From: Jeff King <peff@peff.net>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Cc: git@vger.kernel.org, Junio C Hamano <gitster@pobox.com>,
Johannes Schindelin <Johannes.Schindelin@gmx.de>,
Andrei Rybak <rybak.a.v@gmail.com>
Subject: Re: [PATCH v3 0/3]
Date: Wed, 30 Jun 2021 13:45:11 -0400 [thread overview]
Message-ID: <YNytp0JAIaQih0Y4@coredump.intra.peff.net> (raw)
In-Reply-To: <YNyrDxUO1PlGJvCn@coredump.intra.peff.net>
On Wed, Jun 30, 2021 at 01:34:07PM -0400, Jeff King wrote:
> As an aside, having to have a separate bundle_header_init() and
> BUNDLE_HEADER_INIT is annoying (because they both must be kept up to
> date with each other), but quite common in our code base. I wonder if
> writing:
>
> void bundle_header_init(struct bundle_header *header)
> {
> struct bundle_header blank = BUNDLE_HEADER_INIT;
> memcpy(header, &blank, sizeof(*header));
> }
>
> would let a smart enough compiler just init "header" in place without
> the extra copy (the performance of a single bundle_header almost
> certainly doesn't matter, but it might for other types).
>
> Just musing. ;)
For my own curiosity, the answer is yes: https://godbolt.org/z/s54dc6ss9
With "gcc -O2" the memcpy goes away and we init "header" directly.
If we want to start using this technique widely, I don't think it should
be part of your series, though. This probably applies to quite a few
data structures, so it would make more sense to have a series which
converts several.
-Peff
next prev parent reply other threads:[~2021-06-30 17:45 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-17 11:21 [PATCH 0/3] bundle.c: remove "ref_list" in favor of string-list.c API Ævar Arnfjörð Bjarmason
2021-06-17 11:21 ` [PATCH 1/3] bundle cmd: stop leaking memory from parse_options_cmd_bundle() Ævar Arnfjörð Bjarmason
2021-06-17 11:21 ` [PATCH 2/3] bundle.c: use a temporary variable for OIDs and names Ævar Arnfjörð Bjarmason
2021-06-17 11:21 ` [PATCH 3/3] bundle: remove "ref_list" in favor of string-list.c API Ævar Arnfjörð Bjarmason
2021-06-19 2:12 ` Andrei Rybak
2021-06-21 15:16 ` [PATCH v2 0/3] bundle.c: " Ævar Arnfjörð Bjarmason
2021-06-21 15:16 ` [PATCH v2 1/3] bundle cmd: stop leaking memory from parse_options_cmd_bundle() Ævar Arnfjörð Bjarmason
2021-06-24 16:54 ` Jeff King
2021-06-24 19:28 ` Ævar Arnfjörð Bjarmason
2021-06-21 15:16 ` [PATCH v2 2/3] bundle.c: use a temporary variable for OIDs and names Ævar Arnfjörð Bjarmason
2021-06-21 15:16 ` [PATCH v2 3/3] bundle: remove "ref_list" in favor of string-list.c API Ævar Arnfjörð Bjarmason
2021-06-24 17:11 ` Jeff King
2021-06-24 19:31 ` Ævar Arnfjörð Bjarmason
2021-06-29 1:02 ` Junio C Hamano
2021-06-24 17:14 ` [PATCH v2 0/3] bundle.c: " Jeff King
2021-06-30 14:06 ` [PATCH v3 0/3] Ævar Arnfjörð Bjarmason
2021-06-30 14:06 ` [PATCH v3 1/3] bundle cmd: stop leaking memory from parse_options_cmd_bundle() Ævar Arnfjörð Bjarmason
2021-06-30 17:26 ` Jeff King
2021-06-30 18:00 ` Ævar Arnfjörð Bjarmason
2021-07-01 15:41 ` Jeff King
2021-06-30 14:06 ` [PATCH v3 2/3] bundle.c: use a temporary variable for OIDs and names Ævar Arnfjörð Bjarmason
2021-06-30 14:06 ` [PATCH v3 3/3] bundle: remove "ref_list" in favor of string-list.c API Ævar Arnfjörð Bjarmason
2021-06-30 21:18 ` Junio C Hamano
2021-06-30 17:34 ` [PATCH v3 0/3] Jeff King
2021-06-30 17:45 ` Jeff King [this message]
2021-06-30 18:00 ` Ævar Arnfjörð Bjarmason
2021-07-01 10:53 ` Ævar Arnfjörð Bjarmason
2021-07-02 9:57 ` [PATCH v4 0/3] bundle.c: remove "ref_list" in favor of string-list.c API Ævar Arnfjörð Bjarmason
2021-07-02 9:57 ` [PATCH v4 1/3] bundle cmd: stop leaking memory from parse_options_cmd_bundle() Ævar Arnfjörð Bjarmason
2021-07-02 9:57 ` [PATCH v4 2/3] bundle.c: use a temporary variable for OIDs and names Ævar Arnfjörð Bjarmason
2021-07-02 9:57 ` [PATCH v4 3/3] bundle: remove "ref_list" in favor of string-list.c API Ævar Arnfjörð Bjarmason
2021-07-03 10:52 ` [PATCH v4 0/3] bundle.c: " Jeff King
2021-07-03 11:28 ` Ævar Arnfjörð Bjarmason
-- strict thread matches above, loose matches on Subject: below --
2018-11-11 23:58 [PATCH v2 0/2] refactoring branch colorization to ref-filter nbelakovski
2018-12-16 21:57 ` [PATCH v3 0/3] nbelakovski
2018-12-18 17:25 ` Jeff King
2012-02-16 22:14 [PATCH v2 1/3] Move the user-facing test library to test-lib-functions.sh Junio C Hamano
2012-02-17 10:25 ` [PATCH v3 0/3] Thomas Rast
2012-02-17 17:03 ` Junio C Hamano
2012-02-17 23:28 ` Junio C Hamano
2012-02-18 0:51 ` Jeff King
2012-02-18 7:27 ` Junio C Hamano
2012-02-18 8:52 ` Jeff King
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