The following technical report is available from
http://aib.informatik.rwth-aachen.de:
Tangent-Linear Models by Augmented LL-Parsers
Uwe Naumann, Andre Vehreschild
AIB 2005-19
We describe a novel method for the generation of tangent-linear
code by augmentation of LL-parsers generated by the software tool
ANTLR. The main advantage of this approach to source code augmentation
is the missing requirement for an internal representation of the
original program. We consider this work as the basis for further
investigations into how far this technique can be extended in the
context of more sophisticated transformations, for example, the
automatic generation of adjoint codes.
Our prototype tool AD_C_ANTLR currently accepts a subset of the
ANSI C standard. We discuss its theoretical basis, and we present
case studies to underline the elegance of the parser-based approach
to source augmentation.
The following technical report is available from
http://aib.informatik.rwth-aachen.de:
Syntax-directed Derivative Code (Part II: Intraprocedural Adjoint Code)
Uwe Naumann
AIB 2005-17
This is the second instance in a series of papers on single-pass
generation of derivative codes by syntax-directed translation. We
consider the automatic generation of adjoint code by reverse mode
automatic differentiation implemented as the bottom-up propagation
of synthesized attributes on the abstract syntax tree. A proof-of-concept
implementation is presented based on a simple LALR(1) parser generated
by the parser generator bison. The approach offers all advantages
of adjoint codes while exhibiting the highly desirable ease of
implementation.
