linux-kernel - [PATCH next 00/11] minmax: Optimise to reduce .i line length.

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Date: Sun, 28 Jan 2024 19:24:03 +0000
From: David Laight <David.Laight@...LAB.COM>
To: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, "'Linus
 Torvalds'" <torvalds@...ux-foundation.org>, Netdev <netdev@...r.kernel.org>,
	"dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>
CC: 'Andy Shevchenko' <andriy.shevchenko@...ux.intel.com>, 'Andrew Morton'
	<akpm@...ux-foundation.org>, "'Matthew Wilcox (Oracle)'"
	<willy@...radead.org>, 'Christoph Hellwig' <hch@...radead.org>, "'Dan
 Carpenter'" <dan.carpenter@...aro.org>, Linus Walleij
	<linus.walleij@...aro.org>, "David S . Miller" <davem@...emloft.net>,
	"linux-btrfs@...r.kernel.org" <linux-btrfs@...r.kernel.org>, 'Jens Axboe'
	<axboe@...nel.dk>
Subject: [PATCH next 00/11] minmax: Optimise to reduce .i line length.

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

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

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