| 摘要 |
PURPOSE:To prevent the failure of forecasting of a branching destination even when the address of the branching destination is the indirectly modified address by providing a branching history table and registering an indirect word to store a branching destination address. CONSTITUTION:Plural branching history tables 2 are provided with an instruc tion address part 2a to store an instruction address, a branching destination information part 2b to store the branching destination address or the branching destination indirect word address and an indirect word flag part 2c to store an indirect word flag as a pair. Concerning the unregistered instruction or the instruction which fails to forecast the branching destination, out of the branching instruction during the execution, it is detected by the decoding infor mation of an instruction word whether or not the branching destination address of the branching instruction is given by the indirect modification. The informa tion (indirect word flag), the branching destination address calculated by an instruction address calculating part or the indirect word address is registered in the table 2 and used for the later forecasting. Thus, even when the address of the branching destination is the indirectly modified address, the forecasting failure of the branching destination can be prevented.
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