VLIW Across Multiple Superscalar Processors on a Single Chip

Advances in IC technology increase the integration density for higher clock rates and provide more opportunities for microprocessor design. In this paper, we propose a new paradigm to exploit instruction-level parallelism (ILP) across multiple superscalar processors on a single chip by taking advantages of both VLIW-style static scheduling techniques and dynamic scheduling of superscalar architecture. In the proposed paradigm, ILP is exploited by a compiler from a sequential program and this VLIW-like-parallelized code is further parallelized by 2-way superscalar engines at run-time. Superscalar processors are connected by an aggregate function network, which can enforce the necessary static timing constraints and provide appropriate inter-processor data communication mechanisms that are needed for ILP. The aggregate function operations are statically scheduled and implement not only fine-grain communication and control, but also simple global computations resembling systolic array operations within the network.