2nd European Workshop on Automatic Differentiation

Thursday November 17- Friday November 18, 2005

Whitworth Conference Centre

Cranfield University (Shrivenham Campus)

Defence Academy of the UK

Shrivenham, Swindon

M. Maier, B. Christianson  and U.  Naumann

Toward CompAD-II

Abstract:  The first part of the Differentiation-enabled Compiler Technology project (CompAD-I) resulted in forward mode and simple tape-based reverse mode capabilities inside a research prototype of the NAGWare Fortran 95 compiler. For CompAD-II we plan full support for adjoints by source transformation based on the compiler's internal representation. First steps have been made as part of a collaboration between the University of Hertfordshire and RWTH Aachen University. We have implemented a C++ interface to the compiler's native C API. The debug engine for the internal representation has been enhanced. The new interface has been used to implement the control-flow reversal for well-structured programs. In addition to the description of the new functionalities we will give a summary of the CompAD-II proposal that has been submitted to EPSRC. Ultimately we intend to generate second-order adjoint code by generating a tangent-linear model of the adjoint assembler code that is produced by the  compiler.

Slides: MaierNov05.pdf