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From: richard clark <richard.xnu.clark@gmail.com>
Date: Wed, 10 Jan 2024 13:59:53 +0800
Message-ID: <CAJNi4rM_w5JKjug1PtV+tHyk11DUhRJ-K1pSDE6P1x8KSU2wrg@mail.gmail.com>
Subject: Re: undefined reference to `__aarch64_cas4_sync' error on arm64
 native build
To: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Xi Ruoyao <xry111@xry111.site>, Mark Rutland <mark.rutland@arm.com>, gcc-help@gcc.gnu.org, 
	linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Content-Type: text/plain; charset="UTF-8"

Hi Segher,

A ported driver in linux kernel calls '__sync_val_compare_and_swap',
the cross-compiler 'aarch64-linux-gnu-gcc' doesn't complain
'__aarch64_cas1_sync' undefined reference, but the native compiler
will complain. As Mark mentioned, I double check that both cross and
native compiler should have  ''-moutline-atomics' option enabled, do
you know the reason for that?