From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id EF4A0385828E; Mon, 25 Sep 2023 17:01:26 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org EF4A0385828E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1695661286; bh=u2JqaNdqK6bCwYgYyTs3AIBPWHpXfMmJWIP5OHEFVE4=; h=From:To:Subject:Date:In-Reply-To:References:From; b=N7oiyv6xQzEcgTTy1nj6sTpF21z1doO4ASUCLAqvnLens4W4Mg+zcBGWKehE/x6zv 8NzHa4oeAF2OIZ0K+2ebvIE6Te40gnS9lcsNr7LyE2YvwKAOZ2iiy8P5XC2ggQVSjI UBTvqW+OoWcBZ+FYPfdx8zXaJHlnyEb4+3bB/9Q8= From: "brjd_epdjq36 at kygur dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/111570] -march=generic prints error Date: Mon, 25 Sep 2023 17:01:24 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Version: 13.2.0 X-Bugzilla-Keywords: diagnostic X-Bugzilla-Severity: normal X-Bugzilla-Who: brjd_epdjq36 at kygur dot com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: 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: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D111570 --- Comment #2 from Brjd --- Thank you and I also read this guide. My point is that the generic arch mig= ht be possible in theory. If the gcc builds for the oldest CPU with x86_64, i= s it possible that code will run on all modern CPU since their subset includes a= lso that of their predecessor.=20 How about making it default to that generic or baseline build for that limi= ted CPU? If I could ask you also more questions, let me ask you about this problem. = The guide doesn't mention anything about the specific arch. If -march=3Dcpu wha= t is better -mtune=3Dcpu where cpu is the same as in arch or -mtune=3Dgeneric so= that the code tunes to all CPU kinds of this family.If the tune is empty, is it default generic or native and the arch is not clear either. One question more, I am not able to find a guide about the gcc build and no information whether the gcc may be built in targets like LLVM and clang. For example, is it possible to build first only the LLVM, then stop and resume = with clang etc. or first, gcc's only c modiule and its submodules, then stop and resume with its g++ module and submodules, next with libgcc, libstdc++ etc= .?=20 It would be great, especially for long bootstraps and stage 2, but I find o= nly make all-gcc, target-libgcc which however build almost all of the compiler.=