linux-kernel - Re: [PATCH 08/12] tools/nolibc: gettimeofday(): avoid libgcc 64-bit divisions

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Message-Id: <d3fe59df-a6cd-46dc-8821-0c2831e503b6@app.fastmail.com>
Date: Thu, 30 Oct 2025 15:57:11 +0100
From: "Arnd Bergmann" <arnd@...db.de>
To: Thomas Weißschuh <linux@...ssschuh.net>,
 "Willy Tarreau" <w@....eu>, shuah <shuah@...nel.org>
Cc: linux-kernel@...r.kernel.org, linux-kselftest@...r.kernel.org
Subject: Re: [PATCH 08/12] tools/nolibc: gettimeofday(): avoid libgcc 64-bit divisions

On Wed, Oct 29, 2025, at 17:02, Thomas Weißschuh wrote:
> timespec::tv_nsec is going to be 64-bit wide even on 32-bit
> architectures. As not all architectures support 64-bit division
> instructions, calls to libgcc (__divdi3()) may be emitted by the
> compiler which are not provided by nolibc.
>
> As tv_nsec is guaranteed to always fit into an uint32_t, perform a
> 32-bit division instead.
>
> Signed-off-by: Thomas Weißschuh <linux@...ssschuh.net>

Reviewed-by: Arnd Bergmann <arnd@...db.de>