On 10/25/06, Devang Patel <[EMAIL PROTECTED]> wrote:
> > One way to achieve this is to mark n_1 (in your example) as
> > "do not dead strip because I know it is used" , kind of attribute((used)).
>
> This is what as I understand LOOP_HEADER is used for.

Big difference. New tree vs TREE_USED or DECL_PRESERVE_P bit.

DECL_PRESERVE_P wouldn't work, because afaiu the number of iterations
is stored in an SSA_NAME tree node , not a *DECL node.

You could use TREE_USED,  but your suggestion implies that dead code
should be retained in the program, just for the sake of knowing how
many iterations a loop has. I wouldn't be surprised if some passes are
not prepared to handle that, and it sounds like just a really bad
idea.

Gr.
Steven

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