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