To decrease the number of load instructions and store instructions and to improve the execution performance of objects by batching memory access to different basic blocks.

Data belonging to different basic blocks in an object program to be processed are taken out as object data of batch access. In consideration of the relation among the different basic blocks, the position where a batch load instruction or batch store instruction should be generated is determined. Only when a 'nondependency' condition is met, the batch load instruction or batch store instruction is generated. Consequently, memory access operations which are not always all performed and belong to the difference basic blocks can be carried out at a time. Specially, when loop expansion is applied to a loop including an if statement, adjacent-element referring groups of arrays appearing as a result of the loop expansion belong to the different basic blocks and the effect that batch processing becomes possible is large.