TuBound - A Conceptually New Tool for Worst-Case Execution Time Analysis

TuBound is a conceptually new tool for the worst-case execution time (WCET) analysis of programs. A distinctive feature of TuBound is the seamless integration of a WCET analysis component and of a compiler in a uniform tool. TuBound enables the programmer to provide hints improving the precision of the WCET computation on the high-level program source code, while preserving the advantages of using an optimizing compiler and the accuracy of a WCET analysis performed on the low-level machine code. This way, TuBound ideally serves the needs of both the programmer and the WCET analysis by providing them the interface on the very abstraction level that is most appropriate and convenient to them. In this paper we present the system architecture of TuBound, discuss the internal work-flow of the tool, and report on first measurements using benchmarks from Maelardalen University. TuBound took also part in the WCET Tool Challenge 2008

The WCET Tool Challenge 2011

Following the successful WCET Tool Challenges in 2006 and 2008, the third event in this series was organized in 2011, again with support from the ARTIST DESIGN Network of Excellence. Following the practice established in the previous Challenges, the WCET Tool Challenge 2011 (WCC'11) defined two kinds of problems to be solved by the Challenge participants with their tools, WCET problems, which ask for bounds on the execution time, and flow-analysis problems, which ask for bounds on the number of times certain parts of the code can be executed. The benchmarks to be used in WCC'11 were debie1, PapaBench, and an industrial-strength application from the automotive domain provided by Daimler AG. Two default execution platforms were suggested to the participants, the ARM7 as "simple target'' and the MPC5553/5554 as a "complex target,'' but participants were free to use other platforms as well. Ten tools participated in WCC'11: aiT, Astr\'ee, Bound-T, FORTAS, METAMOC, OTAWA, SWEET, TimeWeaver, TuBound and WCA

Embedded Program Annotations for WCET Analysis

We present __builtin_ais_annot(), a user-friendly, versatile way to transfer annotations (also known as flow facts) written on the source code level to the machine code level. To do so, we couple two tools often used during the development of safety-critical hard real-time systems, the formally verified C compiler CompCert and the static WCET analyzer aiT. CompCert stores the AIS annotations given via __builtin_ais_annot() in a special section of the ELF binary, which can later be extracted automatically by aiT

ALF - A Language for WCET Flow Analysis

Static Worst-Case Execution Time (WCET) analysis derives upper bounds for the execution times of programs. Such bounds are crucial when designing and verifying real-time systems. A key component in static WCET analysis is the flow analysis, which derives bounds on the number of times different code entities can be executed. Examples of flow information derived by a flow analysis are loop bounds and infeasible paths. Flow analysis can be performed on source code, intermediate code, or binary code: for the latter, there is a proliferation of instruction sets. Thus, flow analysis must deal with many code formats. However, the basic flow analysis techniques are more or less the same regardless of the code format. Thus, an interesting option is to define a common code format for flow analysis, which also allows for easy translation from the other formats. Flow analyses for this common format will then be portable, in principle supporting all types of code formats which can be translated to this format. Further, a common format simplifies the development of flow analyses, since only one specific code format needs to be targeted. This paper presents such a common code format, the ALF language (ARTIST2 Language for WCET Flow Analysis)

Programmiersprachen und Rechenkonzepte

Seit 1984 veranstaltet die GI-Fachgruppe "Programmiersprachen und Rechenkonzepte", die aus den ehemaligen Fachgruppen 2.1.3 "Implementierung von Programmiersprachen" und 2.1.4 "Alternative Konzepte für Sprachen und Rechner" hervorgegangen ist, regelmäßig im Frühjahr einen Workshop im Physikzentrum Bad Honnef. Das Treffen dient in erster Linie dem gegenseitigen Kennenlernen, dem Erfahrungsaustausch, der Diskussion und der Vertiefung gegenseitiger Kontakte

Programmiersprachen und Rechenkonzepte

Seit 1984 veranstaltet die GI-Fachgruppe "Programmiersprachen und Rechenkonzepte" regelmäßig im Frühjahr einen Workshop im Physikzentrum Bad Honnef. Das Treffen dient in erster Linie dem gegenseitigen Kennenlernen, dem Erfahrungsaustausch, der Diskussion und der Vertiefung gegenseitiger Kontakte. In diesem Forum werden Vorträge und Demonstrationen sowohl bereits abgeschlossener als auch noch laufender Arbeiten vorgestellt, unter anderem (aber nicht ausschließlich) zu Themen wie - Sprachen, Sprachparadigmen, - Korrektheit von Entwurf und Implementierung, -Werkzeuge, -Software-/Hardware-Architekturen, -Spezifikation, Entwurf, - Validierung, Verifikation, - Implementierung, Integration, - Sicherheit (Safety und Security), - eingebettete Systeme, - hardware-nahe Programmierung. In diesem Technischen Bericht sind einige der präsentierten Arbeiten zusammen gestellt