Re: [PATCH 20/37] target/i386: reimplement 0x0f 0x60-0x6f, add AVX

[Richard Henderson]

On 9/12/22 00:04, Paolo Bonzini wrote:
> +/*
> + * 00 = p*  Pq, Qq (if mmx not NULL; no VEX)
> + * 66 = vp* Vx, Hx, Wx
> + *
> + * These are really the same encoding, because 1) V is the same as P when VEX.V
> + * is not present 2) P and Q are the same as H and W apart from MM/XMM
> + */
> +static inline void gen_binary_int_sse(DisasContext *s, CPUX86State *env, 
> X86DecodedInsn *decode,
> +                                      SSEFunc_0_eppp mmx, SSEFunc_0_eppp xmm, 
> SSEFunc_0_eppp ymm)

No need to inline.

> +{
> +    assert (!!mmx == !!(decode->e.special == X86_SPECIAL_MMX));
> +
> +    if (mmx && (s->prefix & PREFIX_VEX) && !(s->prefix & PREFIX_DATA)) {
> +        /* VEX encoding is not applicable to MMX instructions.  */
> +        gen_illegal_opcode(s);
> +        return;
> +    }
> +    if (!(s->prefix & PREFIX_DATA)) {
> +        mmx(cpu_env, s->ptr0, s->ptr1, s->ptr2);
> +    } else if (!s->vex_l) {
> +        xmm(cpu_env, s->ptr0, s->ptr1, s->ptr2);
> +    } else {
> +        ymm(cpu_env, s->ptr0, s->ptr1, s->ptr2);
> +    }

And a reminder from earlier patches that generating the pointers here would be better, as 
well as zeroing the high ymm bits for vex xmm insns.

> +static void gen_MOVD_to(DisasContext *s, CPUX86State *env, X86DecodedInsn 
> *decode)
> +{
> +    MemOp ot = decode->op[2].ot;
> +    int vec_len = sse_vec_len(s, decode);
> +    int lo_ofs = decode->op[0].offset
> +        - xmm_offset(decode->op[0].ot)
> +        + xmm_offset(ot);
> +
> +    tcg_gen_gvec_dup_imm(MO_64, decode->op[0].offset, vec_len, vec_len, 0);
> +
> +    switch (ot) {
> +    case MO_32:
> +#ifdef TARGET_X86_64
> +        tcg_gen_trunc_tl_i32(s->tmp3_i32, s->T1);
> +        tcg_gen_st_i32(s->tmp3_i32, cpu_env, lo_ofs);
> +        break;

Use tcg_gen_st32_tl and omit the trunc.
Alternately, zero extend in T1 and fall through...

> +    case MO_64:
> +#endif
> +        tcg_gen_st_tl(s->T1, cpu_env, lo_ofs);

This could also be

    tcg_gen_gvec_dup_i64(MO_64, offset, 8, sse_vec_max_len, s->T1);

to do the store and clear in one call.



r~