Messages in this thread | | | Date | Tue, 20 May 2008 15:53:26 -0700 (PDT) | Subject | Re: [PATCH] [POWERPC] Improve (in|out)_beXX() asm code | From | David Miller <> |
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From: Scott Wood <scottwood@freescale.com> Date: Tue, 20 May 2008 17:43:58 -0500
> David Miller wrote: > > The __volatile__ in the asm construct disallows movement of the > > inline asm relative to statements surrounding it. > > > > The only reason barrier() in kernel.h needs a memory clobber is > > because of a bug in ancient versions of gcc. In fact, I think > > that memory clobber might even be removable. > > Current versions of GCC seem quite happy to move non-asm memory accesses > around a volatile asm without a memory clobber; see the test Trent posted.
Indeed, and even the GCC manual is clear about this.
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