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Re: Bug in CFG or CD-DCE?



On Jul 13, 2004, at 4:02 AM, Diego Novillo wrote:


On Tue, 2004-07-13 at 06:53, Diego Novillo wrote:
On Tue, 2004-07-13 at 03:46, Steven Bosscher wrote:

Whether there's a FALLTHRU edge or not is irrelevant.  Block L22
is not control dependent on block L41, itt is control dependent on
block L26.

Exactly.  Though, I did try clearing/recomputing PDOM info.  That's
where the bug may be, ultimately.

Wait.  I don't think that's right.  This code is testing CD with PDOM.
In this case, block L22 *does* post-dominate block L41.

I do not know if it is useful or not but it is possible that cd-dce
receives stale post dominator graph through calculate_dominance_info (...).
I ran into it when one pass calculates post dominators, second
patch updates CFG and cd-dce as third pass receives stale post dominators.
My fix was to free post dominators at the end of the pass that calculates
post dominators.


--
Devang


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