From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 117107 invoked by alias); 23 Jul 2019 13:15:38 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 114883 invoked by uid 89); 23 Jul 2019 13:15:30 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-2.2 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.1 spammy=HX-Gm-Message-State:APjAAAU, our X-HELO: mail-lf1-f65.google.com Received: from mail-lf1-f65.google.com (HELO mail-lf1-f65.google.com) (209.85.167.65) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 23 Jul 2019 13:15:27 +0000 Received: by mail-lf1-f65.google.com with SMTP id b29so22085213lfq.1 for ; Tue, 23 Jul 2019 06:15:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=l3U+T/+vQT4PDKCCaR9biq8JVpq4Fyxe4Qzs/tw0LIo=; b=uSD6nvxAXGUw5kXI1EVpBx1E28axGko8w+oIXqVZ/sEzU+5NncEoui/31Jh6PXIwRV G/A82DL+kY3qnLLg3bqPEQm3phfXK9LGZiBKVtVhNcb0rmQN71QW5WN/vrhQDYQB1Z36 QyECXLWLTADRrUlG+vT9A0Gnp9FO84AZMCB2jhr63XZ7sqG1iLHKc8si+ov/Vwi0l8j9 Hed9vOF27nJVHJhRnxt3P1jBpWsoUVsWNuloiTjqy9nBtsFJy9AX9vVFHRptNia5etU9 35niWgbXj6XtLKmXwnEXEIsWDN8GQXfWasUjqgX6qhmv6lBri3teKqNoVW1uc5OWnKd1 1edw== MIME-Version: 1.0 References: <95f20c0a-81a3-2319-326b-3c5baf71e2d1@suse.cz> <20190723092040.czs64os2qymax7sq@kam.mff.cuni.cz> <7b383b21-89ad-52ed-1fb1-e44723e8be86@redhat.com> In-Reply-To: <7b383b21-89ad-52ed-1fb1-e44723e8be86@redhat.com> From: Richard Biener Date: Tue, 23 Jul 2019 13:22:00 -0000 Message-ID: Subject: Re: [PATCH] Come up with -flto=auto option. To: Jeff Law Cc: Jan Hubicka , =?UTF-8?Q?Martin_Li=C5=A1ka?= , GCC Patches , Michael Matz Content-Type: text/plain; charset="UTF-8" X-IsSubscribed: yes X-SW-Source: 2019-07/txt/msg01514.txt.bz2 On Tue, Jul 23, 2019 at 3:09 PM Jeff Law wrote: > > On 7/23/19 3:20 AM, Jan Hubicka wrote: > >> Hi. > >> > >> As we as openSUSE started using -flto, I see it very handy to have > >> an option value that will automatically detect number of cores > >> that can be used for parallel LTRANS phase. > >> > >> Thoughts? > > Hi, > > great you found time to make this. It should become the default for > > -flto IMO. > I was going to hack it into the rpm configury bits since we have access > to the # cores there. But an auto-selector within GCC is even better. > > BTW, isn't this all going to wreck havoc with reproducible builds since > partitioning can affect code generation? That's one of our open > questions... Partitioning is independent on N in -flto=N it's just dependent on the LTO partitioning --params. Richard. > Jeff