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charset="us-ascii" Content-ID: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: Dell.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: SA0PR19MB4508.namprd19.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 1b819823-ba92-41a3-e8e3-08da761db040 X-MS-Exchange-CrossTenant-originalarrivaltime: 04 Aug 2022 13:31:50.9051 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 945c199a-83a2-4e80-9f8c-5a91be5752dd X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: 81j8PLbTYT2eqfRZqYi6LFdlXQvekf5DnfZ8VT1gqPO2cLwnP5MOZh1sFN1rwSSD0f20alDRAlhiDT/Hb/VNsw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR19MB4512 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-08-04_03,2022-08-04_02,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 phishscore=0 priorityscore=1501 impostorscore=0 lowpriorityscore=0 mlxlogscore=612 mlxscore=0 adultscore=0 clxscore=1011 spamscore=0 suspectscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2206140000 definitions=main-2208040061 X-Proofpoint-GUID: AH0uHlywa4sCoVKEORNaqkGayBD-LS95 X-Proofpoint-ORIG-GUID: AH0uHlywa4sCoVKEORNaqkGayBD-LS95 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=734 bulkscore=0 adultscore=0 suspectscore=0 spamscore=0 malwarescore=0 mlxscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2206140000 definitions=main-2208040061 X-Spam-Status: No, score=-3.2 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 04 Aug 2022 13:32:07 -0000 > On Aug 4, 2022, at 9:17 AM, Chung-Lin Tang wrot= e: >=20 > On 2022/6/28 10:06 PM, Jakub Jelinek wrote: >> On Thu, Jun 23, 2022 at 11:47:59PM +0800, Chung-Lin Tang wrote: >>> with the way that chunk_size < 1 is handled for gomp_iter_dynamic_next: >>>=20 >>> (1) chunk_size <=3D -1: wraps into large unsigned value, seems to work = though. >>> (2) chunk_size =3D=3D 0: infinite loop >>>=20 >>> The (2) behavior is obviously not desired. This patch fixes this by cha= nging >> Why? It is a user error, undefined behavior, we shouldn't slow down val= id >> code for users who don't bother reading the standard. >=20 > This is loop init code, not per-iteration. The overhead really isn't that= much. >=20 > The question should be, if GCC having infinite loop behavior is reasonabl= e, > even if it is undefined in the spec. I wouldn't think so. The way I see "undefined code" is that you can't comp= lain about "wrong code" produced by the compiler. But for the compiler to = malfunction on wrong input is an entirely differerent matter. For one thin= g, it's hard to fix your code if the compiler fails. How would you locate = the offending source line? paul