In autonomous embedded systems --- which become more and more present in our daily life --- energy management is a crucial issue. Although it has been widely studied from a hardware point of view, this domain remains less explored in software, especially with respect to compiler support where historically optimizations generally dealt with speed. This paper thus aims at providing a survey of low-power and low-energy compilation techniques. It briefly introduces low-level techniques, then presents more largely higher-level techniques, especially those pertaining to memory management and operation modes of resources, before drawing the domain perspectives.