An information processing system having a plurality of arithmetic units such as a general instruction arithmetic unit and a floating point instruction arithmetic unit comprises means provided for each of the arithmetic units, for generating a condition code for use in branch judgement of a conditional branch instruction, branch judgement means provided in each arithmetic unit for judging success or failure of a branch of the conditional branch instruction by using the condition generated by the respective code generating means, and a judgement unit decision circuit responsive to the operation state of each arithmetic unit for generating an instruction signal indicating which of the judging means is to be operated to and supplying it to the branch judgement means, whereby branch control is carried out by using either one of the branch judgement results obtained in the respective arithmetic units as a valid one.