From: Yury Norov <yury.norov@gmail.com>
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: linux-kernel@vger.kernel.org, linux-m68k@lists.linux-m68k.org,
linux-arch@vger.kernel.org, linux-sh@vger.kernel.org,
Alexey Klimov <aklimov@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Arnd Bergmann <arnd@arndb.de>, David Sterba <dsterba@suse.com>,
Dennis Zhou <dennis@kernel.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Jianpeng Ma <jianpeng.ma@intel.com>,
Joe Perches <joe@perches.com>,
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Rich Felker <dalias@libc.org>,
Stefano Brivio <sbrivio@redhat.com>,
Wei Yang <richard.weiyang@linux.alibaba.com>,
Wolfram Sang <wsa+renesas@sang-engineering.com>,
Yoshinori Sato <ysato@users.sourceforge.jp>
Subject: Re: [PATCH 04/14] lib: introduce BITS_{FIRST,LAST} macro
Date: Thu, 11 Mar 2021 20:30:57 -0800 [thread overview]
Message-ID: <20210312043057.GA137474@yury-ThinkPad> (raw)
In-Reply-To: <b371c94c-7480-5af4-d2bd-481436f535eb@rasmusvillemoes.dk>
On Thu, Feb 18, 2021 at 11:51:43PM +0100, Rasmus Villemoes wrote:
> On 18/02/2021 05.05, Yury Norov wrote:
> > BITMAP_{LAST,FIRST}_WORD_MASK() in linux/bitmap.h duplicates the
> > functionality of GENMASK(). The scope of there macros is wider
> > than just bitmap. This patch defines 4 new macros: BITS_FIRST(),
> > BITS_LAST(), BITS_FIRST_MASK() and BITS_LAST_MASK() in linux/bits.h
> > on top of GENMASK() and replaces BITMAP_{LAST,FIRST}_WORD_MASK()
> > to avoid duplication and increase the scope of the macros.
> >
>
> Please include some info on changes in generated code, if any. When the
> parameter to the macro is a constant I'm sure it all folds to a
> compile-time constant either way, but when it's not, I'm not sure gcc
> can do the same optimizations when the expressions become more complicated.
After applying all patches till "tools: introduce SMALL_CONST() macro",
there's no visible changes in code generation:
scripts/bloat-o-meter vmlinux.before vmlinux
add/remove: 1/2 grow/shrink: 2/0 up/down: 17/-16 (1)
Function old new delta
ethtool_get_drvinfo 900 908 +8
e843419@0cf2_0001309d_7f0 - 8 +8
vermagic 48 49 +1
e843419@0d45_000138bb_f68 8 - -8
e843419@0cc9_00012bce_198c 8 - -8
Total: Before=26092016, After=26092017, chg +0.00%
The build is arm64, and the compilerr is:
aarch64-linux-gnu-gcc (Linaro GCC 7.3-2018.05) 7.3.1 20180425
next prev parent reply other threads:[~2021-03-12 4:31 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-18 4:04 [PATCH v3 00/14] lib/find_bit: fast path for small bitmaps Yury Norov
2021-02-18 4:04 ` [PATCH 01/14] tools: disable -Wno-type-limits Yury Norov
2021-02-18 4:05 ` [PATCH 02/14] tools: bitmap: sync function declarations with the kernel Yury Norov
2021-02-18 4:05 ` [PATCH 03/14] arch: rearrange headers inclusion order in asm/bitops for m68k and sh Yury Norov
2021-02-18 4:05 ` [PATCH 04/14] lib: introduce BITS_{FIRST,LAST} macro Yury Norov
2021-02-18 22:51 ` Rasmus Villemoes
2021-03-12 4:30 ` Yury Norov [this message]
2021-02-18 4:05 ` [PATCH 05/14] tools: sync BITS_MASK macros with the kernel Yury Norov
2021-02-18 4:05 ` [PATCH 06/14] bitsperlong.h: introduce SMALL_CONST() macro Yury Norov
2021-02-18 23:07 ` Rasmus Villemoes
2021-03-12 5:28 ` Yury Norov
2021-03-12 9:12 ` Rasmus Villemoes
2021-03-12 21:53 ` Yury Norov
2021-02-18 4:05 ` [PATCH 07/14] tools: " Yury Norov
2021-02-18 4:05 ` [PATCH 08/14] lib/Kconfig: introduce FAST_PATH option Yury Norov
2021-02-18 15:15 ` Andy Shevchenko
2021-02-18 19:24 ` Yury Norov
2021-02-19 10:52 ` Andy Shevchenko
2021-02-18 4:05 ` [PATCH 09/14] lib: inline _find_next_bit() wrappers Yury Norov
2021-02-18 4:05 ` [PATCH 10/14] tools: sync find_next_bit implementation Yury Norov
2021-02-18 4:05 ` [PATCH 11/14] lib: add fast path for find_next_*_bit() Yury Norov
2021-02-18 15:24 ` Andy Shevchenko
2021-02-18 4:05 ` [PATCH 12/14] lib: add fast path for find_first_*_bit() and find_last_bit() Yury Norov
2021-02-18 4:05 ` [PATCH 13/14] tools: sync lib/find_bit implementation Yury Norov
2021-02-18 4:05 ` [PATCH 14/14] MAINTAINERS: Add entry for the bitmap API Yury Norov
2021-02-18 15:28 ` Andy Shevchenko
2021-02-18 15:34 ` Yury Norov
2021-03-12 9:15 ` Rasmus Villemoes
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
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210312043057.GA137474@yury-ThinkPad \
--to=yury.norov@gmail.com \
--cc=aklimov@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=andriy.shevchenko@linux.intel.com \
--cc=arnd@arndb.de \
--cc=dalias@libc.org \
--cc=dennis@kernel.org \
--cc=dsterba@suse.com \
--cc=geert@linux-m68k.org \
--cc=glaubitz@physik.fu-berlin.de \
--cc=jianpeng.ma@intel.com \
--cc=joe@perches.com \
--cc=jpoimboe@redhat.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-m68k@lists.linux-m68k.org \
--cc=linux-sh@vger.kernel.org \
--cc=linux@rasmusvillemoes.dk \
--cc=richard.weiyang@linux.alibaba.com \
--cc=sbrivio@redhat.com \
--cc=wsa+renesas@sang-engineering.com \
--cc=ysato@users.sourceforge.jp \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.