VICTORIA - VMX indirect compute technology oriented towards in-line acceleration

Abstract

There is increasing interest in the use of accelerators in computer systems. Accelerators are processor-attached hardware units that can perform certain functions faster than the conventional general purpose processor. In this paper, we describe the VICTORIA PowerPC architecture, which is based on the iVMX accelerator technology. The iVMX accelerator extends the existing VMX architecture with indirect register addressing. That approach greatly extends the architected space of registers and opens the door for highly optimized vector algorithms that can sustain very high processing rates. The large space of registers is directly controlled by the executing code and offers a sufficiently large storage to hold sizeable intermediate results. This helps reduce the negative effects of limited memory bandwidth and high memory latency. The iVMX accelerator is an example of in-line accelerator; that is, the instructions that drive the accelerator are part of the same stream that drives the main processor. Compared to off-line accelerators, which execute their own instruction stream, in-line accelerators present a much more convenient programming model. Copyright 2006 ACM.