On 2017-07-01 13:26, Richard Henderson wrote:
> The rotation is to the left, but extract shifts to the right.
> The computation of the extract parameters needs adjusting.
>
> For the entry condition, simplify
>
> 64 - rot + len <= 64
> -rot + len <= 0
> len <= rot
>
> Reported-by: David Hildenbrand <da...@redhat.com>
> Suggested-by: Aurelien Jarno <aurel...@aurel32.net>
> Signed-off-by: Richard Henderson <r...@twiddle.net>
> ---
> target/s390x/translate.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/target/s390x/translate.c b/target/s390x/translate.c
> index 1f0c401..89b2ea5 100644
> --- a/target/s390x/translate.c
> +++ b/target/s390x/translate.c
> @@ -3472,8 +3472,8 @@ static ExitStatus op_risbg(DisasContext *s, DisasOps *o)
> }
>
> /* In some cases we can implement this with extract. */
> - if (imask == 0 && pos == 0 && len > 0 && rot + len <= 64) {
> - tcg_gen_extract_i64(o->out, o->in2, rot, len);
> + if (imask == 0 && pos == 0 && len > 0 && len <= rot) {
> + tcg_gen_extract_i64(o->out, o->in2, 64 - rot, len);
> return NO_EXIT;
> }
Reviewed-by: Aurelien Jarno <aurel...@aurel32.net>
--
Aurelien Jarno GPG: 4096R/1DDD8C9B
aurel...@aurel32.net http://www.aurel32.net
