git@vger.kernel.org list mirror (unofficial, one of many)
 help / color / mirror / code / Atom feed
From: Elijah Newren <newren@gmail.com>
To: Derrick Stolee <stolee@gmail.com>
Cc: Git Mailing List <git@vger.kernel.org>
Subject: Re: [PATCH v2 07/20] merge-ort: avoid repeating fill_tree_descriptor() on the same tree
Date: Wed, 11 Nov 2020 09:13:02 -0800	[thread overview]
Message-ID: <CABPp-BGk8FBt8WWw_h8t2jiE4quBoMeaco19F-fJ6V_vOnsNww@mail.gmail.com> (raw)
In-Reply-To: <c4b9b64c-f0a0-5824-44b9-072370cfc465@gmail.com>

On Wed, Nov 11, 2020 at 6:51 AM Derrick Stolee <stolee@gmail.com> wrote:
>
> On 11/2/2020 3:43 PM, Elijah Newren wrote:
> > @@ -99,6 +99,15 @@ static int collect_merge_info_callback(int n,
> >       unsigned mbase_null = !(mask & 1);
> >       unsigned side1_null = !(mask & 2);
> >       unsigned side2_null = !(mask & 4);
> > +     unsigned side1_matches_mbase = (!side1_null && !mbase_null &&
> > +                                     names[0].mode == names[1].mode &&
> > +                                     oideq(&names[0].oid, &names[1].oid));
> > +     unsigned side2_matches_mbase = (!side2_null && !mbase_null &&
> > +                                     names[0].mode == names[2].mode &&
> > +                                     oideq(&names[0].oid, &names[2].oid));
> > +     unsigned sides_match = (!side1_null && !side2_null &&
> > +                             names[1].mode == names[2].mode &&
> > +                             oideq(&names[1].oid, &names[2].oid));
>
> If the *_null values were in an array, instead, then all of these
> lines could be grouped as a macro:
>
>         unsigned null_oid[3] = {
>                 !(mask & 1),
>                 !(mask & 2),
>                 !(mask & 4)
>         };
>
>         #define trivial_merge(i,j) (!null_oid[i] && !null_oid[j] && \
>                                     names[i].mode == names[j].mode && \
>                                     oideq(&names[i].oid, &names[j].oid))
>
>         unsigned side1_matches_mbase = trivial_merge(0, 1);
>         unsigned side2_matches_mbase = trivial_merge(0, 2);
>         unsigned sides_match = trivial_merge(1, 2);

Hmm, I like it.  I think I'll rename trivial_merge() to
non_null_match() (trivial merge suggests it can immediately be
resolved which is not necessarily true if rename detection is on), but
otherwise I'll use this.

> I briefly considered making these last three an array, as well,
> except the loop below doesn't use 'i' in a symmetrical way:
>
> > +                     if (i == 1 && side1_matches_mbase)
> > +                             t[1] = t[0];
> > +                     else if (i == 2 && side2_matches_mbase)
> > +                             t[2] = t[0];
> > +                     else if (i == 2 && sides_match)
> > +                             t[2] = t[1];
>
> Since the 'i == 2' case has two possible options, it wouldn't be
> possible to just have 'side_matches[i]' here.
>
> > +                     else {
> > +                             const struct object_id *oid = NULL;
> > +                             if (dirmask & 1)
> > +                                     oid = &names[i].oid;
> > +                             buf[i] = fill_tree_descriptor(opt->repo,
> > +                                                           t + i, oid);
> > +                     }
>
> I do appreciate the reduced recursion here!

Technically, not my own optimization; I just copied from
unpack-trees.c:traverse_trees_recursive() -- though the code looks
slightly different because I didn't want to compare oids multiple
times (I use the side match variables earlier in the function as
well).

  reply	other threads:[~2020-11-11 17:13 UTC|newest]

Thread overview: 84+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-02 20:43 [PATCH v2 00/20] fundamentals of merge-ort implementation Elijah Newren
2020-11-02 20:43 ` [PATCH v2 01/20] merge-ort: setup basic internal data structures Elijah Newren
2020-11-06 22:05   ` Jonathan Tan
2020-11-06 22:45     ` Elijah Newren
2020-11-09 20:55       ` Jonathan Tan
2020-11-02 20:43 ` [PATCH v2 02/20] merge-ort: add some high-level algorithm structure Elijah Newren
2020-11-02 20:43 ` [PATCH v2 03/20] merge-ort: port merge_start() from merge-recursive Elijah Newren
2020-11-11 13:52   ` Derrick Stolee
2020-11-11 16:22     ` Elijah Newren
2020-11-02 20:43 ` [PATCH v2 04/20] merge-ort: use histogram diff Elijah Newren
2020-11-11 13:54   ` Derrick Stolee
2020-11-11 16:47     ` Elijah Newren
2020-11-11 16:51       ` Derrick Stolee
2020-11-11 17:03         ` Elijah Newren
2020-11-02 20:43 ` [PATCH v2 05/20] merge-ort: add an err() function similar to one from merge-recursive Elijah Newren
2020-11-11 13:58   ` Derrick Stolee
2020-11-11 17:07     ` Elijah Newren
2020-11-11 17:10       ` Derrick Stolee
2020-11-02 20:43 ` [PATCH v2 06/20] merge-ort: implement a very basic collect_merge_info() Elijah Newren
2020-11-06 22:19   ` Jonathan Tan
2020-11-06 23:10     ` Elijah Newren
2020-11-09 20:59       ` Jonathan Tan
2020-11-11 14:38   ` Derrick Stolee
2020-11-11 17:02     ` Elijah Newren
2020-11-02 20:43 ` [PATCH v2 07/20] merge-ort: avoid repeating fill_tree_descriptor() on the same tree Elijah Newren
2020-11-11 14:51   ` Derrick Stolee
2020-11-11 17:13     ` Elijah Newren [this message]
2020-11-11 17:21       ` Eric Sunshine
2020-11-02 20:43 ` [PATCH v2 08/20] merge-ort: compute a few more useful fields for collect_merge_info Elijah Newren
2020-11-06 22:52   ` Jonathan Tan
2020-11-06 23:41     ` Elijah Newren
2020-11-09 22:04       ` Jonathan Tan
2020-11-09 23:05         ` Elijah Newren
2020-11-02 20:43 ` [PATCH v2 09/20] merge-ort: record stage and auxiliary info for every path Elijah Newren
2020-11-06 22:58   ` Jonathan Tan
2020-11-07  0:26     ` Elijah Newren
2020-11-09 22:09       ` Jonathan Tan
2020-11-09 23:08         ` Elijah Newren
2020-11-11 15:26   ` Derrick Stolee
2020-11-11 18:16     ` Elijah Newren
2020-11-11 22:06       ` Elijah Newren
2020-11-12 18:23         ` Derrick Stolee
2020-11-12 18:39       ` Derrick Stolee
2020-11-02 20:43 ` [PATCH v2 10/20] merge-ort: avoid recursing into identical trees Elijah Newren
2020-11-11 15:31   ` Derrick Stolee
2020-11-02 20:43 ` [PATCH v2 11/20] merge-ort: add a preliminary simple process_entries() implementation Elijah Newren
2020-11-11 19:51   ` Jonathan Tan
2020-11-12  1:48     ` Elijah Newren
2020-11-02 20:43 ` [PATCH v2 12/20] merge-ort: have process_entries operate in a defined order Elijah Newren
2020-11-11 16:09   ` Derrick Stolee
2020-11-11 18:58     ` Elijah Newren
2020-11-02 20:43 ` [PATCH v2 13/20] merge-ort: step 1 of tree writing -- record basenames, modes, and oids Elijah Newren
2020-11-11 20:01   ` Jonathan Tan
2020-11-11 20:24     ` Elijah Newren
2020-11-12 20:39       ` Jonathan Tan
2020-11-02 20:43 ` [PATCH v2 14/20] merge-ort: step 2 of tree writing -- function to create tree object Elijah Newren
2020-11-11 20:47   ` Jonathan Tan
2020-11-11 21:21     ` Elijah Newren
2020-11-02 20:43 ` [PATCH v2 15/20] merge-ort: step 3 of tree writing -- handling subdirectories as we go Elijah Newren
2020-11-12 20:15   ` Jonathan Tan
2020-11-12 22:30     ` Elijah Newren
2020-11-24 20:19       ` Elijah Newren
2020-11-25  2:07         ` Jonathan Tan
2020-11-26 18:13           ` Elijah Newren
2020-11-30 18:41             ` Jonathan Tan
2020-11-02 20:43 ` [PATCH v2 16/20] merge-ort: basic outline for merge_switch_to_result() Elijah Newren
2020-11-02 20:43 ` [PATCH v2 17/20] merge-ort: add implementation of checkout() Elijah Newren
2020-11-02 20:43 ` [PATCH v2 18/20] tree: enable cmp_cache_name_compare() to be used elsewhere Elijah Newren
2020-11-02 20:43 ` [PATCH v2 19/20] merge-ort: add implementation of record_unmerged_index_entries() Elijah Newren
2020-11-02 20:43 ` [PATCH v2 20/20] merge-ort: free data structures in merge_finalize() Elijah Newren
2020-11-03 14:49 ` [PATCH v2 00/20] fundamentals of merge-ort implementation Derrick Stolee
2020-11-03 16:36   ` Elijah Newren
2020-11-07  6:06     ` Elijah Newren
2020-11-07 15:02       ` Derrick Stolee
2020-11-07 19:39         ` Elijah Newren
2020-11-09 12:30           ` Derrick Stolee
2020-11-09 17:13             ` Elijah Newren
2020-11-09 19:51               ` Derrick Stolee
2020-11-09 22:44                 ` Elijah Newren
2020-11-11 17:08 ` Derrick Stolee
2020-11-11 18:35   ` Elijah Newren
2020-11-11 20:48     ` Derrick Stolee
2020-11-11 21:18       ` Elijah Newren
2020-11-29  7:43 [PATCH " Elijah Newren via GitGitGadget
2020-12-04 20:47 ` [PATCH v2 " Elijah Newren via GitGitGadget
2020-12-04 20:47   ` [PATCH v2 07/20] merge-ort: avoid repeating fill_tree_descriptor() on the same tree Elijah Newren via GitGitGadget

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: http://vger.kernel.org/majordomo-info.html

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CABPp-BGk8FBt8WWw_h8t2jiE4quBoMeaco19F-fJ6V_vOnsNww@mail.gmail.com \
    --to=newren@gmail.com \
    --cc=git@vger.kernel.org \
    --cc=stolee@gmail.com \
    --subject='Re: [PATCH v2 07/20] merge-ort: avoid repeating fill_tree_descriptor() on the same tree' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

git@vger.kernel.org list mirror (unofficial, one of many)

This inbox may be cloned and mirrored by anyone:

	git clone --mirror https://public-inbox.org/git
	git clone --mirror http://ou63pmih66umazou.onion/git
	git clone --mirror http://czquwvybam4bgbro.onion/git
	git clone --mirror http://hjrcffqmbrq6wope.onion/git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V1 git git/ https://public-inbox.org/git \
		git@vger.kernel.org
	public-inbox-index git

Example config snippet for mirrors.
Newsgroups are available over NNTP:
	nntp://news.public-inbox.org/inbox.comp.version-control.git
	nntp://7fh6tueqddpjyxjmgtdiueylzoqt6pt7hec3pukyptlmohoowvhde4yd.onion/inbox.comp.version-control.git
	nntp://ie5yzdi7fg72h7s4sdcztq5evakq23rdt33mfyfcddc5u3ndnw24ogqd.onion/inbox.comp.version-control.git
	nntp://4uok3hntl7oi7b4uf4rtfwefqeexfzil2w6kgk2jn5z2f764irre7byd.onion/inbox.comp.version-control.git
	nntp://news.gmane.io/gmane.comp.version-control.git
 note: .onion URLs require Tor: https://www.torproject.org/

code repositories for project(s) associated with this inbox:

	https://80x24.org/mirrors/git.git

AGPL code for this site: git clone https://public-inbox.org/public-inbox.git