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Re: [Patch][aarch64] Use IFUNCs to enable LSE instructions in libatomic on aarch64
- From: Steve Ellcey <sellcey at cavium dot com>
- To: James Greenhalgh <james dot greenhalgh at arm dot com>
- Cc: Szabolcs Nagy <Szabolcs dot Nagy at arm dot com>, gcc-patches <gcc-patches at gcc dot gnu dot org>, nd <nd at arm dot com>
- Date: Thu, 07 Dec 2017 07:58:08 -0800
- Subject: Re: [Patch][aarch64] Use IFUNCs to enable LSE instructions in libatomic on aarch64
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On Thu, 2017-12-07 at 09:56 +0000, James Greenhalgh wrote:
>
> One obvious thing I missed in the review is that this change will break
> bootstrap on systems with older assemblers. Practically, that's those of
> us who are holding out on Ubuntu 14.04. -march=armv8-a+lse would go back
> a little further, so would be preferable, but even this won't get bootstrap
> back on older systems.
>
> Is there anything you can do to check for assembler support before turning
> on IFUNCS for libatomic, or am I best to just start configuring with
> --disable-gnu-indirect-function ?
>
> Thanks,
> James
It should be possible to check for assembler support. I will work on a
patch to do that.
Steve Ellcey
sellcey@cavium.com