Subversion Repositories planix.SVN

#ifndef nil
#include <u.h>
#endif

typedef long Word;
typedef long long Vlong;
typedef unsigned long Single;

/* use u.h's FPdbleword */
#define Double  FPdbleword
#define h hi
#define l lo

enum {
        FractBits       = 28,
        CarryBit        = 0x10000000,
        HiddenBit       = 0x08000000,
        MsBit           = HiddenBit,
        NGuardBits      = 3,
        GuardMask       = 0x07,
        LsBit           = (1<<NGuardBits),

        SingleExpBias   = 127,
        SingleExpMax    = 255,
        DoubleExpBias   = 1023,
        DoubleExpMax    = 2047,

        ExpBias         = DoubleExpBias,
        ExpInfinity     = DoubleExpMax,
};

typedef struct {
        /* order matters: must start with s, e, l, h in that order */
        unsigned char s;
        short e;
        /* double bits */
        long l;                         /* 0000FFFFFFFFFFFFFFFFFFFFFFFFFGGG */
        long h;                         /* 0000HFFFFFFFFFFFFFFFFFFFFFFFFFFF */
} Internal;

#define IsWeird(n)      ((n)->e >= ExpInfinity)
#define IsInfinity(n)   (IsWeird(n) && (n)->h == HiddenBit && (n)->l == 0)
#define SetInfinity(n)  ((n)->e = ExpInfinity, (n)->h = HiddenBit, (n)->l = 0)
#define IsNaN(n)        (IsWeird(n) && (((n)->h & ~HiddenBit) || (n)->l))
#define SetQNaN(n)      ((n)->s = 0, (n)->e = ExpInfinity,              \
                         (n)->h = HiddenBit|(LsBit<<1), (n)->l = 0)
#define IsZero(n)       ((n)->e == 1 && (n)->h == 0 && (n)->l == 0)
#define SetZero(n)      ((n)->e = 1, (n)->h = 0, (n)->l = 0)

/*
 * fpi.c
 */
extern void fpiround(Internal *);
extern void fpiadd(Internal *, Internal *, Internal *);
extern void fpisub(Internal *, Internal *, Internal *);
extern void fpimul(Internal *, Internal *, Internal *);
extern void fpidiv(Internal *, Internal *, Internal *);
extern int fpicmp(Internal *, Internal *);
extern void fpinormalise(Internal*);

/*
 * fpimem.c
 */
extern void fpis2i(Internal *, void *);
extern void fpid2i(Internal *, void *);
extern void fpiw2i(Internal *, void *);
extern void fpiv2i(Internal *, void *);
extern void fpii2s(void *, Internal *);
extern void fpii2d(void *, Internal *);
extern void fpii2w(Word *, Internal *);
extern void fpii2v(Vlong *, Internal *);