gcc 4.1 implements compiler builtins for atomic ops

John David Anglin dave@hiauly1.hia.nrc.ca
Mon Jun 27 17:38:00 GMT 2005


> > Damn, these things should be in glibc, not the compiler !
> 
> I want to use the vDSO to hide the light-weight-syscall behind a
> versionable interface.

I'm not so sure.  Calls are expensive.  Also, they affect memory
barrier semantics.  If the operations are not a full barrier, gcc
needs to know.  See extend.texi in gcc 4.1.

> If gcc required atomic operations they would come from glibc or the
> vDSO. I am willing to pay the price of a function call. In gcc I will
> just emit a libcall.

Dave
-- 
J. David Anglin                                  dave.anglin@nrc-cnrc.gc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6602)



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