target/s390x: Fix risbg handling

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

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Reported-by: David Hildenbrand <david@redhat.com>
Suggested-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Richard Henderson 2017-07-01 13:20:24 -07:00
parent 19d70587b5
commit dbdaaff43a

View File

@ -3479,8 +3479,8 @@ static ExitStatus op_risbg(DisasContext *s, DisasOps *o)
} }
/* In some cases we can implement this with extract. */ /* In some cases we can implement this with extract. */
if (imask == 0 && pos == 0 && len > 0 && rot + len <= 64) { if (imask == 0 && pos == 0 && len > 0 && len <= rot) {
tcg_gen_extract_i64(o->out, o->in2, rot, len); tcg_gen_extract_i64(o->out, o->in2, 64 - rot, len);
return NO_EXIT; return NO_EXIT;
} }