| 摘要 |
PURPOSE:To process a branch instruction with a higher speed by quickening a fetching operation for a branch destination instruction word of a branch instruction in a pipe line controlling system in a large computer. CONSTITUTION:In a case when a load instruction is stored in an instruction register 3 and an unconditional instruction in a branch register 4, a controlling part 12 stores a virtual address computed from an address adder 6 in a virtual address register 8, and fetches an instruction word according to a value of the register 8 against a cash memory 9 and stores in an instruction buffer 1. Since in this register 7 an operand address has been computed according to an instruction of the register 3, if an unconditional branch instruction is detected in the register 4, then a branch prefetching operation is preferred, thereby allowing an operand fetching operation to be done after a branch destination instruction word fetching operation. |
