Abstract: To reduce the redundant memory access caused by unnecessary registers overflow in binary translation, as the registers mapping in binary translation ignores the difference of register requirements among basic blocks and loop blocks, an efficient dynamic and static combined registers mapping optimization algorithm based on priority is proposed, introduces the idea of allocating global register statically and allocating local register dynamically. Firstly, global register is mapped statically to reduce the global register overflow cost and maintenance overhead, according to statistical features of different registers used on the source platform and the life cycle of variable. Then, the number of registers requested by intermediate instruction can be obtained, based on the intermediate representation. Therefore, the priority of registers allocation is determined. Lastly, dynamically allocate the registers in order to reduce the number of registers overflow, to reduce the expansion rate of the generated local code and memory access times. Thus, the performance of the target program is improved. The test results of NBENCH, representative recursive programs and SPEC2006 show that, the algorithm effectively reduces the memory access of local code, and improves the program performance with an average increase of 8.56%, 8.14%, and 8.01%, respectively.

Key words: binary translation, register allocation, quick emulator (QEMU), feedback static QEMU (FD-SQEMU), TCG intermediate code