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* [Bug tree-optimization/30099]  New: missed value numbering optimization (conditional-based assertions)
@ 2006-12-07  5:55 dann at godzilla dot ics dot uci dot edu
  2006-12-07 14:14 ` [Bug tree-optimization/30099] " rguenth at gcc dot gnu dot org
  2006-12-09  6:33 ` pinskia at gcc dot gnu dot org
  0 siblings, 2 replies; 3+ messages in thread
From: dann at godzilla dot ics dot uci dot edu @ 2006-12-07  5:55 UTC (permalink / raw)
  To: gcc-bugs

The following 2 functions should be compiled to the same assembly. 
This is one of Briggs' compiler benchmarks.

void vnum_test10(int *data)
{
  int i = data[0];
  int m = i + 1;
  int j = data[1];
  int n = j + 1;
  data[2] = m + n;
  if (i == j)
    data[3] = (m - n) * 21;
}
void vnum_result10(int *data)
{
  int i = data[0];
  int m = i + 1;
  int j = data[1];
  int n = j + 1;
  data[2] = m + n;
  if (i == j)
    data[3] = 0;
}


-- 
           Summary: missed value numbering optimization (conditional-based
                    assertions)
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dann at godzilla dot ics dot uci dot edu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30099


^ permalink raw reply	[flat|nested] 3+ messages in thread

* [Bug tree-optimization/30099] missed value numbering optimization (conditional-based assertions)
  2006-12-07  5:55 [Bug tree-optimization/30099] New: missed value numbering optimization (conditional-based assertions) dann at godzilla dot ics dot uci dot edu
@ 2006-12-07 14:14 ` rguenth at gcc dot gnu dot org
  2006-12-09  6:33 ` pinskia at gcc dot gnu dot org
  1 sibling, 0 replies; 3+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2006-12-07 14:14 UTC (permalink / raw)
  To: gcc-bugs



------- Comment #1 from rguenth at gcc dot gnu dot org  2006-12-07 14:13 -------
Confirmed.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rguenth at gcc dot gnu dot
                   |                            |org
           Severity|normal                      |enhancement
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |missed-optimization
   Last reconfirmed|0000-00-00 00:00:00         |2006-12-07 14:13:46
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30099


^ permalink raw reply	[flat|nested] 3+ messages in thread

* [Bug tree-optimization/30099] missed value numbering optimization (conditional-based assertions)
  2006-12-07  5:55 [Bug tree-optimization/30099] New: missed value numbering optimization (conditional-based assertions) dann at godzilla dot ics dot uci dot edu
  2006-12-07 14:14 ` [Bug tree-optimization/30099] " rguenth at gcc dot gnu dot org
@ 2006-12-09  6:33 ` pinskia at gcc dot gnu dot org
  1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2006-12-09  6:33 UTC (permalink / raw)
  To: gcc-bugs



------- Comment #2 from pinskia at gcc dot gnu dot org  2006-12-09 06:32 -------
Basically what needs here is that if we get i == j, then we need to also add
asserts (in VRP) for all the uses of i and j, which makes it an almost useless
to do :).

There might be another bug about this filed by me.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30099


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2006-12-09  6:33 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2006-12-07  5:55 [Bug tree-optimization/30099] New: missed value numbering optimization (conditional-based assertions) dann at godzilla dot ics dot uci dot edu
2006-12-07 14:14 ` [Bug tree-optimization/30099] " rguenth at gcc dot gnu dot org
2006-12-09  6:33 ` pinskia at gcc dot gnu dot org

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