/*
 * pdp10-arith.h -- arithmetic on PDP10 integer types
 * Copyright (C) 2013-2018  Mikael Pettersson
 *
 * This file is part of pdp10-tools.
 *
 * pdp10-tools 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 3 of the License, or
 * (at your option) any later version.
 *
 * pdp10-tools 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 pdp10-tools.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef PDP10_ARITH_H
#define PDP10_ARITH_H

#include "pdp10-stdint.h"

/* Zero-extend a pdp10_{u,}int36_t to the full width of its representation type.
 * Use this to prepare operands before unsigned operations, or to correct results
 * after signed operations.
 */
static inline pdp10_uint36_t pdp10_zext_uint36(pdp10_uint36_t x)
{
    return x & PDP10_UINT36_MAX;
}

/* Sign-extend a pdp10_int36_t to the full width of its representation type.
 * Use this to prepare operands before signed operations.
 *
 * Based on the following trick for sign-extending an octet x: ((x & 0xff) ^ 0x80) - 0x80,
 * c.f. <http://sourceware.org/ml/binutils/2001-05/msg00093.html>.
 */
static inline pdp10_int36_t pdp10_sext_int36(pdp10_uint36_t x)
{
    const pdp10_uint36_t PDP10_UINT36_SBIT = ~(PDP10_UINT36_MAX >> 1) & PDP10_UINT36_MAX;

    return ((x & PDP10_UINT36_MAX) ^ PDP10_UINT36_SBIT) - PDP10_UINT36_SBIT;
}

/* Sign-extend a pdp10_uint18_t to the full width of its representation type. */
static inline pdp10_uint18_t pdp10_sext_uint18(pdp10_uint18_t x)
{
    const pdp10_uint18_t PDP10_UINT18_SBIT = ~(PDP10_UINT18_MAX >> 1) & PDP10_UINT18_MAX;

    return ((x & PDP10_UINT18_MAX) ^ PDP10_UINT18_SBIT) - PDP10_UINT18_SBIT;
}

static inline pdp10_uint36_t pdp10_neg_int36(pdp10_uint36_t x)
{
    return pdp10_zext_uint36(-pdp10_sext_int36(x));
}

static inline pdp10_uint36_t pdp10_not_int36(pdp10_uint36_t x)
{
    return pdp10_zext_uint36(~pdp10_sext_int36(x));
}

static inline pdp10_uint36_t pdp10_add_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return pdp10_zext_uint36(pdp10_sext_int36(x) + pdp10_sext_int36(y));
}

static inline pdp10_uint36_t pdp10_sub_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return pdp10_zext_uint36(pdp10_sext_int36(x) - pdp10_sext_int36(y));
}

static inline pdp10_uint36_t pdp10_mul_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return pdp10_zext_uint36(pdp10_sext_int36(x) * pdp10_sext_int36(y));
}

static inline pdp10_uint36_t pdp10_div_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return pdp10_zext_uint36(pdp10_sext_int36(x) / pdp10_sext_int36(y));
}

static inline pdp10_uint36_t pdp10_rem_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return pdp10_zext_uint36(pdp10_sext_int36(x) % pdp10_sext_int36(y));
}

static inline pdp10_uint36_t pdp10_lsl_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return pdp10_zext_uint36(pdp10_zext_uint36(x) << pdp10_zext_uint36(y));
}

static inline pdp10_uint36_t pdp10_lsr_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return pdp10_zext_uint36(pdp10_zext_uint36(x) >> pdp10_zext_uint36(y));
}

static inline pdp10_uint36_t pdp10_asr_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return pdp10_zext_uint36(pdp10_sext_int36(x) >> pdp10_zext_uint36(y));
}

static inline pdp10_uint36_t pdp10_or_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return (pdp10_zext_uint36(x) | pdp10_zext_uint36(y));
}

static inline pdp10_uint36_t pdp10_and_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return (pdp10_zext_uint36(x) & pdp10_zext_uint36(y));
}

static inline pdp10_uint36_t pdp10_xor_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return (pdp10_zext_uint36(x) ^ pdp10_zext_uint36(y));
}

static inline int pdp10_eq_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return pdp10_zext_uint36(x) == pdp10_zext_uint36(y);
}

static inline int pdp10_ne_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return pdp10_zext_uint36(x) != pdp10_zext_uint36(y);
}

static inline int pdp10_lt_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return pdp10_sext_int36(x) < pdp10_sext_int36(y);
}

static inline int pdp10_gt_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return pdp10_sext_int36(x) > pdp10_sext_int36(y);
}

static inline int pdp10_ge_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return pdp10_sext_int36(x) >= pdp10_sext_int36(y);
}

static inline int pdp10_le_int36(pdp10_uint36_t x, pdp10_uint36_t y)
{
    return pdp10_sext_int36(x) <= pdp10_sext_int36(y);
}

static inline int pdp10_nonzero_int36(pdp10_uint36_t x)
{
    return pdp10_zext_uint36(x) != 0;
}

#endif /* PDP10_ARITH_H */