From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-x22e.google.com (mail-lj1-x22e.google.com [IPv6:2a00:1450:4864:20::22e]) by sourceware.org (Postfix) with ESMTPS id A97BB3857C51 for ; Fri, 18 Nov 2022 19:59:17 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org A97BB3857C51 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=vrull.eu Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=vrull.eu Received: by mail-lj1-x22e.google.com with SMTP id t10so8158752ljj.0 for ; Fri, 18 Nov 2022 11:59:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=vrull.eu; s=google; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=iX/KN/H5UyA/oA5tEQgUiIOfz1EKtGiQWWOsvc0x+uM=; b=eO/fdnEBhklrAfr4vvTXFQbIDQNzpmo3HnUBVJw9LNLltmyWyJcPIfr6Xwc9AZDeag +33OEV4gsnABDgwuBDMReJ3ePgYrsbafc2jrt7FwrKKgPrDW5yex6WXBxl4B36Xb0/9n pot0UX1X1fyVfDiVgsbGVoEJW4S2N4lY7wzcNQGH/X+15dfqTc81EsYBCymjD8nASJvk PtmZ7xhrm+5r6VmLJxjb0LelR4d+h8ybi5ozK9UtzsWBS1V7PmgCBNpNWEM7z7MBeFbT xeeKSgqAdeJChv81wt9NCOYZISRf01EAvC9LaZcXZbnD/qMnqH1a5R4ZfOqoSx3098uO 4FJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=iX/KN/H5UyA/oA5tEQgUiIOfz1EKtGiQWWOsvc0x+uM=; b=IMIQ1S/sGfn0/F43Y6mR+UxODezohQvLX5MIA5zBYy2EmKBqeCCJWSjQFChdgUfqmZ grqSIDFzzZK7whReK5ZmvEOLbFHWko5HM9COLxrlMp5NmDjxkXA3YPJVh/GT+k0Z7+6U 5wxn37PwaE6MHRSFuHdgBdwsFyUu5prEFm2EafKFlLyRaPH/QrpQ4vayDhHd29b+ptYx 9tO51PLqFjUoP8KCklmHyxdhe+8BGQs/p2sEjvw53bfzT00e6mMMrGZ77PnIBK1uadg0 DPM+6RqFnXJrsx8FuKopIriuM0igRC4NHmIhQt31w8fX3+pJFdHvoukfOLazgs/WqrE4 2nHw== X-Gm-Message-State: ANoB5pmH4v5CVKc7pCT+8V2gLKeu9KV5kBUgWSYl3pHwoavxWGsrpAFc d+RyTPz/FNsjQWiT4vKlFHeZ0WM3g8pVlHISn3Ss7JDxFIqr6Ov2 X-Google-Smtp-Source: AA0mqf478rPvnvSxiwXo4U2dm8lUmv5wQH50csWvVzkWNv/YVgruVPNP187iRL46LPbD6sno0pg3PY5QV0UztYGf1/o= X-Received: by 2002:a2e:9c51:0:b0:277:e8e:8d90 with SMTP id t17-20020a2e9c51000000b002770e8e8d90mr3152444ljj.243.1668801556279; Fri, 18 Nov 2022 11:59:16 -0800 (PST) MIME-Version: 1.0 References: <20221108195730.2701496-1-philipp.tomsich@vrull.eu> <0ba55dec-3d59-a63e-5e5d-c99cf89f64ca@gmail.com> In-Reply-To: <0ba55dec-3d59-a63e-5e5d-c99cf89f64ca@gmail.com> From: Philipp Tomsich Date: Fri, 18 Nov 2022 20:59:04 +0100 Message-ID: Subject: Re: [PATCH] RISC-V: Optimize slli(.uw)? + addw + zext.w into sh[123]add + zext.w To: Jeff Law Cc: gcc-patches@gcc.gnu.org, Christoph Muellner , Palmer Dabbelt , Kito Cheng , Vineet Gupta , Jeff Law Content-Type: multipart/alternative; boundary="000000000000f6871205edc42311" X-Spam-Status: No, score=-3.2 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,HTML_MESSAGE,JMQ_SPF_NEUTRAL,RCVD_IN_DNSWL_NONE,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: --000000000000f6871205edc42311 Content-Type: text/plain; charset="UTF-8" On Fri, 18 Nov 2022 at 20:52, Jeff Law wrote: > Something to consider. We're gaining a lot of > > (subreg:SI (reg:DI) 0) kinds of operands. > > > Would it make sense to make an operand predicate that accepted > > (reg:SI) or (subreg:SI (reg:DI) 0)? > > > It will reduce my compaints about subregs :-) But the real reason I'm > suggesting we consider adding such a predicate is, AFIACT, it it gives > combine a chance to eliminate the subreg. I haven't actually tested > this, but it seems like it might be worth a quick experiment independent > of these patches (and probably targeted towards gcc-14 rather than gcc-13). > I like the idea. Definitively something to consider. We'll give this a try. --Philipp. --000000000000f6871205edc42311--