| 摘要 |
PURPOSE:To compress an objective program to improve execution efficiency by classifying zero or positive data, whose word length is equal to a fraction of integer of a maximum wordlength loadable to a general register, as data with a sign except data having '1' at the highest order bit to generate only a load instruction. CONSTITUTION:In a system which is not provided with a function to load data which has not a sign to a general register, inputted integer type data whose value is zero or positive and has not '1' at the bit position, where is a fraction of integer of the maximum word length loadable to the register, like the 8th bit or the 16th bit is classified as data with a sign by a front end part, and only the load instruction of this data is generated by a code generating part. Consequently, '0' clear of upper bits in the general register is unnecessary in this case, and therefore, the objective program is compressed and the execution efficiency is improved. |
