From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) by sourceware.org (Postfix) with ESMTPS id B85243858C36 for ; Fri, 10 Nov 2023 14:41:02 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org B85243858C36 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=ispras.ru Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=ispras.ru ARC-Filter: OpenARC Filter v1.0.0 sourceware.org B85243858C36 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=83.149.199.84 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1699627263; cv=none; b=IaGSaPRVcaOezoej/zEw7PVcdphansMTp76rnX3bEDRzoX0RUhnP2wE8gPxSZ81t9O1oLurjEDeXrqfIyycMCJ9rlEzFuLolVg1RudOSLLexzs9pb+fVIK2+MF/FN7cbR/oFfIlBp+Fn8m98IofO92IMQVVWvBSVmuw1tDaUMB4= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1699627263; c=relaxed/simple; bh=ylBiVifev7kQ3G5BLJewqqOGe1x1VFxb3WD3WRHV4FQ=; h=Date:From:To:Subject:Message-ID:MIME-Version; b=fMcfoCXqDvnYtjGQDV483ZjkkW8Oifr4ybIIpLkN7dD41p3Y0kdy6EJhIAZlct57H1KZfML/8pcAUBgbXdyO+Mv6mYGMMy+fjCMOF08w2+yowcFiJqr2x7oZKPJNIZwSVT0y9mDTsfPbmHR3Rdr5t+J5RmEoVmw9ndLlcWbZ7yE= ARC-Authentication-Results: i=1; server2.sourceware.org Received: from [10.10.3.121] (unknown [10.10.3.121]) by mail.ispras.ru (Postfix) with ESMTPS id 5489140F1DFC; Fri, 10 Nov 2023 14:41:01 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.ispras.ru 5489140F1DFC Date: Fri, 10 Nov 2023 17:41:01 +0300 (MSK) From: Alexander Monakov To: Richard Biener cc: Jeff Law , "Kewen.Lin" , Maxim Kuvyrkov , GCC Patches , Richard Sandiford , Jeff Law , Vladimir Makarov , zhroma@ispras.ru, Andrey Belevantsev , Segher Boessenkool , Peter Bergner , Michael Meissner , Alexandre Oliva Subject: Re: PING^1 [PATCH v3] sched: Change no_real_insns_p to no_real_nondebug_insns_p [PR108273] In-Reply-To: Message-ID: <7eb725d9-de7c-87ba-5ebd-f2e1485c5854@ispras.ru> References: <85b4098e-a72f-d013-ff17-8097971f71ba@linux.ibm.com> <09FEFDAE-698B-4B06-A896-8088B9B31539@linaro.org> <4675c26c-f230-b6d6-27c5-bc9f74736e38@linux.ibm.com> <41a4d065-c4b6-4a67-adf0-e84e942616c7@gmail.com> <93ce3468-a1ee-e77c-cbeb-a8c67a303bf9@ispras.ru> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="8323328-1665363882-1699627261=:1321" X-Spam-Status: No, score=-3.1 required=5.0 tests=BAYES_00,KAM_DMARC_STATUS,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323328-1665363882-1699627261=:1321 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT On Fri, 10 Nov 2023, Richard Biener wrote: > On Fri, Nov 10, 2023 at 3:18 PM Alexander Monakov wrote: > > > > > > On Fri, 10 Nov 2023, Richard Biener wrote: > > > > > > I'm afraid ignoring debug-only BBs goes contrary to overall var-tracking design: > > > > DEBUG_INSNs participate in dependency graph so that schedulers can remove or > > > > mutate them as needed when moving real insns across them. > > > > > > Note that debug-only BBs do not exist - the BB would be there even without debug > > > insns! > > > > Yep, sorry, I misspoke when I earlier said > > > > >> and cause divergence when passing through a debug-only BB which would not be > > >> present at all without -g. > > > > They are present in the region, but skipped via no_real_insns_p. > > > > > So instead you have to handle BBs with just debug insns the same you > > > handle a completely empty BB. > > > > Yeah. There would be no problem if the scheduler never used no_real_insns_p > > and handled empty and non-empty BBs the same way. > > And I suppose it would be OK to do that. Empty BBs are usually removed by > CFG cleanup so the situation should only happen in rare corner cases where > the fix would be to actually run CFG cleanup ... Yeah, sel-sched invokes 'cfg_cleanup (0)' up front, and I suppose that may be a preferable compromise for sched-rgn as well. I'm afraid one does not simply remove all uses of no_real_insns_p from sched-rgn, but would be happy to be wrong about that. Alexander --8323328-1665363882-1699627261=:1321--