From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: [PATCH v2] eal: fix clang compilation error on ARM64
Date: Wed, 11 Apr 2018 14:48:24 -0700
Message-ID: <20180411144824.062e1432@xeon-e3>
References: <20180406110103.29163-1-pbhagavatula@caviumnetworks.com>
 <20180411170150.11985-1-pbhagavatula@caviumnetworks.com>
 <2796123.plAjDWPncV@xps>
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Cc: Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>, dev@dpdk.org,
 jerin.jacob@caviumnetworks.com, ferruh.yigit@intel.com,
 konstantin.ananyev@intel.com
To: Thomas Monjalon <thomas@monjalon.net>
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On Wed, 11 Apr 2018 22:42:55 +0200
Thomas Monjalon <thomas@monjalon.net> wrote:

> 11/04/2018 19:01, Pavan Nikhilesh:
> > Use __atomic_exchange_n instead of __atomic_exchange_(2/4/8).
> > The error was:
> > 	include/generic/rte_atomic.h:215:9: error:
> > 		implicit declaration of function '__atomic_exchange_2'
> > 		is invalid in C99
> > 	include/generic/rte_atomic.h:494:9: error:
> > 		implicit declaration of function '__atomic_exchange_4'
> > 		is invalid in C99
> > 	include/generic/rte_atomic.h:772:9: error:
> > 		implicit declaration of function '__atomic_exchange_8'
> > 		is invalid in C99
> > 
> > Fixes: ff2863570fcc ("eal: introduce atomic exchange operation")
> > 
> > Signed-off-by: Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>  
> 
> We did not understand why this error is seen only on ARM
> (hopefully we won't discover it somewhere else),
> but it is a pragmatic fix.
> 
> Applied, thanks

Maybe Gcc always defines its own builtin functions.