From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 42CEA42DE1; Thu, 6 Jul 2023 04:55:33 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id D917D40144; Thu, 6 Jul 2023 04:55:32 +0200 (CEST) Received: from mail-oo1-f50.google.com (mail-oo1-f50.google.com [209.85.161.50]) by mails.dpdk.org (Postfix) with ESMTP id 33983400D5 for ; Thu, 6 Jul 2023 04:55:31 +0200 (CEST) Received: by mail-oo1-f50.google.com with SMTP id 006d021491bc7-5661e8f4c45so122825eaf.1 for ; Wed, 05 Jul 2023 19:55:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20221208.gappssmtp.com; s=20221208; t=1688612130; x=1691204130; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=Aq4dxacjHfEv0EL/AfKYWcQ1FI/0+uM2fTx7CfGDQts=; b=WJbcukDwpNcq7VOePHIX5efKuiNIR5AZ7U9oyyNWFrLeGGQ5nB7hAxxWf3b5kuPNkA xNlI5JX8MUxQFZa52d7TNeZh5JiUCD+q1nAsUIj9vrhcp4N3LRD60zkCWMlInU/wxEOL Zmo3JweQz5QccCAgVSwAD1RZ8QiZLRUMz7A7sY0g2TQrw9pfOCRFYZPOfy2epLkXrm9i 52RyfjybN60NQ8lwD1AKYbEfk7NvpMYxkEzJmQ/Uo4itEICyBYBlQd6RrGzgpd3WaZoQ lqB13+pbKBs68J2cOb2hCcf6JMqk8y3UKl3DmODL/8++0GlR0+VocRIhs4uqu1BpQwUg 3/4g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688612130; x=1691204130; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Aq4dxacjHfEv0EL/AfKYWcQ1FI/0+uM2fTx7CfGDQts=; b=g+Tr9eDriAEztyBuZUTZKhirPBqHNpiz7T/flXW8trenA4c9b8wSUNrk2Awp2/3x3c wdRiBNqGllwPHX5Vx7Q4zxjJWgSyCiyw5MtoVxKI5Y6Xvd31+HE180tyr+gRR+wrWotH ztvijqR5CJpGa2l0LTqMzqcV+Or0GRuSSG9+21zg4N4BjgstSHMwtdTXdCXKUjIIUEF7 j+BCfpK+6M1uC143fppMlWUX4OqH990keoPoVFsdcOLk4h6sAa+ABNy5UjTouX9t5y+M y8sNTCVs32JWY5A3A4FpVNY2IfJdOWkjZlIfp4oiHt3PWvi3sn+Csw69QxXl+Ic8nBLY d4HQ== X-Gm-Message-State: ABy/qLbk0Bt+lLGcVBaxWgZLid/ma1JbyPV4GpNR/LCmAaX7IIpKbDNp iGhHrkkWEEwbUq4OMynYDo07Mw== X-Google-Smtp-Source: APBJJlHPFNxvIQtCJ0+aWXEbNmHJB6eT0Y/sf6kvme7TF5V+VRHdu468ISpmfg4J8/ymdtRfLs76/w== X-Received: by 2002:a05:6808:3084:b0:3a1:df81:a22d with SMTP id bl4-20020a056808308400b003a1df81a22dmr543935oib.37.1688612130433; Wed, 05 Jul 2023 19:55:30 -0700 (PDT) Received: from hermes.local (204-195-120-218.wavecable.com. [204.195.120.218]) by smtp.gmail.com with ESMTPSA id r8-20020a635d08000000b00553dcfc2179sm228862pgb.52.2023.07.05.19.55.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Jul 2023 19:55:30 -0700 (PDT) Date: Wed, 5 Jul 2023 19:55:28 -0700 From: Stephen Hemminger To: Mahdi Rakhshandehroo Cc: dev@dpdk.org Subject: Re: [PATCH v2] meson: add support for clang LTO Message-ID: <20230705195528.38e57918@hermes.local> In-Reply-To: <20220401045435.60172-1-mahdi.rakhshandehroo@gmail.com> References: <20220401045435.60172-1-mahdi.rakhshandehroo@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org On Thu, 31 Mar 2022 21:54:35 -0700 Mahdi Rakhshandehroo wrote: > Currently, building DPDK with clang + LTO is unsupported, which is a > showstopper for cross-language interprocedural optimizations. The root > cause is that pmdinfogen expects to scan through the section headers of > generated ELF object files, but clang's "-flto" flag generates LLVM > bitcode instead. This patch enables LTO builds with clang, provided that > the linker is set to lld. > > The mechanism of action is clang's "-fembed-bitcode" flag, which acts > similarly to gcc's "-ffat-lto-objects" - the compiler outputs a normal > ELF object file that keeps pmdinfogen happy, but also embeds IR bitcode > in a special section of the ELF that lld can then use to construct the > final binary. > > Signed-off-by: Mahdi Rakhshandehroo > --- This patch still has several build failures such as Intel compiler. Please resolve and resubmit