From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) by sourceware.org (Postfix) with ESMTP id 60FA03858CDB for ; Sat, 30 Dec 2023 18:14:32 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 60FA03858CDB Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=kernel.crashing.org ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 60FA03858CDB Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=63.228.1.57 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1703960073; cv=none; b=vyn/Mm7xB+5GE9SFUdmXvBxMptXFN4Z4O0dSpGPgv+Fbgd/N7mr7pDx8Vf58LznOVmDKAhdqFbgy8kA5PF186w5jtwMTfLgL0gW4fNLF1rAk2vwjPZJUkqzEAIe/8Q3eyPfmjr/UsIMR/2kWeEIZvqBbEEwvicOY2RWZkcG3AxQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1703960073; c=relaxed/simple; bh=iX0X4zrNQVvcypBEiBxm4rvb/H2dtLd6rGP9Fi2zDgU=; h=Date:From:To:Subject:Message-ID:Mime-Version; b=uJnI+WbHUN/IF1rUmcuOA3F7agbjXWapEufLW5YiCPP7asqroywLQ9W6P8dDZvavisb0rY+ipWY2+fZ8aILU6XkItA/fx8QU2wfpUGQv2FcgiQNW0x+EdRu6Odbd+euP3VL4gqEozenhjigMjPgvgztyFef2BLSoVd51wKSeitU= ARC-Authentication-Results: i=1; server2.sourceware.org Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 3BUIDSEk011005; Sat, 30 Dec 2023 12:13:28 -0600 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 3BUIDSjw011004; Sat, 30 Dec 2023 12:13:28 -0600 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Sat, 30 Dec 2023 12:13:28 -0600 From: Segher Boessenkool To: gcc-patches@gcc.gnu.org, jlaw@ventanamicro.com, rdapp.gcc@gmail.com, richard.sandiford@arm.com Subject: Re: [PATCH] Add a late-combine pass [PR106594] Message-ID: <20231230181328.GX19790@gate.crashing.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00,JMQ_SPF_NEUTRAL,KAM_DMARC_STATUS,SPF_HELO_PASS,SPF_PASS,TXREP,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 server2.sourceware.org List-Id: Hi! On Tue, Oct 24, 2023 at 07:49:10PM +0100, Richard Sandiford wrote: > This patch adds a combine pass that runs late in the pipeline. But it is not. It is a completely new thing, and much closer to fwprop than to combine, too. Could you rename it to something else, please? Something less confusing to both users and maintainers :-) > There are two instances: one between combine and split1, So, what kind of things does this do that the real combine does not? And, same question but for fwprop. That would be the crucial motivation for why we want to have this new pass at all :-) > The pass currently has a single objective: remove definitions by > substituting into all uses. The easy case ;-) Segher