Section: New Software and Platforms

Bee

Participants : Christophe Alias, Alain Darte.

Bee is a source-to-source optimizer that resizes and reallocates optimally the arrays used by a program under scheduling constraints. Bee applies a fine-grain lifetime analysis for arrays. Then, the mathematical optimization of the Cl@k tool (Section  5.3 ) finds the array allocation (expressed as an affine lattice). Finally, Bee derives the actual array allocation and generates the C code accordingly. Bee was – to our knowledge – the first complete (i.e., with an element-wise lifetime analyzer integrated with an allocator) array contraction tool. Bee allows to allocate and to size the channels in process networks, providing a global affine schedule. This feature is fundamental in HLS (see Section  3.1.2 ) and more generally in automatic parallelization where communication buffers must be allocated and sized. An online demonstrator is available at http://compsys-tools.ens-lyon.fr/bee/index.html .

Bee is registered at the APP (“agence de protection des programmes”) and has been transferred to the XtremLogic start-up under an Inria licence. It is also used as an external tool by the compiler Gecos developed in the Cairn team at Irisa. Bee has been implemented by Christophe Alias, using the PoCo compiler infrastructure (see Section  5.6 ). It represents more than 2400 lines of C++ code.