Re: [PATCH v4 06/21] target/loongarch: Add fixed point bit instruction translation

[Richard Henderson]

On 9/2/21 2:40 PM, Song Gao wrote:
> +static void gen_clz_w(TCGv dest, TCGv src1)
> +{
> +    tcg_gen_clzi_tl(dest, src1, TARGET_LONG_BITS);
> +    tcg_gen_subi_tl(dest, dest, TARGET_LONG_BITS - 32);
> +}
> +
> +static void gen_clo_w(TCGv dest, TCGv src1)
> +{
> +    tcg_gen_not_tl(dest, src1);
> +    gen_clz_w(dest, dest);
> +}

This doesn't work, quite.  You need

    tcg_gen_not_tl(dest, src1);
    tcg_gen_ext32u_tl(dest, dest);
    gen_clz_w(dest, dest);

> +static void gen_ctz_w(TCGv dest, TCGv src1)
> +{
> +    tcg_gen_ori_tl(dest, src1, (target_ulong)MAKE_64BIT_MASK(32, 32));
> +    tcg_gen_ctzi_tl(dest, dest, 64);
> +}
> +
> +static void gen_cto_w(TCGv dest, TCGv src1)
> +{
> +    tcg_gen_not_tl(dest, src1);
> +    gen_ctz_w(dest, dest);
> +}

Likewise, this needs the OR after the NOT.
Alternately, zero-extend and use

  tcg_gen_ctzi_tl(dest, dest, 32);

> +static void gen_revb_2w(TCGv dest, TCGv src1)
> +{
> +    tcg_gen_bswap64_i64(dest, src1);
> +    tcg_gen_rotri_i64(dest, dest, 32);
> +}
> +
> +static bool trans_revb_2h(DisasContext *ctx, arg_revb_2h *a)
> +{
> +    ctx->dst_ext = EXT_SIGN;
> +    TCGv dest = gpr_dst(ctx, a->rd);
> +    TCGv src1 = gpr_src(ctx, a->rj, EXT_NONE);
> +    TCGv mask = tcg_constant_tl(0x00FF00FF);
> +    TCGv t0 = tcg_temp_new();
> +    TCGv t1 = tcg_temp_new();
> +
> +    tcg_gen_shri_tl(t0, src1, 8);
> +    tcg_gen_and_tl(t0, t0, mask);
> +    tcg_gen_and_tl(t1, src1, mask);
> +    tcg_gen_shli_tl(t1, t1, 8);
> +    tcg_gen_or_tl(dest, t0, t1);
> +    gen_set_gpr(ctx, a->rd, dest);
> +
> +    tcg_temp_free(t0);
> +    tcg_temp_free(t1);
> +    return true;
> +}

Split out the center of this so you can use gen_r2.

> +static bool trans_revb_4h(DisasContext *ctx, arg_revb_4h *a)
> +{
> +    TCGv dest = gpr_dst(ctx, a->rd);
> +    TCGv src1 = gpr_src(ctx, a->rj, EXT_NONE);
> +    TCGv mask = tcg_constant_tl(0x00FF00FF00FF00FFULL);
> +    TCGv t0 = tcg_temp_new();
> +    TCGv t1 = tcg_temp_new();
> +
> +    tcg_gen_shri_tl(t0, src1, 8);
> +    tcg_gen_and_tl(t0, t0, mask);
> +    tcg_gen_and_tl(t1, src1, mask);
> +    tcg_gen_shli_tl(t1, t1, 8);
> +    tcg_gen_or_tl(dest, t0, t1);
> +
> +    tcg_temp_free(t0);
> +    tcg_temp_free(t1);
> +    return true;
> +}

Likewise.

> +static bool trans_revh_2w(DisasContext *ctx, arg_revh_2w *a)
> +{
> +    TCGv dest = gpr_dst(ctx, a->rd);
> +    TCGv src1 = gpr_src(ctx, a->rj, EXT_NONE);
> +    TCGv_i64 t0 = tcg_temp_new_i64();
> +    TCGv_i64 t1 = tcg_temp_new_i64();
> +    TCGv_i64 mask = tcg_constant_i64(0x0000ffff0000ffffull);
> +
> +    tcg_gen_shri_i64(t0, src1, 16);
> +    tcg_gen_and_i64(t1, src1, mask);
> +    tcg_gen_and_i64(t0, t0, mask);
> +    tcg_gen_shli_i64(t1, t1, 16);
> +    tcg_gen_or_i64(dest, t1, t0);
> +
> +    tcg_temp_free_i64(t0);
> +    tcg_temp_free_i64(t1);
> +
> +    return true;
> +}

Likewise.

> +
> +static bool trans_revh_d(DisasContext *ctx, arg_revh_d *a)
> +{
> +    TCGv dest = gpr_dst(ctx, a->rd);
> +    TCGv src1 = gpr_src(ctx, a->rj, EXT_NONE);
> +    TCGv t0 = tcg_temp_new();
> +    TCGv t1 = tcg_temp_new();
> +    TCGv mask = tcg_constant_tl(0x0000FFFF0000FFFFULL);
> +
> +    tcg_gen_shri_tl(t1, src1, 16);
> +    tcg_gen_and_tl(t1, t1, mask);
> +    tcg_gen_and_tl(t0, src1, mask);
> +    tcg_gen_shli_tl(t0, t0, 16);
> +    tcg_gen_or_tl(t0, t0, t1);

> +    tcg_gen_shri_tl(t1, t0, 32);
> +    tcg_gen_shli_tl(t0, t0, 32);
> +    tcg_gen_or_tl(dest, t0, t1);

This last is rotate by 32.

> +static void gen_maskeqz(TCGv dest, TCGv src1, TCGv src2)
> +{
> +    TCGv cond1 = tcg_constant_tl(0);
> +
> +    tcg_gen_movcond_tl(TCG_COND_EQ, dest, src2, cond1, cond1, src1);
> +}
> +
> +static void gen_masknez(TCGv dest, TCGv src1, TCGv src2)
> +{
> +    TCGv cond1 = tcg_constant_tl(0);
> +
> +    tcg_gen_movcond_tl(TCG_COND_NE, dest, src2, cond1, cond1, src1);
> +}

s/cond1/zero/g


r~