As microprocessors evolve into heterogeneous architectures with multi-cores of MPUs and GPUs, programming model supports become important for programming such architectures. To address this issue, OpenCL is proposed. Currently, most of OpenCL implementations take LLVM as their infrastructures. This presents an opportunity to demonstrate whether OpenCL can be effectively implemented on other compiler infrastructures. For example, Open64, which is another open source compiler and known to generate efficient codes for microprocessors, can contribute further to performance improvements and enhancing the adoption of heterogeneous computing based on OpenCL. In this paper, we describe the flow to enable an OpenCL compiler based on Open64 infrastructures for ATI GPUs. Our work includes the extension of the front-end parser for OpenCL, the generation of high-level intermediate representations with OpenCL linguistics, performing high-level optimization, and finally applying OpenCL specific optimization for code generations. Preliminary experimental results show that our compiler based on Open64 is able to generate efficient codes for OpenCL programs.