[PATCH] D18164: [tsan] Do not instrument reads/writes to instruction profile counters.

[Xinliang David Li via llvm-commits]

On Thu, Mar 17, 2016 at 1:18 PM, Dmitry Vyukov <dvyukov at google.com> wrote:

> dvyukov added a comment.
>
> > I am not sure what 'pretend' here means. It is possible that value '1'
> is still visible to other threads, or not?
>
>
> Well, if we eliminate it, then it won't be visible.
>
> If we don't eliminate it, then value 1 may or may not be visible to other
> threads depending on scheduler (among other things). There are no
> requirements for scheduler. So implementation in which value 1 is never
> visible to other threads is legal.
>

I need to see the actual specification on the standard that this is legal :)

Note that the DSE example can be changed to:

atomic_store(p, 1);

....lots of other code not touching memory

atomic_store(p, 2);


David




>
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> http://reviews.llvm.org/D18164
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