From owner-freebsd-arm@FreeBSD.ORG Thu Dec 18 14:51:52 2014 Return-Path: Delivered-To: freebsd-arm@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 8A230488 for ; Thu, 18 Dec 2014 14:51:52 +0000 (UTC) Received: from mail-pd0-f169.google.com (mail-pd0-f169.google.com [209.85.192.169]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4EFCC25E0 for ; Thu, 18 Dec 2014 14:51:52 +0000 (UTC) Received: by mail-pd0-f169.google.com with SMTP id z10so1578194pdj.0 for ; Thu, 18 Dec 2014 06:51:51 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:sender:subject:mime-version:content-type:from :in-reply-to:date:cc:message-id:references:to; bh=rD/Pm0XEpaCcg14dHYfT3WCE7Bzxzr7rqJbuRe5FETE=; b=jvH+k1DcI4YImFSQl9w9heO0MEMwNZ7sXXsm39NJzp3ipwE3QVe56ezAkGwHiClmkI hdXAgqzjMftglqpdBfqDIHkPhmvPFlHjiBNURkMls4dKqUogB91IgrV0N3SypP/CAfu1 wQLTSFA6QhuiPbqicorB1dH9ws5nyMi7tg4q4PtB7eS3K+l60spvTFJDuaIRz8OOF6LN naJqJ3o3idDZKYk2ipytZY8ABF3gEe4rVZ4R+LTh+K8YLaAr03g/dQAAkqRClFESszwR xgo+FaV6CSrJT9zg7iddMp8d49xkJWb8eq/gSrszx5OuTEioWSyOBCd3bdZN4WjQ61gE mGwA== X-Gm-Message-State: ALoCoQm8W9OvEEk1MlsAsMbU7LePO/8Be98Qdi2UzPz5qT9LHneDjFQ3+AuvlaRor79U9lCwJewt X-Received: by 10.68.68.130 with SMTP id w2mr3928581pbt.167.1418914311460; Thu, 18 Dec 2014 06:51:51 -0800 (PST) Received: from [10.64.27.55] ([69.53.236.236]) by mx.google.com with ESMTPSA id kw10sm7082469pab.29.2014.12.18.06.51.49 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 18 Dec 2014 06:51:50 -0800 (PST) Sender: Warner Losh Subject: Re: RFT: Please help testing the llvm/clang 3.5.0 import Mime-Version: 1.0 (Mac OS X Mail 8.1 \(1993\)) Content-Type: multipart/signed; boundary="Apple-Mail=_8585A9CA-84EF-42F8-B871-2B3E958B1A69"; protocol="application/pgp-signature"; micalg=pgp-sha512 X-Pgp-Agent: GPGMail 2.5b3 From: Warner Losh In-Reply-To: Date: Thu, 18 Dec 2014 07:51:47 -0700 Message-Id: <9D9850F8-62D6-4A85-BED3-1B4AB4DE5C14@bsdimp.com> References: <8598B1D4-5485-426F-B6D6-22BF26AC5FE1@FreeBSD.org> <21650.55288.425711.209975@jerusalem.litteratus.org> To: Dimitry Andric X-Mailer: Apple Mail (2.1993) Cc: FreeBSD ARM , Robert Huff , NGie Cooper , FreeBSD ports , FreeBSD-Current X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 18 Dec 2014 14:51:52 -0000 --Apple-Mail=_8585A9CA-84EF-42F8-B871-2B3E958B1A69 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii > On Dec 18, 2014, at 7:44 AM, Dimitry Andric wrote: > > On 18 Dec 2014, at 14:34, Robert Huff wrote: >> Dimitry Andric writes: >> >>>> - Could a "MK_CLANG_ALL_TARGETS" or something similar option be >>>> added to src.opts.mk to fine tune this process for those of us who >>>> don't want to build a cross-compile toolchain every iteration for our >>>> target MACHINE/MACHINE_ARCH? >>> >>> I would be fine with something like this, as long as it is turned off by >>> default, or if it is only used for the bootstrap stages. It is actually >>> an extremely useful feature of clang that you can target multiple >>> architectures with one compiler binary. >> >> Point of information: this seems useful for developers, and >> (almost entirely) useless for everyone else. Are there other >> cohorts that want this badly? >> If that's correct, and there's a simple switch for >> configuration ... why should this default to what's useful for the >> (much?) smaller number of people? About what am I ignorant? > > It's not a simple switch, at least not now. If you use the upstream > build system for llvm, e.g. autoconf or CMake, it has an option to > select all the architectures that are supported. Several config files > are then generated differently, and parts of the target support > subdirectories are selectively enabled or disabled. > > In fact, we already build just a subset of the available architectures, > since FreeBSD only supports about 5 of them. We can probably arrange > for a more minimal configuration in our build system, but since the > build time saved is quite small, I don't think it makes much sense in > complicating our build system even further. > > If people are really so interested in shaving off a little, for more > complication, that is fine with me. But unfortunately, I have too many > tasks on my plate right now, and I cannot work on it. Besides, doing > such a new feature now would interfere with the current branch work. With the recent parallelism work, the is true. It might save a couple percent off the build time. Before those changes, though, disabling all non target arches saved about 10% of the buildworld time. Creating a hack to do this is easy (which is how I measured it). But Dimitry is right that creating a robust solution is hard. Even harder if you want it to be completely clean. > Also, after the 3.5.0 import, there are much more interesting fish to > fry, in my opinion. For example, importing newer versions of libc++ and > compiler-rt, which can bring address sanitizer support, etc. I tend to agree. IMHO, supporting the work going on to bring the meta-mode stuff will pay far higher dividends than optimizing this corner of the build. Warner --Apple-Mail=_8585A9CA-84EF-42F8-B871-2B3E958B1A69 Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP using GPGMail -----BEGIN PGP SIGNATURE----- Comment: GPGTools - https://gpgtools.org iQIcBAEBCgAGBQJUkuoDAAoJEGwc0Sh9sBEAC2cP/RZEnJNk6MLxkknDLYxAZNsm pu69tosuAMV1rbYPjRjRwJxAhASrEsAq7vSGGMRjKIxtmXh5FILqm6EMPIPpnGdw zWGD6ILWp1OWCp9niZY3C6Ps4dyOERhGZwW+S5yDCRFARGBvU7G4fQ7hp9QzztPf ZJOLWeVcIYIKq0wQdeFxb5EzYRTWzg40LBBh3ko8b7ZTK4xTzuEqynGp78nrkDe3 vxeKNGZtcQCIOCHMSvZECwG8q/ZG6aim9QE9OaB8rrbMl1rdQS3Yjb4zaLNRJhaT q2YWrVo32Po7QVAlan0SymZe+wdu9pVfeqmyjvOEB2s/esjacOgAZxDc7gV2hKfE ZVE8DIyaaDItRrqTsaCPCW37/VVXrkDMTvj+5finiKf+/0BqKazLaBmLKUDRahZf ylIH+YtQB2K/wVc2POuJyfcLzyF4yCQHZdnBSaan2aonb9ob1Rovdz3FP96M+gJ5 8g3CKF87ZtnwUSAGZOZJ8mvaQvl6l8w50s8eE12KOuHJTXSJIrJZCOb9A0DBSTMS vD4VOnX0mTcXGa+4yME5j1cXHgjzqr7xxT//ofdkpbw1FXz4v/wzuVNNeKwHOdWV RJthyZVWplsoFkqetPwXUwJgWsCqkupx/1bUiYd7YWEu0BJpY9oBX44z2yc8hvm5 n1ug/eyRZtpdJOP4bqXp =k1B6 -----END PGP SIGNATURE----- --Apple-Mail=_8585A9CA-84EF-42F8-B871-2B3E958B1A69--