一种基于数据分解的ARM非法立即数处理技术  

A Processing Technique for Illegal Immediate Data of ARM Based on Data Resolution

作　　者：库少平[1] 王胜[1] 胡芸珊[2] 

机构地区：[1]武汉理工大学计算机科学与技术学院,湖北武汉430070 [2]华中科技大学武昌分校,湖北武汉430064

出　　处：《武汉理工大学学报（信息与管理工程版）》2009年第2期251-254,共4页Journal of Wuhan University of Technology：Information & Management Engineering

基　　金：国家自然科学基金资助项目(50375113)

摘　　要：为了解决非法立即数的传送问题，ARM汇编语言设置了LDR伪指令，但LDR伪指令因需要访问存储器而增大了时间开销。针对这一问题提出了一种基于数据分解的非法立即数处理技术，以降低指令的时间开销。给出了数据合法性的判断方法和数据分解的步骤，将非法数分解为2～4个合法数的和。结果表明，当非法数分解为2—3个合法数的和时，与LDR伪指令相比采用分解法能减少时间开销，而当非法数需要分解为4个数的和时，宜采用LDR指令。LDR pseudo instruction was designed in ARM assembly language to solve the transmission problem of illegal immediate data. LDR pseudo instruction needs much time in execution since it is necessary to access memory. A novel processing technique for illegal immediate data based on data resolution was proposed to lower the execution time of instructions. A way was proposed to determine whether or not a datum is legal. The step for data resolution was presented. An illegal datum can be resolved to be the sum of 2 -4 legal data. The analysis result reveals that when an illegal datum is resolved to be the sum of 2 -3 legal data, the resolution method can save time compared with LDR pseudo instruction. But when an illegal datum is resolved to be the sum of 4 data, it is better to use LDR pseudo instruction.

关 键 词：ARM 汇编语言 立即数 

分 类 号：TP313[自动化与计算机技术—计算机软件与理论]