The Development And Research On SIMD Compilation Optimization Of Compilers For Media Processor

Compiler is an important part of computer system. Usually, it is used to translate source codewritten in a high-level programming language to assembly code or machine code. With thedevelopment of the high-level languages and the structure (or the architecture) of the processors,the design of the compiler is becoming more and more complex and difficult. Media processorsare widely used in the digital signal processing and multimedia processing. In order to meet thespecial needs in media processing, they have a common characteristic in the hardware designingand implementation—SIMD. Nowdays, several compilers have been developed to generate SIMDinstructions. But, their support to SIMD instructions is not good enough as people wished. Thisthesis is involved with some research on compilation techniques for media processors with SIMDinstructions.Nowdays many multimedia applications are written in assembly code by hand. Although thiscan take full advantages of the processor's capability, including SIMD, it will lead to poorreadability, portability problem and high cost of software development and maintainance. In orderto ultilize SIMD instruction fully, we need compiler to translate the high-level languages to SIMDinstructions of media processors automatically. This is called SIMD compilation optimization.MD32 is a 32-bit media processor designed by information and Communication Institute ofZhejiang University, mainly facing to media processing. It has both the characteristics of RISCand DSP, and provides SIMD instructions called MDS Instructions Set which is based on MMXtechnique.The traditional compiler cannot generate SIMD instructions very well because of thecharacteristics of SIMD instructions and the code generation of compilers. An improved approachof instruction selection has been designed and implemented in this thesis to support SIMDinstruction generation.MD32 is still being constantly developed and the ability of MD32 for media processing isimproving. In order to adapt the changes of the target machine, the retargetable compilersupporting SIMD instructions is needed. A SIMD compilation optimization approach based on theintermediate representation is proposed in this thesis. This approach improves the performance ofcode effectively. Meanwhile, it can also keep the retargetablity of the original compiler and adaptthe change in instruction of the target machine.