From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752743AbbA1Uwo (ORCPT ); Wed, 28 Jan 2015 15:52:44 -0500 Received: from mout.kundenserver.de ([212.227.126.187]:57456 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752439AbbA1Uwl (ORCPT ); Wed, 28 Jan 2015 15:52:41 -0500 From: Arnd Bergmann To: Dmitry Kasatkin , David Howells , Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-crypto@vger.kernel.org, Herbert Xu , "David S. Miller" Subject: [PATCH] MPILIB: avoid assembler warning Date: Wed, 28 Jan 2015 17:24:36 +0100 Message-ID: <16372019.BFlLRod3Eu@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:WhzkrIhzJFbWFYzNeGRe5c+XjIU3D2331xRk6aqNs2jxlmsr3dx B9iNra5nvVVVXr1bek2rKsbPPv0/ShLNShjlPSSnlSGyKtb5+0FUvw0W+oLrViLpdVJ7Ggv LZVwrg2YyqGCJB16RSjQ2QwQojEccrfr23tusqmbsV4qOaYJf4FXnX2lWahxs6+xe5Ftfik NSz+110Rior3PUxmzr3RQ== X-UI-Out-Filterresults: notjunk:1; Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A wrapper around the umull assembly instruction might reuse the input register as an output, which is undefined on some ARM machines, as pointed out by this assembler warning: CC lib/mpi/generic_mpih-mul1.o /tmp/ccxJuxIy.s: Assembler messages: /tmp/ccxJuxIy.s:53: rdhi, rdlo and rm must all be different CC lib/mpi/generic_mpih-mul2.o /tmp/ccI0scAD.s: Assembler messages: /tmp/ccI0scAD.s:53: rdhi, rdlo and rm must all be different CC lib/mpi/generic_mpih-mul3.o /tmp/ccMvVQcp.s: Assembler messages: /tmp/ccMvVQcp.s:53: rdhi, rdlo and rm must all be different This changes the constraints to force different registers to be used as output. Signed-off-by: Arnd Bergmann --- Not sure who would be the best person to pick this patch up. diff --git a/lib/mpi/longlong.h b/lib/mpi/longlong.h index aac511417ad1..c4dbdb506174 100644 --- a/lib/mpi/longlong.h +++ b/lib/mpi/longlong.h @@ -216,7 +216,7 @@ extern UDItype __udiv_qrnnd(UDItype *, UDItype, UDItype, UDItype); __asm__ ("%@ Inlined umul_ppmm\n" \ "umull %r1, %r0, %r2, %r3" \ : "=&r" ((USItype)(xh)), \ - "=r" ((USItype)(xl)) \ + "=&r" ((USItype)(xl)) \ : "r" ((USItype)(a)), \ "r" ((USItype)(b)) \ : "r0", "r1")