From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40282) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f3x6P-0002mB-U1 for qemu-devel@nongnu.org; Thu, 05 Apr 2018 01:06:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f3x6L-000830-6j for qemu-devel@nongnu.org; Thu, 05 Apr 2018 01:06:25 -0400 References: <20180207225540.31698-1-richard.henderson@linaro.org> <20180207225540.31698-17-richard.henderson@linaro.org> <20180404164908.GA7582@flamenco> <330b4559-52a5-50d6-3a85-da7bb0850107@linaro.org> <0f10b5a5-2be0-4b6b-3c58-e718a062f07d@linaro.org> From: Thomas Huth Message-ID: <84a25fa4-d1a6-0e9c-a28f-770baeff0ce4@redhat.com> Date: Thu, 5 Apr 2018 07:06:08 +0200 MIME-Version: 1.0 In-Reply-To: <0f10b5a5-2be0-4b6b-3c58-e718a062f07d@linaro.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PULL 16/20] target/arm: Use vector infrastructure for aa64 compares List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Richard Henderson , "Emilio G. Cota" Cc: peter.maydell@linaro.org, =?UTF-8?Q?Alex_Benn=c3=a9e?= , qemu-devel@nongnu.org, David Gibson , Laurent Vivier , "qemu-ppc@nongnu.org" On 05.04.2018 02:54, Richard Henderson wrote: > On 04/05/2018 10:07 AM, Richard Henderson wrote: >> On 04/05/2018 02:49 AM, Emilio G. Cota wrote: >>> 1. grab this binary: >>> http://cs.columbia.edu/~cota/qemu/nbench-aarch64 >>> 2. run it on a PowerPC host with: >>> $ aarch64-linux-user/qemu-aarch64 nbench-aarch64 -V >>> >>> Note: the "-V" (or "-v") flag is important! Without it, there's no se= gfault. >> >> How quickly? I did not see one up until it exited for lack of NNET.DA= T. >> >> I will note that I am using gcc 7.2 on gcc112 (/opt/cfarm/gcc-latest/b= in/gcc). >> >> Are you using gcc 4.8.5, and is commit 74912f6dad in your tree? >> That commit might have made a difference... >=20 > Bah. I confirm that it doesn't, and that the test still fails. >=20 > Since qemu does work on the same host when built with gcc 7.2, I can on= ly blame > this failure on a compiler bug wrt gcc 4.8 on ppc64. >=20 > I have not tracked down exactly what's going wrong, and probably won't = unless > someone feels that it's worthwhile. This only begs the question of whe= ther we > should blacklist this compiler entirely. Certainly it's old enough tha= t it's > probably not worth fixing. GCC 4.8 is still used in enterprise distros like RHEL7 and AFAIK also in SLES 12 ... so blacklisting this compiler does not sound like a good idea to me. Thomas