Messages in this thread | | | Date | Sun, 12 Aug 2007 02:54:16 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: [PATCH] make atomic_t volatile on all architectures |
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On Sun, 12 Aug 2007, Martin Schwidefsky wrote: > > The duplication "=m" and "m" with the same constraint is rather > annoying.
It's not only annoying, it causes gcc to generate bad code too. At least certain versions of gcc will generate the address *twice*, even if there is obviously only one address used.
If you have problems with "+m", you are often actually better off using just "m" and then adding a memory clobber. But that has other code generation downsides.
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