[Bug tree-optimization/86504] vectorization failure for a nest loop

2019-04-10 Thread tnfchris at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86504

Tamar Christina  changed:

   What|Removed |Added

 Status|NEW |ASSIGNED

[Bug tree-optimization/86504] vectorization failure for a nest loop

2019-04-10 Thread tnfchris at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86504

Tamar Christina  changed:

   What|Removed |Added

   Assignee|unassigned at gcc dot gnu.org  |tnfchris at gcc dot 
gnu.org

--- Comment #7 from Tamar Christina  ---
Cheers, Thanks Richard, I'll grab this one too then.

[Bug tree-optimization/86504] vectorization failure for a nest loop

2019-04-10 Thread rsandifo at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86504

rsandifo at gcc dot gnu.org  changed:

   What|Removed |Added

 Status|ASSIGNED|NEW
   Assignee|rsandifo at gcc dot gnu.org|unassigned at gcc dot 
gnu.org

--- Comment #6 from rsandifo at gcc dot gnu.org  
---
(In reply to Tamar Christina from comment #5)
> Hi Richard,
> 
> Do you still plan on working on this? Otherwise I'd like to take it over for
> GCC10.

I've already committed the patch mentioned in #c4 (can't remember
which patch it was offhand) but it turned out not to fix this PR
after all.  So please go ahead.

[Bug tree-optimization/86504] vectorization failure for a nest loop

2019-04-09 Thread tnfchris at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86504

Tamar Christina  changed:

   What|Removed |Added

 CC||tnfchris at gcc dot gnu.org

--- Comment #5 from Tamar Christina  ---
Hi Richard,

Do you still plan on working on this? Otherwise I'd like to take it over for
GCC10.

[Bug tree-optimization/86504] vectorization failure for a nest loop

2018-07-20 Thread rsandifo at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86504

rsandifo at gcc dot gnu.org  changed:

   What|Removed |Added

 Status|NEW |ASSIGNED
 CC||rsandifo at gcc dot gnu.org
   Assignee|unassigned at gcc dot gnu.org  |rsandifo at gcc dot 
gnu.org

--- Comment #4 from rsandifo at gcc dot gnu.org  
---
About to post a patch.

[Bug tree-optimization/86504] vectorization failure for a nest loop

2018-07-12 Thread rguenth at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86504

Richard Biener  changed:

   What|Removed |Added

 Target||arm
 CC||rguenth at gcc dot gnu.org
 Blocks||53947

--- Comment #3 from Richard Biener  ---
The issue is the inner complete loop unrolling pass which unrolls loops up to
16 times (a --param controls that number).  You can get good code via
-fdisable-tree-cunrolli for example.

So the vectorization issue would be that basic-block vectorization doesn't
catch this in a very nice way - on x86 we pull out the invariant computation
and have a vectorized (outer) loop storing to d.  But we fail to
vectorize the add because we are restricted to a single basic-block and the
stores are still in the inner loop (obviously):

t.c:9:15: note: not vectorized: no grouped stores in basic block.

instead we see

  _238 = MEM[(char *)_s2 + 15B];
  _239 = (unsigned char) _238;
  _240 = _236 + _239;
  _242 = (char) _240;
  _234 = {_32, _46, _60, _74, _88, _102, _116, _130, _144, _158, _172, _186,
_200, _214, _228, _242};
  vect_cst__237 = _234;

   [local count: 63136020]:
  # vectp_g_d.0_227 = PHI 
  # ivtmp_31 = PHI 
  MEM[(char *)vectp_g_d.0_227] = vect_cst__237;
  vectp_g_d.0_15 = vectp_g_d.0_227 + 16;
  ivtmp_241 = ivtmp_31 + 1;
  if (ivtmp_241 < 128)
goto ; [99.00%]
  else
goto ; [1.00%]

   [local count: 62498283]:
  goto ; [100.00%]

   [local count: 637738]:
  return;

so this is a duplicate of the bug that says BB vectorization doesn't consider
a vector CONSTRUCTOR as sink.


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53947
[Bug 53947] [meta-bug] vectorizer missed-optimizations

[Bug tree-optimization/86504] vectorization failure for a nest loop

2018-07-12 Thread ktkachov at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86504

ktkachov at gcc dot gnu.org changed:

   What|Removed |Added

   Keywords||missed-optimization
 Status|UNCONFIRMED |NEW
   Last reconfirmed||2018-07-12
 CC||ktkachov at gcc dot gnu.org
 Ever confirmed|0   |1

--- Comment #2 from ktkachov at gcc dot gnu.org ---
Confirmed, I've seen this in other similar loops. Thanks for filing a bug
report for this

[Bug tree-optimization/86504] vectorization failure for a nest loop

2018-07-12 Thread jiangning.liu at amperecomputing dot com
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86504

--- Comment #1 from Jiangning Liu  ---
Created attachment 44387
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44387=edit
bad vectorizatoin result for boundary size 8