dat.h

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

#define	mpdighi  (mpdigit)(1<<(Dbits-1))
#define DIGITS(x) ((Dbits - 1 + (x))/Dbits)

// for converting between int's and mpint's
#define MAXUINT ((uint)-1)
#define MAXINT (MAXUINT>>1)
#define MININT (MAXINT+1)

// for converting between vlongs's and mpint's
#define MAXUVLONG (~0ULL)
#define MAXVLONG (MAXUVLONG>>1)
#define MINVLONG (MAXVLONG+1ULL)