From: Andrew Haley <aph@redhat.com>
To: Tom Horsley <horsley1953@gmail.com>, gcc@gcc.gnu.org
Subject: Re: aarch64 TLS optimizations?
Date: Fri, 17 May 2019 14:59:00 -0000 [thread overview]
Message-ID: <63dde7b4-a4dc-9837-2d00-66ec3fd67fbf@redhat.com> (raw)
In-Reply-To: <20190517095110.5bd041d6@tomh>
On 5/17/19 2:51 PM, Tom Horsley wrote:
> I'm trying (for reason too complex to go into) to
> locate the TLS offset of the tcache_shutting_down
> variable from malloc in the ubuntu provided
> glibc on aarch64 ubuntu 18.04.
>
> Various "normal" TLS variables appear to operate
> much like x86_64 with a GOT table entry where the
> TLS offset of the variable gets stashed.
>
> But in the ubuntu glibc there is no GOT entry for
> that variable, and disassembly of the code shows
> that it seems to "just know" the offset to use.
>
> Is there some kind of magic TLS optimization that
> can happen for certain variables on aarch64? I'm trying
> to understand how it could know the offset like
> it appears to do in the code.
https://www.fsfla.org/~lxoliva/writeups/TLS/paper-lk2006.pdf
--
Andrew Haley
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671
next prev parent reply other threads:[~2019-05-17 14:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-17 13:51 Tom Horsley
2019-05-17 14:59 ` Andrew Haley [this message]
2019-05-20 15:43 ` Szabolcs Nagy
2019-05-20 15:59 ` Tom Horsley
2019-05-20 17:08 ` Szabolcs Nagy
2019-05-20 17:14 ` Tom Horsley
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