From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pj1-x1033.google.com (mail-pj1-x1033.google.com [IPv6:2607:f8b0:4864:20::1033]) by sourceware.org (Postfix) with ESMTPS id BE0343858D37 for ; Wed, 28 Dec 2022 01:32:24 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org BE0343858D37 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-pj1-x1033.google.com with SMTP id n65-20020a17090a2cc700b0021bc5ef7a14so14748435pjd.0 for ; Tue, 27 Dec 2022 17:32:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=bGSfDJHMU3wL0v7ReUMq16IGPhQ92RkD5p3Ox+UgiPE=; b=OaFDvJfoPBB1pnD9hh8nvGCnUwevlG1fVCF2yHl4W6o3dhht9AmRdTnnhcAJqyr8y3 kqJ/Mpt0Rro412Z55FbWG7MWfOGNHJjxugyuM4F1448OFMUpE1WSkHXow+9vvUyA0FkD t7e3bXw7T/85wkik/OkhXZsdgw2qYewOBJUO+5MA9X0zliBYOkOx3zlIeuuofpW7W9Tf psvHChnoqJuLrGTjGL+vGFXGisa7ZwL2zmhXSY8uU5wBrns/noFm9F2YM9Uv3wIBqhsQ WHoFK5L28/nxlybuzYP9pU5/XSEgzYwyJ1fF3WysPPda5t0u7WuJVsI0dCBK9D0arlzQ YaWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=bGSfDJHMU3wL0v7ReUMq16IGPhQ92RkD5p3Ox+UgiPE=; b=T1UgGxGDBijWHS9WpSfkgQX6X+8+hyXkdWNaiTDjaaT9Dd+zsiPLpcHWE0zrqAfTSg q2wVz7K5B56TvvVlbYmhbed8j1yiZ7eYENzB85JpLN49Yz5eTdm79+4ajQtYBQS6hNW9 S1AA5xB85fscC6NoVBTIoeOYs2JjdAv9fCY14M5EmsprsXAxPQe+R11gCfJmaHQlnPim NchW+y9MQ0aTDcwyXInZHYlyu7GDgGGWaAYuvM7ZkhxKUnDMyTkLV9js/kDJcXG2fXNO JiLIAkp2pYd69zV8KcEi0y73J9NVvnbBAL5FoMp14Lj/Q4pEz9bawEYMXCyx6/3ul0ij AfDA== X-Gm-Message-State: AFqh2krpxopex/uMuSv0Ww9JdVke72PmUfUBPseVQWdYaOn4Pwfrf4pS HY5tLyMJSsQ4h+nirVoV1Pg= X-Google-Smtp-Source: AMrXdXuy12O/K97w+3Jkiz+HLqkZkwZ5DvKc0gxCUvxEMSLkpvMLa/NygRCk/u4YExzJFZfAIBkNBQ== X-Received: by 2002:a17:902:d58c:b0:189:9841:8ffe with SMTP id k12-20020a170902d58c00b0018998418ffemr27638017plh.9.1672191143661; Tue, 27 Dec 2022 17:32:23 -0800 (PST) Received: from ?IPV6:2601:681:8600:13d0::f0a? ([2601:681:8600:13d0::f0a]) by smtp.gmail.com with ESMTPSA id x5-20020a170902ec8500b0017854cee6ebsm9720038plg.72.2022.12.27.17.32.22 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 27 Dec 2022 17:32:23 -0800 (PST) Message-ID: <5ef0e5d4-f9f2-68a6-0971-83e642f601ee@gmail.com> Date: Tue, 27 Dec 2022 18:32:21 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.1 Subject: Re: [x86 PATCH] Provide zero_extend versions/variants of several patterns. Content-Language: en-US To: Roger Sayle , 'GCC Patches' Cc: 'Uros Bizjak' References: <00e801d91a59$df0f3e70$9d2dbb50$@nextmovesoftware.com> From: Jeff Law In-Reply-To: <00e801d91a59$df0f3e70$9d2dbb50$@nextmovesoftware.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-3.0 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,KAM_SHORT,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP 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: On 12/27/22 18:15, Roger Sayle wrote: > > Back in September, the review of my patch for PR rtl-optimization/106594, > https://gcc.gnu.org/pipermail/gcc-patches/2022-September/601501.html > suggested that I submit the x86 backend bits, independently and first. > > The executive summary is that the middle-end doesn't have a preferred > canonical form for expressing zero-extension, sometimes using an AND > and sometimes using zero_extend. Pending changes to RTL simplification > will/may alter some of these representations, so a few additional > patterns are required to recognize these alternate representations > and avoid any testsuite regressions. Oh and internally other forms can show up. Like paired shifts. In fact, I think paired shifts are canonical inside at least some parts of combine. jeff