ARM: __sync_synchronize does not generate code

[Richard Earnshaw]

On Wed, 2009-08-12 at 19:08 -0400, Ross Ridge wrote:

> If there isn't any way to implement a useful memory barrier on a
> given target (the "NOP" case Richard Earnshaw mentioned), then the
> existing behavior is actually what I'd expect.  I'd never expect GCC to
> emit a libcall to an undefined function.

The "NOP" I'm talking about here is a function that is a no-op, not an
assembly instruction.  That is, the function just returns as soon as
it's called.  A smart linker might even remove the call to such a
subroutine.

R.