Re: [PATCH 1/24] make atomic_read() behave consistently on alpha

On Sat, Aug 11, 2007 at 02:38:40AM +0200, Segher Boessenkool wrote:

quoted

quoted

That means GCC cannot compile Linux; it already optimises
some accesses to scalars to smaller accesses when it knows
it is allowed to.  Not often though, since it hardly ever
helps in the cost model it employs.

Please give an example code snippet + gcc version + arch
to back this up.

	unsigned char f(unsigned long *p)
	{
	        return *p & 1;
	}

This doesn't really matter since we only care about the LSB.
Do you have an example where gcc reads it non-atmoically and
we care about all parts?

Cheers,
-- 
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