[Bug tree-optimization/17517] [4.0 Regression] ICE: SSA corruption

["stevenb at suse dot de" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From stevenb at suse dot de  2004-09-16 16:50 -------
Subject: Re:  [4.0 Regression] ICE: SSA corruption

On Thursday 16 September 2004 18:26, amacleod at redhat dot com wrote:
> ------- Additional Comments From amacleod at redhat dot com  2004-09-16
> 16:26 ------- I noticed my comment was a little vague. Did you apply the
> patch I attached? Thats the one that fixes the bug. The patch embedded in
> the comment fixes the follow on problem when -fdump-tree-all-all is used. 
> You will need both patches.
>
> The attached patch is the one which fixes the bug. At least it should :-)

Heh, no you were clear enough.

The patch that you attached does not fix the bug for me, with the patch
applied I still see an ICE, 

stevenb@kalman:/space/stevenb/build/gcc> ./cc1plus -w -quiet -O2 t.cc

Different root vars: checker$ptr and p across an abnormal edge from BB3->BB6
t.cc: In function `void pipe()':
t.cc:25466: internal compiler error: SSA corruption
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

This is with the original test case, not the reduced one.

In copyrename1 I see no complaints about "Abnormal PHI barrier" that
would prevent coalescing.  In copyrename2, I have the following:


;; Function void pipe() (_Z4pipev)

Try : checker$ptr_324(P324) & p_36(P36) : Abnormal PHI barrier.  No coalesce.
Try : D.61354_279(P279) & checker$ptr_327(P327) : Abnormal PHI barrier.  No coalesce.
Try : checker$ptr_320(P320) & p_274(P274) --> P320 p
Try : D.61458_157(P157) & checker$ptr_325(P325) : Abnormal PHI barrier.  No coalesce.
Try : checker$ptr_329(P329) & checker$ptr_327(P327) : Same root, coalesced --> P329.
Try : checker$ptr_329(P329) & p_320(P320) --> P329 p
Try : checker$ptr_327(P329) & checker$ptr_324(P324) : Abnormal PHI barrier.  No coalesce.
Try : checker$ptr_327(P329) & p_329(P329) : Already coalesced.
Try : checker$ptr_325(P325) & checker$ptr_324(P324) : Same root, coalesced --> P325.
Try : checker$ptr_325(P325) & checker$ptr_327(P329) : Abnormal PHI barrier.  No coalesce.

Partition map

Partition 36 (p_36 - 36 )
Partition 157 (D.61458_157 - 157 )
Partition 279 (D.61354_279 - 279 )
Partition 325 (checker$ptr_325 - 324 325 )
Partition 329 (p_329 - 274 320 327 329 )

Coalesced checker$ptr_327 to p_329

I can attach the full dumps if you want them.




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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17517