White paper: Encoding Compiler and Encoded Processing Martin S¨ ußkraut, Ute Schiffel, Andr´ e Schmitt, and Christof Fetzer Computer Science Department Technische Universit¨ at Dresden Dresden, Germany February 27, 2011 1 Introduction In the future, decreasing feature sizes of integrated circuits will lead to less reliable hard- ware [3]. Currently used hardware-based solutions to detect hardware errors are expensive and usually an order of magnitude slower than commodity hardware [2]. Thus, due to economic pressure, more and more critical systems need to be based on unreliable com- modity hardware. However, commodity hardware not only exhibits fail-stop behavior but also more difficult to detect and to mask silent data corruptions (SDCs), i.e., commodity systems will also generate erroneous output instead of crashing. SDCs are transient or permanent. Double- or triple-modular redundancy can detect transient corruptions. However, such redundancy requires a more complicated and expen- sive hardware setup compared to our solution. Permanent corruptions cannot be detected by double- or triple-modular redundancy. However, in the future, hardware aging will lead to more permanent corruptions [3]. Our vision is to enable the use of cost effective unreliable commodity hardware in safety critical systems. To achieve our vision, we extend the limited failure detection capabilities of commodity hardware with the help of software. In addition to a more sophisticated failure detection, system architects can apply well known toleration approaches to mask SDCs. Our approach works well with retries, fail-over, and graceful degradation. 1