/*
 *  x86 condition code helpers
 *
 *  Copyright (c) 2008 Fabrice Bellard
 *
 * 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 2.1 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/>.
 */

#define DATA_BITS (1 << (3 + SHIFT))

#if DATA_BITS == 8
#define SUFFIX b
#define DATA_TYPE uint8_t
#define WIDER_TYPE uint32_t
#elif DATA_BITS == 16
#define SUFFIX w
#define DATA_TYPE uint16_t
#define WIDER_TYPE uint32_t
#elif DATA_BITS == 32
#define SUFFIX l
#define DATA_TYPE uint32_t
#if HOST_LONG_BITS >= 64
#define WIDER_TYPE uint64_t
#endif
#elif DATA_BITS == 64
#define SUFFIX q
#define DATA_TYPE uint64_t
#else
#error unhandled operand size
#endif

#define SIGN_MASK (((DATA_TYPE)1) << (DATA_BITS - 1))

/* dynamic flags computation */

static uint32_t glue(compute_all_cout, SUFFIX)(DATA_TYPE dst, DATA_TYPE carries)
{
    uint32_t af_cf, pf, zf, sf, of;

    /* PF, ZF, SF computed from result.  */
    pf = compute_pf(dst);
    zf = (dst == 0) * CC_Z;
    sf = lshift(dst, 8 - DATA_BITS) & CC_S;

    /*
     * AF, CF, OF computed from carry out vector.  To compute AF and CF, rotate it
     * left by one so cout(DATA_BITS - 1) is in bit 0 and cout(3) in bit 4.
     *
     * To compute OF, place the highest two carry bits into OF and the bit
     * immediately to the right of it; then, adding CC_O / 2 XORs them.
     */
    af_cf = ((carries << 1) | (carries >> (DATA_BITS - 1))) & (CC_A | CC_C);
    of = (lshift(carries, 12 - DATA_BITS) + CC_O / 2) & CC_O;
    return pf + zf + sf + af_cf + of;
}

static uint32_t glue(compute_all_add, SUFFIX)(DATA_TYPE dst, DATA_TYPE src1)
{
    DATA_TYPE src2 = dst - src1;
    DATA_TYPE carries = ADD_COUT_VEC(src1, src2, dst);
    return glue(compute_all_cout, SUFFIX)(dst, carries);
}

static int glue(compute_c_add, SUFFIX)(DATA_TYPE dst, DATA_TYPE src1)
{
    return dst < src1;
}

static uint32_t glue(compute_all_adc, SUFFIX)(DATA_TYPE dst, DATA_TYPE src1,
                                         DATA_TYPE src3)
{
    DATA_TYPE src2 = dst - src1 - src3;
    DATA_TYPE carries = ADD_COUT_VEC(src1, src2, dst);
    return glue(compute_all_cout, SUFFIX)(dst, carries);
}

static int glue(compute_c_adc, SUFFIX)(DATA_TYPE dst, DATA_TYPE src1,
                                       DATA_TYPE src3)
{
#ifdef WIDER_TYPE
    WIDER_TYPE src13 = (WIDER_TYPE) src1 + (WIDER_TYPE) src3;

    return dst < src13;
#else
    return src3 ? dst <= src1 : dst < src1;
#endif
}

static uint32_t glue(compute_all_sub, SUFFIX)(DATA_TYPE dst, DATA_TYPE src2)
{
    DATA_TYPE src1 = dst + src2;
    DATA_TYPE carries = SUB_COUT_VEC(src1, src2, dst);
    return glue(compute_all_cout, SUFFIX)(dst, carries);
}

static int glue(compute_c_sub, SUFFIX)(DATA_TYPE dst, DATA_TYPE src2)
{
    DATA_TYPE src1 = dst + src2;

    return src1 < src2;
}

static uint32_t glue(compute_all_sbb, SUFFIX)(DATA_TYPE dst, DATA_TYPE src2,
                                         DATA_TYPE src3)
{
    DATA_TYPE src1 = dst + src2 + src3;
    DATA_TYPE carries = SUB_COUT_VEC(src1, src2, dst);
    return glue(compute_all_cout, SUFFIX)(dst, carries);
}

static int glue(compute_c_sbb, SUFFIX)(DATA_TYPE dst, DATA_TYPE src2,
                                       DATA_TYPE src3)
{
#ifdef WIDER_TYPE
    WIDER_TYPE src23 = (WIDER_TYPE) src2 + (WIDER_TYPE) src3;
    DATA_TYPE src1 = dst + src23;

    return src1 < src23;
#else
    DATA_TYPE src1 = dst + src2 + src3;

    return (src3 ? src1 <= src2 : src1 < src2);
#endif
}

static uint32_t glue(compute_all_logic, SUFFIX)(DATA_TYPE dst, DATA_TYPE src1)
{
    uint32_t cf, pf, af, zf, sf, of;

    cf = 0;
    pf = compute_pf(dst);
    af = 0;
    zf = (dst == 0) * CC_Z;
    sf = lshift(dst, 8 - DATA_BITS) & CC_S;
    of = 0;
    return cf + pf + af + zf + sf + of;
}

static uint32_t glue(compute_all_inc, SUFFIX)(DATA_TYPE dst, DATA_TYPE src1)
{
    uint32_t cf, pf, af, zf, sf, of;

    cf = src1;
    pf = compute_pf(dst);
    af = (dst ^ (dst - 1)) & CC_A; /* bits 0..3 are all clear */
    zf = (dst == 0) * CC_Z;
    sf = lshift(dst, 8 - DATA_BITS) & CC_S;
    of = (dst == SIGN_MASK) * CC_O;
    return cf + pf + af + zf + sf + of;
}

static uint32_t glue(compute_all_dec, SUFFIX)(DATA_TYPE dst, DATA_TYPE src1)
{
    uint32_t cf, pf, af, zf, sf, of;

    cf = src1;
    pf = compute_pf(dst);
    af = (dst ^ (dst + 1)) & CC_A; /* bits 0..3 are all set */
    zf = (dst == 0) * CC_Z;
    sf = lshift(dst, 8 - DATA_BITS) & CC_S;
    of = (dst == SIGN_MASK - 1) * CC_O;
    return cf + pf + af + zf + sf + of;
}

static uint32_t glue(compute_all_shl, SUFFIX)(DATA_TYPE dst, DATA_TYPE src1)
{
    uint32_t cf, pf, af, zf, sf, of;

    cf = (src1 >> (DATA_BITS - 1)) & CC_C;
    pf = compute_pf(dst);
    af = 0; /* undefined */
    zf = (dst == 0) * CC_Z;
    sf = lshift(dst, 8 - DATA_BITS) & CC_S;
    /* of is defined iff shift count == 1 */
    of = lshift(src1 ^ dst, 12 - DATA_BITS) & CC_O;
    return cf + pf + af + zf + sf + of;
}

static int glue(compute_c_shl, SUFFIX)(DATA_TYPE dst, DATA_TYPE src1)
{
    return (src1 >> (DATA_BITS - 1)) & CC_C;
}

static uint32_t glue(compute_all_sar, SUFFIX)(DATA_TYPE dst, DATA_TYPE src1)
{
    uint32_t cf, pf, af, zf, sf, of;

    cf = src1 & 1;
    pf = compute_pf(dst);
    af = 0; /* undefined */
    zf = (dst == 0) * CC_Z;
    sf = lshift(dst, 8 - DATA_BITS) & CC_S;
    /* of is defined iff shift count == 1 */
    of = lshift(src1 ^ dst, 12 - DATA_BITS) & CC_O;
    return cf + pf + af + zf + sf + of;
}

/* NOTE: we compute the flags like the P4. On olders CPUs, only OF and
   CF are modified and it is slower to do that.  Note as well that we
   don't truncate SRC1 for computing carry to DATA_TYPE.  */
static uint32_t glue(compute_all_mul, SUFFIX)(DATA_TYPE dst, target_long src1)
{
    uint32_t cf, pf, af, zf, sf, of;

    cf = (src1 != 0);
    pf = compute_pf(dst);
    af = 0; /* undefined */
    zf = (dst == 0) * CC_Z;
    sf = lshift(dst, 8 - DATA_BITS) & CC_S;
    of = cf * CC_O;
    return cf + pf + af + zf + sf + of;
}

static uint32_t glue(compute_all_bmilg, SUFFIX)(DATA_TYPE dst, DATA_TYPE src1)
{
    uint32_t cf, pf, af, zf, sf, of;

    cf = (src1 == 0);
    pf = 0; /* undefined */
    af = 0; /* undefined */
    zf = (dst == 0) * CC_Z;
    sf = lshift(dst, 8 - DATA_BITS) & CC_S;
    of = 0;
    return cf + pf + af + zf + sf + of;
}

static int glue(compute_c_bmilg, SUFFIX)(DATA_TYPE dst, DATA_TYPE src1)
{
    return src1 == 0;
}

static int glue(compute_all_blsi, SUFFIX)(DATA_TYPE dst, DATA_TYPE src1)
{
    uint32_t cf, pf, af, zf, sf, of;

    cf = (src1 != 0);
    pf = 0; /* undefined */
    af = 0; /* undefined */
    zf = (dst == 0) * CC_Z;
    sf = lshift(dst, 8 - DATA_BITS) & CC_S;
    of = 0;
    return cf + pf + af + zf + sf + of;
}

static int glue(compute_c_blsi, SUFFIX)(DATA_TYPE dst, DATA_TYPE src1)
{
    return src1 != 0;
}

#undef DATA_BITS
#undef SIGN_MASK
#undef DATA_TYPE
#undef SUFFIX
#undef WIDER_TYPE