From owner-freebsd-toolchain@FreeBSD.ORG  Fri Apr 15 16:39:59 2011
Return-Path: <owner-freebsd-toolchain@FreeBSD.ORG>
Delivered-To: freebsd-toolchain@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 771E7106566C;
	Fri, 15 Apr 2011 16:39:59 +0000 (UTC) (envelope-from dim@FreeBSD.org)
Received: from tensor.andric.com (cl-327.ede-01.nl.sixxs.net
	[IPv6:2001:7b8:2ff:146::2])
	by mx1.freebsd.org (Postfix) with ESMTP id 3A6718FC0A;
	Fri, 15 Apr 2011 16:39:59 +0000 (UTC)
Received: from [IPv6:2001:7b8:3a7:0:e08b:5a2b:d410:1403] (unknown
	[IPv6:2001:7b8:3a7:0:e08b:5a2b:d410:1403])
	(using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits))
	(No client certificate requested)
	by tensor.andric.com (Postfix) with ESMTPSA id 229525C59;
	Fri, 15 Apr 2011 18:39:58 +0200 (CEST)
Message-ID: <4DA874F3.9050101@FreeBSD.org>
Date: Fri, 15 Apr 2011 18:40:19 +0200
From: Dimitry Andric <dim@FreeBSD.org>
Organization: The FreeBSD Project
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US;
	rv:1.9.2.17) Gecko/20110415 Lanikai/3.1.11pre
MIME-Version: 1.0
To: Alexander Best <arundel@freebsd.org>
References: <20110414234106.GA22718@freebsd.org>
In-Reply-To: <20110414234106.GA22718@freebsd.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: freebsd-toolchain@freebsd.org, cfe-commits@cs.uiuc.edu
Subject: Re: clang and 3dnow(a)
X-BeenThere: freebsd-toolchain@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Maintenance of FreeBSD's integrated toolchain
	<freebsd-toolchain.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-toolchain>, 
	<mailto:freebsd-toolchain-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-toolchain>
List-Post: <mailto:freebsd-toolchain@freebsd.org>
List-Help: <mailto:freebsd-toolchain-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-toolchain>, 
	<mailto:freebsd-toolchain-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 15 Apr 2011 16:39:59 -0000

On 2011-04-15 01:41, Alexander Best wrote:
> per coincidence i discovered the following contrary behavior between gcc and
> clang:
>
> -mno-mmx implies -mno-3dnow under gcc. under clang -mno-mmx will *not* imply
> -mno-3dnow!
>
> is this a clang design feature or a bug? fixing it would be trivial (see
> attached patch).

I don't think it was intentionally designed, nor that it is a bug.  It
it just arbitrary what you disable when you specify '-mno-mmx'.

However, it would probably be nice if clang emulated gcc's behaviour
here.

Adding cfe-commits@ in the loop, to see if the clang guys think this is
desirable.


diff --git a/contrib/llvm/tools/clang/lib/Basic/Targets.cpp b/contrib/llvm/tools/clang/lib/Basic/Targets.cpp
index 55321f2..1af7c52 100644
--- a/contrib/llvm/tools/clang/lib/Basic/Targets.cpp
+++ b/contrib/llvm/tools/clang/lib/Basic/Targets.cpp
@@ -1133,8 +1133,9 @@ bool X86TargetInfo::setFeatureEnabled(llvm::StringMap<bool> &Features,
        Features["avx"] = true;
    } else {
      if (Name == "mmx")
-      Features["mmx"] = Features["sse"] = Features["sse2"] = Features["sse3"] =
-        Features["ssse3"] = Features["sse41"] = Features["sse42"] = false;
+      Features["mmx"] = Features["3dnow"] = Features["3dnowa"] =
+       Features["sse"] = Features["sse2"] = Features["sse3"] =
+       Features["ssse3"] = Features["sse41"] = Features["sse42"] = false;
      else if (Name == "sse")
        Features["sse"] = Features["sse2"] = Features["sse3"] =
          Features["ssse3"] = Features["sse41"] = Features["sse42"] = false;