linux-kernel - [PATCH 0/2] do_div() with constant divisor simplification

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Message-ID: <20240705022334.1378363-1-nico@fluxnic.net>
Date: Thu,  4 Jul 2024 22:20:27 -0400
From: Nicolas Pitre <nico@...xnic.net>
To: Arnd Bergmann <arnd@...db.de>,
	Russell King <linux@...linux.org.uk>
Cc: Nicolas Pitre <npitre@...libre.com>,
	linux-arch@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 0/2] do_div() with constant divisor simplification

While working on mul_u64_u64_div_u64() improvements I realized that there
is a better way to perform a 64x64->128 bits multiplication that doesn't
involve any conditionals to handle overflows. It even produces equivalent
or better code than the provided ARM assembly alternative.

And the best part is:

 arch/arm/include/asm/div64.h |  52 -----------------
 include/asm-generic/div64.h  | 105 +++++++++++------------------------
 2 files changed, 31 insertions(+), 126 deletions(-)