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Peter Anvin" , "Nathan Chancellor" , Juergen Gross , "Peter Zijlstra" , Andy Lutomirski , "llvm@lists.linux.dev" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH v3] x86: use builtins to read eflags Thread-Topic: [PATCH v3] x86: use builtins to read eflags Thread-Index: AQHYHG/CSK+t8Kagc0eLuNqaUHH4EKyJWp+w Date: Tue, 8 Feb 2022 09:14:49 +0000 Message-ID: <0d93ea4d847b42ca9c5603cb97cbda8a@AcuMS.aculab.com> References: <20211229021258.176670-1-morbo@google.com> <20220204005742.1222997-1-morbo@google.com> In-Reply-To: Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: base64 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RDNS_NONE, SPF_HELO_NONE,T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org RnJvbTogTmljayBEZXNhdWxuaWVycw0KPiBTZW50OiAwNyBGZWJydWFyeSAyMDIyIDIyOjEyDQo+ IA0KPiBPbiBUaHUsIEZlYiAzLCAyMDIyIGF0IDQ6NTcgUE0gQmlsbCBXZW5kbGluZyA8bW9yYm9A Z29vZ2xlLmNvbT4gd3JvdGU6DQo+ID4NCj4gPiBHQ0MgYW5kIENsYW5nIGJvdGggaGF2ZSBidWls dGlucyB0byByZWFkIGFuZCB3cml0ZSB0aGUgRUZMQUdTIHJlZ2lzdGVyLg0KPiA+IFRoaXMgYWxs b3dzIHRoZSBjb21waWxlciB0byBkZXRlcm1pbmUgdGhlIGJlc3Qgd2F5IHRvIGdlbmVyYXRlIHRo aXMNCj4gPiBjb2RlLCB3aGljaCBjYW4gaW1wcm92ZSBjb2RlIGdlbmVyYXRpb24uDQo+ID4NCj4g PiBUaGlzIGlzc3VlIGFyb3NlIGR1ZSB0byBDbGFuZydzIGlzc3VlIHdpdGggdGhlICI9cm0iIGNv bnN0cmFpbnQuICBDbGFuZw0KPiA+IGNob29zZXMgdG8gYmUgY29uc2VydmF0aXZlIGluIHRoZXNl IHNpdHVhdGlvbnMsIGFuZCBzbyB1c2VzIG1lbW9yeQ0KPiA+IGluc3RlYWQgb2YgcmVnaXN0ZXJz LiBUaGlzIGlzIGEga25vd24gaXNzdWUsIHdoaWNoIGlzIGN1cnJlbnRseSBiZWluZw0KPiA+IGFk ZHJlc3NlZC4NCg0KSG93IG11Y2ggcGVyZm9ybWFuY2Ugd291bGQgYmUgbG9zdCBieSBqdXN0IHVz aW5nICI9ciI/DQoNCllvdSBnZXQgdHdvIGluc3RydWN0aW9ucyBpZiB0aGUgYWN0dWFsIHRhcmdl dCBpcyBtZW1vcnkuDQpUaGlzIG1pZ2h0IGJlIGEgbWFyZ2luYWwgY29kZSBzaXplIGluY3JlYXNl IC0gYnV0IG5vdCBtdWNoLA0KSXQgbWlnaHQgYWxzbyBzbG93IHRoaW5ncyBkb3duIGlmIHRoZSBl eGVjdXRpb24gaXMgbGltaXRlZA0KYnkgdGhlIGluc3RydWN0aW9uIGRlY29kZXIuDQoNCkJ1dCBv biBJbnRlbCBjcHUgJ3BvcCBtZW1vcnknIGlzIDIgdW9wcywgZXhhY3RseSB0aGUgc2FtZQ0KYXMg J3BvcCByZWdpc3RlcicgJ3N0b3JlIHJlZ2lzdGVyJyAoYW5kIEkgdGhpbmsgYW1kIGlzIHNpbWls YXIpLg0KU28gdGhlIGFjdHVhbCBleGVjdXRpb24gdGltZSBpcyBleGFjdGx5IHRoZSBzYW1lIGZv ciBib3RoLg0KDQpBbHNvIGl0IGxvb2tzIGxpa2UgY2xhbmcncyBidWlsdGluIGlzIGVmZmVjdGl2 ZWx5ICI9ciIuDQpDb21waWxpbmc6DQpsb25nIGZsOw0Kdm9pZCBuYXRpdmVfc2F2ZV9mbCh2b2lk KSB7DQogICAgICAgZmwgPSBfX2J1aWx0aW5faWEzMl9yZWFkZWZsYWdzX3U2NCgpOw0KfQ0KTm90 IG9ubHkgZ2VuZXJhdGVzIGEgc3RhY2sgZnJhbWUsIGl0IGFsc28gZ2VuZXJhdGVzOg0KcHVzaGY7 IHBvcCAlcmF4OyBtb3YgbWVtLCAlcmF4Lg0KDQoJRGF2aWQNCg0KLQ0KUmVnaXN0ZXJlZCBBZGRy ZXNzIExha2VzaWRlLCBCcmFtbGV5IFJvYWQsIE1vdW50IEZhcm0sIE1pbHRvbiBLZXluZXMsIE1L MSAxUFQsIFVLDQpSZWdpc3RyYXRpb24gTm86IDEzOTczODYgKFdhbGVzKQ0K