Binary translation

When Digital Equipment Corp. began designing the Alpha AXP architecture, the Alpha AXP team was concerned with running existing VAX code and MIPS code on the new Alpha AXP computers. The Alpha AXP migration tools team turned to open-ended binary translation. One team member wrote a VAX-to-VAX binary translator as a proof of concept. The team set several goals, including: 1. open-ended translation of almost all user-mode applications from the OpenVMS VAX system to the OpenVMS AXP system, 2. run-time performance of translated code on Alpha AXP computers that meets or exceeds the performance of the original code on the original architecture, and 3. generation of explicit messages that give reasons and specify what source changes are necessary when translation is not possible. To achieve these goals, the team created VEST, to translate OpenVMS VAX binary images to OpenVMS AXP images and mx, to translate ULTRIX MIPS images to DEC OSF/1 AXP images. The team also built a run-time environment in which to execute the translated code.