architecture. To achieve this goal, a cost model must be developed to estimate the execution time of an individual trace. This paper presents the design and implementation of a system for extracting JIT trace information from the Pycket JIT compiler. We define three increasingly parametric cost models for Pycket traces. We perform a search of the cost model parameter space using genetic algorithms to identify the best weightings for those parameters. We test the accuracy of these cost models for predicting the cost of individual traces on a set of loop-based micro-benchmarks. We also compare the accuracy of the cost models for predicting whole program execution time over the Pycket benchmark suite. Our results show that the weighted cost model using the weightings found from the genetic algorithm search has the best accuracy

Spot

The South Carolina Department of Natural Resources published guides to many threatened animals living in the state. This guide gives information about the Sciaenidae, including description, status, habitat, conservation challenges & recommendations, and measures of success

Striped Killifish

The South Carolina Department of Natural Resources published guides to many threatened animals living in the state. This guide gives information about the Striped Killifish, including description, status, habitat, conservation challenges & recommendations, and measures of success

Understanding representation : contrasting gesture and sketching in design through dual-process theory

Representation is essential to design work. While there is a multitude of research on, for example, gesture, prototyping, and sketching, there is a critical need for a more general account of design representation, able to explain diverse results across representation modes and design tasks. We address this need by experimentally testing dual-process theory hypotheses regarding the impact of gesture and sketching on a range of design tasks, including reproduction, evaluation, elaboration, ideation, and selection. Central to this is the (mis)match between representation mode at input/response, and the interaction between Type 1 and Type 2 processing. These findings support a novel dual-process explanation of design representation, suggest resolutions to previously contradictory findings, and provide implications for design theory, education, and practice

Electroweak oblique parameters as a probe of the trilinear Higgs boson self-interaction

We calculate the two-loop contributions from a modified trilinear Higgs self-interaction, κλλSMvh3, to the electroweak oblique parameters S and T. Using the current bounds on S and T from electroweak measurements, we find the 95% C.L. constraint on the modified trilinear coupling to be −14.0≤κλ≤17.4. The largest effects on S and T arise from two insertions of the modified trilinear coupling that result in T/S≃−3/2; remarkably, this is nearly parallel to the axis of the tightest experimental constraint in the S-T plane. No contributions to S and T arise from a modified Higgs quartic coupling at two-loop order. These calculations utilized a gauge-invariant parameterization of the trilinear Higgs coupling in terms of higher dimensional operators (H†H)n with n≥3. Interestingly, the bounds on κλ that we obtain are comparable to constraints from di-Higgs production at the LHC as well as recent bounds from single Higgs production at the LHC