It is determined whether an i-th instruction is for a memory access. If the i-th instruction is the memory access, it is determined whether an address to access according to the i-th instruction coincides with an address that has been accessed by a first execution block. If the addresses coincide with each other, it is determined whether a cycle of a second execution block currently executing precedes that of the first execution block. If the cycle of the second execution block precedes that of the first executing block, a memory model is accessed. A necessary number of cycles for execution of a j-th instruction is added to the current number of cycles, and the address, a cycle, data, and a data size at the time of the current access (before re-writing) are written in a delay table.