[Bug tree-optimization/18439] New: vectorizer failed for vector normalization

[Bug tree-optimization/18439] New: vectorizer failed for vector normalization

[giovannibajo at libero dot it]

Vectorizer fails to handle this:

-----------------------------------------------------
extern "C" double sqrt(double);

#define NUMPOINTS 50000

static float points[NUMPOINTS][4];
static float opoints[NUMPOINTS][4];
static bool flags[NUMPOINTS];

void NormalizeVectors (void)
{
  int i, r;
  float s, x, y, z;
  static float d = 0.0;

  d += 0.2;
  if (d > 4) d = 0.0;

  for (r=0; r<4; r++)
  {
    for (i=0; i<NUMPOINTS; i++)
    {
      x = points[i][0];
      y = points[i][1];
      z = points[i][2];
      s = x * x
        + y * y
        + z * z;
      s = d / sqrt (s);
      opoints[i][0] = x * s;
      opoints[i][1] = y * s;
      opoints[i][2] = z * s;
      flags[i] = true;
    }
  }
}
-----------------------------------------------------

loop at bench.cc:79: not vectorized: unhandled data ref: d.0_36 = d
loop at bench.cc:79: bad data references.



This is a bit more complex than the other two I posted, I guess. Anyway, the 
first problem seems related to the static variable.

-- 
           Summary: vectorizer failed for vector normalization
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: giovannibajo at libero dot it
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18439

[Bug tree-optimization/18439] vectorizer failed for vector normalization

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-11-12 02:43 -------
Confirmed, ICC can do this but does not because it is not very inefficient to do it.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-11-12 02:43:29
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18439

[Bug tree-optimization/18439] vectorizer failed for vector normalization

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-02-11 14:19 -------
Really there are two problems which cause the missed vectorizor.  One is that we don't scalarize the 
static variables that well.  So that is the bug which really needs to be fixed first and really is not related 
to the vectorizor at all.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
   Last reconfirmed|2004-11-12 02:43:29         |2005-02-11 14:19:47
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18439

[Bug tree-optimization/18439] vectorizer failed for vector normalization

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-02-11 14:47 -------
I filed PR 19905 for the missed optimization not really related (but blocking) the tree vectorizor.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |19905


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18439