matlab里为何double型运算比int64型运算快很多

matlab里为何double型运算比int64型运算快很多代码1：tica = ones(1000,1000);b = 2*ones(1000,1000);for kkkkkk=1:100 c = a.*b;endtoc;tica = ones(1000,1000,'uint64');b = 2*ones(1000,1000,'uint64');for kkkkkk=1:100 c = a.*b;endtoc结果是：Elapsed time is 0.517186 seconds.Elapsed time is 1.052175 seconds.代码2：ticfor kkkkkk=1:1000000 a = 1234*1e7;endtoc;tica0 = uint64(1234);for kkkkkk=1:1000000 a = a0*1e7;endtoc结果是：Elapsed time is 0.004122 seconds.Elapsed time is 5.845563 seconds.这是怎么回事?