From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759368Ab2CSTly (ORCPT ); Mon, 19 Mar 2012 15:41:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:64630 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759297Ab2CSTlw (ORCPT ); Mon, 19 Mar 2012 15:41:52 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <161084.1332177826@turing-police.cc.vt.edu> References: <161084.1332177826@turing-police.cc.vt.edu> <1121.1332169437@redhat.com> <20120318235114.GA30497@thor.bakeyournoodle.com> <20120318184105.GC2095@windriver.com> <9942.1332170491@redhat.com> To: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com, Tony Breeds , Paul Gortmaker , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: linux-next: triage for March 18, 2012 Date: Mon, 19 Mar 2012 19:41:44 +0000 Message-ID: <8010.1332186104@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Valdis.Kletnieks@vt.edu wrote: > Umm.. it's not clear to *me* that it's intended to be a negative 16 bit? Or > am I just missing context not present in the patch? > > (I have no idea if the rest of the patch is OK or not, but that comment > didn't give me warm fuzzies....) Sorry, I haven't explained it well. The patch permits a 64-bit hosted assembler to represent a large 32-bit unsigned integer (such as 0xfffffff1) as a negative integer where the instruction being assembled has a signed immediate operand. For instance, the ANDI instruction on FRV takes a small signed integer (10 bits IIRC) that it sign-extends to 32-bits before using - so to clear a single low-order bit, I pass in, say, ~0x2 and the assembler represents this as a negative value. The problem was that in a 64-bit hosted assembler, the unsigned 32-bit integer gets converted to an unsigned 64-bit integer - which doesn't then appear negative (whereas in a 32-bit hosted assembler it does). David