Mapping a mathematical expression onto a Montium ALU using GNU Bison

Abstract

The Montium processing tile [1], [4] contains a number of complex ALUs which can perform many different operations in many different ways. In the Chameleon tool flow [2], it is necessary to automatically determine whether a certain mathematical expression can be mapped onto an ALU and to automatically generate an ALU configuration for this expression. This paper describes how the parser generator GNU Bison [5] is used to determine whether a mapping is possible and how Generalized LR Parsing [6] is used to cope with ambiguities and to generate all possible mappings of a specific expression onto an ALU