/* Copyright (C) 1989, 1995, 1997, 1998 Aladdin Enterprises.  All rights reserved.

   This file is part of Aladdin Ghostscript.

   Aladdin Ghostscript is distributed with NO WARRANTY OF ANY KIND.  No author
   or distributor accepts any responsibility for the consequences of using it,
   or for whether it serves any particular purpose or works at all, unless he
   or she says so in writing.  Refer to the Aladdin Ghostscript Free Public
   License (the "License") for full details.

   Every copy of Aladdin Ghostscript must include a copy of the License,
   normally in a plain ASCII text file named PUBLIC.  The License grants you
   the right to copy, modify and redistribute Aladdin Ghostscript, but only
   under certain conditions described in the License.  Among other things, the
   License requires that the copyright notice and this notice be preserved on
   all copies.
 */

/*$Id: zrelbit.c $ */
/* Relational, boolean, and bit operators */
#include "ghost.h"
#include "oper.h"
#include "gsutil.h"
#include "idict.h"
#include "store.h"

/* ------ Standard operators ------ */

/* Define the type test for eq and its relatives. */
#define EQ_CHECK_READ(opp, dflt)\
    switch ( r_type(opp) ) {\
	case t_string:\
	    check_read(*(opp));\
	    break;\
	default:\
	    dflt;\
  }

/* Forward references */
private int obj_le(P2(os_ptr, os_ptr));

/* <obj1> <obj2> eq <bool> */
private int
zeq(register os_ptr op)
{
    EQ_CHECK_READ(op - 1, check_op(2));
    EQ_CHECK_READ(op, DO_NOTHING);
    make_bool(op - 1, (obj_eq(op - 1, op) ? 1 : 0));
    pop(1);
    return 0;
}

/* <obj1> <obj2> ne <bool> */
private int
zne(register os_ptr op)
{	/* We'll just be lazy and use eq. */
    int code = zeq(op);

    if (!code)
	op[-1].value.boolval ^= 1;
    return code;
}

/* <num1> <num2> ge <bool> */
/* <str1> <str2> ge <bool> */
private int
zge(register os_ptr op)
{
    int code = obj_le(op, op - 1);

    if (code < 0)
	return code;
    make_bool(op - 1, code);
    pop(1);
    return 0;
}

/* <num1> <num2> gt <bool> */
/* <str1> <str2> gt <bool> */
private int
zgt(register os_ptr op)
{
    int code = obj_le(op - 1, op);

    if (code < 0)
	return code;
    make_bool(op - 1, code ^ 1);
    pop(1);
    return 0;
}

/* <num1> <num2> le <bool> */
/* <str1> <str2> le <bool> */
private int
zle(register os_ptr op)
{
    int code = obj_le(op - 1, op);

    if (code < 0)
	return code;
    make_bool(op - 1, code);
    pop(1);
    return 0;
}

/* <num1> <num2> lt <bool> */
/* <str1> <str2> lt <bool> */
private int
zlt(register os_ptr op)
{
    int code = obj_le(op, op - 1);

    if (code < 0)
	return code;
    make_bool(op - 1, code ^ 1);
    pop(1);
    return 0;
}

/* <num1> <num2> .max <num> */
/* <str1> <str2> .max <str> */
private int
zmax(register os_ptr op)
{
    int code = obj_le(op - 1, op);

    if (code < 0)
	return code;
    if (code) {
	ref_assign(op - 1, op);
    }
    pop(1);
    return 0;
}

/* <num1> <num2> .min <num> */
/* <str1> <str2> .min <str> */
private int
zmin(register os_ptr op)
{
    int code = obj_le(op - 1, op);

    if (code < 0)
	return code;
    if (!code) {
	ref_assign(op - 1, op);
    }
    pop(1);
    return 0;
}

/* <bool1> <bool2> and <bool> */
/* <int1> <int2> and <int> */
private int
zand(register os_ptr op)
{
    switch (r_type(op)) {
	case t_boolean:
	    check_type(op[-1], t_boolean);
	    op[-1].value.boolval &= op->value.boolval;
	    break;
	case t_integer:
	    check_type(op[-1], t_integer);
	    op[-1].value.intval &= op->value.intval;
	    break;
	default:
	    return_op_typecheck(op);
    }
    pop(1);
    return 0;
}

/* <bool> not <bool> */
/* <int> not <int> */
private int
znot(register os_ptr op)
{
    switch (r_type(op)) {
	case t_boolean:
	    op->value.boolval = !op->value.boolval;
	    break;
	case t_integer:
	    op->value.intval = ~op->value.intval;
	    break;
	default:
	    return_op_typecheck(op);
    }
    return 0;
}

/* <bool1> <bool2> or <bool> */
/* <int1> <int2> or <int> */
private int
zor(register os_ptr op)
{
    switch (r_type(op)) {
	case t_boolean:
	    check_type(op[-1], t_boolean);
	    op[-1].value.boolval |= op->value.boolval;
	    break;
	case t_integer:
	    check_type(op[-1], t_integer);
	    op[-1].value.intval |= op->value.intval;
	    break;
	default:
	    return_op_typecheck(op);
    }
    pop(1);
    return 0;
}

/* <bool1> <bool2> xor <bool> */
/* <int1> <int2> xor <int> */
private int
zxor(register os_ptr op)
{
    switch (r_type(op)) {
	case t_boolean:
	    check_type(op[-1], t_boolean);
	    op[-1].value.boolval ^= op->value.boolval;
	    break;
	case t_integer:
	    check_type(op[-1], t_integer);
	    op[-1].value.intval ^= op->value.intval;
	    break;
	default:
	    return_op_typecheck(op);
    }
    pop(1);
    return 0;
}

/* <int> <shift> bitshift <int> */
private int
zbitshift(register os_ptr op)
{
    int shift;

    check_type(*op, t_integer);
    check_type(op[-1], t_integer);
#define MAX_SHIFT (arch_sizeof_long * 8 - 1)
    if (op->value.intval < -MAX_SHIFT || op->value.intval > MAX_SHIFT)
	op[-1].value.intval = 0;
#undef MAX_SHIFT
    else if ((shift = op->value.intval) < 0)
	op[-1].value.intval = ((ulong)(op[-1].value.intval)) >> -shift;
    else
	op[-1].value.intval <<= shift;
    pop(1);
    return 0;
}

/* ------ Extensions ------ */

/* <obj1> <obj2> .identeq <bool> */
private int
zidenteq(register os_ptr op)
{
    EQ_CHECK_READ(op - 1, check_op(2));
    EQ_CHECK_READ(op, DO_NOTHING);
    make_bool(op - 1, (obj_ident_eq(op - 1, op) ? 1 : 0));
    pop(1);
    return 0;

}

/* <obj1> <obj2> .identne <bool> */
private int
zidentne(register os_ptr op)
{	/* We'll just be lazy and use .identeq. */
    int code = zidenteq(op);

    if (!code)
	op[-1].value.boolval ^= 1;
    return code;
}

/* ------ Initialization procedure ------ */

const op_def zrelbit_op_defs[] =
{
    {"2and", zand},
    {"2bitshift", zbitshift},
    {"2eq", zeq},
    {"2ge", zge},
    {"2gt", zgt},
    {"2le", zle},
    {"2lt", zlt},
    {"2.max", zmax},
    {"2.min", zmin},
    {"2ne", zne},
    {"1not", znot},
    {"2or", zor},
    {"2xor", zxor},
		/* Extensions */
    {"2.identeq", zidenteq},
    {"2.identne", zidentne},
    op_def_end(0)
};

/* ------ Internal routines ------ */

/* Compare two operands (both numeric, or both strings). */
/* Return 1 if op[-1] <= op[0], 0 if op[-1] > op[0], */
/* or a (negative) error code. */
private int
obj_le(register os_ptr op1, register os_ptr op)
{
    switch (r_type(op1)) {
	case t_integer:
	    switch (r_type(op)) {
		case t_integer:
		    return (op1->value.intval <= op->value.intval);
		case t_real:
		    return ((double)op1->value.intval <= op->value.realval);
		default:
		    return_op_typecheck(op);
	    }
	case t_real:
	    switch (r_type(op)) {
		case t_real:
		    return (op1->value.realval <= op->value.realval);
		case t_integer:
		    return (op1->value.realval <= (double)op->value.intval);
		default:
		    return_op_typecheck(op);
	    }
	case t_string:
	    check_read(*op1);
	    check_read_type(*op, t_string);
	    return (bytes_compare(op1->value.bytes, r_size(op1),
				  op->value.bytes, r_size(op)) <= 0);
	default:
	    return_op_typecheck(op1);
    }
}
