spinlock variable protection

Matwey V. Kornilov matwey.kornilov at gmail.com
Fri Jan 30 09:20:21 EST 2015

2015-01-30 16:52 GMT+03:00 buyitian <buyitian at gmail.com>:
> Please check the assembly code to double confirm the GCC behavior.
> Why will GCC change the order as what you mentioned? Only assembly code can tell you.

It does not change at the moment. I think it can change it.

Because from line
  ret = hdl->count;
until line
  return ret;
there is no access to either ret or hdl->count. So it is reasonable to
optimizer to think that their values are the same and eliminate
unneeded variable.

With best regards,
Matwey V. Kornilov

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