From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [RFC][PATCH 0/3] gcc work-around and math128 Date: Tue, 24 Apr 2012 10:27:22 -0700 Message-ID: <4F96E27A.1010503@zytor.com> References: <20120424161039.293018424@chello.nl> <4F96E154.2060100@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from terminus.zytor.com ([198.137.202.10]:35982 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755725Ab2DXR1e (ORCPT ); Tue, 24 Apr 2012 13:27:34 -0400 In-Reply-To: <4F96E154.2060100@zytor.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Linus Torvalds , Andrew Morton , Juri Lelli On 04/24/2012 10:22 AM, H. Peter Anvin wrote: > On 04/24/2012 09:10 AM, Peter Zijlstra wrote: >> >> So far its just mult, add and cmp for u128, no divisions quite yet. I realize >> that on 32bit archs mult_u128 will result in like 8 multiplication >> instructions that's still nowhere near the most expensive thing ever. >> > > Please add shifts, at the very least. > Oh, and a constant constructor. -hpa