We propose a new method of eliminating range checks in connection with array index expressions and assignments to variables of subrange types. Contrary to the approaches documented in the literature, we work on an extended static single assignment form (XSA) very near the target level. This gives signiicant advantages over previous attempts since many questions don't occur at all or else in a s...

The mechanism of copy-on-write is recently used in speculative and deterministic parallel systems. In these systems, copy-on-write happens when a task modifies a variable for the first time. At the program level, the copying is a form of renaming. This paper extends the formalism of static single assignment (SSA) to introduce a program representation called task static single assignment (T-SSA)...

Advanced Traveler Information Systems (ATIS) and Advanced Traffic Management Systems (ATMS) have the potential to contribute to the solution of the traffic congestion problem. However, for these systems to be effective, the generated strategies should be proactive (i.e. based on predicted traffic conditions) as opposed to reactive, in order to avoid many undesirable effects such as overreaction...

Greater speed is needed because of the desire to do larger and more complex problems, and greater accuracy is needed because, without it, there can be large errors in estimates of the impacts of plans and projects. The discussion below purposely limits technical detail so as to be accessible to a wide audience of users and managers, but there are numerous references that provide a full discussi...

In previous work we have shown that more precise type analysis can be achieved by exploiting union types and static single assignment (SSA) intermediate representation (IR) of code. In this paper we exploit static single information (SSI), an extension of SSA proposed in literature and adopted by some compilers, to allow assignments of more precise types to variables in conditional branches. In...

This work pleads for the use of the concept of strategies, and their network-theoretic representation as hyperpaths, for modeling network assignment problems. While this concept describes adequately the behavior of users in transit systems, we show that it can apply as well to networks where arc capacities are rigid. This opens up a whole new field of research and raises several questions, from...

This paper presents a path-based traffic assignment algorithm for solving the static deterministic user equilibrium traffic assignment problem. It uses the concepts of the path shift-propensity factor and the sensitivity of path costs with respect to path flows in the flow update process, and is labeled as the slope-based path shift-propensity algorithm (SPSA). It seeks to enable faster converg...

In this paper we introduce the basic methodology for analyzing and debugging programs. We first convert programs into their loop-free equivalents and from this into the static single assignment form. From the static single assignment form we derive a corresponding constraint satisfaction problem. The constraint representation can be directly used for debugging. From the corresponding hyper-tree...

Partial redundancy elimination (PRE) is a program transformation that identifies and eliminates expressions that are redundant on at least one (but not necessarily all) execution paths of a program without increasing any path length. Chow, Kennedy, et al. devised an algorithm (SSAPRE) for performing partial redundancy elimination on intermediate representation in static single assignment (SSA) ...

adio regulatory bodies are recognizing that the rigid spectrum assignment granting exclusive use to licensed services is highly inefficient, due to the high variability of the traffic statistics across time, space, and frequency. Recent Federal Communications Commission (FCC) measurements show that, in fact, the spectrum usage is typically concentrated over certain portions of the spectrum, whi...