Re: [Chicken-users] More on aliasing.

[Peter Keller]

On Mon, Jul 08, 2002 at 04:05:17PM -0400, Anthony Carrico wrote:
> No, I didn't mean the register declaration.

I'm  sorry for my confusion.

> On Fri, 5 Jul 2002, Peter Keller wrote:
> > pieces of memory if the memory is _defined_ as being contiguous in
> > memory like a union or a struct.
> 
> I was just wondering if this definition you mentioned was strict enough to
> prevent the compiler from putting (register sized) unions into machine
> registers even when their address was never actually used. If so, then
> obviously this restriction could really slow down union code vs. the
> equivalent casting code. I hope this is the case, otherwise the strict
> aliasing optimization switch wouldn't be very useful for this kind of
> code.

I don't know if it is strict enough without digging around in some language
specs and trying out some test code to see what the assembly looks like.

I guess if it did slow down execution a little, you'd have to balance the
readability and debuggability of the generated code with the speed of it.

-pete