An integrated functional solution for multi-core programming on the cell broadband engine
Nathaniel Azuelos · eScholarship@McGill (McGill) · 2009
Recent efforts in microprocessor development tend to the coexistence of several Central Processing Units (CPUs) on a single chip. The Cell Broadband Engine (CBE), the fruit of collaboration between Sony, Toshiba and IBM, integrates IBM's legacy PowerPC CPU with a new set of simple cores, all of which communicate through a high speed bus. The multiple cores on the CBE allow users to exploit the parallel nature of their programs. However, it is often difficult to effciently extract the parallelism from an application and to distribute tasks in a suitable fashion. We propose a dataflow approach to CBE computing where the compiler is in charge of task partitioning and of the infrastructure for runtime distribution of tasks. In this work, we present the NCC programming language, Squid compiler and runtime environment. NCC is a strict functional dataflow language that forces explicit variable dependencies, in order to exploit parallelism in the application. NCC code is thus written by the user without specifying parallelism explicitly. The Squid Compiler draws a virtual data flow graph from the NCC source. This graph is then partitionned according to implementation specific criteria into tasks and supertasks. The individual tasks are then translated to ANSI-C, and supertasks are analyzed and transformed into scheduling structures. All tasks are executed by the CBE's simple cores. The Squid Runtime Environment (SRE) interacts with the generated scheduler to order tasks' execution, running the supertasks' scheduling, and managing garbage collection. The SRE runs on the CBE's PowerPC core as a separate thread to implement a host-device paradigm, and as resident code on the s