From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.86.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0C8357E for ; Thu, 24 Mar 2022 22:54:08 +0000 (UTC) Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-231-THU0TZx9N2OyJfewrvht5w-1; Thu, 24 Mar 2022 22:54:05 +0000 X-MC-Unique: THU0TZx9N2OyJfewrvht5w-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) by AcuMS.aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) with Microsoft SMTP Server (TLS) id 15.0.1497.32; Thu, 24 Mar 2022 22:54:05 +0000 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.033; Thu, 24 Mar 2022 22:54:05 +0000 From: David Laight To: 'Nick Desaulniers' , Borislav Petkov CC: Nathan Chancellor , x86-ml , lkml , "llvm@lists.linux.dev" , Mark Rutland , Peter Zijlstra , Josh Poimboeuf Subject: RE: clang memcpy calls Thread-Topic: clang memcpy calls Thread-Index: AQHYP68jFJQQj1SZ3U2APgeueTpytqzPHokA Date: Thu, 24 Mar 2022 22:54:04 +0000 Message-ID: <7c95cb9c9255448bb74d1f1f694abffb@AcuMS.aculab.com> References: 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] Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: 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 RnJvbTogTmljayBEZXNhdWxuaWVycw0KPiBTZW50OiAyNCBNYXJjaCAyMDIyIDE4OjQ0DQo+IA0K PiBPbiBUaHUsIE1hciAyNCwgMjAyMiBhdCA0OjE5IEFNIEJvcmlzbGF2IFBldGtvdiA8YnBAYWxp ZW44LmRlPiB3cm90ZToNCj4gPg0KPiA+IEhpIGZvbGtzLA0KPiA+DQo+ID4gc28gSSd2ZSBiZWVu IGxvb2tpbmcgYXQgYSByZWNlbnQgb2JqdG9vbCBub2luc3RyIHdhcm5pbmcgZnJvbSBjbGFuZw0K PiA+IGJ1aWxkczoNCj4gPg0KPiA+IHZtbGludXgubzogd2FybmluZzogb2JqdG9vbDogc3luY19y ZWdzKCkrMHgyMDogY2FsbCB0byBtZW1jcHkoKSBsZWF2ZXMgLm5vaW5zdHIudGV4dCBzZWN0aW9u DQo+ID4NCj4gPiBUaGUgaXNzdWUgaXMgdGhhdCBjbGFuZyBnZW5lcmF0ZXMgYSBtZW1jcHkoKSBj YWxsIHdoZW4gYSBzdHJ1Y3QgY29weQ0KPiA+IGhhcHBlbnM6DQo+ID4NCj4gPiAgICAgICAgIGlm IChyZWdzICE9IGVyZWdzKQ0KPiA+ICAgICAgICAgICAgICAgICAqcmVncyA9ICplcmVnczsNCj4g DQo+IFNwZWNpZmljYWxseSwgdGhpcyBpcyBjb3B5aW5nIG9uZSBzdHJ1Y3QgcHRfcmVncyB0byBh bm90aGVyLiBJdCBsb29rcw0KPiBsaWtlIHRoZSBzaXplb2Ygc3RydWN0IHB0X3JlZ3MgaXMganVz dCBsYXJnZSBlbm91Z2ggdG8gaGF2ZSBjbGFuZyBlbWl0DQo+IHRoZSBsaWJjYWxsLg0KPiBodHRw czovL2dvZGJvbHQub3JnL3ovc2N4NmFhOGpxDQo+IE90aGVyd2lzZSBjbGFuZyB3aWxsIGFsc28g dXNlIHJlcDsgbW92c3E7IHdoZW4gLW1uby1zc2UgLU8yIGlzIHNldCBhbmQNCj4gdGhlIHN0cnVj dHMgYXJlIGJlbG93IEFSQklUUkFSWV9USFJFU0hPTEQuICBTaG91bGQgQVJCSVRSQVJZX1RIUkVT SE9MRA0KPiBiZSByYWlzZWQgc28gdGhhdCB3ZSBjb250aW51ZSB0byBpbmxpbmUgdGhlIG1lbWNw eT8gKnNocnVnKg0KDQpJJ3ZlIGp1c3QgbG9va2VkIGF0IHNvbWUgaW5zdHJ1Y3Rpb24gdGltaW5n cy4NCkZvciAzMiBieXRlIGFsaWduZWQgY29waWVzIGl0IGFjdHVhbGx5IGxvb2tzIGxpa2UgJ3Jl cCBtb3ZzJw0KKHByb2JhYmx5IG1vdnNxKSBpcyBhY3R1YWxseSByZWFzb25hYmxlIGZvciBsYXJn ZSBidWZmZXJzDQpvbiBhbGwgbWFpbnN0cmVhbSBJbnRlbCBjcHUgc2luY2Ugc2FuZHkgYnJpZ2Uu DQpPbiB0aGUgbW9yZSByZWNlbnQgb25lcyBpdCBydW5zIGF0IDMyIGJ5dGVzL2Nsb2NrLg0KSXQg bWF5IG5vdCBiZSB0aGF0IGJhZCBmb3Igc2hvcnRlciBhbmQgbm9uIDMyIGJ5dGUgYWxpZ25lZA0K YnVmZmVycyBhcyB3ZWxsLg0KDQpDZXJ0YWlubHkgSSBjYW4ndCBzZWUgYSByZWFzb24gZm9yIGNh bGxpbmcgbWVtY3B5KCkgZm9yDQpsYXJnZSBjb3BpZXMhDQoNCkF0IGxlYXN0IG5vIG9uZSB1c2Vz IFA0IGFueSBtb3JlLCBzZXR1cCBsYXRlbmN5IHdhcyBzb21ldGhpbmcNCmxpa2UgMTg2IGNsb2Nr cyENCg0KSSB3YXMgdGhpbmtpbmcgdGhhdCAncmVwIG1vdnNxJyBvbmx5IG1hZGUgYW55IHNlbnNl IHdpdGggLU9zLg0KQnV0IGl0IHNlZW1zIHRvIGJlIGJldHRlciB0aGFuIEkgdGhvdWdodC4NCihJ IG1pZ2h0IGV2ZW4gaGF2ZSBtZWFzdXJlZCBpdCBydW5uaW5nICdmYXN0JyBvbiBJdnkgYnJpZGdl LikNCg0KCURhdmlkDQoNCi0NClJlZ2lzdGVyZWQgQWRkcmVzcyBMYWtlc2lkZSwgQnJhbWxleSBS b2FkLCBNb3VudCBGYXJtLCBNaWx0b24gS2V5bmVzLCBNSzEgMVBULCBVSw0KUmVnaXN0cmF0aW9u IE5vOiAxMzk3Mzg2IChXYWxlcykNCg==