Method and device for extending immediate operand in computer instruction

Abstract

The invention discloses a method and device for extending an immediate operand in a computer instruction. At least one immediate operand extending instruction is newly increased in an RISC instruction system, during the programming process, an immediate operand the digit number of which is larger than the length of an immediate operand domain of an execution instruction is divided into a high-order immediate operand field and a low-order immediate operand field, the high-order immediate operand field is subjected to signed extension or unsigned extension and then is stored in the immediate operand domain of the immediate operand extending instruction, and the low-order immediate operand field just fills up the immediate operand domain of the execution instruction; during the instruction fetching process, the newly-increased immediate operand extending instruction and the execution instruction following closely are sent into respective decoders synchronously to carry out decoding; during the decoding process, the immediate operand output by the immediate operand extending instruction decoder is subjected to logical left shift and then is merged with the immediate operand output by the execution instruction decoder, after the merging process, the immediate operand the digit number of which is larger than the length of the immediate operand domain of the execution instruction is obtained. By employing the method for extending the immediate operand in the computer instruction, the program execution efficiency can be greatly improved, and time and space are saved.

Description

technical field [0001] The invention belongs to the field of computers, and in particular relates to a method and a device for extending an immediate number in a computer instruction, so that the RISC computer instruction can obtain an immediate number whose number of digits is greater than that of the immediate number domain of an execution instruction. Background technique [0002] At present, computer systems are mainly divided into CISC system and RISC system, and corresponding to these two systems, there are two different styles of instruction specifications. The CISC system appeared first, and its instruction set is characterized by a relatively large scale, the immediate number that the instruction can carry can be large, and the length of each instruction is inconsistent, the most representative is the X86 instruction set; while the RISC system appeared relatively late, its instruction set features The scale is relatively small, only commonly used instructions are in...

AI Technical Summary

Problems solved by technology

[0020] In order to solve the problem that the existing RISC instruction system obtains large immediate data and execute low efficiency, but also maintain the advantages of RISC instruction system simplification and uniform length, the present invention proposes a method for extending the immediate data in computer instructions, using this The method RISC computer instruction can also quickly obtain an immediate value whose digit exceeds the immediate value field of the execution instruction

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