Patent US 5,377,339

A computer for simultaneously executing plural instructions decides the kind of operation and the possibility of simultaneous execution for the plural instructions as the instructions are read out from a main memory to a cache memory. The plural instructions and a corresponding decision result are stored in the cache memory. The decision process is performed for several groups of the plural instructions read out from the main memory to the cache memory in order. Then, the plural instructions are respectively assigned to a corresponding operation unit according to the decision result, and are subsequently executed by the corresponding operation unit. As a result of this arrangement, the repeated decision process for the plural instructions is not necessary when they are later read out from the cache memory to the operation unit.