x86 descriptor-based TLS local dynamic fix

[Ian Lance Taylor]

Alexandre Oliva <aoliva@redhat.com> writes:

> I've noticed the other day that either I made a mistake when
> forward-porting the TLS descriptor code from an earlier release on
> which I first wrote it, or combine changed in such a way that the code
> I put in was ineffective.
> 
> Whatever the reason, this patch fixes it, such that we generate code
> as expected, namely, when there is access to a single local dynamic
> variable, we revert to general dynamic, and we don't fail to use
> segment register-based addressing modes to access such varables when
> possible.
> 
> I'm checking this in as obvious.  It does not affect code in the
> default TLS access models, only when compiling with -mtls-dialect=gnu2

Any chance you could write some docs for the -mtls-dialect option?

Ian