/* Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this software; see the file COPYING.  If not, write to
 * the Free Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 *
 * As a special exception, the Free Software Foundation gives permission
 * for additional uses of the text contained in its release of SCM.
 *
 * The exception is that, if you link the SCM library with other files
 * to produce an executable, this does not by itself cause the
 * resulting executable to be covered by the GNU General Public License.
 * Your use of that executable is in no way restricted on account of
 * linking the SCM library code into it.
 *
 * This exception does not however invalidate any other reasons why
 * the executable file might be covered by the GNU General Public License.
 *
 * This exception applies only to the code released by the
 * Free Software Foundation under the name SCM.  If you copy
 * code from other Free Software Foundation releases into a copy of
 * SCM, as the General Public License permits, the exception does
 * not apply to the code that you add in this way.  To avoid misleading
 * anyone as to the status of such modified files, you must delete
 * this exception notice from them.
 *
 * If you write modifications of your own for SCM, it is your choice
 * whether to permit this exception to apply to your modifications.
 * If you do not wish that, delete this exception notice.
 */

/* "subr.c" integer and other Scheme procedures
   Author: Aubrey Jaffer */

#include <ctype.h>
#include "scm.h"

#define	s_length (s_st_length+7)
#define s_append (s_st_append+7)

char	s_make_string[] = "make-string";
char	s_list[] = "list";

static char	s_setcar[] = "set-car!", s_setcdr[] = "set-cdr!",
	s_reverse[] = "reverse", s_list_ref[] = "list-ref";
static char	s_memq[] = "memq", s_member[] = "member",
	s_assq[] = "assq", s_assoc[] = "assoc";
static char	s_symbol2string[] = "symbol->string",
	s_str2symbol[] = "string->symbol";
extern char s_inexactp[];
#define s_exactp (s_inexactp+2)
static char	s_oddp[] = "odd?", s_evenp[] = "even?";
static char	s_quotient[] = "quotient",
	s_remainder[] = "remainder", s_modulo[] = "modulo";
static char	s_gcd[] = "gcd";

static char s_ci_eq[] = "char-ci=?",
	s_ch_lessp[] = "char<?", s_ch_leqp[] = "char<=?",
	s_ci_lessp[] = "char-ci<?", s_ci_leqp[] = "char-ci<=?",
	s_ch_grp[] = "char>?", s_ch_geqp[] = "char>=?",
	s_ci_grp[] = "char-ci>?", s_ci_geqp[] = "char-ci>=?";
static char	s_ch_alphap[] = "char-alphabetic?",
	s_ch_nump[] = "char-numeric?",
	s_ch_whitep[] = "char-whitespace?",
	s_ch_upperp[] = "char-upper-case?",
	s_ch_lowerp[] = "char-lower-case?";
static char	s_char2int[] = "char->integer", s_int2char[] = "integer->char",
	s_ch_upcase[] = "char-upcase", s_ch_downcase[] = "char-downcase";

static char	s_st_length[] = "string-length",
	s_st_ref[] = "string-ref", s_st_set[] = "string-set!";
static char	s_st_equal[] = "string=?", s_stci_equal[] = "string-ci=?",
	s_st_lessp[] = "string<?", s_stci_lessp[] = "string-ci<?";
static char	s_substring[] = "substring", s_st_append[] = "string-append";

static char	s_ve_length[] = "vector-length",
	s_ve_ref[] = "vector-ref", s_ve_set[] = "vector-set!";

SCM lnot(x)
     SCM x;
{
	return FALSEP(x) ? BOOL_T : BOOL_F;
}
SCM booleanp(obj)
     SCM obj;
{
	if (BOOL_F==obj) return BOOL_T;
	if (BOOL_T==obj) return BOOL_T;
	return BOOL_F;
}
SCM eq(x, y)
     SCM x, y;
{
	if (x==y) return BOOL_T;
	else return BOOL_F;
}

SCM consp(x)
     SCM x;
{
	if (IMP(x)) return BOOL_F;
	return CONSP(x) ? BOOL_T : BOOL_F;
}
SCM setcar(pair, value)
     SCM pair, value;
{
	ASRTER(NIMP(pair) && CONSP(pair), pair, ARG1, s_setcar);
	CAR(pair) = value;
	return UNSPECIFIED;
}
SCM setcdr(pair, value)
     SCM pair, value;
{
	ASRTER(NIMP(pair) && CONSP(pair), pair, ARG1, s_setcdr);
	CDR(pair) = value;
	return UNSPECIFIED;
}
SCM nullp(x)
     SCM x;
{
	return NULLP(x) ? BOOL_T : BOOL_F;
}
long ilength(sx)
     SCM sx;
{
	register long i = 0;
	register SCM x = sx;
	do {
		if (IMP(x)) return NULLP(x) ? i : -1;
		if (NCONSP(x)) return -2;
		x = CDR(x);
		i++;
		if (IMP(x)) return NULLP(x) ? i : -1;
		if (NCONSP(x)) return -2;
		x = CDR(x);
		i++;
		sx = CDR(sx);
	}
	while (x != sx);
	return -1;
}
SCM listp(x)
     SCM x;
{
	if (ilength(x)<0) return BOOL_F;
	else return BOOL_T;
}
SCM list(objs)
     SCM objs;
{
	return objs;
}
SCM length(x)
     SCM x;
{
	SCM i = MAKINUM(ilength(x));
	ASRTER(i >= INUM0, x, ARG1, s_length);
	return i;
}
SCM append(args)
     SCM args;
{
	SCM res = EOL;
	SCM *lloc = &res, arg;
	if (IMP(args)) {
		ASRTER(NULLP(args), args, ARGn, s_append);
		return res;
		}
	ASRTER(CONSP(args), args, ARGn, s_append);
	while (1) {
		arg = CAR(args);
		args = CDR(args);
		if (IMP(args)) {
			*lloc = arg;
			ASRTER(NULLP(args), args, ARGn, s_append);
			return res;
		}
		ASRTER(CONSP(args), args, ARGn, s_append);
		for (;NIMP(arg);arg = CDR(arg)) {
			ASRTER(CONSP(arg), arg, ARGn, s_append);
			*lloc = cons(CAR(arg), EOL);
			lloc = &CDR(*lloc);
		}
		ASRTER(NULLP(arg), arg, ARGn, s_append);
	}
}
SCM reverse(lst)
     SCM lst;
{
	SCM res = EOL;
	SCM p = lst;
	for (;NIMP(p);p = CDR(p)) {
		ASRTER(CONSP(p), lst, ARG1, s_reverse);
		res = cons(CAR(p), res);
	}
	ASRTER(NULLP(p), lst, ARG1, s_reverse);
	return res;
}
SCM list_ref(lst, k)
     SCM lst, k;
{
	register long i;
	ASRTER(INUMP(k), k, ARG2, s_list_ref);
	i = INUM(k);
	ASRTER(i >= 0, k, ARG2, s_list_ref);
	while (i-- > 0) {
		ASRTGO(NIMP(lst) && CONSP(lst), erout);
		lst = CDR(lst);
	}
erout:	ASRTER(NIMP(lst) && CONSP(lst),
	       NULLP(lst)?k:lst, NULLP(lst)?OUTOFRANGE:ARG1, s_list_ref);
	return CAR(lst);
}
SCM memq(x, lst)
     SCM x, lst;
{
	for (;NIMP(lst);lst = CDR(lst)) {
		ASRTER(CONSP(lst), lst, ARG2, s_memq);
		if (CAR(lst)==x) return lst;
	}
	ASRTER(NULLP(lst), lst, ARG2, s_memq);
	return BOOL_F;
}
SCM member(x, lst)
     SCM x, lst;
{
	for (;NIMP(lst);lst = CDR(lst)) {
		ASRTER(CONSP(lst), lst, ARG2, s_member);
		if (NFALSEP(equal(CAR(lst), x))) return lst;
	}
	ASRTER(NULLP(lst), lst, ARG2, s_member);
	return BOOL_F;
}
SCM assq(x, alist)
     SCM x, alist;
{
	SCM tmp;
	for (;NIMP(alist);alist = CDR(alist)) {
		ASRTER(CONSP(alist), alist, ARG2, s_assq);
		tmp = CAR(alist);
		ASRTER(NIMP(tmp) && CONSP(tmp), alist, ARG2, s_assq);
		if (CAR(tmp)==x) return tmp;
	}
	ASRTER(NULLP(alist), alist, ARG2, s_assq);
	return BOOL_F;
}
SCM assoc(x, alist)
     SCM x, alist;
{
	SCM tmp;
	for (;NIMP(alist);alist = CDR(alist)) {
		ASRTER(CONSP(alist), alist, ARG2, s_assoc);
		tmp = CAR(alist);
		ASRTER(NIMP(tmp) && CONSP(tmp), alist, ARG2, s_assoc);
		if (NFALSEP(equal(CAR(tmp), x))) return tmp;
	}
	ASRTER(NULLP(alist), alist, ARG2, s_assoc);
	return BOOL_F;
}

extern long tc16_promise;
SCM promisep(x)
     SCM x;
{
       return NIMP(x) && (TYP16(x)==tc16_promise) ? BOOL_T : BOOL_F;
}

SCM symbolp(x)
     SCM x;
{
	if (IMP(x)) return BOOL_F;
	return SYMBOLP(x) ? BOOL_T : BOOL_F;
}
SCM symbol2string(s)
     SCM s;
{
	ASRTER(NIMP(s) && SYMBOLP(s), s, ARG1, s_symbol2string);
	return makfromstr(CHARS(s), (sizet)LENGTH(s));
}
SCM string2symbol(s)
     SCM s;
{
	ASRTER(NIMP(s) && STRINGP(s), s, ARG1, s_str2symbol);
	s = intern(CHARS(s), (sizet)LENGTH(s));
	return CAR(s);
}

SCM exactp(x)
     SCM x;
{
	if (INUMP(x)) return BOOL_T;
#ifdef BIGDIG
	if (NIMP(x) && BIGP(x)) return BOOL_T;
#endif
	return BOOL_F;
}
SCM oddp(n)
     SCM n;
{
#ifdef BIGDIG
	if (NINUMP(n)) {
	  ASRTER(NIMP(n) && BIGP(n), n, ARG1, s_oddp);
	  return (1 & BDIGITS(n)[0]) ? BOOL_T : BOOL_F;
	}
#else
	ASRTER(INUMP(n), n, ARG1, s_oddp);
#endif
	return (4 & (int)n) ? BOOL_T : BOOL_F;
}
SCM evenp(n)
     SCM n;
{
#ifdef BIGDIG
	if (NINUMP(n)) {
	  ASRTER(NIMP(n) && BIGP(n), n, ARG1, s_evenp);
	  return (1 & BDIGITS(n)[0]) ? BOOL_F : BOOL_T;
	}
#else
	ASRTER(INUMP(n), n, ARG1, s_evenp);
#endif
	return (4 & (int)n) ? BOOL_F : BOOL_T;
}
SCM lquotient(x, y)
     SCM x, y;
{
  register long z;
#ifdef BIGDIG
  if (NINUMP(x)) {
    long w;
    ASRTER(NIMP(x) && BIGP(x), x, ARG1, s_quotient);
    if (NINUMP(y)) {
      ASRTGO(NIMP(y) && BIGP(y), bady);
      return divbigbig(BDIGITS(x), NUMDIGS(x), BDIGITS(y), NUMDIGS(y),
		       BIGSIGN(x) ^ BIGSIGN(y), 2);
    }
    z = INUM(y);
    ASRTGO(z, ov);
    if (1==z) return x;
    if (z < 0) z = -z;
    if (z < BIGRAD) {
      w = copybig(x, BIGSIGN(x) ? (y>0) : (y<0));
      divbigdig(BDIGITS(w), NUMDIGS(w), (BIGDIG)z);
      return normbig(w);
    }
# ifndef DIGSTOOBIG
    w = pseudolong(z);
    return divbigbig(BDIGITS(x), NUMDIGS(x), (BIGDIG *)&w, DIGSPERLONG,
		     BIGSIGN(x) ? (y>0) : (y<0), 2);
# else
    { BIGDIG zdigs[DIGSPERLONG];
      longdigs(z, zdigs);
      return divbigbig(BDIGITS(x), NUMDIGS(x), zdigs, DIGSPERLONG,
		       BIGSIGN(x) ? (y>0) : (y<0), 2);
    }
# endif
  }
  if (NINUMP(y)) {
# ifndef RECKLESS
    if (!(NIMP(y) && BIGP(y)))
    bady: wta(y, (char *)ARG2, s_quotient);
# endif
    return INUM0;
  }
#else
  ASRTER(INUMP(x), x, ARG1, s_quotient);
  ASRTER(INUMP(y), y, ARG2, s_quotient);
#endif
  if ((z = INUM(y))==0)
  ov: wta(y, (char *)OVFLOW, s_quotient);
  z = INUM(x)/z;
#ifdef BADIVSGNS
  {
# if (__TURBOC__==1)
    long t = ((y<0) ? -INUM(x) : INUM(x))%INUM(y);
# else
    long t = INUM(x)%INUM(y);
# endif
    if (t==0) ;
    else if (t < 0)
      if (x < 0) ;
      else z--;
    else if (x < 0) z++;
  }
#endif
  if (!FIXABLE(z))
#ifdef BIGDIG
    return long2big(z);
#else
  wta(x, (char *)OVFLOW, s_quotient);
#endif
  return MAKINUM(z);
}
SCM lremainder(x, y)
     SCM x, y;
{
  register long z;
#ifdef BIGDIG
  if (NINUMP(x)) {
    ASRTER(NIMP(x) && BIGP(x), x, ARG1, s_remainder);
    if (NINUMP(y)) {
      ASRTGO(NIMP(y) && BIGP(y), bady);
      return divbigbig(BDIGITS(x), NUMDIGS(x), BDIGITS(y), NUMDIGS(y),
		       BIGSIGN(x), 0);
    }
    if (!(z = INUM(y))) goto ov;
    return divbigint(x, z, BIGSIGN(x), 0);
  }
  if (NINUMP(y)) {
# ifndef RECKLESS
    if (!(NIMP(y) && BIGP(y)))
    bady: wta(y, (char *)ARG2, s_remainder);
# endif
    return x;
  }
#else
  ASRTER(INUMP(x), x, ARG1, s_remainder);
  ASRTER(INUMP(y), y, ARG2, s_remainder);
#endif
  if (!(z = INUM(y)))
  ov: wta(y, (char *)OVFLOW, s_remainder);
#if (__TURBOC__==1)
  if (z < 0) z = -z;
#endif
  z = INUM(x)%z;
#ifdef BADIVSGNS
  if (!z) ;
  else if (z < 0)
	  if (x < 0) ;
	  else z += INUM(y);
  else if (x < 0) z -= INUM(y);
#endif
  return MAKINUM(z);
}
SCM modulo(x, y)
     SCM x, y;
{
  register long yy, z;
#ifdef BIGDIG
  if (NINUMP(x)) {
    ASRTER(NIMP(x) && BIGP(x), x, ARG1, s_modulo);
    if (NINUMP(y)) {
      ASRTGO(NIMP(y) && BIGP(y), bady);
      return divbigbig(BDIGITS(x), NUMDIGS(x), BDIGITS(y), NUMDIGS(y),
		       BIGSIGN(y), (BIGSIGN(x) ^ BIGSIGN(y)) ? 1 : 0);
    }
    if (!(z = INUM(y))) goto ov;
    return divbigint(x, z, z < 0, (BIGSIGN(x) ? (z > 0) : (z < 0)) ? 1 : 0);
  }
  if (NINUMP(y)) {
# ifndef RECKLESS
    if (!(NIMP(y) && BIGP(y)))
    bady: wta(y, (char *)ARG2, s_modulo);
# endif
    return (BIGSIGN(y) ? (INUM(x)>0) : (INUM(x)<0)) ? sum(x, y) : x;
  }
#else
  ASRTER(INUMP(x), x, ARG1, s_modulo);
  ASRTER(INUMP(y), y, ARG2, s_modulo);
#endif
  if (!(yy = INUM(y)))
  ov: wta(y, (char *)OVFLOW, s_modulo);
#if (__TURBOC__==1)
  z = INUM(x);
  z = ((yy<0) ? -z : z)%yy;
#else
  z = INUM(x)%yy;
#endif
  return MAKINUM(((yy<0) ? (z>0) : (z<0)) ? z+yy : z);
}

SCM lgcd(x, y)
     SCM x, y;
{
  register long u, v, k, t;
 tailrec:
  if (UNBNDP(y)) return UNBNDP(x) ? INUM0 : x;
#ifdef BIGDIG
  if (NINUMP(x)) {
    big_gcd:
    ASRTER(NIMP(x) && BIGP(x), x, ARG1, s_gcd);
    if (BIGSIGN(x)) x = copybig(x, 0);
  newy:
    if (NINUMP(y)) {
      ASRTER(NIMP(y) && BIGP(y), y, ARG2, s_gcd);
      if (BIGSIGN(y)) y = copybig(y, 0);
      switch (bigcomp(x, y)) {
      case -1:
      swaprec: t = lremainder(x, y); x = y; y = t; goto tailrec;
      case  0: return x;
      case  1: y = lremainder(y, x); goto newy;
      }
      /* instead of the switch, we could just return lgcd(y, modulo(x, y)); */
    }
    if (INUM0==y) return x; goto swaprec;
  }
  if (NINUMP(y)) { t=x; x=y; y=t; goto big_gcd;}
#else
  ASRTER(INUMP(x), x, ARG1, s_gcd);
  ASRTER(INUMP(y), y, ARG2, s_gcd);
#endif
  u = INUM(x);
  if (u<0) u = -u;
  v = INUM(y);
  if (v<0) v = -v;
  else if (0==v) goto getout;
  if (0==u) {u = v; goto getout;}
  for (k = 1;!(1 & ((int)u|(int)v));k <<= 1, u >>= 1, v >>= 1);
  if (1 & (int)u) t = -v;
  else {
    t = u;
b3:
    t = SRS(t, 1);
  }
  if (!(1 & (int)t)) goto b3;
  if (t>0) u = t;
  else v = -t;
  t = u-v;
  if (t) goto b3;
  u = u*k;
getout:
  if (!POSFIXABLE(u))
#ifdef BIGDIG
    return long2big(u);
#else
    wta(x, (char *)OVFLOW, s_gcd);
#endif
  return MAKINUM(u);
}
SCM llcm(n1, n2)
     SCM n1, n2;
{
  SCM d;
  if (UNBNDP(n2)) {
    n2 = MAKINUM(1L);
    if (UNBNDP(n1)) return n2;
  }
  d = lgcd(n1, n2);
  if (INUM0==d) return d;
  return scm_iabs(product(n1, lquotient(n2, d)));
}

/* Emulating 2's complement bignums with sign magnitude arithmetic:

   Logand:
   X	Y	Result	Method:
		 (len)
   +	+	+ x	(map digit:logand X Y)
   +	-	+ x	(map digit:logand X (lognot (+ -1 Y)))
   -	+	+ y	(map digit:logand (lognot (+ -1 X)) Y)
   -	-	-	(+ 1 (map digit:logior (+ -1 X) (+ -1 Y)))

   Logior:
   X	Y	Result	Method:

   +	+	+	(map digit:logior X Y)
   +	-	- y	(+ 1 (map digit:logand (lognot X) (+ -1 Y)))
   -	+	- x	(+ 1 (map digit:logand (+ -1 X) (lognot Y)))
   -	-	- x	(+ 1 (map digit:logand (+ -1 X) (+ -1 Y)))

   Logxor:
   X	Y	Result	Method:

   +	+	+	(map digit:logxor X Y)
   +	-	-	(+ 1 (map digit:logxor X (+ -1 Y)))
   -	+	-	(+ 1 (map digit:logxor (+ -1 X) Y))
   -	-	+	(map digit:logxor (+ -1 X) (+ -1 Y))

   Logtest:
   X	Y	Result

   +	+	(any digit:logand X Y)
   +	-	(any digit:logand X (lognot (+ -1 Y)))
   -	+	(any digit:logand (lognot (+ -1 X)) Y)
   -	-	#t

*/

#ifdef BIGDIG

SCM	scm_big_ior P((BIGDIG *x, sizet nx, int xsgn, SCM bigy));
SCM	scm_big_and P((BIGDIG *x, sizet nx, int xsgn, SCM bigy, int zsgn));
SCM	scm_big_xor P((BIGDIG *x, sizet nx, int xsgn, SCM bigy));
SCM	scm_big_test P((BIGDIG *x, sizet nx, int xsgn, SCM bigy));
SCM	scm_big_ash P((SCM x, long cnt));

SCM scm_copy_big_dec(b, sign)
     SCM b;
     int sign;
{
  long num = -1;
  sizet nx = NUMDIGS(b);
  sizet i = 0;
  SCM ans = mkbig(nx, sign);
  BIGDIG *src = BDIGITS(b), *dst = BDIGITS(ans);
  if (BIGSIGN(b)) do {
    num += src[i];
    if (num < 0) {dst[i] = num + BIGRAD; num = -1;}
    else {dst[i] = BIGLO(num); num = 0;}
  } while (++i < nx);
  else
    while (nx--) dst[nx] = src[nx];
  return ans;
}

SCM scm_copy_smaller(x, nx, zsgn)
     BIGDIG *x;
     sizet nx;
     int zsgn;
{
  long num = -1;
  sizet i = 0;
  SCM z = mkbig(nx, zsgn);
  BIGDIG *zds = BDIGITS(z);
  if (zsgn) do {
    num += x[i];
    if (num < 0) {zds[i] = num + BIGRAD; num = -1;}
    else {zds[i] = BIGLO(num); num = 0;}
  } while (++i < nx);
  else do zds[i] = x[i]; while (++i < nx);
  return z;
}

SCM scm_big_ior(x, nx, xsgn, bigy)
     BIGDIG *x;
     SCM bigy;
     sizet nx;		/* Assumes nx <= NUMDIGS(bigy) */
     int xsgn;		/* Assumes xsgn equals either 0 or 0x0100 */
{
  long num = -1;
  sizet i = 0, ny = NUMDIGS(bigy);
  SCM z = scm_copy_big_dec(bigy, xsgn & BIGSIGN(bigy));
  BIGDIG *zds = BDIGITS(z);
  if (xsgn) {
    do {
      num += x[i];
      if (num < 0) {zds[i] |= num + BIGRAD; num = -1;}
      else {zds[i] |= BIGLO(num); num = 0;}
    } while (++i < nx);
    /* =========  Need to increment zds now =========== */
    i = 0; num = 1;
    while (i < ny) {
      num += zds[i];
      zds[i++] = BIGLO(num);
      num = BIGDN(num);
      if (!num) return z;
    }
    adjbig(z, 1 + ny);		/* OOPS, overflowed into next digit. */
    BDIGITS(z)[ny] = 1;
    return z;
  }
  else do zds[i] = zds[i] | x[i]; while (++i < nx);
  return z;
}

SCM scm_big_xor(x, nx, xsgn, bigy)
     BIGDIG *x;
     SCM bigy;
     sizet nx;		/* Assumes nx <= NUMDIGS(bigy) */
     int xsgn;		/* Assumes xsgn equals either 0 or 0x0100 */
{
  long num = -1;
  sizet i = 0, ny = NUMDIGS(bigy);
  SCM z = scm_copy_big_dec(bigy, xsgn ^ BIGSIGN(bigy));
  BIGDIG *zds = BDIGITS(z);
  if (xsgn) do {
    num += x[i];
    if (num < 0) {zds[i] ^= num + BIGRAD; num = -1;}
    else {zds[i] ^= BIGLO(num); num = 0;}
  } while (++i < nx);
  else do {
    zds[i] = zds[i] ^ x[i];
  } while (++i < nx);

  if (xsgn ^ BIGSIGN(bigy)) {
    /* =========  Need to increment zds now =========== */
    i = 0; num = 1;
    while (i < ny) {
      num += zds[i];
      zds[i++] = BIGLO(num);
      num = BIGDN(num);
      if (!num) return normbig(z);
    }
  }
  return normbig(z);
}

SCM scm_big_and(x, nx, xsgn, bigy, zsgn)
     BIGDIG *x;
     SCM bigy;
     sizet nx;		/* Assumes nx <= NUMDIGS(bigy) */
     int xsgn;		/* Assumes xsgn equals either 0 or 0x0100 */
     int zsgn;		/* return sign equals either 0 or 0x0100 */
{
  long num = -1;
  sizet i = 0;
  SCM z;
  BIGDIG *zds;
  if (xsgn==zsgn) {
    z = scm_copy_smaller(x, nx, zsgn);
    x = BDIGITS(bigy);
    xsgn = BIGSIGN(bigy);
  }
  else z = scm_copy_big_dec(bigy, zsgn);
  zds = BDIGITS(z);

  if (zsgn) {
    if (xsgn) do {
      num += x[i];
      if (num < 0) {zds[i] &= num + BIGRAD; num = -1;}
      else {zds[i] &= BIGLO(num); num = 0;}
    } while (++i < nx);
    else do zds[i] = zds[i] & ~x[i]; while (++i < nx);
    /* =========  need to increment zds now =========== */
    i = 0; num = 1;
    while (i < nx) {
      num += zds[i];
      zds[i++] = BIGLO(num);
      num = BIGDN(num);
      if (!num) return normbig(z);
    }
  }
  else if (xsgn) do {
    num += x[i];
    if (num < 0) {zds[i] &= ~(num + BIGRAD); num = -1;}
    else {zds[i] &= ~BIGLO(num); num = 0;}
  } while (++i < nx);
  else do zds[i] = zds[i] & x[i]; while (++i < nx);
  return normbig(z);
}

SCM scm_big_test(x, nx, xsgn, bigy)
     BIGDIG *x;
     SCM bigy;
     sizet nx;		/* Assumes nx <= NUMDIGS(bigy) */
     int xsgn;		/* Assumes xsgn equals either 0 or 0x0100 */
{
  BIGDIG *y;
  sizet i = 0;
  long num = -1;
  if (BIGSIGN(bigy) & xsgn) return BOOL_T;
  if (NUMDIGS(bigy) != nx && xsgn) return BOOL_T;
  y = BDIGITS(bigy);
  if (xsgn)
    do {
      num += x[i];
      if (num < 0) {
	if (y[i] & ~(num + BIGRAD)) return BOOL_T;
	num = -1;
      }
      else {
	if (y[i] & ~BIGLO(num)) return BOOL_T;
	num = 0;
      }
    } while (++i < nx);
  else if (BIGSIGN(bigy))
    do {
      num += y[i];
      if (num < 0) {
	if (x[i] & ~(num + BIGRAD)) return BOOL_T;
	num = -1;
      }
      else {
	if (x[i] & ~BIGLO(num)) return BOOL_T;
	num = 0;
      }
    } while (++i < nx);
  else
    do if (x[i] & y[i]) return BOOL_T;
    while (++i < nx);
  return BOOL_F;
}

static SCM scm_copy_big_2scomp P((SCM x, sizet blen, int sign));
static void scm_2scomp1 P((SCM b));
static SCM scm_copy_big_2scomp(x, blen, sign)
     SCM x;
     sizet blen;
     int sign;
{
  sizet nres = (blen + BITSPERDIG - 1)/BITSPERDIG;
  SCM res;
  BIGDIG *rds;
  long num = 0;
  sizet i;
  if (INUMP(x)) {
    long lx = INUM(x);
    if (nres < (LONG_BIT + BITSPERDIG - 1)/BITSPERDIG)
      nres = (LONG_BIT + BITSPERDIG - 1)/BITSPERDIG;
    res = mkbig(nres, sign);
    rds = BDIGITS(res);
    if (lx < 0) {
      lx = -lx;
      for (i = 0; i < nres; i++) {
	num -= BIGLO(lx);
	lx = BIGDN(lx);
	if (num < 0) {
	  rds[i] = num + BIGRAD;
	  num = -1;
	}
	else {
	  rds[i] = num;
	  num = 0;
	}
      }
    }
    else {
      for (i = 0; i < nres; i++) {
	rds[i] = BIGLO(lx);
	lx = BIGDN(lx);
      }
    }
  }
  else {
    BIGDIG *xds = BDIGITS(x);
    sizet nx = NUMDIGS(x);
    if (nres < nx)
      nres = nx;
    res = mkbig(nres, sign);
    rds = BDIGITS(res);
    if (BIGSIGN(x)) {
      for (i = 0; i < nx; i++) {
	num -= xds[i];
	if (num < 0) {
	  rds[i] = num + BIGRAD;
	  num = -1;
	}
	else {
	  rds[i] = num;
	  num = 0;
	}
      }
      for (; i < nres; i++)
	rds[i] = BIGRAD - 1;
    }
    else {
      for (i = 0; i < nx; i++)
	rds[i] = xds[i];
      for (; i < nres; i++)
	rds[i] = 0;
    }
  }
  return res;
}
static void scm_2scomp1(b)
     SCM b;
{
  long num = 0;
  sizet i, n = NUMDIGS(b);
  BIGDIG *bds = BDIGITS(b);
  for (i = 0; i < n; i++) {
    num -= bds[i];
    if (num < 0) {
      bds[i] = num + BIGRAD;
      num = -1;
    }
    else {
      bds[i] = num;
      num = 0;
    }
  }
}

SCM scm_big_ash(x, cnt)
     SCM x;
     long cnt;
{
  SCM res;
  BIGDIG *resds;
  unsigned long d;
  int sign, ishf;
  long i, fshf, blen, n;
  if (INUMP(x)) {
    blen = LONG_BIT;
    sign = INUM(x) < 0 ? 0x0100 : 0;
  }
  else {
    blen = NUMDIGS(x)*BITSPERDIG;
    sign = BIGSIGN(x);
  }
  if (cnt < 0) {
    if (blen <= -cnt) return sign ? MAKINUM(-1) : INUM0;
    ishf = (-cnt) / BITSPERDIG;
    fshf = (-cnt) % BITSPERDIG;
    res = scm_copy_big_2scomp(x, blen, sign);
    resds = BDIGITS(res);
    n = NUMDIGS(res) - ishf - 1;
    for (i = 0; i < n; i++) {
      d = (resds[i + ishf]>>fshf) |
	((resds[i + ishf + 1])<<(BITSPERDIG - fshf) & (BIGRAD - 1));
      resds[i] = d;
    }
    d = (resds[i + ishf]>>fshf);
    if (sign) d |= ((BIGRAD - 1)<<(BITSPERDIG - fshf) & (BIGRAD - 1));
    resds[i] = d;
    n = NUMDIGS(res);
    d = sign ? BIGRAD - 1 : 0;
    for (i++; i < n; i++)
      resds[i] = d;
  }
  else {
    ishf = cnt / BITSPERDIG;
    fshf = cnt % BITSPERDIG;
    res = scm_copy_big_2scomp(x, blen + cnt, sign);
    resds = BDIGITS(res);
    for (i = NUMDIGS(res) - 1; i > ishf; i--) {
      d = (((resds[i - ishf])<<fshf) & (BIGRAD - 1)) |
	((resds[i - ishf - 1])>>(BITSPERDIG - fshf));
      resds[i] = d;
    }
    d = (((resds[i - ishf])<<fshf) & (BIGRAD - 1));
    resds[i] = d;
    for (i--; i >= 0; i--)
      resds[i] = 0;
  }
  if (sign) scm_2scomp1(res);
  return normbig(res);
}
#endif

static char s_logand[] = "logand", s_lognot[] = "lognot",
	    s_logior[] = "logior", s_logxor[] = "logxor",
	    s_logtest[] = "logtest", s_logbitp[] = "logbit?",
            s_copybit[] = "copy-bit",
            s_copybitfield[] = "copy-bit-field",
	    s_ash[] = "ash", s_logcount[] = "logcount",
	    s_bitwise_bit_count[] = "bitwise-bit-count",
	    s_intlength[] = "integer-length",
	    s_bitfield[] = "bit-field",
            s_bitif[] = "bitwise-if";

SCM scm_logior(x, y)
     SCM x, y;
{
  if (UNBNDP(y)) {
    if (UNBNDP(x)) return INUM0;
#ifndef RECKLESS
    if (!(NUMBERP(x)))
    badx: wta(x, (char *)ARG1, s_logior);
#endif
    return x;
  }
#ifdef BIGDIG
  if (NINUMP(x)) {
    SCM t;
    ASRTGO(NIMP(x) && BIGP(x), badx);
    if (INUMP(y)) {t = x; x = y; y = t; goto intbig;}
    ASRTGO(NIMP(y) && BIGP(y), bady);
    if (NUMDIGS(x) > NUMDIGS(y)) {t = x; x = y; y = t;}
    if ((!BIGSIGN(x)) && !BIGSIGN(y))
      return scm_big_ior(BDIGITS(x), NUMDIGS(x), BIGSIGN(x), y);
    return scm_big_and(BDIGITS(x), NUMDIGS(x), BIGSIGN(x), y, 0x0100);
  }
  if (NINUMP(y)) {
# ifndef RECKLESS
    if (!(NIMP(y) && BIGP(y)))
    bady: wta(y, (char *)ARG2, s_logior);
# endif
  intbig: {
# ifndef DIGSTOOBIG
    long z = pseudolong(INUM(x));
    if ((!(x < 0)) && !BIGSIGN(y))
      return scm_big_ior((BIGDIG *)&z, DIGSPERLONG, (x < 0) ? 0x0100 : 0, y);
    return scm_big_and((BIGDIG *)&z, DIGSPERLONG, (x < 0) ? 0x0100 : 0, y,
			  0x0100);
# else
    BIGDIG zdigs[DIGSPERLONG];
    longdigs(INUM(x), zdigs);
    if ((!(x < 0)) && !BIGSIGN(y))
      return scm_big_ior(zdigs, DIGSPERLONG, (x < 0) ? 0x0100 : 0, y);
    return scm_big_and(zdigs, DIGSPERLONG, (x < 0) ? 0x0100 : 0, y, 0x0100);
# endif
  }}
#else
  ASRTGO(INUMP(x), badx);
  ASRTER(INUMP(y), y, ARG2, s_logior);
#endif
  return MAKINUM(INUM(x) | INUM(y));
}

SCM scm_logand(x, y)
     SCM x, y;
{
  if (UNBNDP(y)) {
    if (UNBNDP(x)) return MAKINUM(-1);
#ifndef RECKLESS
    if (!(NUMBERP(x)))
    badx: wta(x, (char *)ARG1, s_logand);
#endif
    return x;
  }
#ifdef BIGDIG
  if (NINUMP(x)) {
    SCM t;
    ASRTGO(NIMP(x) && BIGP(x), badx);
    if (INUMP(y)) {t = x; x = y; y = t; goto intbig;}
    ASRTGO(NIMP(y) && BIGP(y), bady);
    if (NUMDIGS(x) > NUMDIGS(y)) {t = x; x = y; y = t;}
    if ((BIGSIGN(x)) && BIGSIGN(y))
      return scm_big_ior(BDIGITS(x), NUMDIGS(x), 0x0100, y);
    return scm_big_and(BDIGITS(x), NUMDIGS(x), BIGSIGN(x), y, 0);
  }
  if (NINUMP(y)) {
# ifndef RECKLESS
    if (!(NIMP(y) && BIGP(y)))
    bady: wta(y, (char *)ARG2, s_logand);
# endif
  intbig: {
# ifndef DIGSTOOBIG
    long z = pseudolong(INUM(x));
    if ((x < 0) && BIGSIGN(y))
      return scm_big_ior((BIGDIG *)&z, DIGSPERLONG, 0x0100, y);
    return scm_big_and((BIGDIG *)&z, DIGSPERLONG, (x < 0) ? 0x0100 : 0, y,
			  0);
# else
    BIGDIG zdigs[DIGSPERLONG];
    longdigs(INUM(x), zdigs);
    if ((x < 0) && BIGSIGN(y))
      return scm_big_ior(zdigs, DIGSPERLONG, 0x0100, y);
    return scm_big_and(zdigs, DIGSPERLONG, (x < 0) ? 0x0100 : 0, y, 0);
# endif
  }}
#else
  ASRTGO(INUMP(x), badx);
  ASRTER(INUMP(y), y, ARG2, s_logand);
#endif
  return MAKINUM(INUM(x) & INUM(y));
}

SCM scm_logxor(x, y)
     SCM x, y;
{
  if (UNBNDP(y)) {
    if (UNBNDP(x)) return INUM0;
#ifndef RECKLESS
    if (!(NUMBERP(x)))
    badx: wta(x, (char *)ARG1, s_logxor);
#endif
    return x;
  }
#ifdef BIGDIG
  if (NINUMP(x)) {
    SCM t;
    ASRTGO(NIMP(x) && BIGP(x), badx);
    if (INUMP(y)) {t = x; x = y; y = t; goto intbig;}
    ASRTGO(NIMP(y) && BIGP(y), bady);
    if (NUMDIGS(x) > NUMDIGS(y)) {t = x; x = y; y = t;}
    return scm_big_xor(BDIGITS(x), NUMDIGS(x), BIGSIGN(x), y);
  }
  if (NINUMP(y)) {
# ifndef RECKLESS
    if (!(NIMP(y) && BIGP(y)))
    bady: wta(y, (char *)ARG2, s_logxor);
# endif
  intbig: {
# ifndef DIGSTOOBIG
    long z = pseudolong(INUM(x));
    return scm_big_xor((BIGDIG *)&z, DIGSPERLONG, (x < 0) ? 0x0100 : 0, y);
# else
    BIGDIG zdigs[DIGSPERLONG];
    longdigs(INUM(x), zdigs);
    return scm_big_xor(zdigs, DIGSPERLONG, (x < 0) ? 0x0100 : 0, y);
# endif
  }}
#else
  ASRTGO(INUMP(x), badx);
  ASRTER(INUMP(y), y, ARG2, s_logxor);
#endif
  return (x ^ y) + INUM0;
}

SCM scm_logtest(x, y)
     SCM x, y;
{
#ifndef RECKLESS
    if (!(NUMBERP(x)))
    badx: wta(x, (char *)ARG1, s_logtest);
#endif
#ifdef BIGDIG
  if (NINUMP(x)) {
    SCM t;
    ASRTGO(NIMP(x) && BIGP(x), badx);
    if (INUMP(y)) {t = x; x = y; y = t; goto intbig;}
    ASRTGO(NIMP(y) && BIGP(y), bady);
    if (NUMDIGS(x) > NUMDIGS(y)) {t = x; x = y; y = t;}
    return scm_big_test(BDIGITS(x), NUMDIGS(x), BIGSIGN(x), y);
  }
  if (NINUMP(y)) {
# ifndef RECKLESS
    if (!(NIMP(y) && BIGP(y)))
    bady: wta(y, (char *)ARG2, s_logtest);
# endif
  intbig: {
# ifndef DIGSTOOBIG
    long z = pseudolong(INUM(x));
    return scm_big_test((BIGDIG *)&z, DIGSPERLONG, (x < 0) ? 0x0100 : 0, y);
# else
    BIGDIG zdigs[DIGSPERLONG];
    longdigs(INUM(x), zdigs);
    return scm_big_test(zdigs, DIGSPERLONG, (x < 0) ? 0x0100 : 0, y);
# endif
  }}
#else
  ASRTGO(INUMP(x), badx);
  ASRTER(INUMP(y), y, ARG2, s_logtest);
#endif
  return (INUM(x) & INUM(y)) ? BOOL_T : BOOL_F;
}

SCM scm_logbitp(index, j1)
     SCM index, j1;
{
  ASRTER(INUMP(index) && INUM(index) >= 0, index, ARG1, s_logbitp);
#ifdef BIGDIG
  if (NINUMP(j1)) {
    ASRTER(NIMP(j1) && BIGP(j1), j1, ARG2, s_logbitp);
    if (NUMDIGS(j1) * BITSPERDIG < INUM(index)) return BOOL_F;
    else if (BIGSIGN(j1)) {
      long num = -1;
      sizet i = 0;
      BIGDIG *x = BDIGITS(j1);
      sizet nx = INUM(index)/BITSPERDIG;
      while (!0) {
	num += x[i];
	if (nx==i++)
	  return ((1L << (INUM(index)%BITSPERDIG)) & num) ? BOOL_F : BOOL_T;
	if (num < 0) num = -1;
	else num = 0;
      }
    }
    else return (BDIGITS(j1)[INUM(index)/BITSPERDIG] &
		 (1L << (INUM(index)%BITSPERDIG))) ? BOOL_T : BOOL_F;
  }
#else
  ASRTER(INUMP(j1), j1, ARG2, s_logbitp);
#endif
  if (INUM(index) >= LONG_BIT) return j1 < 0 ? BOOL_T : BOOL_F;
  return ((1L << INUM(index)) & INUM(j1)) ? BOOL_T : BOOL_F;
}

SCM scm_copybit(index, j1, bit)
     SCM index, j1, bit;
{
  ASRTER(INUMP(index) && INUM(index) >= 0, index, ARG1, s_copybit);
#ifdef BIGDIG
  {
    SCM res;
    BIGDIG *rds;
    sizet i = INUM(index);
    int sign;
    if (!INUMP(j1)) {
      ASRTER(NIMP(j1) && BIGP(j1), j1, ARG2, s_copybit);
      sign = BIGSIGN(j1);
    ovflow:
      res = scm_copy_big_2scomp(j1, i + 1, sign);
      rds = BDIGITS(res);
      if (NFALSEP(bit))
	rds[i / BITSPERDIG] |= 1 << (i % BITSPERDIG);
      else
	rds[i / BITSPERDIG] &= ~(1 << (i % BITSPERDIG));
      if (sign) scm_2scomp1(res);
      return normbig(res);
    }
    if (i >= LONG_BIT - 3) {
      sign = INUM(j1) < 0 ? 0x0100 : 0;
      goto ovflow;
    }
  }
#else
  ASRTER(INUMP(j1), j1, ARG2, s_copybit);
  ASRTER(INUM(index) < LONG_BIT - 3, index, OUTOFRANGE, s_copybit);
#endif
  if (NFALSEP(bit))
    return MAKINUM(INUM(j1) | (1L << INUM(index)));
  else
    return MAKINUM(INUM(j1) & (~(1L << INUM(index))));
}

SCM scm_lognot(n)
     SCM n;
{
  return difference(MAKINUM(-1L), n);
}

SCM scm_ash(n, cnt)
     SCM n, cnt;
{
  SCM res = INUM(n);
  ASRTER(INUMP(cnt), cnt, ARG2, s_ash);
  cnt = INUM(cnt);
  if (INUMP(n)) {
    if (cnt < 0) {
      if (-cnt >= LONG_BIT) return INUM0;
      return MAKINUM(SRS(res, -cnt));
    }
    if (cnt >= LONG_BIT) goto ovflow;
    res = MAKINUM(res<<cnt);
    if (INUM(res)>>cnt != INUM(n))
      goto ovflow;
    else
      return res;
  }
#ifdef BIGDIG
  ASRTER(NIMP(n) && BIGP(n), n, ARG1, s_ash);
 ovflow:
  if (0==cnt) return n;
  return scm_big_ash(n, cnt);
#else
 ovflow:
  wta(n, INUMP(n) ? (char *)OVFLOW : (char *)ARG1, s_ash);
  return UNSPECIFIED;	/* kill warning */
#endif
}

SCM scm_bitfield(n, start, end)
     SCM n, start, end;
{
  int sign;
  ASRTER(INUMP(start), start, ARG2, s_bitfield);
  ASRTER(INUMP(end), end, ARG3, s_bitfield);
  start = INUM(start); end = INUM(end);
  ASRTER(end >= start, MAKINUM(end), OUTOFRANGE, s_bitfield);
#ifdef BIGDIG
  if (NINUMP(n)) {
    BIGDIG *ds;
    sizet i, nd;
    ASRTER(NIMP(n) && BIGP(n), n, ARG1, s_bitfield);
    sign = BIGSIGN(n);
  big:
    if (sign) n = scm_copy_big_2scomp(n, (sizet)end, 0);
    n = scm_big_ash(n, -start);
    if (INUMP(n)) {
      if (end - start >= LONG_BIT - 2) return n;
      return MAKINUM(INUM(n) & ((1L<<(end - start)) - 1));
    }
    nd = NUMDIGS(n);
    ds = BDIGITS(n);
    i = (end - start) / BITSPERDIG;
    if (i >= nd) return n;
    ds[i] &= ((1 << ((end - start) % BITSPERDIG)) - 1);
    for (++i; i < nd; i++) ds[i] = 0;
    return normbig(n);
  }
  if (end >= LONG_BIT - 2) {
    sign = INUM(n) < 0;
    goto big;
  }
#else
  ASRTER(INUMP(n), n, ARG1, s_bitfield);
  ASRTER(end < LONG_BIT - 2, MAKINUM(end), OUTOFRANGE, s_bitfield);
#endif
  return MAKINUM((INUM(n)>>start) & ((1L<<(end - start)) - 1));
}

SCM scm_bitif(mask, n0, n1)
     SCM mask, n0, n1;
{
#ifdef BIGDIG
  if (NINUMP(mask) || NINUMP(n0) || NINUMP(n1))
    return scm_logior(scm_logand(mask, n0),
		      scm_logand(scm_lognot(mask), n1));
#else
  ASRTER(INUMP(mask), mask, ARG1, s_bitif);
  ASRTER(INUMP(n0), n0, ARG2, s_bitif);
  ASRTER(INUMP(n1), n1, ARG3, s_bitif);
#endif
  return MAKINUM((INUM(mask) & INUM(n0)) | (~(INUM(mask)) & INUM(n1)));
}

SCM scm_copybitfield(to, from, rest)
     SCM to, from, rest;
{
  long len;
  SCM start, end;
#ifndef RECKLESS
  if (!(NIMP(rest) && CONSP(rest)))
    wna: wta(UNDEFINED, (char *)WNA, s_copybitfield);
#endif
  start = CAR(rest);
  rest = CDR(rest);
  ASRTGO(NIMP(rest) && CONSP(rest), wna);
  end = CAR(rest);
  ASRTGO(NULLP(CDR(rest)), wna);
  ASRTER(INUMP(start) && INUM(start)>=0, start, ARG2, s_copybitfield);
  len = INUM(end) - INUM(start);
  ASRTER(INUMP(end), end, ARG3, s_copybitfield);
  ASRTER(len >= 0, MAKINUM(len), OUTOFRANGE, s_copybitfield);
#ifdef BIGDIG
  if (NINUMP(from) || NINUMP(to) || (INUM(end) >= LONG_BIT - 2)) {
    SCM mask = difference(scm_ash(MAKINUM(1L), MAKINUM(len)), MAKINUM(1L));
    mask = scm_ash(mask, start);
    return scm_logior(scm_logand(mask, scm_ash(from, start)),
		      scm_logand(scm_lognot(mask), to));
  }
#else
  ASRTER(INUMP(to), to, ARG1, s_copybitfield);
  ASRTER(INUMP(from), from, ARG4, s_copybitfield);
  ASRTER(INUM(end) < LONG_BIT - 2, end, OUTOFRANGE, s_copybitfield);
#endif
  {
    long mask = ((1L<<len) - 1)<<INUM(start);
    return MAKINUM((mask & (INUM(from)<<INUM(start))) | ((~mask) & INUM(to)));
  }
}

char logtab[] = {0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4};
SCM scm_bitwise_bit_count(n)
     SCM n;
{
  register unsigned long c = 0;
  register long nn;
#ifdef BIGDIG
  if (NINUMP(n)) {
    sizet i; BIGDIG *ds, d;
    ASRTER(NIMP(n) && BIGP(n), n, ARG1, s_bitwise_bit_count);
    if (BIGSIGN(n))
      return scm_lognot(scm_bitwise_bit_count(difference(MAKINUM(-1L), n)));
    ds = BDIGITS(n);
    for (i = NUMDIGS(n); i--; )
      for (d = ds[i]; d; d >>= 4) c += logtab[15 & d];
    if (BIGSIGN(n))
      return MAKINUM(-1 - c);
    return MAKINUM(c);
  }
#else
  ASRTER(INUMP(n), n, ARG1, s_bitwise_bit_count);
#endif
  if ((nn = INUM(n)) < 0) nn = -1 - nn;
  for (; nn; nn >>= 4) c += logtab[15 & nn];
  if (n < 0)
    return MAKINUM(-1 - c);
  return MAKINUM(c);
}

SCM scm_logcount(n)
     SCM n;
{
  register unsigned long c = 0;
  register long nn;
#ifdef BIGDIG
  if (NINUMP(n)) {
    ASRTER(NIMP(n) && BIGP(n), n, ARG1, s_logcount);
    if (BIGSIGN(n)) return scm_bitwise_bit_count(difference(MAKINUM(-1L), n));
    return scm_bitwise_bit_count(n);
  }
#else
  ASRTER(INUMP(n), n, ARG1, s_logcount);
#endif
  if ((nn = INUM(n)) < 0) nn = -1 - nn;
  for (; nn; nn >>= 4) c += logtab[15 & nn];
  return MAKINUM(c);
}

char ilentab[] = {0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4};
SCM scm_intlength(n)
     SCM n;
{
  register unsigned long c = 0;
  register long nn;
  unsigned int l = 4;
#ifdef BIGDIG
  if (NINUMP(n)) {
    BIGDIG *ds, d;
    ASRTER(NIMP(n) && BIGP(n), n, ARG1, s_intlength);
    if (BIGSIGN(n)) return scm_intlength(difference(MAKINUM(-1L), n));
    ds = BDIGITS(n);
    d = ds[c = NUMDIGS(n)-1];
    for (c *= BITSPERDIG; d; d >>= 4) {c += 4; l = ilentab[15 & d];}
    return MAKINUM(c - 4 + l);
  }
#else
  ASRTER(INUMP(n), n, ARG1, s_intlength);
#endif
  if ((nn = INUM(n)) < 0) nn = -1 - nn;
  for (;nn; nn >>= 4) {c += 4; l = ilentab[15 & nn];}
  return MAKINUM(c - 4 + l);
}

SCM charp(x)
     SCM x;
{
	return ICHRP(x) ? BOOL_T : BOOL_F;
}
SCM char_lessp(x, y)
     SCM x, y;
{
	ASRTER(ICHRP(x), x, ARG1, s_ch_lessp);
	ASRTER(ICHRP(y), y, ARG2, s_ch_lessp);
	return (ICHR(x) < ICHR(y)) ? BOOL_T : BOOL_F;
}
SCM char_leqp(x, y)
     SCM x, y;
{
	ASRTER(ICHRP(x), x, ARG1, s_ch_leqp);
	ASRTER(ICHRP(y), y, ARG2, s_ch_leqp);
	return (ICHR(x) <= ICHR(y)) ? BOOL_T : BOOL_F;
}
SCM char_grp(x, y)
     SCM x, y;
{
	ASRTER(ICHRP(x), x, ARG1, s_ch_grp);
	ASRTER(ICHRP(y), y, ARG2, s_ch_grp);
	return (ICHR(x) > ICHR(y)) ? BOOL_T : BOOL_F;
}
SCM char_geqp(x, y)
     SCM x, y;
{
	ASRTER(ICHRP(x), x, ARG1, s_ch_geqp);
	ASRTER(ICHRP(y), y, ARG2, s_ch_geqp);
	return (ICHR(x) >= ICHR(y)) ? BOOL_T : BOOL_F;
}
SCM chci_eq(x, y)
     SCM x, y;
{
	ASRTER(ICHRP(x), x, ARG1, s_ci_eq);
	ASRTER(ICHRP(y), y, ARG2, s_ci_eq);
	return (upcase[ICHR(x)]==upcase[ICHR(y)]) ? BOOL_T : BOOL_F;
}
SCM chci_lessp(x, y)
     SCM x, y;
{
	ASRTER(ICHRP(x), x, ARG1, s_ci_lessp);
	ASRTER(ICHRP(y), y, ARG2, s_ci_lessp);
	return (upcase[ICHR(x)] < upcase[ICHR(y)]) ? BOOL_T : BOOL_F;
}
SCM chci_leqp(x, y)
     SCM x, y;
{
	ASRTER(ICHRP(x), x, ARG1, s_ci_leqp);
	ASRTER(ICHRP(y), y, ARG2, s_ci_leqp);
	return (upcase[ICHR(x)] <= upcase[ICHR(y)]) ? BOOL_T : BOOL_F;
}
SCM chci_grp(x, y)
     SCM x, y;
{
	ASRTER(ICHRP(x), x, ARG1, s_ci_grp);
	ASRTER(ICHRP(y), y, ARG2, s_ci_grp);
	return (upcase[ICHR(x)] > upcase[ICHR(y)]) ? BOOL_T : BOOL_F;
}
SCM chci_geqp(x, y)
     SCM x, y;
{
	ASRTER(ICHRP(x), x, ARG1, s_ci_geqp);
	ASRTER(ICHRP(y), y, ARG2, s_ci_geqp);
	return (upcase[ICHR(x)] >= upcase[ICHR(y)]) ? BOOL_T : BOOL_F;
}
SCM char_alphap(chr)
     SCM chr;
{
	ASRTER(ICHRP(chr), chr, ARG1, s_ch_alphap);
	return (isascii(ICHR(chr)) && isalpha(ICHR(chr))) ? BOOL_T : BOOL_F;
}
SCM char_nump(chr)
     SCM chr;
{
	ASRTER(ICHRP(chr), chr, ARG1, s_ch_nump);
	return (isascii(ICHR(chr)) && isdigit(ICHR(chr))) ? BOOL_T : BOOL_F;
}
SCM char_whitep(chr)
     SCM chr;
{
	ASRTER(ICHRP(chr), chr, ARG1, s_ch_whitep);
	return (isascii(ICHR(chr)) && isspace(ICHR(chr))) ? BOOL_T : BOOL_F;
}
SCM char_upperp(chr)
     SCM chr;
{
	ASRTER(ICHRP(chr), chr, ARG1, s_ch_upperp);
	return (isascii(ICHR(chr)) && isupper(ICHR(chr))) ? BOOL_T : BOOL_F;
}
SCM char_lowerp(chr)
     SCM chr;
{
	ASRTER(ICHRP(chr), chr, ARG1, s_ch_lowerp);
	return (isascii(ICHR(chr)) && islower(ICHR(chr))) ? BOOL_T : BOOL_F;
}
SCM char2int(chr)
     SCM chr;
{
	ASRTER(ICHRP(chr), chr, ARG1, s_char2int);
	return MAKINUM(ICHR(chr));
}
SCM int2char(n)
     SCM n;
{
  ASRTER(INUMP(n), n, ARG1, s_int2char);
  ASRTER((n >= INUM0) && (n < MAKINUM(CHAR_CODE_LIMIT)),
	 n, OUTOFRANGE, s_int2char);
  return MAKICHR(INUM(n));
}
SCM char_upcase(chr)
     SCM chr;
{
	ASRTER(ICHRP(chr), chr, ARG1, s_ch_upcase);
	return MAKICHR(upcase[ICHR(chr)]);
}
SCM char_downcase(chr)
     SCM chr;
{
	ASRTER(ICHRP(chr), chr, ARG1, s_ch_downcase);
	return MAKICHR(downcase[ICHR(chr)]);
}

SCM stringp(x)
     SCM x;
{
	if (IMP(x)) return BOOL_F;
	return STRINGP(x) ? BOOL_T : BOOL_F;
}
SCM string(chrs)
     SCM chrs;
{
	SCM res;
	register unsigned char *data;
	long i = ilength(chrs);
	ASRTER(i >= 0, chrs, ARG1, s_string);
	res = makstr(i);
	data = UCHARS(res);
	for (;NNULLP(chrs);chrs = CDR(chrs)) {
		ASRTER(ICHRP(CAR(chrs)), chrs, ARG1, s_string);
		*data++ = ICHR(CAR(chrs));
	}
	return res;
}
SCM make_string(k, chr)
     SCM k, chr;
{
	SCM res;
	register unsigned char *dst;
	register long i;
	ASRTER(INUMP(k) && (k >= 0), k, ARG1, s_make_string);
	i = INUM(k);
	res = makstr(i);
	dst = UCHARS(res);
	if (!UNBNDP(chr)) {
	  ASRTER(ICHRP(chr), chr, ARG2, s_make_string);
	  for (i--;i >= 0;i--) dst[i] = ICHR(chr);
	}
	return res;
}
SCM st_length(str)
     SCM str;
{
	ASRTER(NIMP(str) && STRINGP(str), str, ARG1, s_st_length);
	return MAKINUM(LENGTH(str));
}
SCM st_ref(str, k)
     SCM str, k;
{
	ASRTER(NIMP(str) && STRINGP(str), str, ARG1, s_st_ref);
	ASRTER(INUMP(k), k, ARG2, s_st_ref);
	ASRTER(INUM(k) < LENGTH(str) && INUM(k) >= 0, k, OUTOFRANGE, s_st_ref);
	return MAKICHR(UCHARS(str)[INUM(k)]);
}
SCM st_set(str, k, chr)
     SCM str, k, chr;
{
	ASRTER(NIMP(str) && STRINGP(str), str, ARG1, s_st_set);
	ASRTER(INUMP(k), k, ARG2, s_st_set);
	ASRTER(ICHRP(chr), chr, ARG3, s_st_set);
	ASRTER(INUM(k) < LENGTH(str) && INUM(k) >= 0, k, OUTOFRANGE, s_st_set);
	UCHARS(str)[INUM(k)] = ICHR(chr);
	return UNSPECIFIED;
}
SCM st_equal(s1, s2)
     SCM s1, s2;
{
	register sizet i;
	register unsigned char *c1, *c2;
	ASRTER(NIMP(s1) && STRINGP(s1), s1, ARG1, s_st_equal);
	ASRTER(NIMP(s2) && STRINGP(s2), s2, ARG2, s_st_equal);
	i = LENGTH(s2);
	if (LENGTH(s1) != i) return BOOL_F;
	c1 = UCHARS(s1);
	c2 = UCHARS(s2);
	while(0 != i--) if (*c1++ != *c2++) return BOOL_F;
	return BOOL_T;
}
SCM stci_equal(s1, s2)
     SCM s1, s2;
{
	register sizet i;
	register unsigned char *c1, *c2;
	ASRTER(NIMP(s1) && STRINGP(s1), s1, ARG1, s_stci_equal);
	ASRTER(NIMP(s2) && STRINGP(s2), s2, ARG2, s_stci_equal);
	i = LENGTH(s2);
	if (LENGTH(s1) != i) return BOOL_F;
	c1 = UCHARS(s1);
	c2 = UCHARS(s2);
	while(0 != i--) if (upcase[*c1++] != upcase[*c2++]) return BOOL_F;
	return BOOL_T;
}
SCM st_lessp(s1, s2)
     SCM s1, s2;
{
	register sizet i, len;
	register unsigned char *c1, *c2;
	register int c;
	ASRTER(NIMP(s1) && STRINGP(s1), s1, ARG1, s_st_lessp);
	ASRTER(NIMP(s2) && STRINGP(s2), s2, ARG2, s_st_lessp);
	len = LENGTH(s1);
	i = LENGTH(s2);
	if (len>i) i = len;
	c1 = UCHARS(s1);
	c2 = UCHARS(s2);
	for (i = 0;i<len;i++) {
		c = (*c1++ - *c2++);
		if (c>0) return BOOL_F;
		if (c<0) return BOOL_T;
	}
	return (LENGTH(s2) != len) ? BOOL_T : BOOL_F;
}
SCM st_leqp(s1, s2)
     SCM s1, s2;
{
  return BOOL_NOT(st_lessp(s2, s1));
}
SCM st_grp(s1, s2)
     SCM s1, s2;
{
  return st_lessp(s2, s1);
}
SCM st_geqp(s1, s2)
     SCM s1, s2;
{
  return BOOL_NOT(st_lessp(s1, s2));
}
SCM stci_lessp(s1, s2)
     SCM s1, s2;
{
	register sizet i, len;
	register unsigned char *c1, *c2;
	register int c;
	ASRTER(NIMP(s1) && STRINGP(s1), s1, ARG1, s_stci_lessp);
	ASRTER(NIMP(s2) && STRINGP(s2), s2, ARG2, s_stci_lessp);
	len = LENGTH(s1);
	i = LENGTH(s2);
	if (len>i) i=len;
	c1 = UCHARS(s1);
	c2 = UCHARS(s2);
	for (i = 0;i<len;i++) {
		c = (upcase[*c1++] - upcase[*c2++]);
		if (c>0) return BOOL_F;
		if (c<0) return BOOL_T;
	}
	return (LENGTH(s2) != len) ? BOOL_T : BOOL_F;
}
SCM stci_leqp(s1, s2)
     SCM s1, s2;
{
  return BOOL_NOT(stci_lessp(s2, s1));
}
SCM stci_grp(s1, s2)
     SCM s1, s2;
{
  return stci_lessp(s2, s1);
}
SCM stci_geqp(s1, s2)
     SCM s1, s2;
{
  return BOOL_NOT(stci_lessp(s1, s2));
}
SCM substring(str, start, end)
     SCM str, start, end;
{
	long l;
	ASRTER(NIMP(str) && STRINGP(str), str, ARG1, s_substring);
	ASRTER(INUMP(start), start, ARG2, s_substring);
	ASRTER(INUMP(end), end, ARG3, s_substring);
	ASRTER(INUM(start) <= LENGTH(str), start, OUTOFRANGE, s_substring);
	ASRTER(INUM(end) <= LENGTH(str), end, OUTOFRANGE, s_substring);
	l = INUM(end)-INUM(start);
	ASRTER(l >= 0, MAKINUM(l), OUTOFRANGE, s_substring);
	return makfromstr(&CHARS(str)[INUM(start)], (sizet)l);
}
SCM st_append(args)
     SCM args;
{
	SCM res;
	register long i = 0;
	register SCM l, s;
	register unsigned char *data;
	for (l = args;NIMP(l);) {
		ASRTER(CONSP(l), l, ARGn, s_st_append);
		s = CAR(l);
		ASRTER(NIMP(s) && STRINGP(s), s, ARGn, s_st_append);
		i += LENGTH(s);
		l = CDR(l);
	}
	ASRTER(NULLP(l), args, ARGn, s_st_append);
	res = makstr(i);
	data = UCHARS(res);
	for (l = args;NIMP(l);l = CDR(l)) {
		s = CAR(l);
		for (i = 0;i<LENGTH(s);i++) *data++ = UCHARS(s)[i];
	}
	return res;
}

SCM vectorp(x)
     SCM x;
{
	if (IMP(x)) return BOOL_F;
	return VECTORP(x) ? BOOL_T : BOOL_F;
}
SCM vector_length(v)
     SCM v;
{
	ASRTER(NIMP(v) && VECTORP(v), v, ARG1, s_ve_length);
	return MAKINUM(LENGTH(v));
}
SCM vector(l)
     SCM l;
{
	SCM res;
	register SCM *data;
	long i = ilength(l);
	ASRTER(i >= 0, l, ARG1, s_vector);
	res = make_vector(MAKINUM(i), UNSPECIFIED);
	data = VELTS(res);
	for (;NIMP(l);l = CDR(l)) *data++ = CAR(l);
	return res;
}
SCM vector_ref(v, k)
     SCM v, k;
{
  ASRTER(NIMP(v) && VECTORP(v), v, ARG1, s_ve_ref);
  ASRTER(INUMP(k), k, ARG2, s_ve_ref);
  ASRTER((INUM(k) < LENGTH(v)) && (INUM(k) >= 0), k, OUTOFRANGE, s_ve_ref);
  return VELTS(v)[((long) INUM(k))];
}
SCM vector_set(v, k, obj)
     SCM v, k, obj;
{
  ASRTER(NIMP(v) && VECTORP(v), v, ARG1, s_ve_set);
  ASRTER(INUMP(k), k, ARG2, s_ve_set);
  ASRTER((INUM(k) < LENGTH(v)) && (INUM(k) >= 0), k, OUTOFRANGE, s_ve_set);
  VELTS(v)[((long) INUM(k))] = obj;
  return UNSPECIFIED;
}
char	s_make_vector[] = "make-vector";
SCM make_vector(k, fill)
     SCM k, fill;
{
  SCM v;
  register long i;
  register SCM *velts;
#ifdef SHORT_SIZET
  ASRTER(INUMP(k), k, ARG1, s_make_vector);
#else
  ASRTER(INUMP(k) && (!(~LENGTH_MAX & INUM(k))), k, ARG1, s_make_vector);
#endif
  if (UNBNDP(fill)) fill = UNSPECIFIED;
  i = INUM(k);
  DEFER_INTS;
  v = must_malloc_cell(i ? i*sizeof(SCM) : 1L,
		       MAKE_LENGTH(i, tc7_vector), s_vector);
  velts = VELTS(v);
  while(--i >= 0) (velts)[i] = fill;
  ALLOW_INTS;
  return v;
}
#ifdef BIGDIG
char s_big_OVFLOW[] = "numerical overflow; NUMDIGS_MAX <";
char s_bignum[] = "bignum";
SCM mkbig(nlen, sign)
     sizet nlen;
     int sign;
{
  SCM v;
  if (NUMDIGS_MAX <= nlen) wta(MAKINUM(nlen), s_big_OVFLOW, s_bignum);
  DEFER_INTS;
  v = must_malloc_cell((0L+nlen)*sizeof(BIGDIG),
		       MAKE_NUMDIGS(nlen, sign ? tc16_bigneg : tc16_bigpos),
		       s_bignum);
  ALLOW_INTS;
  return v;
}
SCM big2inum(b, l)
     SCM b;
     sizet l;
{
  unsigned long num = 0;
  BIGDIG *tmp = BDIGITS(b);
  while (l--) num = BIGUP(num) + tmp[l];
  if (TYP16(b)==tc16_bigpos) {
    if (POSFIXABLE(num)) return MAKINUM(num);
  }
  else if (UNEGFIXABLE(num)) return MAKINUM(-(long)num);
  return b;
}
char s_adjbig[] = "adjbig";
SCM adjbig(b, nlen)
     SCM b;
     sizet nlen;
{
  long nsiz = nlen;
  if (((nsiz << 16) >> 16) != nlen)
    wta(MAKINUM(nsiz), s_big_OVFLOW, s_adjbig);
  DEFER_INTS;
  must_realloc_cell(b, (long)(NUMDIGS(b)*sizeof(BIGDIG)),
		    (long)(nsiz*sizeof(BIGDIG)), s_adjbig);
  SETNUMDIGS(b, nsiz, TYP16(b));
  ALLOW_INTS;
  return b;
}
SCM normbig(b)
     SCM b;
{
# ifndef _UNICOS
  sizet nlen = NUMDIGS(b);
# else
  int nlen = NUMDIGS(b);   /* unsigned nlen breaks on Cray when nlen => 0 */
# endif
  BIGDIG *zds = BDIGITS(b);
  while (nlen-- && !zds[nlen]); nlen++;
  if (nlen * BITSPERDIG/CHAR_BIT <= sizeof(SCM))
    if (INUMP(b = big2inum(b, (sizet)nlen))) return b;
  if (NUMDIGS(b)==nlen) return b;
  return adjbig(b, (sizet)nlen);
}
SCM copybig(b, sign)
     SCM b;
     int sign;
{
  sizet i = NUMDIGS(b);
  SCM ans = mkbig(i, sign);
  BIGDIG *src = BDIGITS(b), *dst = BDIGITS(ans);
  while (i--) dst[i] = src[i];
  return ans;
}
SCM long2big(n)
     long n;
{
  sizet i = 0;
  BIGDIG *digits;
  SCM ans = mkbig(DIGSPERLONG, n<0);
  digits = BDIGITS(ans);
  if (n < 0) n = -n;
  while (i < DIGSPERLONG) {
    digits[i++] = BIGLO(n);
    n = BIGDN((unsigned long)n);
  }
  return ans;
}
SCM ulong2big(n)
     unsigned long n;
{
  sizet i = 0;
  BIGDIG *digits;
  SCM ans = mkbig(DIGSPERLONG, 0);
  digits = BDIGITS(ans);
  while (i < DIGSPERLONG) {
    digits[i++] = BIGLO(n);
    n = BIGDN(n);
  }
  return ans;
}

int bigcomp(x, y)
     SCM x, y;
{
  int xsign = BIGSIGN(x);
  int ysign = BIGSIGN(y);
  long xlen;
  sizet ylen;
  if (ysign < xsign) return 1;
  if (ysign > xsign) return -1;
  if ((ylen = NUMDIGS(y)) > (xlen = NUMDIGS(x))) return (xsign) ? -1 : 1;
  if (ylen < xlen) return (xsign) ? 1 : -1;
  while(xlen-- && (BDIGITS(y)[xlen]==BDIGITS(x)[xlen]));
  if (-1==xlen) return 0;
  return (BDIGITS(y)[xlen] > BDIGITS(x)[xlen]) ?
    (xsign ? -1 : 1) : (xsign ? 1 : -1);
}

# ifndef DIGSTOOBIG
long pseudolong(x)
    long x;
{
  union {
    long l;
    BIGDIG bd[DIGSPERLONG];
  } p;
  sizet i = 0;
  if (x < 0) x = -x;
  while (i < DIGSPERLONG) {p.bd[i++] = BIGLO(x); x = BIGDN(x);}
/*  p.bd[0] = BIGLO(x); p.bd[1] = BIGDN(x); */
  return p.l;
}
# else
void longdigs(x, digs)
     long x;
     BIGDIG digs[DIGSPERLONG];
{
  sizet i = 0;
  if (x < 0) x = -x;
  while (i < DIGSPERLONG) {digs[i++] = BIGLO(x); x = BIGDN(x);}
}
# endif

SCM addbig(x, nx, xsgn, bigy, sgny)
     BIGDIG *x;
     SCM bigy;
     sizet nx;		/* Assumes nx <= NUMDIGS(bigy) */
     int xsgn, sgny;	/* Assumes xsgn and sgny equal either 0 or 0x0100 */
{
  long num = 0;
  sizet i = 0, ny = NUMDIGS(bigy);
  SCM z = copybig(bigy, BIGSIGN(bigy) ^ sgny);
  BIGDIG *zds = BDIGITS(z);
  if (xsgn ^ BIGSIGN(z)) {
    do {
      num += (long) zds[i] - x[i];
      if (num < 0) {zds[i] = num + BIGRAD; num = -1;}
      else {zds[i] = BIGLO(num); num = 0;}
    } while (++i < nx);
    if (num && nx==ny) {
      num = 1; i = 0;
      CAR(z) ^= 0x0100;
      do {
	num += (BIGRAD-1) - zds[i];
	zds[i++] = BIGLO(num);
	num = BIGDN(num);
      } while (i < ny);
    }
    else while (i < ny) {
      num += zds[i];
      if (num < 0) {zds[i++] = num + BIGRAD; num = -1;}
      else {zds[i++] = BIGLO(num); num = 0;}
    }
  } else {
    do {
      num += (long) zds[i] + x[i];
      zds[i++] = BIGLO(num);
      num = BIGDN(num);
    } while (i < nx);
    if (!num) return z;
    while (i < ny) {
      num += zds[i];
      zds[i++] = BIGLO(num);
      num = BIGDN(num);
      if (!num) return z;
    }
    if (num) {z = adjbig(z, ny+1); BDIGITS(z)[ny] = num; return z;}
  }
  return normbig(z);
}

SCM mulbig(x, nx, y, ny, sgn)
     BIGDIG *x, *y;
     sizet nx, ny;
     int sgn;
{
  sizet i = 0, j = nx + ny;
  unsigned long n = 0;
  SCM z = mkbig(j, sgn);
  BIGDIG *zds = BDIGITS(z);
  while (j--) zds[j] = 0;
  do {
    j = 0;
    if (x[i]) {
      do {
	n += zds[i + j] + ((unsigned long) x[i] * y[j]);
	zds[i + j++] = BIGLO(n);
	n = BIGDN(n);
      } while (j < ny);
      if (n) {zds[i + j] = n; n = 0;}
    }
  } while (++i < nx);
  return normbig(z);
}
unsigned int divbigdig(ds, h, div)
     BIGDIG *ds;
     sizet h;
     BIGDIG div;
{
  register unsigned long t2 = 0;
  while(h--) {
    t2 = BIGUP(t2) + ds[h];
    ds[h] = t2 / div;
    t2 %= div;
  }
  return t2;
}
SCM divbigint(x, z, sgn, mode)
     SCM x;
     long z;
     int sgn, mode;
{
  if (z < 0) z = -z;
  if (z < BIGRAD) {
    register unsigned long t2 = 0;
    register BIGDIG *ds = BDIGITS(x);
    sizet nd = NUMDIGS(x);
    while(nd--) t2 = (BIGUP(t2) + ds[nd]) % z;
    if (mode && t2) t2 = z - t2;
    return MAKINUM(sgn ? -(long)t2 : t2);
  }
  {
# ifndef DIGSTOOBIG
    unsigned long t2 = pseudolong(z);
    return divbigbig(BDIGITS(x), NUMDIGS(x), (BIGDIG *)&t2,
		     DIGSPERLONG, sgn, mode);
# else
    BIGDIG t2[DIGSPERLONG];
    longdigs(z, t2);
    return divbigbig(BDIGITS(x), NUMDIGS(x), t2, DIGSPERLONG, sgn, mode);
# endif
  }
}
SCM divbigbig(x, nx, y, ny, sgn, modes)
     BIGDIG *x, *y;
     sizet nx, ny;
     int sgn, modes;
     /* modes description
	0	remainder
	1	modulo
	2	quotient
	3	quotient but returns 0 if division is not exact. */
{
  sizet i = 0, j = 0;
  long num = 0;
  unsigned long t2 = 0;
  SCM z, newy;
  BIGDIG  d = 0, qhat, *zds, *yds;
  /* algorithm requires nx >= ny */
  if (nx < ny)
    switch (modes) {
    case 0:			/* remainder -- just return x */
      z = mkbig(nx, sgn); zds = BDIGITS(z);
      do {zds[i] = x[i];} while (++i < nx);
      return z;
    case 1:			/* modulo -- return y-x */
      z = mkbig(ny, sgn); zds = BDIGITS(z);
      do {
	num += (long) y[i] - x[i];
	if (num < 0) {zds[i] = num + BIGRAD; num = -1;}
	else {zds[i] = num; num = 0;}
      } while (++i < nx);
      while (i < ny) {
	num += y[i];
	if (num < 0) {zds[i++] = num + BIGRAD; num = -1;}
	else {zds[i++] = num; num = 0;}
      }
      goto doadj;
    case 2: return INUM0;	/* quotient is zero */
    case 3: return 0;		/* the division is not exact */
    }

  z = mkbig(nx==ny ? nx+2 : nx+1, sgn); zds = BDIGITS(z);
  if (nx==ny) zds[nx+1] = 0;
  while(!y[ny-1]) ny--;		/* in case y came in as a psuedolong */
  if (y[ny-1] < (BIGRAD>>1)) {  /* normalize operands */
    d = BIGRAD/(y[ny-1]+1);
    newy = mkbig(ny, 0); yds = BDIGITS(newy);
    while(j < ny)
      {t2 += (unsigned long) y[j]*d; yds[j++] = BIGLO(t2); t2 = BIGDN(t2);}
    y = yds; j = 0; t2 = 0;
    while(j < nx)
      {t2 += (unsigned long) x[j]*d; zds[j++] = BIGLO(t2); t2 = BIGDN(t2);}
    zds[j] = t2;
  }
  else {zds[j = nx] = 0; while (j--) zds[j] = x[j];}
  j = nx==ny ? nx+1 : nx;	/* dividend needs more digits than divisor */
  do {				/* loop over digits of quotient */
    if (zds[j]==y[ny-1]) qhat = BIGRAD-1;
    else qhat = (BIGUP(zds[j]) + zds[j-1])/y[ny-1];
    if (!qhat) continue;
    i = 0; num = 0; t2 = 0;
    do {			/* multiply and subtract */
      t2 += (unsigned long) y[i] * qhat;
      num += zds[j - ny + i] - BIGLO(t2);
      if (num < 0) {zds[j - ny + i] = num + BIGRAD; num = -1;}
      else {zds[j - ny + i] = num; num = 0;}
      t2 = BIGDN(t2);
    } while (++i < ny);
    num += zds[j - ny + i] - t2; /* borrow from high digit; don't update */
    while (num) {		/* "add back" required */
      i = 0; num = 0; qhat--;
      do {
	num += (long) zds[j - ny + i] + y[i];
	zds[j - ny + i] = BIGLO(num);
	num = BIGDN(num);
      } while (++i < ny);
      num--;
    }
    if (modes & 2) zds[j] = qhat;
  } while (--j >= ny);
  switch (modes) {
  case 3:			/* check that remainder==0 */
    for (j = ny;j && !zds[j-1];--j) ; if (j) return 0;
  case 2:			/* move quotient down in z */
    j = (nx==ny ? nx+2 : nx+1) - ny;
    for (i = 0;i < j;i++) zds[i] = zds[i+ny];
    ny = i;
    break;
  case 1:			/* subtract for modulo */
    i = 0; num = 0; j = 0;
    do {num += y[i] - zds[i];
	j = j | zds[i];
	if (num < 0) {zds[i] = num + BIGRAD; num = -1;}
	else {zds[i] = num; num = 0;}
      } while (++i < ny);
    if (!j) return INUM0;
  case 0:			/* just normalize remainder */
    if (d) divbigdig(zds, ny, d);
  }
 doadj:
  for (j = ny;j && !zds[j-1];--j) ;
  if (j * BITSPERDIG <= sizeof(SCM)*CHAR_BIT)
    if (INUMP(z = big2inum(z, j))) return z;
  return adjbig(z, j);
}
#endif

static iproc cxrs[] = {
	{"cr", 0},
	{"car", 0}, {"cdr", 0},
	{"caar", 0}, {"cadr", 0}, {"cdar", 0}, {"cddr", 0},
	{"caaar", 0}, {"caadr", 0}, {"cadar", 0}, {"caddr", 0},
	{"cdaar", 0}, {"cdadr", 0}, {"cddar", 0}, {"cdddr", 0},
	{"caaaar", 0}, {"caaadr", 0}, {"caadar", 0}, {"caaddr", 0},
	{"cadaar", 0}, {"cadadr", 0}, {"caddar", 0}, {"cadddr", 0},
	{"cdaaar", 0}, {"cdaadr", 0}, {"cdadar", 0}, {"cdaddr", 0},
	{"cddaar", 0}, {"cddadr", 0}, {"cdddar", 0}, {"cddddr", 0},
	{0, 0}};

static iproc subr1s[] = {
	{"not", lnot},
	{"boolean?", booleanp},
	{"pair?", consp},
	{"null?", nullp},
	{"list?", listp},
	{s_length, length},
	{s_reverse, reverse},
	{"symbol?", symbolp},
	{s_symbol2string, symbol2string},
	{s_str2symbol, string2symbol},
	{s_exactp, exactp},
	{s_oddp, oddp},
	{s_evenp, evenp},
	{s_lognot, scm_lognot},
	{s_logcount, scm_logcount},
	{s_bitwise_bit_count, scm_bitwise_bit_count},
	{s_intlength, scm_intlength},
	{"char?", charp},
	{s_ch_alphap, char_alphap},
	{s_ch_nump, char_nump},
	{s_ch_whitep, char_whitep},
	{s_ch_upperp, char_upperp},
	{s_ch_lowerp, char_lowerp},
	{s_char2int, char2int},
	{s_int2char, int2char},
	{s_ch_upcase, char_upcase},
	{s_ch_downcase, char_downcase},
	{"string?", stringp},
	{s_st_length, st_length},
	{"vector?", vectorp},
	{s_ve_length, vector_length},
	{"procedure?", procedurep},
	{"promise?", promisep},
	{0, 0}};

static char s_acons[] = "acons";
static iproc subr2s[] = {
	{&s_acons[1], cons},
	{s_setcar, setcar},
	{s_setcdr, setcdr},
	{s_list_ref, list_ref},
	{s_memq, memq},
	{s_member, member},
	{s_assq, assq},
	{s_assoc, assoc},
	{s_quotient, lquotient},
	{s_remainder, lremainder},
	{s_modulo, modulo},
	{s_logtest, scm_logtest},
	{s_logbitp, scm_logbitp},
	{s_ash, scm_ash},
	{s_st_ref, st_ref},
	{"string<=?", st_leqp},
	{"string-ci<=?", stci_leqp},
	{s_ve_ref, vector_ref},
	{0, 0}};

static iproc lsubrs[] = {
	{s_list, list},
	{s_append, append},
	{s_string, string},
	{s_st_append, st_append},
	{s_vector, vector},
	{0, 0}};

static iproc subr2os[] = {
	{s_make_string, make_string},
	{s_make_vector, make_vector},
	{0, 0}};

static iproc asubrs[] = {
	{s_gcd, lgcd},
	{"lcm", llcm},
	{s_logand, scm_logand},
	{s_logior, scm_logior},
	{s_logxor, scm_logxor},
	{0, 0}};

static iproc rpsubrs[] = {
	{"eq?", eq},
	{"equal?", equal},
	{"char=?", eq},
	{s_ch_lessp, char_lessp},
	{s_ci_eq, chci_eq},
	{s_ci_lessp, chci_lessp},
	{s_ch_leqp, char_leqp},
	{s_ci_leqp, chci_leqp},
	{s_ch_grp, char_grp},
	{s_ci_grp, chci_grp},
	{s_ch_geqp, char_geqp},
	{s_ci_geqp, chci_geqp},

	{s_st_equal, st_equal},
	{s_stci_equal, stci_equal},
	{s_st_lessp, st_lessp},
	{s_stci_lessp, stci_lessp},
	{"string>?", st_grp},
	{"string-ci>?", stci_grp},
	{"string>=?", st_geqp},
	{"string-ci>=?", stci_geqp},
	{0, 0}};

static iproc subr3s[] = {
	{s_bitfield, scm_bitfield},
	{s_bitif, scm_bitif},
	{s_copybit, scm_copybit},
	{s_substring, substring},
	{s_acons, acons},
	{s_st_set, st_set},
	{s_ve_set, vector_set},
	{0, 0}};

void init_iprocs(subra, type)
     iproc *subra;
     int type;
{
  for (;subra->string; subra++)
    make_subr(subra->string,
	      type,
	      subra->cproc);
}

void init_subrs()
{
  init_iprocs(cxrs, tc7_cxr);
  init_iprocs(subr1s, tc7_subr_1);
  init_iprocs(subr2s, tc7_subr_2);
  init_iprocs(subr2os, tc7_subr_2o);
  init_iprocs(rpsubrs, tc7_rpsubr);
  init_iprocs(lsubrs, tc7_lsubr);
  init_iprocs(asubrs, tc7_asubr);
  init_iprocs(subr3s, tc7_subr_3);
  make_subr(s_copybitfield, tc7_lsubr_2, scm_copybitfield);
}