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DIR:OUT; SFP:1101; X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 19 Aug 2020 17:47:39.3613 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: e56731cc-98be-4f53-0843-08d84467f744 X-MS-Exchange-CrossTenant-Id: f34e5979-57d9-4aaa-ad4d-b122a662184d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=f34e5979-57d9-4aaa-ad4d-b122a662184d; Ip=[63.35.35.123]; Helo=[64aa7808-outbound-1.mta.getcheckrecipient.com] X-MS-Exchange-CrossTenant-AuthSource: DB5EUR03FT004.eop-EUR03.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: HE1PR0801MB1675 X-Spam-Status: No, score=-9.7 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, MSGID_FROM_MTA_HEADER, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_PASS, SPF_PASS, TXREP, UNPARSEABLE_RELAY 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: Wed, 19 Aug 2020 17:47:45 -0000 Segher Boessenkool writes: > [ Please don't post new patch series as replies to old ] > > On Wed, Jul 22, 2020 at 12:02:33PM +0200, Andrea Corallo wrote: >> This first patch implements the addition of a new RTX instruction class >> FILLER_INSN, which has been white listed to allow placement of NOPs >> outside of a basic block. This is to allow padding after unconditional >> branches. This is favorable so that any performance gained from >> diluting branches is not paid straight back via excessive eating of >> nops. >> >> It was deemed that a new RTX class was less invasive than modifying >> behavior in regards to standard UNSPEC nops. > > Deemed, by whom? There are several people very against it, too. You > need to modify only one simple behaviour (maybe in a handful of places), > making a new RTX class for that is excessive. Hi Segher, That's understood and agreed. I haven't posted any new patch on this, the quoted mail is an old one. I just wanted to discuss how to proceede this way with my mail of today. Thanks for your feedback! Andrea