Re: [qemu-s390x] [Qemu-devel] [PATCH v1 4/5] s390x/tcg: Implement VECTOR ISOLATE STRING

[Richard Henderson]

On 5/15/19 1:31 PM, David Hildenbrand wrote:
> +#define DEF_VISTR(BITS)                                                      
>   \
> +static int vistr##BITS(void *v1, const void *v2)
> +{
> +    S390Vector tmp = {};
> +    int i, cc = 3;
> +
> +    for (i = 0; i < (128 / BITS); i++) {
> +        const uint##BITS##_t data = s390_vec_read_element##BITS(v2, i);
> +
> +        if (!data) {
> +            cc = 0;
> +            break;
> +        }
> +        s390_vec_write_element##BITS(&tmp, i, data);
> +    }
> +    *(S390Vector *)v1 = tmp;
> +    return cc;
> +}
> +DEF_VISTR(8)
> +DEF_VISTR(16)
> +DEF_VISTR(32)

Based on previous, this becomes

    cc = 3;
    a0 = s390_vec_read_element64(v2, 0);
    a1 = s390_vec_read_element64(v2, 1);

    z0 = zero_search(a0, m);
    if (z0) {
        i = clz64(z0);
        a0 &= ~(UINT64_MAX >> i);
        a1 = 0;
        cc = 0;
    } else {
        z1 = zero_search(a1, m);
        if (z1) {
            i = clz64(z1);
            a1 &= ~(UINT64_MAX >> i);
            cc = 0;
        }
    }

    s390_vec_write_element64(v1, 0, a0);
    s390_vec_write_element64(v1, 1, a1);
    return cc;


r~