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Re: -fno-tree-cselim not working?


Andi Kleen <andi@firstfloor.org> writes:

> Ian Lance Taylor <iant@google.com> writes:
> >
> > This code isn't going to be a problem, because spin_unlock presumably
> > includes a memory barrier.
> 
> At least in the Linux kernel and also in glibc for mutexes locks are just plain
> function calls, which are not necessarily full memory barriers.

True, and problematic in some cases--but a function call which gcc
can't see is a memory barrier for all addressable memory.

Ian


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