| 摘要 |
PROBLEM TO BE SOLVED: To easily decide whether the exception caused by a multicycle instruction is equal to an imprecise exception and to increase the instruction processing speed by providing an imprecise exception decision flag to decide whether the exception caused by the corresponding multicycle instruction is equal to an imprecise exception. SOLUTION: When a multicycle instruction is not canceled in a C phase, the multicycle instruction is surely executed even though a subsequent instruction causes an exception excluding a case where the multicycle instruction itself causes an exception. Then each of imprecise exception decision flags 23-26 decides the exception that is caused and fixed by the corresponding multicycle instruction in a C1 phase as a precise exception as long as the exception is asserted and then performs the normal precise exception processing. If the exception is negated, the exception is decided as an imprecise exception and the corresponding processing is carried out. Thus, the resources can be saved.
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