Properties of rescheduling size invariance for dynamic rescheduling-based VLIW cross-generation compatibility

The object-code compatibility problem in VLIW architectures stems from thei r statically scheduled nature. Dynamic rescheduling (DR) [1] is a technique to solve the compatibility problem in VLIWs. DR reschedules program code p ages at first-time page faults, i.e., when the code pages are accessed for the first time during execution. Treating a page of code as the unit of res cheduling makes it susceptible to the hazards of changes in the page size d uring the process of rescheduling. This paper shows that the changes in the page size are only due to insertion and/or deletion of NOPs in the code. F urther, it presents an ISA encoding, called list encoding, which does not r equire explicit encoding of the NOPs in the code. Algorithms to perform res cheduling on acyclic code and cyclic code are presented, followed by the di scussion of the property of rescheduling-size invariance (RSI) satisfied by list encoding.