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From: David Laight <David.Laight@ACULAB.COM>
To: "'linux-kernel@vger.kernel.org'" <linux-kernel@vger.kernel.org>,
	"'Linus Torvalds'" <torvalds@linux-foundation.org>,
	'Netdev' <netdev@vger.kernel.org>,
	"'dri-devel@lists.freedesktop.org'"
	<dri-devel@lists.freedesktop.org>
Cc: 'Jens Axboe' <axboe@kernel.dk>,
	"'Matthew Wilcox (Oracle)'" <willy@infradead.org>,
	'Christoph Hellwig' <hch@infradead.org>,
	"'linux-btrfs@vger.kernel.org'" <linux-btrfs@vger.kernel.org>,
	"'Andrew Morton'" <akpm@linux-foundation.org>,
	'Andy Shevchenko' <andriy.shevchenko@linux.intel.com>,
	"'David S . Miller'" <davem@davemloft.net>,
	'Dan Carpenter' <dan.carpenter@linaro.org>,
	"'Jani Nikula'" <jani.nikula@linux.intel.com>
Subject: [PATCH next v2 00/11] minmax: Optimise to reduce .i line length
Date: Sun, 25 Feb 2024 16:46:20 +0000	[thread overview]
Message-ID: <0fff52305e584036a777f440b5f474da@AcuMS.aculab.com> (raw)

The changes to minmax.h that changed the type check to a signedness
check significantly increased the length of the expansion.
In some cases it has also significantly increased compile type.
This is particularly noticable for nested expansions.

The fact that _Static_assert() only requires a compile time constant
not a constant expression allows a lot of simplification.

The other thing that compilicates the expansion is the necessity of
returning a constant expression from constant arguments (for VLA).
I can only find a handful of places this is done.
Penalising most of the code for these few cases seems 'suboptimal'.
Instead I've added min_const() and max_const() for VLA and static
initialisers, these check the arguments are constant to avoid misuse.

Patch [9] is dependant on the earlier patches.
Patch [10] isn't dependant on them.
Patch [11] depends on both 9 and 10.

Changes for v2:
- Typographical and spelling corrections to the commit messages.
  Patches unchanged.

David Laight (11):
  [1] minmax: Put all the clamp() definitions together
  [2] minmax: Use _Static_assert() instead of static_assert()
  [3] minmax: Simplify signedness check
  [4] minmax: Replace multiple __UNIQUE_ID() by directly using __COUNTER__
  [5] minmax: Move the signedness check out of __cmp_once() and
    __clamp_once()
  [6] minmax: Remove 'constexpr' check from __careful_clamp()
  [7] minmax: minmax: Add __types_ok3() and optimise defines with 3
    arguments
  [8] minmax: Add min_const() and max_const()
  [9] tree-wide: minmax: Replace all the uses of max() for array sizes with
    max_const().
  [10] block: Use a boolean expression instead of max() on booleans
  [11] minmax: min() and max() don't need to return constant expressions

 block/blk-settings.c                          |   2 +-
 drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c        |   2 +-
 drivers/gpu/drm/drm_color_mgmt.c              |   4 +-
 drivers/input/touchscreen/cyttsp4_core.c      |   2 +-
 .../net/can/usb/etas_es58x/es58x_devlink.c    |   2 +-
 fs/btrfs/tree-checker.c                       |   2 +-
 include/linux/minmax.h                        | 211 ++++++++++--------
 lib/vsprintf.c                                |   4 +-
 net/ipv4/proc.c                               |   2 +-
 net/ipv6/proc.c                               |   2 +-
 10 files changed, 127 insertions(+), 106 deletions(-)

-- 
2.17.1

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)


             reply	other threads:[~2024-02-25 16:46 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-25 16:46 David Laight [this message]
2024-02-25 16:48 ` [PATCH next v2 01/11] minmax: Put all the clamp() definitions together David Laight
2024-02-25 16:49 ` [PATCH next v2 02/11] minmax: Use _Static_assert() instead of static_assert() David Laight
2024-02-26  9:28   ` Jani Nikula
2024-02-26 10:07     ` David Laight
2024-02-26 10:27       ` Jani Nikula
2024-02-25 16:49 ` [PATCH next v2 03/11] minmax: Simplify signedness check David Laight
2024-02-27  1:34   ` kernel test robot
2024-02-27  9:10     ` David Laight
2024-02-25 16:50 ` [PATCH next v2 04/11] minmax: Replace multiple __UNIQUE_ID() by directly using __COUNTER__ David Laight
2024-02-25 16:51 ` [PATCH next v2 05/11] minmax: Move the signedness check out of __cmp_once() and __clamp_once() David Laight
2024-02-25 16:52 ` [PATCH next v2 06/11] minmax: Remove 'constexpr' check from __careful_clamp() David Laight
2024-02-25 16:53 ` [PATCH next v2 07/11] minmax: minmax: Add __types_ok3() and optimise defines with 3 arguments David Laight
2024-02-25 16:53 ` [PATCH next v2 08/11] minmax: Add min_const() and max_const() David Laight
2024-02-25 17:13   ` Linus Torvalds
2024-02-25 21:09     ` David Laight
2024-02-25 21:26     ` David Laight
2024-02-26  1:11       ` Dave Airlie
2024-02-25 16:54 ` [PATCH next v2 09/11] tree-wide: minmax: Replace all the uses of max() for array sizes with max_const() David Laight
2024-02-25 16:56 ` [PATCH next v2 10/11] block: Use a boolean expression instead of max() on booleans David Laight
2024-02-25 16:56 ` [PATCH next v2 11/11] minmax: min() and max() don't need to return constant expressions David Laight
2024-02-26  9:42   ` kernel test robot
2024-02-26 10:16     ` David Laight
2024-02-26 10:56   ` kernel test robot

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