| 摘要 |
PROBLEM TO BE SOLVED: To suppress as much as possible the deterioration of pipeline processing efficiency due to a branch instruction. SOLUTION: This branch instruction control system in a microinstruction is provided with a branch prediction information memory storage information generating circuit 15 for generating branch prediction information constituted of the storage position of a condition branch instruction whose branch succeeds in a microinstruction storage memory 2 and the storage position of a software instruction starting the condition branch instruction in the memory and an information bit indicating valid information, a branch prediction information memory 10 for storing the branch prediction information, and a predicting direction deciding circuit 16 for comparing the storage position of the started condition branch instruction in the microinstruction storage memory 2 and the storage position of the software instruction starting the condition branch instruction in the memory with the branch prediction information, and defining the next instruction as the destination of branch instruction only when the storage positions are made coincident with the branch prediction information, and the information bit indicates the valid information, and for defining the next instruction as the following instruction in the other case.
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