php 大数据数学运算库 BCMath Arbitrary Precision Mathematics? BC Math Functions bcadd ― Add two arbitrary precision numbers bccomp ― Compare two arbitrary precision numbers bcdiv ― Divide two arbitrary precision numbers bcmod ― Get modulus of an arbitrary precision number bcmul ― Multiply two arbitrary precision number bcpow ― Raise an arbitrary precision number to another bcpowmod ― Raise an arbitrary precision number to another, reduced by a specified modulus bcscale ― Set default scale parameter for all bc math functions bcsqrt ― Get the square root of an arbitrary precision number bcsub ― Subtract one arbitrary precision number from another