A VLIW Geometry Processor with Software Bypass Mechanism

Yasunori KIMURA  Akira ASATO  Toshihiro OZAWA  Hiroshi NAKAYAMA  

IEICE TRANSACTIONS on Electronics   Vol.E81-C   No.5   pp.669-679
Publication Date: 1998/05/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Multimedia, Network, and DRAM LSIs)
3D graphics,  geometry processing,  VLIW,  compiler,  

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This paper describes the 'Procyon' processor which is to be used for geometry processing. The objective of this processor is to provide a high performance geometry processor to support next generation 3D graphics such as game and CAD applications. The Procyon processor is a four parallel VLIW processor which makes hardware logic simple. We are pursuing performance improvement by compiler optimization. Procyon has a unique feature called 'Software bypass' as well as special hardware to support 3D graphics processing. Software bypass enables the compiler to make accesses to data on hardware bypass lines. By using this information, the compiler can schedule instructions much more freely and generates efficient VLIW code. Other features of Procyon are multiply-add-accumulate instruction, SIMD instructions and clipping instructions. Procyon VLIW code is held in compacted form, which improves memory performance. A program development environment, such as a pipeline simulator and an assembly code parallelizer, is also prepared for system and application programmers. Preliminary simulation results demonstrate that a performance of 2. 6 M polygons per second at 125 MHz Procyon is attained.