前略、道の上より

    rb_define_method(rb_cFloat, "==", flo_eq, 1);
    rb_define_method(rb_cFloat, "===", flo_eq, 1);

#define flo_eq rb_float_equal


MJIT_FUNC_EXPORTED VALUE
rb_float_equal(VALUE x, VALUE y)
{
    volatile double a, b;

    if (RB_TYPE_P(y, T_FIXNUM) || RB_TYPE_P(y, T_BIGNUM)) {
        return rb_integer_float_eq(y, x);
    }
    else if (RB_TYPE_P(y, T_FLOAT)) {
	b = RFLOAT_VALUE(y);
#if MSC_VERSION_BEFORE(1300)
	if (isnan(b)) return Qfalse;
#endif
    }
    else {
	return num_equal(x, y);
    }
    a = RFLOAT_VALUE(x);
#if MSC_VERSION_BEFORE(1300)
    if (isnan(a)) return Qfalse;
#endif
    return (a == b)?Qtrue:Qfalse;
}

VALUE
rb_integer_float_eq(VALUE x, VALUE y)
{
    double yd = RFLOAT_VALUE(y);
    double yi, yf;

    if (isnan(yd) || isinf(yd))
        return Qfalse;
    yf = modf(yd, &yi);
    if (yf != 0)
        return Qfalse;
    if (FIXNUM_P(x)) {
#if SIZEOF_LONG * CHAR_BIT < DBL_MANT_DIG /* assume FLT_RADIX == 2 */
        double xd = (double)FIX2LONG(x);
        if (xd != yd)
            return Qfalse;
        return Qtrue;
#else
        long xn, yn;
        if (yi < LONG_MIN || LONG_MAX_as_double <= yi)
            return Qfalse;
        xn = FIX2LONG(x);
        yn = (long)yi;
        if (xn != yn)
            return Qfalse;
        return Qtrue;
#endif
    }
    y = rb_dbl2big(yi);
    return rb_big_eq(x, y);
}

typedef struct gmatch *Gmatch;

struct gmatch {
    /* Metafied file name */
    char *name;
    /* Unmetafied file name; embedded nulls can't occur in file names */
    char *uname;
    /*
     * Array of sort strings:  one for each GS_EXEC sort type in
     * the glob qualifiers.
     */
    char **sortstrs;
    off_t size ALIGN64;
    long atime;
    long mtime;
    long ctime;
    long links;
    off_t _size ALIGN64;
    long _atime;
    long _mtime;
    long _ctime;
    long _links;
#ifdef GET_ST_ATIME_NSEC
    long ansec;
    long _ansec;
#endif
#ifdef GET_ST_MTIME_NSEC
    long mnsec;
    long _mnsec;
#endif
#ifdef GET_ST_CTIME_NSEC
    long cnsec;
    long _cnsec;
#endif
};

struct qual {
    struct qual *next;		/* Next qualifier, must match                */
    struct qual *or;		/* Alternative set of qualifiers to match    */
    TestMatchFunc func;		/* Function to call to test match            */
    off_t data ALIGN64;		/* Argument passed to function               */
    int sense;			/* Whether asserting or negating             */
    int amc;			/* Flag for which time to test (a, m, c)     */
    int range;			/* Whether to test <, > or = (as per signum) */
    int units;			/* Multiplier for time or size, respectively */
    char *sdata;		/* currently only: expression to eval        */
};

/* Prefix, suffix for doing zle trickery */

/**/
mod_export char *glob_pre, *glob_suf;

/* Element of a glob sort */
struct globsort {
    /* Sort type */
    int tp;
    /* Sort code to eval, if type is GS_EXEC */
    char *exec;
};

/* Maximum entries in sort array */
#define MAX_SORTS	(12)

/* struct to easily save/restore current state */

struct globdata {
    int gd_pathpos;
    char *gd_pathbuf;

    int gd_matchsz;		/* size of matchbuf                     */
    int gd_matchct;		/* number of matches found              */
    int gd_pathbufsz;		/* size of pathbuf			*/
    int gd_pathbufcwd;		/* where did we chdir()'ed		*/
    Gmatch gd_matchbuf;		/* array of matches                     */
    Gmatch gd_matchptr;		/* &matchbuf[matchct]                   */
    char *gd_colonmod;		/* colon modifiers in qualifier list    */

    /* Qualifiers pertaining to current pattern */
    struct qual *gd_quals;

    /* Other state values for current pattern */
    int gd_qualct, gd_qualorct;
    int gd_range, gd_amc, gd_units;
    int gd_gf_nullglob, gd_gf_markdirs, gd_gf_noglobdots, gd_gf_listtypes;
    int gd_gf_numsort;
    int gd_gf_follow, gd_gf_sorts, gd_gf_nsorts;
    struct globsort gd_gf_sortlist[MAX_SORTS];
    LinkList gd_gf_pre_words, gd_gf_post_words;

    char *gd_glob_pre, *gd_glob_suf;
};

/* The variable with the current globbing state and convenience macros */

static struct globdata curglobdata;

#define matchsz       (curglobdata.gd_matchsz)
#define matchct       (curglobdata.gd_matchct)
#define pathbufsz     (curglobdata.gd_pathbufsz)
#define pathbufcwd    (curglobdata.gd_pathbufcwd)
#define matchbuf      (curglobdata.gd_matchbuf)
#define matchptr      (curglobdata.gd_matchptr)
#define colonmod      (curglobdata.gd_colonmod)
#define quals         (curglobdata.gd_quals)
#define qualct        (curglobdata.gd_qualct)
#define qualorct      (curglobdata.gd_qualorct)
#define g_range       (curglobdata.gd_range)
#define g_amc         (curglobdata.gd_amc)
#define g_units       (curglobdata.gd_units)
#define gf_nullglob   (curglobdata.gd_gf_nullglob)
#define gf_markdirs   (curglobdata.gd_gf_markdirs)
#define gf_noglobdots (curglobdata.gd_gf_noglobdots)
#define gf_listtypes  (curglobdata.gd_gf_listtypes)
#define gf_numsort    (curglobdata.gd_gf_numsort)
#define gf_follow     (curglobdata.gd_gf_follow)
#define gf_sorts      (curglobdata.gd_gf_sorts)
#define gf_nsorts     (curglobdata.gd_gf_nsorts)
#define gf_sortlist   (curglobdata.gd_gf_sortlist)
#define gf_pre_words  (curglobdata.gd_gf_pre_words)
#define gf_post_words (curglobdata.gd_gf_post_words)

/* and macros for save/restore */

#define save_globstate(N) \
  do { \
    queue_signals(); \
    memcpy(&(N), &curglobdata, sizeof(struct globdata)); \
    (N).gd_pathpos = pathpos; \
    (N).gd_pathbuf = pathbuf; \
    (N).gd_glob_pre = glob_pre; \
    (N).gd_glob_suf = glob_suf; \
    pathbuf = NULL; \
    unqueue_signals(); \
  } while (0)

#define restore_globstate(N) \
  do { \
    queue_signals(); \
    zfree(pathbuf, pathbufsz); \
    memcpy(&curglobdata, &(N), sizeof(struct globdata)); \
    pathpos = (N).gd_pathpos; \
    pathbuf = (N).gd_pathbuf; \
    glob_pre = (N).gd_glob_pre; \
    glob_suf = (N).gd_glob_suf; \
    unqueue_signals(); \
  } while (0)

/* pathname component in filename patterns */

struct complist {
    Complist next;
    Patprog pat;
    int closure;		/* 1 if this is a (foo/)# */
    int follow; 		/* 1 to go thru symlinks */
};