From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751084AbWIMSfk (ORCPT ); Wed, 13 Sep 2006 14:35:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751077AbWIMSfi (ORCPT ); Wed, 13 Sep 2006 14:35:38 -0400 Received: from mx1.redhat.com ([66.187.233.31]:63374 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S1751076AbWIMSff (ORCPT ); Wed, 13 Sep 2006 14:35:35 -0400 From: David Howells Subject: [PATCH 1/7] FRV: Fix fls() to handle bit 31 being set correctly [try #3] Date: Wed, 13 Sep 2006 19:35:22 +0100 To: torvalds@osdl.org, akpm@osdl.org Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, dhowells@redhat.com Message-Id: <20060913183522.22109.10565.stgit@warthog.cambridge.redhat.com> Content-Type: text/plain; charset=utf-8; format=fixed Content-Transfer-Encoding: 8bit User-Agent: StGIT/0.10 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: David Howells Fix FRV fls() to handle bit 31 being set correctly (it should return 32 not 0). Signed-Off-By: David Howells --- include/asm-frv/bitops.h | 21 +++++++++++++++++---- 1 files changed, 17 insertions(+), 4 deletions(-) diff --git a/include/asm-frv/bitops.h b/include/asm-frv/bitops.h index 980ae1b..97fb746 100644 --- a/include/asm-frv/bitops.h +++ b/include/asm-frv/bitops.h @@ -161,16 +161,29 @@ #include #include #include -/* - * fls: find last bit set. +/** + * fls - find last bit set + * @x: the word to search + * + * This is defined the same way as ffs: + * - return 32..1 to indicate bit 31..0 most significant bit set + * - return 0 to indicate no bits set */ #define fls(x) \ ({ \ int bit; \ \ - asm("scan %1,gr0,%0" : "=r"(bit) : "r"(x)); \ + asm(" subcc %1,gr0,gr0,icc0 \n" \ + " ckne icc0,cc4 \n" \ + " cscan.p %1,gr0,%0 ,cc4,#1 \n" \ + " csub %0,%0,%0 ,cc4,#0 \n" \ + " csub %2,%0,%0 ,cc4,#1 \n" \ + : "=&r"(bit) \ + : "r"(x), "r"(32) \ + : "icc0", "cc4" \ + ); \ \ - bit ? 33 - bit : bit; \ + bit; \ }) #include