1st seminar:

Title:
Storage Allocation for Embedded Processors.
Jan Sjödin and Carl von Platen.

Content:
In an embedded system is it common to have several memory areas with different properties such as access time and size. An access to a specific memory area is usually restricted to certain native pointer types. The problem is to allocate data and select pointer types in the most effective way.

We present a model of storage allocation that is capable of describing architectures with irregular memory organization and several native pointer types. This model is used in an integer linear programming (ILP) formulation of the problem. An ILP solver is applied to get an optimal solution under the model.

A prototype whole program optimizing C compiler was used to implement the allocator.

2nd seminar:

Title:
Efficient Longest Executable Path Search for Programs with Complex Flows and Pipeline Effects.
Friedhelm Stappert, Andreas Ermedahl and Jakob Engblom.

Content: Current development tools for embedded real-time systems do not efficiently support the timing aspect. The most important timing parameter for scheduling and system analysis is the Worst-Case Execution Time (WCET) of a program.

The presentation will give a short overview of work performed in the WCET research field and present a newly developed and efficient WCET calculation method. The method builds upon Dijkstra's classical longest-path search algorithm but has been extended to take into account low-level machine aspects like pipelining and caches as well as high-level program flow like loops and infeasible paths. The method is more efficient than previous path-based approaches, and can easily handle complex programs. By separating the low-level from the high-level analysis, the method is easy to retarget.

Experiments confirm that speed does not sacrifice precision, and that programs with extreme numbers of potential execution paths can be analyzed quickly.

Both papers will be presented at the CASES 2001 conference:
http://www.crest.gatech.edu/conferences/cases2001/

ASTEC seminar
November 12, 2001

Place: Information technology, Uppsala University
Room: 1113
Time: 15.15-16.00 (+ discussions)

Room 1113 is in building 1, floor 1, room 13 (in the southern part of the building).

Help on how to find ASTEC Seminars.

There will be an extended period for discussions after the seminar.

Speakers are encouraged to give an short (5 min) introduction to the subject at the begining of the talk.
Listeners are excused if they have to leave after 16.00.