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bh=j2ZKMZ8E9Z75S0HKJJkGW1ixZ1CA1Gl+IXoT6JvRfxQ=; b=Tpof6Ffrq2cmqpbpdUAwuwrBFVI9lYoO3RgdPX/nqcuGSNZMVxnSV12PkQP5FhRWO9FQXs 83CWJZr83oVPM0kggc05YDjc2PBBzAD/7yYSFxhlOtaqEZqIqWTGL2JCpW8XefsCnYZDP4 5TkrQBoRtYSLOaeYq1FS+52wJuRaKpQ= X-MC-Unique: c30GZD26MTyec8Rg5CNr2w-1 From: Juan Quintela To: qemu-devel@nongnu.org Cc: Juan Quintela , "Dr. David Alan Gilbert" , Matheus Tavares Bernardino Subject: [PULL 3/7] migration/xbzrle: use ctz64 to avoid undefined result Date: Thu, 16 Mar 2023 16:12:21 +0100 Message-Id: <20230316151225.11362-4-quintela@redhat.com> In-Reply-To: <20230316151225.11362-1-quintela@redhat.com> References: <20230316151225.11362-1-quintela@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer2=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=170.10.129.124; envelope-from=quintela@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer2=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer2=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1678979667048100006 Content-Type: text/plain; charset="utf-8" From: Matheus Tavares Bernardino __builtin_ctzll() produces undefined results when the argument is 0. This can be seen through test-xbzrle, which produces the following warning: ../migration/xbzrle.c:265: runtime error: passing zero to ctz(), which is n= ot a valid argument Replace __builtin_ctzll() with our ctz64() wrapper which properly handles 0. Signed-off-by: Matheus Tavares Bernardino Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Juan Quintela Signed-off-by: Juan Quintela --- migration/xbzrle.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/migration/xbzrle.c b/migration/xbzrle.c index 05366e86c0..21b92d4eae 100644 --- a/migration/xbzrle.c +++ b/migration/xbzrle.c @@ -12,6 +12,7 @@ */ #include "qemu/osdep.h" #include "qemu/cutils.h" +#include "qemu/host-utils.h" #include "xbzrle.h" =20 /* @@ -233,7 +234,7 @@ int xbzrle_encode_buffer_avx512(uint8_t *old_buf, uint8= _t *new_buf, int slen, break; } never_same =3D false; - num =3D __builtin_ctzll(~comp); + num =3D ctz64(~comp); num =3D (num < bytes_to_check) ? num : bytes_to_check; zrun_len +=3D num; bytes_to_check -=3D num; @@ -262,7 +263,7 @@ int xbzrle_encode_buffer_avx512(uint8_t *old_buf, uint8= _t *new_buf, int slen, nzrun_len +=3D 64; break; } - num =3D __builtin_ctzll(comp); + num =3D ctz64(comp); num =3D (num < bytes_to_check) ? num : bytes_to_check; nzrun_len +=3D num; bytes_to_check -=3D num; --=20 2.39.2