From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 609 invoked by alias); 25 Dec 2013 17:59:07 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 573 invoked by uid 48); 25 Dec 2013 17:59:04 -0000 From: "nheghathivhistha at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug libitm/53113] Build fails in x86_avx.cc if AVX disabled but supported by as (Solaris & Linux) Date: Wed, 25 Dec 2013 17:59:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: libitm X-Bugzilla-Version: 4.7.2 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: nheghathivhistha at gmail dot com X-Bugzilla-Status: WAITING X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2013-12/txt/msg02162.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53113 --- Comment #17 from David Kredba --- I can't bootstrap 4.9.0 snapshots without patch attached. My machine is Core2 Quad where are not any avx instructions available. All is compiled from sources (Gentoo) but libitm x86_avx.lo crashes bootstrap. -march=native is by gcc translated to core2 what is correct. I saw qt 4.8.5 qmake reporting AVX available too, which is wrong. After I used -mno-avx it stopped doing it. Gcc knows there is no avx. Binutils reports AVX instruction set support anyway as supported - it can work with it in code. The fact that code produced will not run on host system is not burning them looks like. I recompiled them with -mno-avx to be sure that tests for AVX will fail but GNU as reports them an thus libitm still crashes bootstrap. In my opinion if gcc cannot trust GNU AS it should tell itsef to libitm configure what instructions sets are really available. I think that reproducing needs machine where CPU does not know what AVX is. Thank you.