COMPILING FOR THE CYDRA-5

The Cydra 5 is a VLIW minisupercomputer with hardware designed to accelerate a broad class of inner loops, presenting unique challenges to its compilers. We discuss the organization of its Fortran/77 compiler and several of the key approaches developed to fully exploit the hardware. These include the intermediate representation used; the preparation, overlapped scheduling, and register allocation of inner loops; the speculative execution model used to control global code motion; and the machine model and local instruction scheduling approach.