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

/* 64/64 -> 128 unsigned multiplication */

void HELPER(mlg)(CPUS390XState *env, uint32_t r1, uint64_t v2)

{

#if HOST_LONG_BITS == 64 && defined(__GNUC__)

    /* assuming 64-bit hosts have __uint128_t */

    __uint128_t res = (__uint128_t)env->regs[r1 + 1];

    res *= (__uint128_t)v2;

    env->regs[r1] = (uint64_t)(res >> 64);

    env->regs[r1 + 1] = (uint64_t)res;

#else

    mulu64(&env->regs[r1 + 1], &env->regs[r1], env->regs[r1 + 1], v2);

#endif

}

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

void HELPER(dlg)(CPUS390XState *env, uint32_t r1, uint64_t v2)

{

    uint64_t divisor = v2;

    if (!env->regs[r1]) {

        /* 64 -> 64/64 case */

        env->regs[r1] = env->regs[r1 + 1] % divisor;

        env->regs[r1 + 1] = env->regs[r1 + 1] / divisor;

        return;

    } else {

#if HOST_LONG_BITS == 64 && defined(__GNUC__)

        /* assuming 64-bit hosts have __uint128_t */

        __uint128_t dividend = (((__uint128_t)env->regs[r1]) << 64) |

            (env->regs[r1 + 1]);

        __uint128_t quotient = dividend / divisor;

        __uint128_t remainder = dividend % divisor;

        env->regs[r1 + 1] = quotient;

        env->regs[r1] = remainder;

#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

    }

}

/* 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;

    }

}

/* add with carry 32-bit unsigned */

uint32_t HELPER(addc_u32)(uint32_t cc, uint32_t v1, uint32_t v2)

{

    uint32_t res;

    res = v1 + v2;

    if (cc & 2) {

        res++;

    }

    return res;

}

/* subtract unsigned v2 from v1 with borrow */

uint32_t HELPER(slb)(CPUS390XState *env, uint32_t cc, uint32_t r1, uint32_t v2)

{

    uint32_t v1 = env->regs[r1];

    uint32_t res = v1 + (~v2) + (cc >> 1);

    env->regs[r1] = (env->regs[r1] & 0xffffffff00000000ULL) | res;

    if (cc & 2) {

        /* borrow */

        return v1 ? 1 : 0;

    } else {

        return v1 ? 3 : 2;

    }

}

/* subtract unsigned v2 from v1 with borrow */

uint32_t HELPER(slbg)(CPUS390XState *env, uint32_t cc, uint32_t r1,

                      uint64_t v1, uint64_t v2)

{

    uint64_t res = v1 + (~v2) + (cc >> 1);

    env->regs[r1] = res;

    if (cc & 2) {

        /* borrow */

        return v1 ? 1 : 0;

    } else {

        return v1 ? 3 : 2;

    }

}

/* find leftmost one */

uint32_t HELPER(flogr)(CPUS390XState *env, uint32_t r1, uint64_t v2)

{

    uint64_t res = 0;

    uint64_t ov2 = v2;

    while (!(v2 & 0x8000000000000000ULL) && v2) {

        v2 <<= 1;

        res++;

    }

    if (!v2) {

        env->regs[r1] = 64;

        env->regs[r1 + 1] = 0;

        return 0;

    } else {

        env->regs[r1] = res;

        env->regs[r1 + 1] = ov2 & ~(0x8000000000000000ULL >> res);

        return 2;

    }

}

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;

}