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Re: RFC: Add ___tls_get_addr


On 07/05/2017 11:38 AM, H.J. Lu wrote:
> On x86-64, __tls_get_addr has to realigns stack so that binaries compiled by
> GCCs older than GCC 4.9.4:
> 
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066
> 
> continue to work even if vector instructions are used by functions called
> from __tls_get_addr, which assumes 16-byte stack alignment as specified
> by x86-64 psABI.
> 
> We are considering to add an alternative interface, ___tls_get_addr, to
> glibc, which doesn't realign stack.  Compilers, which properly align stack
> for TLS, call generate call to ___tls_get_addr, instead of __tls_get_addr,
> if ___tls_get_addr is available.
> 
> Any comments?

Overall I agree with the idea.

However, the triple underscore will lead to eventual human error, can we
avoid that error by changing the name in an meaningful way? I don't care
what you choose really.

-- 
Cheers,
Carlos.


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