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Re: Re: Re: Re: Re: Re: LOOP_HEADER tree code?

On 10/25/06, Steven Bosscher <stevenb.gcc@gmail.com> wrote: 

So you would mark n_1 with TREE_USED, and never let it be removed?
What would happen if e.g. the entire loop turns out to be dead code?
Or if the loop is rewritten (e.g. vectorized) in a way that changes
the number of iterations of the loop? Then the assignment to n_1 would
be _really_ dead, but there wouldn't be any way to tell.


When it is really dead, you'll have to remove LOOP_HEADER node
anyway. Right ? Why not instead reset the TREE_USED bit and let DCE do
its job ?

I do not want to drag this discussion further, so I'll stop now.
-
Devang

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