A Library for Explicit Dynamic Code Generation and Optimisation in C++

    Olav Beckmann, Peter Fordham, Alastair Houghton and Paul Kelly

	   Department of Computing, Imperial College London
		   180 Queen s Gate, London SW7 2BZ
			    United Kingdom
		 Email {o.beckmann,p.kelly}@ic.ac.uk

			       Abstract
			       ========

The TaskGraph Library is a C++ library for dynamic code generation,
which combines specialisation with dependence analysis and loop
restructuring.  A TaskGraph represents a fragment of code which is
constructed and manipulated at run-time, then compiled, dynamically
linked and executed.  TaskGraphs are initialised using macros and
overloading, which forms a simplified, C-like sub-language with
first-class arrays and no pointer arithmetic.  Once a TaskGraph has
been constructed, we can analyse dependence structure and perform
optimisations.  In this paper, we present the design of the TaskGraph
library, present several sample applications for this library which
demonstrate its use for runtime code specialisation and optimisation
and discuss related work and future applications and developments of
the library.