Archipelago » qemu

uint32_t helper_fpack16(uint64_t gsr, uint64_t rs2)

{

    int scale = (gsr >> 3) & 0xf;

    uint32_t ret = 0;

    int byte;

    for (byte = 0; byte < 4; byte++) {

        uint32_t val;

        int16_t src = rs2 >> (byte * 16);

        int32_t scaled = src << scale;

        int32_t from_fixed = scaled >> 7;

        val = (from_fixed < 0 ?  0 :

               from_fixed > 255 ?  255 : from_fixed);

        ret |= val << (8 * byte);

    }

    return ret;

}

uint64_t helper_fpack32(uint64_t gsr, uint64_t rs1, uint64_t rs2)

{

    int scale = (gsr >> 3) & 0x1f;

    uint64_t ret = 0;

    int word;

    ret = (rs1 << 8) & ~(0x000000ff000000ffULL);

    for (word = 0; word < 2; word++) {

        uint64_t val;

        int32_t src = rs2 >> (word * 32);

        int64_t scaled = (int64_t)src << scale;

        int64_t from_fixed = scaled >> 23;

        val = (from_fixed < 0 ? 0 :

               (from_fixed > 255) ? 255 : from_fixed);

        ret |= val << (32 * word);

    }

    return ret;

}

uint32_t helper_fpackfix(uint64_t gsr, uint64_t rs2)

{

    int scale = (gsr >> 3) & 0x1f;

    uint32_t ret = 0;

    int word;

    for (word = 0; word < 2; word++) {

        uint32_t val;

        int32_t src = rs2 >> (word * 32);

        int64_t scaled = src << scale;

        int64_t from_fixed = scaled >> 16;

        val = (from_fixed < -32768 ? -32768 :

               from_fixed > 32767 ?  32767 : from_fixed);

        ret |= (val & 0xffff) << (word * 16);

    }

    return ret;

}