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* [Bug tree-optimization/44976] reductions with short variables do not get vectorized
       [not found] <bug-44976-4@http.gcc.gnu.org/bugzilla/>
@ 2021-02-23 10:14 ` rguenth at gcc dot gnu.org
  0 siblings, 0 replies; 2+ messages in thread
From: rguenth at gcc dot gnu.org @ 2021-02-23 10:14 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44976

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |10.1.0
         Resolution|---                         |FIXED
             Status|NEW                         |RESOLVED

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed in GCC 10.

^ permalink raw reply	[flat|nested] 2+ messages in thread

* [Bug tree-optimization/44976] reductions with short variables do not get vectorized
  2010-07-18  5:18 [Bug tree-optimization/44976] New: " roy dot 1rosen at gmail dot com
@ 2010-07-20 14:48 ` rguenth at gcc dot gnu dot org
  0 siblings, 0 replies; 2+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2010-07-20 14:48 UTC (permalink / raw)
  To: gcc-bugs



------- Comment #2 from rguenth at gcc dot gnu dot org  2010-07-20 14:48 -------
t.c:6: note: reduction: not commutative/associative: sum_13 = (short int)
D.2726_12;

this is because

  sum = (short)((int)sum + (int)a[i]);

cannot be folded to

  sum = sum + a[i];

as that exposes new undefined overflow.  Instead we fold it to

  sum = (short)((unsigned short)sum + (unsigned short)a[i]);

which the pattern detection does not handle explicitly.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
  GCC build triplet|elf                         |
   GCC host triplet|linux                       |
 GCC target triplet|ia64                        |
           Keywords|                            |missed-optimization
   Last reconfirmed|0000-00-00 00:00:00         |2010-07-20 14:48:32
               date|                            |
            Summary|short variables do not get  |reductions with short
                   |vectorized                  |variables do not get
                   |                            |vectorized


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44976


^ permalink raw reply	[flat|nested] 2+ messages in thread

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     [not found] <bug-44976-4@http.gcc.gnu.org/bugzilla/>
2021-02-23 10:14 ` [Bug tree-optimization/44976] reductions with short variables do not get vectorized rguenth at gcc dot gnu.org
2010-07-18  5:18 [Bug tree-optimization/44976] New: " roy dot 1rosen at gmail dot com
2010-07-20 14:48 ` [Bug tree-optimization/44976] reductions with " rguenth at gcc dot gnu dot org

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