From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga18.intel.com ([134.134.136.126]:31222 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728541AbeIJTly (ORCPT ); Mon, 10 Sep 2018 15:41:54 -0400 Date: Mon, 10 Sep 2018 17:47:24 +0300 From: Andy Shevchenko Subject: Re: [PATCH v4 0/8] Introduce the for_each_set_clump macro Message-ID: <20180910144724.GY11447@smile.fi.intel.com> References: <20180905150348.GA27089@sophia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-arch-owner@vger.kernel.org List-ID: To: Linus Walleij Cc: William Breathitt Gray , "open list:GPIO SUBSYSTEM" , linux-arch@vger.kernel.org, "linux-kernel@vger.kernel.org" , Andrew Morton Message-ID: <20180910144724.kG85wVF3pWDppNMto_ihblXY_zslbu_y-3lafq0Mt7Y@z> On Mon, Sep 10, 2018 at 09:54:47AM +0200, Linus Walleij wrote: > On Wed, Sep 5, 2018 at 5:04 PM William Breathitt Gray > wrote: > > On Wed, May 16, 2018 at 04:03:51PM +0200, Linus Walleij wrote: > > >On Tue, May 15, 2018 at 6:22 PM, William Breathitt Gray > > > wrote: > > > > > >> For example, suppose you would like to iterate over a 16-bit integer 4 > > >> bits at a time, skipping over 4-bit groups with no set bit, where XXXX > > >> represents the current 4-bit group: > > >> > > >> Example: 1011 1110 0000 1111 > > >> First loop: 1011 1110 0000 XXXX > > >> Second loop: 1011 XXXX 0000 1111 > > >> Third loop: XXXX 1110 0000 1111 > > >> > > >> Each iteration of the loop returns the next 4-bit group that has at > > >> least one set bit. > > >> > > >> The for_each_set_clump macro has six parameters: > > >> > > >> * clump: set to current clump index for the iteration > > >> * index: set to current bitmap word index for the iteration > > >> * offset: bits offset of the found clump in the bitmap word > > >> * bits: bitmap to search within > > >> * size: bitmap size in number of clumps > > >> * clump_size: clump size in number of bits > > >> > > >> The clump_size argument can be an arbitrary number of bits and is not > > >> required to be a multiple of 2. > > > > > >I must say I'm impressed. Very nice arithmetics going on there. > > > > > >If I can get some ACK for the bitops patch I'd be happy to merge > > >it all through the GPIO tree. The users are pretty clear cut. > > > > > >BTW: if I could, I would pull out Donald Knuth's "The Art of Computer > > >Programming vol 4A" chapter 7.1.3 "Bitwise Tricks and Techniques" > > >to see what he has to say about the subject, but I don't have > > >that book as it turns out. > > > > > >Yours, > > >Linus Walleij > > > > Hi Linus, > > > > I'd like to get this patchset merged, but I'm aware that we haven't yet > > received additional ACKs in the past couple months. Are there any > > changes you would like made, or should I resubmit this patchset with > > additional CCs in the hopes of some ACKs for the bitops patch? > > It seems Andy wanted some time and he had ~4 months now > so either he forgot it or has way too much to do. Sorry, indeed, it got piled under huge backlog I have. > > I would say send this patch to Andrew Morton (the bitops patches) > so he can decide on it. He has the right bird's eye view on this > kind of things. Agreed, and please add Rasmus as well. -- With Best Regards, Andy Shevchenko