Re: [Qemu-devel] [PATCH 13/14] i386: optimize setbe

[Richard Henderson]

On 10/06/2012 05:30 AM, Paolo Bonzini wrote:
>          gen_compute_eflags(s);
> -        tcg_gen_shri_tl(reg, cpu_cc_src, 6);
> -        tcg_gen_or_tl(reg, reg, cpu_cc_src);
> -        tcg_gen_andi_tl(reg, reg, 1);
> -        break;
> +        tcg_gen_andi_tl(reg, cpu_cc_src, 0x41);
> +        tcg_gen_setcondi_tl(inv ? TCG_COND_EQ : TCG_COND_NE, reg, reg, 0);
> +        return;

This one's questionable.  Whether it's an improvement really depends
on the host cpu isa.  It's probably more of a benefit if we can avoid
the setcond completely.  See the comments for the next patch.

That said, the patch produces correct code.

Reviewed-by: Richard Henderson <address@hidden>


r~