Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753598Ab2EPOqM (ORCPT ); Wed, 16 May 2012 10:46:12 -0400 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:57705 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752567Ab2EPOqH (ORCPT ); Wed, 16 May 2012 10:46:07 -0400 Message-ID: <1337179563.2985.80.camel@dabdike.int.hansenpartnership.com> Subject: Re: Build regressions/improvements in v3.4-rc7 From: James Bottomley To: Geert Uytterhoeven Cc: linux-kernel@vger.kernel.org, Linuxppc-dev , Parisc List , the arch/x86 maintainers , Dmitry Kasatkin , James Morris Date: Wed, 16 May 2012 15:46:03 +0100 In-Reply-To: References: <1337157034-22773-1-git-send-email-geert@linux-m68k.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1529 Lines: 34 On Wed, 2012-05-16 at 10:47 +0200, Geert Uytterhoeven wrote: > On Wed, May 16, 2012 at 10:30 AM, Geert Uytterhoeven > wrote: > + lib/mpi/generic_mpih-mul1.c: error: inconsistent operand > constraints in an 'asm': => 50:70 > + lib/mpi/generic_mpih-mul2.c: error: inconsistent operand > constraints in an 'asm': => 49:70 > + lib/mpi/generic_mpih-mul3.c: error: inconsistent operand > constraints in an 'asm': => 49:70 > + lib/mpi/mpih-div.c: error: inconsistent operand constraints in an > 'asm': => 135:122, 135:371, 97:122, 106:121, 106:370, 97:371 > > parisc-allmodconfig Wow, lib/mpi/ is a complete horror: it's full of hand crafted asm code. The error in this case appears to be that umul_ppm() is implemented as an xmpyu instruction. That's a floating point instruction. We deliberately compile the kernel with floating point disabled because we don't want to save and restore the floating point register file on each context switch, hence the operand constraints are unsatisfiable. It appears to be completely untested on non-x86 and to have been imported via the security tree ... what are we supposed to do with this? I thought the general principle was that asm code was really supposed to be confined to the arch directories? James -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/