Re: [RFC PATCH v2 21/44] target/loongarch: Implement vmskltz/vmskgez/vmsknz

[Richard Henderson]

On 3/27/23 20:06, Song Gao wrote:
> +void HELPER(vmskltz_b)(CPULoongArchState *env, uint32_t vd, uint32_t vj)
> +{
> +    VReg temp;
> +    VReg *Vd = &(env->fpr[vd].vreg);
> +    VReg *Vj = &(env->fpr[vj].vreg);
> +
> +    temp.D(0) = 0;
> +    temp.D(1) = 0;
> +    temp.H(0) = do_vmskltz_b(Vj->D(0));
> +    temp.H(0) |= (do_vmskltz_b(Vj->D(1)) << 8);
> +    Vd->D(0) = temp.D(0);
> +    Vd->D(1) = 0;
> +}

Better as uint16_t temp, instead of a full VReg.

> +static uint64_t do_vmskltz_d(int64_t val)
> +{
> +    uint64_t m = 0x8000000000000000ULL;
> +    uint64_t c =  val & m;
> +    c |= c << 63;
> +    return c >> 63;
> +}

No mask or shift left required.


r~