On 4/15/08 1:34 PM, Zdenek Dvorak wrote:
Hi,
> To clarify what Richard means, your assertion that "you have updated
> SSA information" is false.
> If you had updated the SSA information, the error would not occur :).
>
> How exactly are you updating the ssa information?
>
> The general way to update SSA for this case would be:
>
> For each statement you have moved:
> Call update_stmt (t);
>
> Then call update_ssa (TODO_update_ssa) (or instead use
> rewrite_into_loop_closed_ssa if this is a loop pass).
>
> If you do not call update_stmt in this case, update_ssa won't actually
> do anything.
actually, it will not do anything even if he calls update_stmt, as the
statements that he is moving are already in ssa form, so update_stmt
will not mark anything for renaming.
You are partially right (and right where it matters, that it won't fix
the problem)
That said, update_stmt on ssa form statements will at least reset the
vuse/vdef back to original variables for renaming.
I don't think so; as long as you do not introduce new vops (which you
should not by just moving the statements), update_stmt is a no-op on
vops too (unless something has changed since the last time I needed
this),
Right. Moving statements in SSA form needs to introduce name->name
mappings (eg, as is done during loop unrolling).
Diego.
