How does tsan guarantee it won't clobber the xmm registers?

[Arthur Eubanks]

Could you be more specific as to which calls you're worried about?

TemplateTable::tsan_observe_get_or_put
<https://github.com/openjdk/tsan/blob/3ec97caa4b3078a4cf1cd269caf1307618a4926a/src/hotspot/cpu/x86/templateTable_x86.cpp#L808>
and TemplateTable::tsan_observe_load_or_store
<https://github.com/openjdk/tsan/blob/3ec97caa4b3078a4cf1cd269caf1307618a4926a/src/hotspot/cpu/x86/templateTable_x86.cpp#L864
> do
save xmm0.


On Thu, May 7, 2020 at 11:52 PM Jie He <Jie.He at arm.com> wrote:

> Hi Arthur
>
> I saw x86 code saves xmm0 because libc functions are called.
> Then I have a question about current tsan instruments in interpreter.
> How does tsan guarantee it won't clobber the xmm registers? I think it
> depends on compiler.
> I couldn't find the documents or code to declare that.
>
> Thanks
> Jie He
>