From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from huawei.com (szxga08-in.huawei.com [45.249.212.255]) by sourceware.org (Postfix) with ESMTPS id DBC70385C019 for ; Mon, 16 Mar 2020 06:29:54 +0000 (GMT) Received: from dggeml406-hub.china.huawei.com (unknown [172.30.72.57]) by Forcepoint Email with ESMTP id 59842F4560DEC3BE77DA; Mon, 16 Mar 2020 14:29:49 +0800 (CST) Received: from DGGEML527-MBX.china.huawei.com ([169.254.6.43]) by dggeml406-hub.china.huawei.com ([10.3.17.50]) with mapi id 14.03.0487.000; Mon, 16 Mar 2020 14:29:39 +0800 From: "Yangfei (Felix)" To: Segher Boessenkool CC: "gcc-patches@gcc.gnu.org" , "Zhanghaijian (A)" Subject: RE: [PATCH PR94026] combine missed opportunity to simplify comparisons with zero Thread-Topic: [PATCH PR94026] combine missed opportunity to simplify comparisons with zero Thread-Index: AdXyACW3FFSh4168SJyjLwmQLnZ34wGhcIMAABOO5wAADpNJgACNkKwg Date: Mon, 16 Mar 2020 06:29:39 +0000 Message-ID: References: <20200312235008.GL22482@gate.crashing.org> <20200313160729.GT22482@gate.crashing.org> In-Reply-To: <20200313160729.GT22482@gate.crashing.org> Accept-Language: zh-CN, en-US Content-Language: zh-CN X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.133.211.139] Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 MIME-Version: 1.0 X-CFilter-Loop: Reflected X-Spam-Status: No, score=-5.0 required=5.0 tests=GIT_PATCH_2, KAM_DMARC_STATUS, SPF_HELO_PASS, SPF_PASS autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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: Mon, 16 Mar 2020 06:29:56 -0000 SGksDQoNCj4gLS0tLS1PcmlnaW5hbCBNZXNzYWdlLS0tLS0NCj4gRnJvbTogU2VnaGVyIEJvZXNz ZW5rb29sIFttYWlsdG86c2VnaGVyQGtlcm5lbC5jcmFzaGluZy5vcmddDQo+IFNlbnQ6IFNhdHVy ZGF5LCBNYXJjaCAxNCwgMjAyMCAxMjowNyBBTQ0KPiBUbzogWWFuZ2ZlaSAoRmVsaXgpIDxmZWxp eC55YW5nQGh1YXdlaS5jb20+DQo+IENjOiBnY2MtcGF0Y2hlc0BnY2MuZ251Lm9yZzsgWmhhbmdo YWlqaWFuIChBKSA8ei56aGFuZ2hhaWppYW5AaHVhd2VpLmNvbT4NCj4gU3ViamVjdDogUmU6IFtQ QVRDSCBQUjk0MDI2XSBjb21iaW5lIG1pc3NlZCBvcHBvcnR1bml0eSB0byBzaW1wbGlmeQ0KPiBj b21wYXJpc29ucyB3aXRoIHplcm8NCj4gDQo+IE9uIEZyaSwgTWFyIDEzLCAyMDIwIGF0IDAzOjIx OjE4QU0gKzAwMDAsIFlhbmdmZWkgKEZlbGl4KSB3cm90ZToNCj4gPiA+IE9uIFdlZCwgTWFyIDA0 LCAyMDIwIGF0IDA4OjM5OjM2QU0gKzAwMDAsIFlhbmdmZWkgKEZlbGl4KSB3cm90ZToNCj4gPiA+ ID4gICBUaGlzIGlzIGEgc2ltcGxlIGZpeCBmb3IgUFI5NDAyNi4NCj4gPiA+ID4gICBXaXRoIHRo aXMgZml4LCBjb21iaW5lIHdpbGwgdHJ5IG1ha2UgYW4gZXh0cmFjdGlvbiBpZiB3ZSBhcmUgaW4N Cj4gPiA+ID4gYSBlcXVhbGl0eQ0KPiA+ID4gY29tcGFyaXNvbiBhbmQgdGhpcyBpcyBhbiBBTkQN Cj4gPiA+ID4gICB3aXRoIGEgY29uc3RhbnQgd2hpY2ggaXMgcG93ZXIgb2YgdHdvIG1pbnVzIG9u ZS4gIFNoaWZ0IGhlcmUNCj4gPiA+ID4gc2hvdWxkIGJlIGFuDQo+ID4gPiBjb25zdGFudC4gIEZv ciBleGFtcGxlLCBjb21iaW5lDQo+ID4gPiA+ICAgd2lsbCB0cmFuc2Zvcm0gKGNvbXBhcmUgKGFu ZCAobHNoaWZ0cnQgeCA4KSA2KSAwKSB0byAoY29tcGFyZQ0KPiA+ID4gPiAoemVyb19leHRyYWN0 DQo+ID4gPiAoeCAyIDkpKSAwKS4NCj4gPiA+DQo+ID4gPiBXaHkgaXMgdGhhdCBhIGdvb2QgdGhp bmc/DQo+ID4NCj4gPiBUaGUgcmVwb3J0ZWQgdGVzdCBjYXNlIGlzIHJlZHVjZWQgZnJvbSBzcGVj MjAxNyA1NDEubGVlbGFfci4gIEkgaGF2ZSBwYXN0ZWQNCj4gb3JpZ2luYWwgY29kZSBzbmlwcGV0 IG9uIHRoZSBidWd6aWxsYS4NCj4gPiBXZSBmb3VuZCBvdGhlciBjb21waWxlcnMgbGlrZSBhb2Nj L2xsdm0gY2FuIGNhdGNoIHRoaXMgcGF0dGVybiBhbmQgc2ltcGxpZnkgaXQuDQo+IA0KPiBUaGF0 IHdhc24ndCBteSBxdWVzdGlvbiwgbGV0IG1lIHJlcGhyYXNlOiB3aHkgd291bGQgd3JpdGluZyBp dCBhcyB6ZXJvX2V4dHJhY3QNCj4gKGluc3RlYWQgb2YgYXMgYSBtb3JlIGNhbm9uaWNhbCBmb3Jt KSBiZSB3YW50ZWQ/DQoNClNvcnJ5IGZvciBub3QgZ2V0dGluZyB5b3VyIHBvaW50IGhlcmUuIA0K DQo+IFRoZSBhYXJjaCBiYWNrZW5kIG9ubHkgaGFzIHplcm9fZXh0cmFjdCBmb3JtdWxhdGlvbnMg Zm9yIG1vc3Qgb2YgdGhlIGJpdGZpZWxkDQo+IGluc3RydWN0aW9ucy4gIElmIHlvdSBmaXggdGhh dCBwcm9ibGVtLCBhbGwgb2YgdGhpcyBzaG91bGQgZ28gYXdheT8gIExpa2UsIHRoZQ0KPiB0ZXN0 Y2FzZSBpbiB0aGUgUFIgc3RhcnRzIHdpdGgNCj4gDQo+IFRyeWluZyA3IC0+IDg6DQo+ICAgICA3 OiByOTk6U0k9cjEwMzpTST4+cjEwNDpTSSMwDQo+ICAgICAgIFJFR19ERUFEIHIxMDQ6U0kNCj4g ICAgICAgUkVHX0RFQUQgcjEwMzpTSQ0KPiAgICAgODogcjEwMDpTST1yOTk6U0kmMHg2DQo+ICAg ICAgIFJFR19ERUFEIHI5OTpTSQ0KPiBGYWlsZWQgdG8gbWF0Y2ggdGhpcyBpbnN0cnVjdGlvbjoN Cj4gKHNldCAocmVnOlNJIDEwMCkNCj4gICAgIChhbmQ6U0kgKGFzaGlmdHJ0OlNJIChyZWc6U0kg MTAzKQ0KPiAgICAgICAgICAgICAoc3VicmVnOlFJIChyZWc6U0kgMTA0KSAwKSkNCj4gICAgICAg ICAoY29uc3RfaW50IDYgWzB4Nl0pKSkNCj4gDQo+IGFuZCB0aGF0IHNob3VsZCBtYXRjaCBhbHJl YWR5ICh0aGF0J3MgYW4gdWJmbSAodWJmeCkpPw0KDQpGb3IgYWFyY2g2NCwgaWYgd2UgdXNlICJ1 YmZtL3ViZngiIGZvciB0aGUgcmVkdWNlZCB0ZXN0IGNhc2UsIHRoZW4gd2Ugc3RpbGwgbmVlZCB0 byBkbyBhIGNvbXBhcmUgd2l0aCB6ZXJvLiAgVGhlbiB3ZSB3b24ndCBnZXQgdGhlIGJlbmVmaXQu ICANCkZvciBhYXJjaDY0LCB3ZSBuZWVkIHRvIGVtaXQgYSAidHN0IiBpbnN0cnVjdGlvbiBoZXJl LiAgU28gd2UgbmVlZCB0byBjYXRjaCBzb21ldGhpbmcgbGlrZTogIA0KDQoxNDkgKHNldCAocmVn OkNDX05aIDY2IGNjKQ0KMTUwICAgICAoY29tcGFyZTpDQ19OWiAoYW5kOlNJIChsc2hpZnRydDpT SSAocmVnOlNJIDEwMikNCjE1MSAgICAgICAgICAgICAgICAgKGNvbnN0X2ludCA4IFsweDhdKSkN CjE1MiAgICAgICAgICAgICAoY29uc3RfaW50IDYgWzB4Nl0pKQ0KMTUzICAgICAgICAgKGNvbnN0 X2ludCAwIFswXSkpKQ0KDQpCdXQgdGhpcyBwYXR0ZXJuIGlzIG5vdCBhY2N1cmF0ZSBlbm91Z2g6 IHdlIGNhbiBvbmx5IGFjY2VwdCBlcXVhbGl0eSBjb21wYXJpc29uIHdpdGggemVybyBoZXJlIChh cyBpbmRpY2F0ZWQgYnkgdGhlIGNoZWNraW5nIG9mIGVxdWFsaXR5X2NvbXBhcmlzb24gaW4gbXkg b3JpZ2luYWwgcGF0Y2gpLiAgDQpBbHNvLCB0aGlzIGlzc3VlIGlzIHRoZXJlIGZvciBwb3J0cyBs aWtlIHg4Ni4gIElmIHdlIGdvIHRoYXQgd2F5LCB0aGVuIHdlIG5lZWQgdG8gaGFuZGxlIGVhY2gg cG9ydCBhZmZlY3RlZC4gIA0KU28gSSBhbSBpbmNsaW5lZCB0byBoYW5kbGUgdGhpcyBpbiBhbiBh cmNoLWluZGVwZW5kZW50IHdheS4gIA0KSSBsb29rZWQgaW50byB0cmVlIHBoYXNlcyBsaWtlIGZ3 cHJvcCAmIGZvbGQtY29uc3QgYmVmb3JlLCBidXQgZGlkbid0IHNlZSBhbiBhcHByb3ByaWF0ZSBw b2ludCB0byBjYXRjaCB0aGlzIG9wcG9ydHVuaXR5LiAgDQpUaGVuIEkgY2FtZSB0byB0aGUgY29t YmluZSBwaGFzZS4gIA0KDQo+IA0KPiA+ID4gKFRoZXJlIHNob3VsZCBiZSB0aG9yb3VnaCB0ZXN0 cyBvbiBtYW55IGFyY2hzLCBzaG93aW5nIGl0IGhlbHBzIG9uDQo+ID4gPiBhdmVyYWdlLCBhbmQg aXQgZG9lc24ndCByZWdyZXNzIGFueXRoaW5nLiAgSSBjYW4gZG8gdGhhdCBmb3IgeW91LCBidXQg bm90DQo+IHJpZ2h0IG5vdykuDQo+ID4NCj4gPiBJIG9ubHkgaGF2ZSBhYXJjaDY0ICYgeDg2XzY0 IGxpbnV4IGF2YWlsYWJsZSBhbmQgaGF2ZSB0ZXN0ZWQgdGhpcyBwYXRjaCB3aXRoDQo+IHNwZWMx NyBvbiBib3RoIHBsYXRmb3Jtcy4NCj4gPiBObyBvYnZpb3VzIGltcHJvdmVtZW50ICYgcmVncmVz c2lvbiB3aXRuZXNzZWQuICBUaGlzIGlzIGV4cGVjdGVkIGFzIG9ubHkNCj4gb25lIGluc3RydWN0 aW9uIGlzIHJlZHVjZWQgaGVyZS4NCj4gDQo+IFdoYXQgc2hvdWxkIGJlIHRlc3RlZCBpcyB3aGF0 IG5ldyBjb21iaW5hdGlvbnMgYXJlIGRvbmUsIGFuZCB3aGljaCBhcmUgKm5vDQo+IGxvbmdlciog ZG9uZS4NCg0KSW4gdGhlb3J5LCB3ZSB3b24ndCBsb3NlIGJ1dCBlbWl0IG1vcmUgemVyb19leHRy YWN0IHdpdGggbXkgcGF0Y2guICANCg0KPiA+ID4gSW4gZ2VuZXJhbCwgd2Ugc2hvdWxkIGhhdmUg KmZld2VyKiB6ZXJvX2V4dHJhY3QsIG5vdCBtb3JlLg0KPiANCj4gU29tZSByZWFzb25zIGZvciB0 aGF0Og0KPiANCj4gMSkgQWxsIHRob3NlIGNhbiBiZSBleHByZXNzZWQgd2l0aCBzaW1wbGVyIG9w ZXJhdGlvbnMgYXMgd2VsbDsNCj4gMikgTW9zdCB2ZXJ5IHNpbWlsYXIgZXhwcmVzc2lvbnMgY2Fu bm90IGJlIGV4cHJlc3NlZCBhcyB6ZXJvX2V4dHJhY3QsDQo+IGFsdGhvdWdoIG1hbnkgYXJjaGl0 ZWN0dXJlcyBjYW4gaGFuZGxlIChzb21lIG9mKSB0aG9zZSBqdXN0IGZpbmU7DQo+IDMpIFRoZSBv cHRpbWl6ZXJzIGRvIG5vdCBoYW5kbGUgemVyb19leHRyYWN0IHZlcnkgd2VsbCBhdCBhbGwgKHRo aXMgaW5jbHVkZXMNCj4gc2ltcGxpZnktcnR4LCB0byBzdGFydCB3aXRoKS4NCj4gDQo+IHNpZ25f ZXh0cmFjdCBpcyBuYXN0aWVyIC0tIHdlIHJlYWxseSB3YW50IHRvIGhhdmUgYSBzaWduX2V4dGVu ZCB0aGF0IHdvcmtzIG9uDQo+IHNlcGFyYXRlIGJpdHMsIG5vdCBhcyBjb2Fyc2UgYXMgYWRkcmVz cyB1bml0cyBhcyB3ZSBoYXZlIG5vdyAtLSBidXQgaXQgY3VycmVudGx5DQo+IGlzbid0IGhhbmRs ZWQgbXVjaCBlaXRoZXIuDQoNClRoYW5rcyBmb3IgZXhwbGFpbmluZyB0aGlzLiAgSSBoYXZlIHRv IGFkbWl0IHRoYXQgSSBkaWRuJ3QgcmVhbGl6ZSB0aGlzIGlzc3VlIHdoZW4gSSB3YXMgY3JlYXRp bmcgbXkgb3JpZ2luYWwgcGF0Y2guICANCg0KDQpGZWxpeA0K