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Import gnuplot 3.7.3

#ifndef lint
static char *RCSid = "$Id: internal.c,v 1.7.2.1 2002/05/16 16:42:56 broeker Exp $";
#endif

/* GNUPLOT - internal.c */

/*[
 * Copyright 1986 - 1993, 1998   Thomas Williams, Colin Kelley
 *
 * Permission to use, copy, and distribute this software and its
 * documentation for any purpose with or without fee is hereby granted,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.
 *
 * Permission to modify the software is granted, but not the right to
 * distribute the complete modified source code.  Modifications are to
 * be distributed as patches to the released version.  Permission to
 * distribute binaries produced by compiling modified sources is granted,
 * provided you
 *   1. distribute the corresponding source modifications from the
 *    released version in the form of a patch file along with the binaries,
 *   2. add special version identification to distinguish your version
 *    in addition to the base release version number,
 *   3. provide your name and address as the primary contact for the
 *    support of your modified version, and
 *   4. retain our contact information in regard to use of the base
 *    software.
 * Permission to distribute the released version of the source code along
 * with corresponding source modifications in the form of a patch file is
 * granted with same provisions 2 through 4 for binary distributions.
 *
 * This software is provided "as is" without express or implied warranty
 * to the extent permitted by applicable law.
]*/


#include "plot.h"
#include "fnproto.h"

/* some machines have trouble with exp(-x) for large x
 * if MINEXP is defined at compile time, use gp_exp(x) instead,
 * which returns 0 for exp(x) with x < MINEXP
 * exp(x) will already have been defined as gp_exp(x) in plot.h
 */

#ifdef MINEXP
double gp_exp(x)
double x;
{
    return (x < (MINEXP)) ? 0.0 : exp(x);
}
#endif

TBOOLEAN undefined;

static void int_check __PROTO((struct value * v));

struct value stack[STACK_DEPTH];

int s_p = -1;			/* stack pointer */


/*
 * System V and MSC 4.0 call this when they wants to print an error message.
 * Don't!
 */
#ifndef _CRAY
# ifdef AMIGA_SC_6_1
#  define matherr __matherr
#  define exception __exception
# endif				/* AMIGA_SC_6_1 */
# if defined(__BORLANDC__) && __BORLANDC__ >= 0x450
#  define matherr _matherr
# endif				/* __BORLANDC__ >= 0x450 */
# if (defined(MSDOS) || defined(DOS386)) && defined(__TURBOC__) || defined(VMS)
int matherr()
#else
int matherr(x)
struct exception *x;
# endif				/* (MSDOS || DOS386) && __TURBOC__ */
{
    return (undefined = TRUE);	/* don't print error message */
}
#endif /* not _CRAY */


void reset_stack()
{
    s_p = -1;
}


void check_stack()
{				/* make sure stack's empty */
    if (s_p != -1)
	fprintf(stderr, "\n\
warning:  internal error--stack not empty!\n\
          (function called with too many parameters?)\n");
}

#define BAD_DEFAULT default: int_error("internal error : type neither INT or CMPLX", NO_CARET); return;

struct value *pop(x)
struct value *x;
{
    if (s_p < 0)
	int_error("stack underflow (function call with missing parameters?)", NO_CARET);
    *x = stack[s_p--];
    return (x);
}


void push(x)
struct value *x;
{
    if (s_p == STACK_DEPTH - 1)
	int_error("stack overflow", NO_CARET);
    stack[++s_p] = *x;
}


#define ERR_VAR "undefined variable: "

void f_push(x)
union argument *x;		/* contains pointer to value to push; */
{
    static char err_str[sizeof(ERR_VAR) + MAX_ID_LEN] = ERR_VAR;
    struct udvt_entry *udv;

    udv = x->udv_arg;
    if (udv->udv_undef) {	/* undefined */
	(void) strcpy(&err_str[sizeof(ERR_VAR) - 1], udv->udv_name);
	int_error(err_str, NO_CARET);
    }
    push(&(udv->udv_value));
}


void f_pushc(x)
union argument *x;
{
    push(&(x->v_arg));
}


void f_pushd1(x)
union argument *x;
{
    push(&(x->udf_arg->dummy_values[0]));
}


void f_pushd2(x)
union argument *x;
{
    push(&(x->udf_arg->dummy_values[1]));
}


void f_pushd(x)
union argument *x;
{
    struct value param;
    (void) pop(&param);
    push(&(x->udf_arg->dummy_values[param.v.int_val]));
}


#define ERR_FUN "undefined function: "

void f_call(x)			/* execute a udf */
union argument *x;
{
    static char err_str[sizeof(ERR_FUN) + MAX_ID_LEN] = ERR_FUN;
    register struct udft_entry *udf;
    struct value save_dummy;

    udf = x->udf_arg;
    if (!udf->at) {		/* undefined */
	(void) strcpy(&err_str[sizeof(ERR_FUN) - 1],
		      udf->udf_name);
	int_error(err_str, NO_CARET);
    }
    save_dummy = udf->dummy_values[0];
    (void) pop(&(udf->dummy_values[0]));

    execute_at(udf->at);
    udf->dummy_values[0] = save_dummy;
}


void f_calln(x)			/* execute a udf of n variables */
union argument *x;
{
    static char err_str[sizeof(ERR_FUN) + MAX_ID_LEN] = ERR_FUN;
    register struct udft_entry *udf;
    struct value save_dummy[MAX_NUM_VAR];

    int i;
    int num_pop;
    struct value num_params;

    udf = x->udf_arg;
    if (!udf->at) {		/* undefined */
	(void) strcpy(&err_str[sizeof(ERR_FUN) - 1],
		      udf->udf_name);
	int_error(err_str, NO_CARET);
    }
    for (i = 0; i < MAX_NUM_VAR; i++)
	save_dummy[i] = udf->dummy_values[i];

    /* if there are more parameters than the function is expecting */
    /* simply ignore the excess */
    (void) pop(&num_params);

    if (num_params.v.int_val > MAX_NUM_VAR) {
	/* pop the dummies that there is no room for */
	num_pop = num_params.v.int_val - MAX_NUM_VAR;
	for (i = 0; i < num_pop; i++)
	    (void) pop(&(udf->dummy_values[i]));

	num_pop = MAX_NUM_VAR;
    } else {
	num_pop = num_params.v.int_val;
    }

    /* pop parameters we can use */
    for (i = num_pop - 1; i >= 0; i--)
	(void) pop(&(udf->dummy_values[i]));

    execute_at(udf->at);
    for (i = 0; i < MAX_NUM_VAR; i++)
	udf->dummy_values[i] = save_dummy[i];
}


static void int_check(v)
struct value *v;
{
    if (v->type != INTGR)
	int_error("non-integer passed to boolean operator", NO_CARET);
}


void f_lnot()
{
    struct value a;
    int_check(pop(&a));
    push(Ginteger(&a, !a.v.int_val));
}


void f_bnot()
{
    struct value a;
    int_check(pop(&a));
    push(Ginteger(&a, ~a.v.int_val));
}


void f_bool()
{				/* converts top-of-stack to boolean */
    int_check(&top_of_stack);
    top_of_stack.v.int_val = !!top_of_stack.v.int_val;
}


void f_lor()
{
    struct value a, b;
    int_check(pop(&b));
    int_check(pop(&a));
    push(Ginteger(&a, a.v.int_val || b.v.int_val));
}

void f_land()
{
    struct value a, b;
    int_check(pop(&b));
    int_check(pop(&a));
    push(Ginteger(&a, a.v.int_val && b.v.int_val));
}


void f_bor()
{
    struct value a, b;
    int_check(pop(&b));
    int_check(pop(&a));
    push(Ginteger(&a, a.v.int_val | b.v.int_val));
}


void f_xor()
{
    struct value a, b;
    int_check(pop(&b));
    int_check(pop(&a));
    push(Ginteger(&a, a.v.int_val ^ b.v.int_val));
}


void f_band()
{
    struct value a, b;
    int_check(pop(&b));
    int_check(pop(&a));
    push(Ginteger(&a, a.v.int_val & b.v.int_val));
}


void f_uminus()
{
    struct value a;
    (void) pop(&a);
    switch (a.type) {
    case INTGR:
	a.v.int_val = -a.v.int_val;
	break;
    case CMPLX:
	a.v.cmplx_val.real =
	    -a.v.cmplx_val.real;
	a.v.cmplx_val.imag =
	    -a.v.cmplx_val.imag;
	break;
	BAD_DEFAULT
    }
    push(&a);
}


void f_eq()
{
    /* note: floating point equality is rare because of roundoff error! */
    struct value a, b;
    register int result = 0;
    (void) pop(&b);
    (void) pop(&a);
    switch (a.type) {
    case INTGR:
	switch (b.type) {
	case INTGR:
	    result = (a.v.int_val ==
		      b.v.int_val);
	    break;
	case CMPLX:
	    result = (a.v.int_val ==
		      b.v.cmplx_val.real &&
		      b.v.cmplx_val.imag == 0.0);
	    break;
	    BAD_DEFAULT
	}
	break;
    case CMPLX:
	switch (b.type) {
	case INTGR:
	    result = (b.v.int_val == a.v.cmplx_val.real &&
		      a.v.cmplx_val.imag == 0.0);
	    break;
	case CMPLX:
	    result = (a.v.cmplx_val.real ==
		      b.v.cmplx_val.real &&
		      a.v.cmplx_val.imag ==
		      b.v.cmplx_val.imag);
	    break;
	    BAD_DEFAULT
	}
	break;
	BAD_DEFAULT
    }
    push(Ginteger(&a, result));
}


void f_ne()
{
    struct value a, b;
    register int result = 0;
    (void) pop(&b);
    (void) pop(&a);
    switch (a.type) {
    case INTGR:
	switch (b.type) {
	case INTGR:
	    result = (a.v.int_val !=
		      b.v.int_val);
	    break;
	case CMPLX:
	    result = (a.v.int_val !=
		      b.v.cmplx_val.real ||
		      b.v.cmplx_val.imag != 0.0);
	    break;
	    BAD_DEFAULT
	}
	break;
    case CMPLX:
	switch (b.type) {
	case INTGR:
	    result = (b.v.int_val !=
		      a.v.cmplx_val.real ||
		      a.v.cmplx_val.imag != 0.0);
	    break;
	case CMPLX:
	    result = (a.v.cmplx_val.real !=
		      b.v.cmplx_val.real ||
		      a.v.cmplx_val.imag !=
		      b.v.cmplx_val.imag);
	    break;
	    BAD_DEFAULT
	}
	break;
	BAD_DEFAULT
    }
    push(Ginteger(&a, result));
}


void f_gt()
{
    struct value a, b;
    register int result = 0;
    (void) pop(&b);
    (void) pop(&a);
    switch (a.type) {
    case INTGR:
	switch (b.type) {
	case INTGR:
	    result = (a.v.int_val >
		      b.v.int_val);
	    break;
	case CMPLX:
	    result = (a.v.int_val >
		      b.v.cmplx_val.real);
	    break;
	    BAD_DEFAULT
	}
	break;
    case CMPLX:
	switch (b.type) {
	case INTGR:
	    result = (a.v.cmplx_val.real >
		      b.v.int_val);
	    break;
	case CMPLX:
	    result = (a.v.cmplx_val.real >
		      b.v.cmplx_val.real);
	    break;
	    BAD_DEFAULT
	}
	break;
	BAD_DEFAULT
    }
    push(Ginteger(&a, result));
}


void f_lt()
{
    struct value a, b;
    register int result = 0;
    (void) pop(&b);
    (void) pop(&a);
    switch (a.type) {
    case INTGR:
	switch (b.type) {
	case INTGR:
	    result = (a.v.int_val <
		      b.v.int_val);
	    break;
	case CMPLX:
	    result = (a.v.int_val <
		      b.v.cmplx_val.real);
	    break;
	    BAD_DEFAULT
	}
	break;
    case CMPLX:
	switch (b.type) {
	case INTGR:
	    result = (a.v.cmplx_val.real <
		      b.v.int_val);
	    break;
	case CMPLX:
	    result = (a.v.cmplx_val.real <
		      b.v.cmplx_val.real);
	    break;
	    BAD_DEFAULT
	}
	break;
	BAD_DEFAULT
    }
    push(Ginteger(&a, result));
}


void f_ge()
{
    struct value a, b;
    register int result = 0;
    (void) pop(&b);
    (void) pop(&a);
    switch (a.type) {
    case INTGR:
	switch (b.type) {
	case INTGR:
	    result = (a.v.int_val >=
		      b.v.int_val);
	    break;
	case CMPLX:
	    result = (a.v.int_val >=
		      b.v.cmplx_val.real);
	    break;
	    BAD_DEFAULT
	}
	break;
    case CMPLX:
	switch (b.type) {
	case INTGR:
	    result = (a.v.cmplx_val.real >=
		      b.v.int_val);
	    break;
	case CMPLX:
	    result = (a.v.cmplx_val.real >=
		      b.v.cmplx_val.real);
	    break;
	    BAD_DEFAULT
	}
	break;
	BAD_DEFAULT
    }
    push(Ginteger(&a, result));
}


void f_le()
{
    struct value a, b;
    register int result = 0;
    (void) pop(&b);
    (void) pop(&a);
    switch (a.type) {
    case INTGR:
	switch (b.type) {
	case INTGR:
	    result = (a.v.int_val <=
		      b.v.int_val);
	    break;
	case CMPLX:
	    result = (a.v.int_val <=
		      b.v.cmplx_val.real);
	    break;
	    BAD_DEFAULT
	}
	break;
    case CMPLX:
	switch (b.type) {
	case INTGR:
	    result = (a.v.cmplx_val.real <=
		      b.v.int_val);
	    break;
	case CMPLX:
	    result = (a.v.cmplx_val.real <=
		      b.v.cmplx_val.real);
	    break;
	    BAD_DEFAULT
	}
	break;
	BAD_DEFAULT
    }
    push(Ginteger(&a, result));
}


void f_plus()
{
    struct value a, b, result;
    (void) pop(&b);
    (void) pop(&a);
    switch (a.type) {
    case INTGR:
	switch (b.type) {
	case INTGR:
	    (void) Ginteger(&result, a.v.int_val +
			    b.v.int_val);
	    break;
	case CMPLX:
	    (void) Gcomplex(&result, a.v.int_val +
			    b.v.cmplx_val.real,
			    b.v.cmplx_val.imag);
	    break;
	    BAD_DEFAULT
	}
	break;
    case CMPLX:
	switch (b.type) {
	case INTGR:
	    (void) Gcomplex(&result, b.v.int_val +
			    a.v.cmplx_val.real,
			    a.v.cmplx_val.imag);
	    break;
	case CMPLX:
	    (void) Gcomplex(&result, a.v.cmplx_val.real +
			    b.v.cmplx_val.real,
			    a.v.cmplx_val.imag +
			    b.v.cmplx_val.imag);
	    break;
	    BAD_DEFAULT
	}
	break;
	BAD_DEFAULT
    }
    push(&result);
}


void f_minus()
{
    struct value a, b, result;
    (void) pop(&b);
    (void) pop(&a);		/* now do a - b */
    switch (a.type) {
    case INTGR:
	switch (b.type) {
	case INTGR:
	    (void) Ginteger(&result, a.v.int_val -
			    b.v.int_val);
	    break;
	case CMPLX:
	    (void) Gcomplex(&result, a.v.int_val -
			    b.v.cmplx_val.real,
			    -b.v.cmplx_val.imag);
	    break;
	    BAD_DEFAULT
	}
	break;
    case CMPLX:
	switch (b.type) {
	case INTGR:
	    (void) Gcomplex(&result, a.v.cmplx_val.real -
			    b.v.int_val,
			    a.v.cmplx_val.imag);
	    break;
	case CMPLX:
	    (void) Gcomplex(&result, a.v.cmplx_val.real -
			    b.v.cmplx_val.real,
			    a.v.cmplx_val.imag -
			    b.v.cmplx_val.imag);
	    break;
	    BAD_DEFAULT
	}
	break;
	BAD_DEFAULT
    }
    push(&result);
}


void f_mult()
{
    struct value a, b, result;
    (void) pop(&b);
    (void) pop(&a);		/* now do a*b */

    switch (a.type) {
    case INTGR:
	switch (b.type) {
	case INTGR:
	    (void) Ginteger(&result, a.v.int_val *
			    b.v.int_val);
	    break;
	case CMPLX:
	    (void) Gcomplex(&result, a.v.int_val *
			    b.v.cmplx_val.real,
			    a.v.int_val *
			    b.v.cmplx_val.imag);
	    break;
	    BAD_DEFAULT
	}
	break;
    case CMPLX:
	switch (b.type) {
	case INTGR:
	    (void) Gcomplex(&result, b.v.int_val *
			    a.v.cmplx_val.real,
			    b.v.int_val *
			    a.v.cmplx_val.imag);
	    break;
	case CMPLX:
	    (void) Gcomplex(&result, a.v.cmplx_val.real *
			    b.v.cmplx_val.real -
			    a.v.cmplx_val.imag *
			    b.v.cmplx_val.imag,
			    a.v.cmplx_val.real *
			    b.v.cmplx_val.imag +
			    a.v.cmplx_val.imag *
			    b.v.cmplx_val.real);
	    break;
	    BAD_DEFAULT
	}
	break;
	BAD_DEFAULT
    }
    push(&result);
}


void f_div()
{
    struct value a, b, result;
    register double square;
    (void) pop(&b);
    (void) pop(&a);		/* now do a/b */

    switch (a.type) {
    case INTGR:
	switch (b.type) {
	case INTGR:
	    if (b.v.int_val)
		(void) Ginteger(&result, a.v.int_val /
				b.v.int_val);
	    else {
		(void) Ginteger(&result, 0);
		undefined = TRUE;
	    }
	    break;
	case CMPLX:
	    square = b.v.cmplx_val.real *
		b.v.cmplx_val.real +
		b.v.cmplx_val.imag *
		b.v.cmplx_val.imag;
	    if (square)
		(void) Gcomplex(&result, a.v.int_val *
				b.v.cmplx_val.real / square,
				-a.v.int_val *
				b.v.cmplx_val.imag / square);
	    else {
		(void) Gcomplex(&result, 0.0, 0.0);
		undefined = TRUE;
	    }
	    break;
	    BAD_DEFAULT
	}
	break;
    case CMPLX:
	switch (b.type) {
	case INTGR:
	    if (b.v.int_val)
		(void) Gcomplex(&result, a.v.cmplx_val.real /
				b.v.int_val,
				a.v.cmplx_val.imag /
				b.v.int_val);
	    else {
		(void) Gcomplex(&result, 0.0, 0.0);
		undefined = TRUE;
	    }
	    break;
	case CMPLX:
	    square = b.v.cmplx_val.real *
		b.v.cmplx_val.real +
		b.v.cmplx_val.imag *
		b.v.cmplx_val.imag;
	    if (square)
		(void) Gcomplex(&result, (a.v.cmplx_val.real *
					  b.v.cmplx_val.real +
					  a.v.cmplx_val.imag *
					  b.v.cmplx_val.imag) / square,
				(a.v.cmplx_val.imag *
				 b.v.cmplx_val.real -
				 a.v.cmplx_val.real *
				 b.v.cmplx_val.imag) /
				square);
	    else {
		(void) Gcomplex(&result, 0.0, 0.0);
		undefined = TRUE;
	    }
	    break;
	    BAD_DEFAULT
	}
	break;
	BAD_DEFAULT
    }
    push(&result);
}


void f_mod()
{
    struct value a, b;
    (void) pop(&b);
    (void) pop(&a);		/* now do a%b */

    if (a.type != INTGR || b.type != INTGR)
	int_error("can only mod ints", NO_CARET);
    if (b.v.int_val)
	push(Ginteger(&a, a.v.int_val % b.v.int_val));
    else {
	push(Ginteger(&a, 0));
	undefined = TRUE;
    }
}


void f_power()
{
    struct value a, b, result;
    register int i, t, count;
    register double mag, ang;
    (void) pop(&b);
    (void) pop(&a);		/* now find a**b */

    switch (a.type) {
    case INTGR:
	switch (b.type) {
	case INTGR:
	    count = abs(b.v.int_val);
	    t = 1;
	    /* this ought to use bit-masks and squares, etc */
	    for (i = 0; i < count; i++)
		t *= a.v.int_val;
	    if (b.v.int_val >= 0)
		(void) Ginteger(&result, t);
	    else if (t != 0)
		(void) Gcomplex(&result, 1.0 / t, 0.0);
	    else {
		undefined = TRUE;
		(void) Gcomplex(&result, 0.0, 0.0);
	    }
	    break;
	case CMPLX:
	    if (a.v.int_val == 0) {
		if (b.v.cmplx_val.imag != 0 || b.v.cmplx_val.real < 0) {
		    undefined = TRUE;
		}
		/* return 1.0 for 0**0 */
		Gcomplex(&result, b.v.cmplx_val.real == 0 ? 1.0 : 0.0, 0.0);
	    } else {
		mag =
		    pow(magnitude(&a), fabs(b.v.cmplx_val.real));
		if (b.v.cmplx_val.real < 0.0) {
		    if (mag != 0.0)
			mag = 1.0 / mag;
		    else
			undefined = TRUE;
		}
		mag *= gp_exp(-b.v.cmplx_val.imag * angle(&a));
		ang = b.v.cmplx_val.real * angle(&a) +
		    b.v.cmplx_val.imag * log(magnitude(&a));
		(void) Gcomplex(&result, mag * cos(ang),
				mag * sin(ang));
	    }
	    break;
	    BAD_DEFAULT
	}
	break;
    case CMPLX:
	switch (b.type) {
	case INTGR:
	    if (a.v.cmplx_val.imag == 0.0) {
		mag = pow(a.v.cmplx_val.real, (double) abs(b.v.int_val));
		if (b.v.int_val < 0) {
		    if (mag != 0.0)
			mag = 1.0 / mag;
		    else
			undefined = TRUE;
		}
		(void) Gcomplex(&result, mag, 0.0);
	    } else {
		/* not so good, but...! */
		mag = pow(magnitude(&a), (double) abs(b.v.int_val));
		if (b.v.int_val < 0) {
		    if (mag != 0.0)
			mag = 1.0 / mag;
		    else
			undefined = TRUE;
		}
		ang = angle(&a) * b.v.int_val;
		(void) Gcomplex(&result, mag * cos(ang),
				mag * sin(ang));
	    }
	    break;
	case CMPLX:
	    if (a.v.cmplx_val.real == 0 && a.v.cmplx_val.imag == 0) {
		if (b.v.cmplx_val.imag != 0 || b.v.cmplx_val.real < 0) {
		    undefined = TRUE;
		}
		/* return 1.0 for 0**0 */
		Gcomplex(&result, b.v.cmplx_val.real == 0 ? 1.0 : 0.0, 0.0);
	    } else {
		mag = pow(magnitude(&a), fabs(b.v.cmplx_val.real));
		if (b.v.cmplx_val.real < 0.0) {
		    if (mag != 0.0)
			mag = 1.0 / mag;
		    else
			undefined = TRUE;
		}
		mag *= gp_exp(-b.v.cmplx_val.imag * angle(&a));
		ang = b.v.cmplx_val.real * angle(&a) +
		    b.v.cmplx_val.imag * log(magnitude(&a));
		(void) Gcomplex(&result, mag * cos(ang),
				mag * sin(ang));
	    }
	    break;
	    BAD_DEFAULT
	}
	break;
	BAD_DEFAULT
    }
    push(&result);
}


void f_factorial()
{
    struct value a;
    register int i;
    register double val = 0.0;

    (void) pop(&a);		/* find a! (factorial) */

    switch (a.type) {
    case INTGR:
	val = 1.0;
	for (i = a.v.int_val; i > 1; i--)    /*fpe's should catch overflows */
	    val *= i;
	break;
    default:
	int_error("factorial (!) argument must be an integer", NO_CARET);
	return;			/* avoid gcc -Wall warning about val */
    }

    push(Gcomplex(&a, val, 0.0));

}


int f_jump(x)
union argument *x;
{
    return (x->j_arg);
}


int f_jumpz(x)
union argument *x;
{
    struct value a;
    int_check(&top_of_stack);
    if (top_of_stack.v.int_val) {	/* non-zero */
	(void) pop(&a);
	return 1;		/* no jump */
    } else
	return (x->j_arg);	/* leave the argument on TOS */
}


int f_jumpnz(x)
union argument *x;
{
    struct value a;
    int_check(&top_of_stack);
    if (top_of_stack.v.int_val)	/* non-zero */
	return (x->j_arg);	/* leave the argument on TOS */
    else {
	(void) pop(&a);
	return 1;		/* no jump */
    }
}


int f_jtern(x)
union argument *x;
{
    struct value a;

    int_check(pop(&a));
    if (a.v.int_val)
	return (1);		/* no jump; fall through to TRUE code */
    else
	return (x->j_arg);	/* go jump to FALSE code */
}