[Bug tree-optimization/20122] New: Wrong code with gcc 4.0 tree-vectorizer

[Bug tree-optimization/20122] New: Wrong code with gcc 4.0 tree-vectorizer

[micis at gmx dot de]

This small test program generates a segfault if it is compiled with:
gcc40 -march=opteron -O2 -ftree-vectorize gccbug.cpp -o gccbug

Segfault does not occur when __attribute__((noinline)) is omitted.
It occurs with snapshot 20050213 and snapshot 20050220,
but not with snapshot 20050130


Michael Cieslinski


==========================
#include <emmintrin.h>

static struct KStructType
{union{
    short         Kernshort[8][24];
    __m128i     KernSSE[8][3];
};} KU          __attribute__(( aligned(16) ));

static void VecBug(short Kernel[8][24]) __attribute__((noinline));
static void VecBug(short Kernel[8][24])
{
    for (int k = 0; k<8; k++)
        for (int i = 0; i<24; i++)
            KU.Kernshort[k][i] = Kernel[k][i];
}

int main (int argc, char **argv)
{
    short Kernel[8][24];
    for (int k = 0; k<8; k++)
        for (int i = 0; i<24; i++)
            Kernel[k][i] = 0;

    VecBug(Kernel);

    return 0;
}

-- 
           Summary: Wrong code with gcc 4.0 tree-vectorizer
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: micis at gmx dot de
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: x86_64-unknown-linux-gnu
  GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20122

[Bug tree-optimization/20122] Wrong code with gcc 4.0 tree-vectorizer

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-02-21 18:49 -------
I think this is related to PR 19716.  Note the tree level looks correct to me.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20122

[Bug tree-optimization/20122] Wrong code with gcc 4.0 tree-vectorizer

[irar at il dot ibm dot com]

------- Additional Comments From irar at il dot ibm dot com  2005-02-24 13:41 -------
I found the problem that causes this. I'll send the patch next week.
Ira

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20122

[Bug tree-optimization/20122] Wrong code with gcc 4.0 tree-vectorizer

[micis at gmx dot de]

------- Additional Comments From micis at gmx dot de  2005-03-02 10:27 -------
After you found the problem, may I ask you to set the status NEW and target 
milestone to 4.0.0 ?
That way this bug would show up in the list of open bugs for gcc40. 

Michael Cieslinski


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20122

[Bug tree-optimization/20122] Wrong code with gcc 4.0 tree-vectorizer

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2005-03-02 11:42 -------
Ira, can you please remember to confirm bugs in Bugzilla when you find them?

Micheal, this bug cannot be fixed in 4.0 since it is not a regression (the 
vectorizer is new). I would argue in favor of a new rule that allows to fix 
bugs in release branches for new features which are disabled by default, but 
for now this bug won't have a 4.0 milestone.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |irar at il dot ibm dot com
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-03-02 11:42:36
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20122

[Bug tree-optimization/20122] Wrong code with gcc 4.0 tree-vectorizer

[irar at il dot ibm dot com]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |irar at il dot ibm dot com
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2005-03-02 11:42:36         |2005-03-02 12:43:57
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20122

[Bug tree-optimization/20122] Wrong code with gcc 4.0 tree-vectorizer

[irar at il dot ibm dot com]

------- Additional Comments From irar at il dot ibm dot com  2005-03-02 12:45 -------
Fixed in http://gcc.gnu.org/ml/gcc-patches/2005-02/msg01788.html. Waiting for 
review.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20122

[Bug tree-optimization/20122] Wrong code with gcc 4.0 tree-vectorizer

[micis at gmx dot de]

------- Additional Comments From micis at gmx dot de  2005-03-03 10:44 -------
I applied you patch and did a full bootstrap on x86_64.
No new regressions. 
It fixes my problem.

Michael Cieslinski


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20122

[Bug tree-optimization/20122] Wrong code with gcc 4.0 tree-vectorizer

[micis at gmx dot de]

------- Additional Comments From micis at gmx dot de  2005-05-02 11:58 -------
The patch given in comment #5 seems to be included in gcc400 and in mainline.
I think this PR should be closed.

Michael Cieslinski


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20122

[Bug tree-optimization/20122] Wrong code with gcc 4.0 tree-vectorizer

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20122