Vega2 is a CMP (chip multi-processor) with 48 processor cores, and several spare cores to improve yield. The chip also contains about 1000 memory macros both inside and outside the processor cores. The larger memories have column redundancy as well. The main DFT challenge for Vega2 is to produce an architecture that makes it easy to identify defective processors, thoroughly test the memories and efficiently apply ATPG patterns.

This paper addresses the issue of compiling concurrent loop nests in the presence of complicated array references and irregularly distributed arrays. Arrays accessed within loops may contain accesses that make it impossible to precisely determine the reference pattern at compile time. This paper proposes a run time support mechanism that is used effectively by a compiler to generate efficient code in these situations. The compiler accepts as input a Fortran 77 program enhanced with specifications for distributing data, and outputs a message passing program that runs on the nodes of a distributed memory machine. The runtime support for the compiler consists of a library of primitives designed to support irregular patterns of distributed array accesses and irregularly distributed array partitions. A variety of performance results on the Intel iPSC/860 are presented.>

Abstract Run‐time preprocessing plays a major role in many efficient algorithms in computer science, as well as playing an important role in exploiting multiprocessor architectures. We give examples that elucidate the importance of run‐time preprocessing and show how these optimizations can be integrated into compilers. To support our arguments, we describe transformations implemented in prototype multiprocessor compilers and present benchmarks from the iPSC2/860, the CM‐2 and the Encore Multimax/320.