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 <aurel...@aurel32.net>
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 f94ba7c..0c609bd 100644
--- a/target/s390x/translate.c
+++ b/target/s390x/translate.c
@@ -3471,8 +3471,8 @@ 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;
}
--
2.9.4
