From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ciao.gmane.io (ciao.gmane.io [116.202.254.214]) by sourceware.org (Postfix) with ESMTPS id 471B8384600C for ; Thu, 23 Mar 2023 07:08:47 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 471B8384600C Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=codesourcery.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=m.gmane-mx.org Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1pfF40-00066D-Rs for gcc@gcc.gnu.org; Thu, 23 Mar 2023 08:08:44 +0100 X-Injected-Via-Gmane: http://gmane.org/ To: gcc@gcc.gnu.org From: Julian Brown Subject: Re: I have questions regarding the 4.3 codebase... Date: Thu, 23 Mar 2023 07:08:34 +0000 Organization: Siemens Message-ID: <20230323070834.17026a71@squid.athome> References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit In-Reply-To: X-Newsreader: Claws Mail 4.1.1git1 (GTK 3.24.36; x86_64-pc-linux-gnu) X-Spam-Status: No, score=-4.7 required=5.0 tests=BAYES_00,HEADER_FROM_DIFFERENT_DOMAINS,KAM_DMARC_STATUS,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Wed, 22 Mar 2023 18:27:28 -0400 Sid Maxwell via Gcc wrote: > Is there anyone on the list with experience with the gcc 4.3 > codebase? I'm currently maintaining a fork of it, with a PDP10 code > generator. > > I've run into an issue involving the transformation of a movmemhi to a > single PDP10 instruction (an xblt, if you're curious). The > transformation appears to 'lose' its knowledge of being a store, > resulting in certain following stores being declared dead, and code > motion that shouldn't happen (e.g. a load moved before the xblt that > depends on the result of the xblt). > > I'm hoping to find someone who can help me diagnose the problem. We > want to use this instruction rather than the copy-word-loop currently > generated for struct assignments. I think we'd need a bit more info than that... what does the movmemhi instruction pattern look like, for example? Julian