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Re: strict aliasing
On Mon, Nov 05, 2007 at 10:15:55AM -0800, Ian Lance Taylor wrote:
> skaller <skaller@users.sourceforge.net> writes:
> > Ah, I see. So turning [strict aliasing] off isn't really all that bad
> > for optimisation.
>
> It depends on the processor. For an in-order processor with a deep
> pipeline (e.g., Itanium, but there are others), the ability to reorder
> loads and stores is very important to permit scheduling flexibility.
> Strict aliasing reportedly makes a difference for x86, but I don't
> think it makes a huge difference.
It also depends on the input: for scientific codes that process both
integer and real data, strict aliasing could make a large difference
on any processor.