From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf1-x12d.google.com (mail-lf1-x12d.google.com [IPv6:2a00:1450:4864:20::12d]) by sourceware.org (Postfix) with ESMTPS id ED5C3385802F for ; Fri, 18 Nov 2022 19:56:25 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org ED5C3385802F 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-lf1-x12d.google.com with SMTP id d6so9890763lfs.10 for ; Fri, 18 Nov 2022 11:56:25 -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=2gpGrFtaHTWSxbLD/nIwbDHRys15sHCP7t9Q0Pg9Z4E=; b=a0fxejAZzWVfOmo3MnDQKL4YM1t6LK+OOAf0TCag+BkVRHsmbz+1DQNjMwoup9xBvb FxDyAu9EoYlRrCBB5zMCR9w2K4hW/yr7RNaJs4Cm7jr69okFuGLs3Ztd8KZsey9p7Znw VzZ12IaMUQyAJCwBpo/8/xBLDSCoZEP/fzkvT2ZRO2EGyudxLvyHoypNHrXpTH2dii3p Vcdm4ZApm17Kj4M0L8ECGXxgpccmexAT7n1Wq6yDdf3eRC5PLAw8yNLH6L3x52ZTHjRV lWbPDZm7rn2ok9+xfzqMUvkJlHhllhzrX5T57sMO5BnWz8wd3ZACa/AqMG1g9xGSrkRS HLNw== 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=2gpGrFtaHTWSxbLD/nIwbDHRys15sHCP7t9Q0Pg9Z4E=; b=qUk1KdWqMVawYIAyombmRMXd4rjYKnhPP/ixDQqZOgej6ZLM5AbcmOpUeav7h3GSnG CBqBIPujfVDqIiCrOqGg7JOEQwmTQG7kUfeX8dZ5IZ6+wySNj9Dn5KIF98vBTqdaXNJ8 1WWeLfkdZKNl7tCY/4G2UQewxxXB5ZEy4QQw4zotF3wOtq7Y8x+d7Fmo9KvE8ws3XtqY BGwhKAuJlbDb8s53YU5EP+FQXCwhG4Lk3eSZn7oh6BmlbcdT6CG8Q+HK3Yro9lM5auLH Gb7CNFIsYAgTBezOgx9fHYAJ1zvKjUJkfPRTOT+tg6cLRd45/WvfZaTdePPo54QXlgsS JDTg== X-Gm-Message-State: ANoB5pnhVT+Dq+GbqsDQuNaTpTjgIE0QWAuwJDGkbKiNS6SAauAPVXIn s/Vw9aXeRO2ntvcmqCNnpys4j7UTaIuhE4CElrLbZg== X-Google-Smtp-Source: AA0mqf4NtFttvsFKFF9lgqmlK8A4+P2JpPJOU7ZFUZWNMm09sQpHw5dFhqB4mM3CQc8w7wUD6SP2wQTDAFSmIrRq0+g= X-Received: by 2002:ac2:58f6:0:b0:4a2:7692:3a0a with SMTP id v22-20020ac258f6000000b004a276923a0amr3022104lfo.71.1668801384280; Fri, 18 Nov 2022 11:56:24 -0800 (PST) MIME-Version: 1.0 References: <20221108195617.2701379-1-philipp.tomsich@vrull.eu> In-Reply-To: From: Philipp Tomsich Date: Fri, 18 Nov 2022 20:56:13 +0100 Message-ID: Subject: Re: [PATCH] RISC-V: split to allow formation of sh[123]add before divw To: Jeff Law Cc: gcc-patches@gcc.gnu.org, Kito Cheng , Vineet Gupta , Palmer Dabbelt , Christoph Muellner , Jeff Law Content-Type: multipart/alternative; boundary="000000000000b60fd205edc4197f" X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,HTML_MESSAGE,JMQ_SPF_NEUTRAL,KAM_SHORT,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: --000000000000b60fd205edc4197f Content-Type: text/plain; charset="UTF-8" Applied to master. Thanks! --Philipp. On Fri, 18 Nov 2022 at 20:37, Jeff Law wrote: > > On 11/8/22 12:56, Philipp Tomsich wrote: > > When using strength-reduction, we will reduce a multiplication to a > > sequence of shifts and adds. If this is performed with 32-bit types > > and followed by a division, the lack of w-form sh[123]add will make > > combination impossible and lead to a slli + addw being generated. > > > > Split the sequence with the knowledge that a w-form div will perform > > implicit sign-extensions. > > > > gcc/ChangeLog: > > > > * config/riscv/bitmanip.md: Add a define_split to optimize > > slliw + addiw + divw into sh[123]add + divw. > > > > gcc/testsuite/ChangeLog: > > > > * gcc.target/riscv/zba-shNadd-05.c: New test. > > OK. I won't complain about the subregs on this one :-) > > > jeff > > > --000000000000b60fd205edc4197f--