| 摘要 |
PURPOSE:To execute the branch processing at a high speed and to decrease the overhead at the time of condition branch instruction by executing a branch decision at the time point when an instruction train which is being executed before a condition branch instruction executed in a pipeline defines a condition code to be referred to be the condition branch instruction, at the time of executing the condition branch instruction. CONSTITUTION:In the case an instruction Prel does not change a condition code referred to by a condition branch instruction, a branch decision is executed by referring to a condition code defined by executing an instruction Pre2. That is, the branch decision (CHK) is executed in a stage of a fetch (IF) of a branch destination instruction by a condition branch instruction. In such a way, comparing with a conventional example, the overhead can be decreased by a one-stage portion, and the branch processing of a high speed can be realized by increasing a small number of hardware. |
