Method for compressing codes of decoding module of instruction set simulator

Abstract

The invention discloses a method for compressing codes of a decoding module of an instruction set simulator. The method comprises the following steps: grouping all instructions according to the distribution condition of instruction decoding feature sections in an instruction set; dividing the instructions with decoding characteristic section distribution into the same group; meanwhile, the occurrence frequencies of all the instructions in the same group are accumulated to serve as the instruction frequency of the group; sorting all the groups in a descending order according to the instructionfrequencies of the groups, and sorting each instruction in the groups in a descending order according to the instruction frequencies of the instructions; generating a decoding code block of each groupaccording to the sorting result, and finally achieving the effect of compressing instructions with the same decoding feature section to the same decoding code block; and meanwhile, instruction decoding in the group is carried out according to a sequence from high to low, so that the code scale of the simulator decoding module is remarkably reduced. The method is suitable for various types of instruction sets, can remarkably reduce the bit matching frequency when the simulator analyzes the instruction, improves the operation efficiency of the simulator, and has a better application prospect.

Description

technical field [0001] The invention relates to instruction set simulation, in particular to a compression method for decoding module codes of the instruction set simulator. Background technique [0002] Because the instruction set simulator has the advantages of getting rid of the limitation of the number of hardware, the running process can be debugged, and the device status can be obtained at any time, it has been widely used in hardware simulation, chip design and other fields. [0003] The decoding module of the instruction set simulator determines the instruction type by matching the instruction operation code, and extracts the information of each feature segment according to the instruction encoding format. In practice, since an instruction set often contains hundreds of instructions, and the decoding module needs to support the identification of all instruction types, the codes of related modules are often very large and extremely complex. In addition, when the simu...

AI Technical Summary

Problems solved by technology

During the decoding process, except for the judgment of the OP field, the judgment of other fields, such as the decoding feature segment, creg field, z field, etc., will be repeated multiple times, resulting in a decrease in the efficiency of the decoding function.

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