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Date: Mon, 9 Oct 2017 07:34:34 -0700
From: Jakub Kicinski <jakub.kicinski@netronome.com>
To: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Arnd Bergmann <arnd@arndb.de>,
        Andrew Morton <akpm@linux-foundation.org>,
        kbuild test robot <fengguang.wu@intel.com>, linux-arch@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] bitfield: Use __ffs64(x) to fix missing __ffsdi2()
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On Mon,  9 Oct 2017 10:40:49 +0200, Geert Uytterhoeven wrote:
> On most architectures[*], gcc turns __builtin_ffsll() into a call to
> __ffsdi2(), which is not provided by any architecture, leading to
> failures like:
> 
>     rcar-gen3-cpg.c:(.text+0x289): undefined reference to `__ffsdi2'
> 
> To fix this, use __ffs64() instead, which is available on all
> architectures.
> 
> [*] Known exceptions are some 64-bit architectures like amd64, arm64,
>     ia64, powerpc64, and tilegx.
> 
> Reported-by: kbuild test robot <fengguang.wu@intel.com>
> Fixes: 3e9b3112ec74f192 ("add basic register-field manipulation macros")
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>

Thanks!