From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 25 Feb 2013 13:21:46 +1100 From: Paul Mackerras To: Alex Williamson Subject: Re: [PATCH 1/2] vfio powerpc: enabled on powernv platform Message-ID: <20130225022146.GC12404@drongo> References: <1360583672-21924-1-git-send-email-aik@ozlabs.ru> <1360583672-21924-2-git-send-email-aik@ozlabs.ru> <1360621003.12392.117.camel@bling.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1360621003.12392.117.camel@bling.home> Cc: kvm@vger.kernel.org, Alexey Kardashevskiy , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, David Gibson List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Feb 11, 2013 at 03:16:43PM -0700, Alex Williamson wrote: > > Why do these all return long (vs int)? Is this a POWER-ism? On ppc64 the compiler tends to generate slightly shorter code with longs than with ints. The reason is that with ints the compiler has to put in "extend sign word" instructions to convert 64-bit values from arithmetic instructions to values in the 32-bit range. Paul.