Archipelago » qemu

/*

 *  S/390 integer helper routines

 *

 *  Copyright (c) 2009 Ulrich Hecht

 *  Copyright (c) 2009 Alexander Graf

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, see <http://www.gnu.org/licenses/>.

 */

#include "cpu.h"

#include "qemu/host-utils.h"

#include "helper.h"

/* #define DEBUG_HELPER */

#ifdef DEBUG_HELPER

#define HELPER_LOG(x...) qemu_log(x)

#else

#define HELPER_LOG(x...)

#endif

/* 64/32 -> 32 signed division */

int64_t HELPER(divs32)(CPUS390XState *env, int64_t a, int64_t b64)

{

    int32_t ret, b = b64;

    int64_t q;

    if (b == 0) {

        runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());

    }

    ret = q = a / b;

    env->retxl = a % b;

    /* Catch non-representable quotient.  */

    if (ret != q) {

        runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());

    }

    return ret;

}

/* 64/32 -> 32 unsigned division */

uint64_t HELPER(divu32)(CPUS390XState *env, uint64_t a, uint64_t b64)

{

    uint32_t ret, b = b64;

    uint64_t q;

    if (b == 0) {

        runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());

    }

    ret = q = a / b;

    env->retxl = a % b;

    /* Catch non-representable quotient.  */

    if (ret != q) {

        runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());

    }

    return ret;

}

/* 64/64 -> 64 signed division */

int64_t HELPER(divs64)(CPUS390XState *env, int64_t a, int64_t b)

{

    /* Catch divide by zero, and non-representable quotient (MIN / -1).  */

    if (b == 0 || (b == -1 && a == (1ll << 63))) {

        runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());

    }

    env->retxl = a % b;

    return a / b;

}

/* 128 -> 64/64 unsigned division */

uint64_t HELPER(divu64)(CPUS390XState *env, uint64_t ah, uint64_t al,

                        uint64_t b)

{

    uint64_t ret;

    /* Signal divide by zero.  */

    if (b == 0) {

        runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());

    }

    if (ah == 0) {

        /* 64 -> 64/64 case */

        env->retxl = al % b;

        ret = al / b;

    } else {

        /* ??? Move i386 idivq helper to host-utils.  */

#ifdef CONFIG_INT128

        __uint128_t a = ((__uint128_t)ah << 64) | al;

        __uint128_t q = a / b;

        env->retxl = a % b;

        ret = q;

        if (ret != q) {

            runtime_exception(env, PGM_FIXPT_DIVIDE, GETPC());

        }

#else

        /* 32-bit hosts would need special wrapper functionality - just abort if

           we encounter such a case; it's very unlikely anyways. */

        cpu_abort(env, "128 -> 64/64 division not implemented\n");

#endif

    }

    return ret;

}

/* absolute value 32-bit */

uint32_t HELPER(abs_i32)(int32_t val)

{

    if (val < 0) {

        return -val;

    } else {

        return val;

    }

}

/* negative absolute value 32-bit */

int32_t HELPER(nabs_i32)(int32_t val)

{

    if (val < 0) {

        return val;

    } else {

        return -val;

    }

}

/* absolute value 64-bit */

uint64_t HELPER(abs_i64)(int64_t val)

{

    HELPER_LOG("%s: val 0x%" PRIx64 "\n", __func__, val);

    if (val < 0) {

        return -val;

    } else {

        return val;

    }

}

/* negative absolute value 64-bit */

int64_t HELPER(nabs_i64)(int64_t val)

{

    if (val < 0) {

        return val;

    } else {

        return -val;

    }

}

/* count leading zeros, for find leftmost one */

uint64_t HELPER(clz)(uint64_t v)

{

    return clz64(v);

}

uint64_t HELPER(cvd)(int32_t bin)

{

    /* positive 0 */

    uint64_t dec = 0x0c;

    int shift = 4;

    if (bin < 0) {

        bin = -bin;

        dec = 0x0d;

    }

    for (shift = 4; (shift < 64) && bin; shift += 4) {

        int current_number = bin % 10;

        dec |= (current_number) << shift;

        bin /= 10;

    }

    return dec;

}

uint64_t HELPER(popcnt)(uint64_t r2)

{

    uint64_t ret = 0;

    int i;

    for (i = 0; i < 64; i += 8) {

        uint64_t t = ctpop32((r2 >> i) & 0xff);

        ret |= t << i;

    }

    return ret;

}