  Modern programmable digital signal processing relies on floating-point
numbers for their ease of use. Fixed-point number formats have the potential to
save resources and improve execution time, but realising this potential burdens
the programmer with the need to define each format, at every step of the
computation. This article reviews existing methods to automatically determine
fixed-point formats, then describes and evaluates the prototype implementation
of automatic fixed-point format determination in the Faust compiler.
