The thesis focuses on a group of programme-specific subject teachers working in the upper secondary school child recreation programme. The aim has been to study who is appointed to these positions, and ways in which their work is affected by national and local requirements. An additional aim has been to examine the factors which affect the teachers' professional identity, and the position which they have acquired at upper secondary school. The theoretical frameworks used are profession theories, discourse theories, Bernstein's curriculum theory, Bourdieu's cultural-sociological concept, and gender theory. The study is qualitative in nature and the empirical data consists of the written accounts and diary entries of ten teachers. The teachers and three school principals were interviewed in autumn 1998. In addition to government reports and guidelines the data also include questionnaire responses from 184 upper secondary teachers. The results indicate that decentralisation has caused many of the tasks and responsibilities generated by the upper secondary reform of the 1990s to become invisible. The teachers, who form a heterogeneous group, are responsible for both a broad multi-disciplinary subject area and work-place teaching for which none of them has been fully trained. The complexity of the student groups, with many students experiencing study difficulties, has imposed considerable demands on the teachers, who have developed approaches and pedagogical techniques for dealing with the students' needs. The teachers' work with students and their experience of cooperation, team work and alternative working methods in line with government aims has proved successful, according to National Agency for Education reports and statements by school principals. Their care-oriented approach has also fitted in well with the government aim of a school for all. In this respect they are clearly professional. However, the teachers do not appear to have established a particularly prominent role for themselves in the upper secondary school system. They are very much seen by others and themselves to occupy a low-status category and to have developed their professional identity within a generalist ideal, whereas the norm at upper secondary school is still characterised by a specialist ideal. / digitalisering@umu

<p>In this thesis we address the problem of optimal code generation for irregular architectures such as Digital Signal Processors (DSPs).</p><p>Code generation consists mainly of three interrelated optimization tasks: instruction selection (with resource allocation), instruction scheduling and register allocation. These tasks have been discovered to be NP-hard for most architectures and most situations. A common approach to code generation consists in solving each task separately, i.e. in a decoupled manner, which is easier from a software engineering point of view. Phase-decoupled compilers produce good code quality for regular architectures, but if applied to DSPs the resulting code is of significantly lower performance due to strong interdependences between the different tasks.</p><p>We developed a novel method for fully integrated code generation at the basic block level, based on dynamic programming. It handles the most important tasks of code generation in a single optimization step and produces an optimal code sequence. Our dynamic programming algorithm is applicable to small, yet not trivial problem instances with up to 50 instructions per basic block if data locality is not an issue, and up to 20 instructions if we take data locality with optimal scheduling of data transfers on irregular processor architectures into account. For larger problem instances we have developed heuristic relaxations.</p><p>In order to obtain a retargetable framework we developed a structured architecture specification language, xADML, which is based on XML. We implemented such a framework, called OPTIMIST that is parameterized by an xADML architecture specification.</p><p>The thesis further provides an Integer Linear Programming formulation of fully integrated optimal code generation for VLIW architectures with a homogeneous register file. Where it terminates successfully, the ILP-based optimizer mostly works faster than the dynamic programming approach; on the other hand, it fails for several larger examples where dynamic programming still provides a solution. Hence, the two approaches complement each other. In particular, we show how the dynamic programming approach can be used to precondition the ILP formulation.</p><p>As far as we know from the literature, this is for the first time that the main tasks of code generation are solved optimally in a single and fully integrated optimization step that additionally considers data placement in register sets and optimal scheduling of data transfers between different registers sets.</p>

In this thesis we address the problem of optimal code generation for irregular architectures such as Digital Signal Processors (DSPs). Code generation consists mainly of three interrelated optimization tasks: instruction selection (with resource allocation), instruction scheduling and register allocation. These tasks have been discovered to be NP-hard for most architectures and most situations. A common approach to code generation consists in solving each task separately, i.e. in a decoupled manner, which is easier from a software engineering point of view. Phase-decoupled compilers produce good code quality for regular architectures, but if applied to DSPs the resulting code is of significantly lower performance due to strong interdependences between the different tasks. We developed a novel method for fully integrated code generation at the basic block level, based on dynamic programming. It handles the most important tasks of code generation in a single optimization step and produces an optimal code sequence. Our dynamic programming algorithm is applicable to small, yet not trivial problem instances with up to 50 instructions per basic block if data locality is not an issue, and up to 20 instructions if we take data locality with optimal scheduling of data transfers on irregular processor architectures into account. For larger problem instances we have developed heuristic relaxations. In order to obtain a retargetable framework we developed a structured architecture specification language, xADML, which is based on XML. We implemented such a framework, called OPTIMIST that is parameterized by an xADML architecture specification. The thesis further provides an Integer Linear Programming formulation of fully integrated optimal code generation for VLIW architectures with a homogeneous register file. Where it terminates successfully, the ILP-based optimizer mostly works faster than the dynamic programming approach; on the other hand, it fails for several larger examples where dynamic programming still provides a solution. Hence, the two approaches complement each other. In particular, we show how the dynamic programming approach can be used to precondition the ILP formulation. As far as we know from the literature, this is for the first time that the main tasks of code generation are solved optimally in a single and fully integrated optimization step that additionally considers data placement in register sets and optimal scheduling of data transfers between different registers sets.