From: Nicolas Pitre <nico@fluxnic.net>
To: Arnd Bergmann <arnd@arndb.de>, Russell King <linux@armlinux.org.uk>
Cc: Nicolas Pitre <npitre@baylibre.com>,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 0/2] do_div() with constant divisor simplification
Date: Thu, 4 Jul 2024 22:20:27 -0400 [thread overview]
Message-ID: <20240705022334.1378363-1-nico@fluxnic.net> (raw)
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(-)
next reply other threads:[~2024-07-05 2:24 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-05 2:20 Nicolas Pitre [this message]
2024-07-05 2:20 ` [PATCH 1/2] ARM: div64: remove custom __arch_xprod_64() Nicolas Pitre
2024-07-05 2:20 ` [PATCH 2/2] asm-generic/div64: reimplement __arch_xprod64() Nicolas Pitre
2024-07-05 8:17 ` Arnd Bergmann
2024-07-07 16:53 ` Nicolas Pitre
2024-07-06 11:13 ` kernel test robot
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