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* [Bug tree-optimization/15458] New: Combine ~ and ^.
@ 2004-05-16  1:55 kazu at cs dot umass dot edu
  2004-05-16 10:02 ` [Bug tree-optimization/15458] " pinskia at gcc dot gnu dot org
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: kazu at cs dot umass dot edu @ 2004-05-16  1:55 UTC (permalink / raw)
  To: gcc-bugs

unsigned int
xornot (unsigned int a)
{
  unsigned int b = a ^ 0xffff;
  unsigned int c = ~b;
  return c;
}

unsigned int
notxor (unsigned int a)
{
  unsigned int b = ~a;
  unsigned int c = b ^ 0xffff;
  return c;
}

The last tree-ssa form looks like:

;; Function xornot (xornot)

xornot (a)
{
  unsigned int c;
  unsigned int b;

<bb 0>:
  b_2 = a_1 ^ 65535;
  c_3 = ~b_2;
  return c_3;

}



;; Function notxor (notxor)

notxor (a)
{
  unsigned int c;
  unsigned int b;

<bb 0>:
  b_2 = ~a_1;
  c_3 = b_2 ^ 65535;
  return c_3;

}

-- 
           Summary: Combine ~ and ^.
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Keywords: pessimizes-code
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kazu at cs dot umass dot edu
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15458


^ permalink raw reply	[flat|nested] 5+ messages in thread
* [Bug tree-optimization/15458] Combine ~ and ^.
  2004-05-16  1:55 [Bug tree-optimization/15458] New: Combine ~ and ^ kazu at cs dot umass dot edu
@ 2004-05-16 10:02 ` pinskia at gcc dot gnu dot org
  2004-05-16 10:49 ` pinskia at gcc dot gnu dot org
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-05-16 10:02 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From pinskia at gcc dot gnu dot org  2004-05-15 12:23 -------
Confirmed.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-05-15 12:23:00
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15458


^ permalink raw reply	[flat|nested] 5+ messages in thread
* [Bug tree-optimization/15458] Combine ~ and ^.
  2004-05-16  1:55 [Bug tree-optimization/15458] New: Combine ~ and ^ kazu at cs dot umass dot edu
  2004-05-16 10:02 ` [Bug tree-optimization/15458] " pinskia at gcc dot gnu dot org
@ 2004-05-16 10:49 ` pinskia at gcc dot gnu dot org
  2004-05-17 18:53 ` pinskia at gcc dot gnu dot org
  2004-06-02 21:14 ` pinskia at gcc dot gnu dot org
  3 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-05-16 10:49 UTC (permalink / raw)
  To: gcc-bugs



-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |15459


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15458


^ permalink raw reply	[flat|nested] 5+ messages in thread
* [Bug tree-optimization/15458] Combine ~ and ^.
  2004-05-16  1:55 [Bug tree-optimization/15458] New: Combine ~ and ^ kazu at cs dot umass dot edu
  2004-05-16 10:02 ` [Bug tree-optimization/15458] " pinskia at gcc dot gnu dot org
  2004-05-16 10:49 ` pinskia at gcc dot gnu dot org
@ 2004-05-17 18:53 ` pinskia at gcc dot gnu dot org
  2004-06-02 21:14 ` pinskia at gcc dot gnu dot org
  3 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-05-17 18:53 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From pinskia at gcc dot gnu dot org  2004-05-17 02:05 -------
Will be fix by PR 15459 when fold is able to optimize ~(a<D1109>_1 ^ 65535) into 
~a<D1104>_1 ^ 65535

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15458


^ permalink raw reply	[flat|nested] 5+ messages in thread
* [Bug tree-optimization/15458] Combine ~ and ^.
  2004-05-16  1:55 [Bug tree-optimization/15458] New: Combine ~ and ^ kazu at cs dot umass dot edu
                   ` (2 preceding siblings ...)
  2004-05-17 18:53 ` pinskia at gcc dot gnu dot org
@ 2004-06-02 21:14 ` pinskia at gcc dot gnu dot org
  3 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-06-02 21:14 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From pinskia at gcc dot gnu dot org  2004-06-02 21:14 -------
I should note that the RTL level does this optimization.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |15785
           Keywords|                            |TREE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15458


^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2004-06-02 21:14 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-05-16  1:55 [Bug tree-optimization/15458] New: Combine ~ and ^ kazu at cs dot umass dot edu
2004-05-16 10:02 ` [Bug tree-optimization/15458] " pinskia at gcc dot gnu dot org
2004-05-16 10:49 ` pinskia at gcc dot gnu dot org
2004-05-17 18:53 ` pinskia at gcc dot gnu dot org
2004-06-02 21:14 ` pinskia at gcc dot gnu dot org

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