Re: [Qemu-devel] [PULL 08/16] tcg/i386: Support vector comparison select value

[Peter Maydell]

On Wed, 22 May 2019 at 23:28, Richard Henderson
<address@hidden> wrote:
>
> We already had backend support for this feature.  Expand the new
> cmpsel opcode using vpblendb.  The combination allows us to avoid
> an extra NOT for some comparison codes.
>
> Signed-off-by: Richard Henderson <address@hidden>
> ---
>  tcg/i386/tcg-target.h     |  2 +-
>  tcg/i386/tcg-target.inc.c | 39 +++++++++++++++++++++++++++++++++++----
>  2 files changed, 36 insertions(+), 5 deletions(-)
>
> diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h
> index 16a83a7f7b..928e8b87bb 100644
> --- a/tcg/i386/tcg-target.h
> +++ b/tcg/i386/tcg-target.h
> @@ -191,7 +191,7 @@ extern bool have_avx2;
>  #define TCG_TARGET_HAS_sat_vec          1
>  #define TCG_TARGET_HAS_minmax_vec       1
>  #define TCG_TARGET_HAS_bitsel_vec       0
> -#define TCG_TARGET_HAS_cmpsel_vec       0
> +#define TCG_TARGET_HAS_cmpsel_vec       -1

This is the only place where we define a TCG_TARGET_HAS_* macro
to something other than 0 or 1, which means that Coverity
complains (CID 1401702) when we use it in a logical boolean expression
  return have_vec && TCG_TARGET_HAS_cmpsel_vec;
later on.

Should it really be -1, or is this a typo for 1 ?

thanks
-- PMM