[Bug tree-optimization/13876] loop not fully optimized

[Bug tree-optimization/13876] loop not fully optimized

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=13876

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |RESOLVED
         Resolution|---                         |FIXED
      Known to fail|                            |

--- Comment #10 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
These all are optimized now so closing as fixed.

[Bug tree-optimization/13876] loop not fully optimized

[pinskia at gcc dot gnu dot org]

------- Comment #9 from pinskia at gcc dot gnu dot org  2007-04-22 18:39 -------
> So, fixed.  Since 4.1 actually.

No, the example in comment #2 is not fixed.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
         Resolution|FIXED                       |
   Target Milestone|4.1.0                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13876

[Bug tree-optimization/13876] loop not fully optimized

[rguenth at gcc dot gnu dot org]

------- Comment #8 from rguenth at gcc dot gnu dot org  2007-04-22 12:49 -------
Loop header copying allows dom to duplicate the latch and thus we can now
eliminate the NotFound check:

;; Function t (t)

t (l, y)
{
  int i;

<bb 2>:
  o ();
  if (l > 0) goto <L15>; else goto <L4>;

<L15>:;
  i = 0;

Invalid sum of incoming frequencies 7098, should be 9100
<L0>:;
  if (MEM[base: y, index: (unsigned int) i, step: 4] != 0) goto <L1>; else goto
<L2>;

<L1>:;
  g ();
  goto <bb 7> (<L4>);

<L2>:;
  i = i + 1;
  if (l > i) goto <L0>; else goto <L4>;

Invalid sum of incoming frequencies 2902, should be 900
<L4>:;
  h () [tail call];
  return;

}


So, fixed.  Since 4.1 actually.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13876

[Bug tree-optimization/13876] loop not fully optimized

[law at redhat dot com]

------- Comment #7 from law at redhat dot com  2006-03-21 15:08 -------
This is a loop optimization issue, not a jump threading bug.  To really
optimize this loop well we will likely need the kinds of analysis found
in "Beyond Induction Variables", the classic paper describing loop flip-flops
and other interesting loop variables that are not simple induction variables.

Anyway, I'm removing this from the set of bugs related to jump threading.

Jeff


-- 

law at redhat dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|law at gcc dot gnu dot org  |
OtherBugsDependingO|19794                       |
              nThis|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13876

[Bug tree-optimization/13876] loop not fully optimized

[pinskia at gcc dot gnu dot org]

------- Comment #6 from pinskia at gcc dot gnu dot org  2006-02-27 14:14 -------
(In reply to comment #5)
> Could it be that this is now fixed?

Nope, the second testcase in comment #2 is still very obvious missing an
optimization with respect with jump threading:
        cmpw cr7,r31,r30
        li r3,0
        cmpwi cr6,r3,0
        bne+ cr7,L6
L6:
        beq- cr6,L4

That is only time I have seen an missed optimization that is so obvious.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13876

[Bug tree-optimization/13876] loop not fully optimized

[steven at gcc dot gnu dot org]

------- Comment #5 from steven at gcc dot gnu dot org  2006-02-27 13:48 -------
Could it be that this is now fixed?


-- 

steven at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |steven at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13876

[Bug tree-optimization/13876] loop not fully optimized

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-05-07 18:52 -------
The orginal testcase in comment #0 is fixed now but not the one in comment #2.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2005-04-16 17:31:17         |2005-05-07 18:52:59
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13876

[Bug tree-optimization/13876] loop not fully optimized

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|3.5.0                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13876