[Bug tree-optimization/37421] New: ICE in vn_reference_insert_pieces at tree-ssa-sccvn.c:1131

[Bug tree-optimization/37421] New: ICE in vn_reference_insert_pieces at tree-ssa-sccvn.c:1131

[dnovillo at gcc dot gnu dot org]

Found with this test case.  Still have not analyzed it, so I'm not quite sure
where we're getting confused:

#include <stdio.h>
#include <string.h>

inline int
bci (const float &source)
{
 int dest;
 memcpy (&dest, &source, sizeof (dest));
 return dest;
}

inline float
bcf (const int &source)
{
 float dest;
 memcpy (&dest, &source, sizeof (dest));
 return dest;
}

float
Foo ()
{
 const int foo = bci (0.0f);
 int bar = foo;
 const int baz = foo & 1;
 if (!baz && (foo & 2))
   bar = 0;
 return bcf (bar);
}

main ()
{
  printf ("Foo() = %f\n", Foo());
}

$ <mainline>/bin/g++ -o mathutil -O2 mathutil.cc
mathutil.cc: In function 'float Foo()':
mathutil.cc:21: internal compiler error: in vn_reference_insert_pieces, at
tree-ssa-sccvn.c:1131
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.


-- 
           Summary: ICE in vn_reference_insert_pieces at tree-ssa-
                    sccvn.c:1131
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dnovillo 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=37421

[Bug tree-optimization/37421] ICE in vn_reference_insert_pieces at tree-ssa-sccvn.c:1131

[rguenth at gcc dot gnu dot org]

------- Comment #1 from rguenth at gcc dot gnu dot org  2008-09-08 12:16 -------
I will have a look.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |rguenth at gcc dot gnu dot
                   |dot org                     |org
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2008-09-08 12:16:17
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37421

[Bug tree-optimization/37421] ICE in vn_reference_insert_pieces at tree-ssa-sccvn.c:1131

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2008-09-08 12:21 -------
ANTIC_OUT[4] := { {view_convert_expr ,integer_cst 0} (0005) }
ANTIC_IN[4] := { {view_convert_expr ,integer_cst 0} (0005) }
S[4] := { {view_convert_expr ,integer_cst 0} (0005) }

so a quick look suggests we fail to properly fold references during PHI
translation.

<bb 4>:
  bar_34 = 0;

<bb 5>:
  # bar_11 = PHI <bar_33(7), bar_33(6), bar_34(4)>
  dest.12_29 = VIEW_CONVERT_EXPR<float>(bar_11);


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37421

[Bug tree-optimization/37421] ICE in vn_reference_insert_pieces at tree-ssa-sccvn.c:1131

[rguenth at gcc dot gnu dot org]

------- Comment #3 from rguenth at gcc dot gnu dot org  2008-09-08 14:56 -------
I have a (good on its own) patch to hide the issue, but I'll try to investigate
the issue some more.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37421

[Bug tree-optimization/37421] ICE in vn_reference_insert_pieces at tree-ssa-sccvn.c:1131

[rguenth at gcc dot gnu dot org]

------- Comment #4 from rguenth at gcc dot gnu dot org  2008-09-08 15:14 -------
It actually is the correct fix.  We valueize expressions in-place, and
copy visiting doesn't follow the chain up until a constant.  So we have

a = 0;
  = VIEW_CONVERT_EXPR <a>;
b = a;
  = VIEW_CONVERT_EXPR <b>;

we first insert VIEW_CONVERT_EXPR <0> in the table, then during processing
of VIEW_CONVERT_EXPR <b> we valueize it to VIEW_CONVERT_EXPR <a> which is
not in the table.  During insertion we valueize again, now getting
VIEW_CONVERT_EXPR <0> which is already in the table so we hit the assert.

Bootstrapping and testing the fix now.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37421

[Bug tree-optimization/37421] ICE in vn_reference_insert_pieces at tree-ssa-sccvn.c:1131

[rguenth at gcc dot gnu dot org]

------- Comment #5 from rguenth at gcc dot gnu dot org  2008-09-08 16:31 -------
Fixed.


-- 

rguenth at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37421

[Bug tree-optimization/37421] ICE in vn_reference_insert_pieces at tree-ssa-sccvn.c:1131

[rguenth at gcc dot gnu dot org]

------- Comment #6 from rguenth at gcc dot gnu dot org  2008-09-08 16:33 -------
Subject: Bug 37421

Author: rguenth
Date: Mon Sep  8 16:31:43 2008
New Revision: 140111

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=140111
Log:
2008-09-08  Richard Guenther  <rguenther@suse.de>

        PR tree-optimization/37421
        * tree-ssa-sccvn.c (visit_copy): Make sure to fully
        valueize the RHS.

        * g++.dg/torture/pr37421.C: New testcase.

Added:
    trunk/gcc/testsuite/g++.dg/torture/pr37421.C
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-sccvn.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37421

[Bug tree-optimization/37421] [4.4 Regression] ICE in vn_reference_insert_pieces at tree-ssa-sccvn.c:1131

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
           Keywords|                            |ice-on-valid-code
            Summary|ICE in                      |[4.4 Regression] ICE in
                   |vn_reference_insert_pieces  |vn_reference_insert_pieces
                   |at tree-ssa-sccvn.c:1131    |at tree-ssa-sccvn.c:1131
   Target Milestone|---                         |4.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37421

[Bug tree-optimization/37421] [4.4 Regression] ICE in vn_reference_insert_pieces at tree-ssa-sccvn.c:1131

[dnovillo at gcc dot gnu dot org]

------- Comment #7 from dnovillo at gcc dot gnu dot org  2008-09-08 20:13 -------
Subject: Bug 37421

Author: dnovillo
Date: Mon Sep  8 20:12:38 2008
New Revision: 140119

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=140119
Log:
2008-09-08  Diego Novillo  <dnovillo@google.com>

        * tree-ssa-pre.c (gate_pre): Re-enable.

        Bring from mainline @140111

        2008-09-08  Richard Guenther  <rguenther@suse.de>

                PR tree-optimization/37421
                * tree-ssa-sccvn.c (visit_copy): Make sure to fully
                valueize the RHS.

testsuite/ChangeLog.lto:

2008-09-08  Diego Novillo  <dnovillo@google.com>

        Bring from mainline @140111

        2008-09-08  Richard Guenther  <rguenther@suse.de>

                PR tree-optimization/37421
                * g++.dg/torture/pr37421.C: New testcase.

        * gcc.dg/lto/lto.exp: Add -pedantic-errors.
        * g++.dg/lto/lto.exp: Likewise.
        * g++.dg/lto/20080908-1.C: Fix return value of main().
        * g++.dg/lto/20080908-3.C: Likewise.



Added:
    branches/lto/gcc/testsuite/g++.dg/torture/pr37421.C
      - copied unchanged from r140111,
trunk/gcc/testsuite/g++.dg/torture/pr37421.C
Modified:
    branches/lto/gcc/ChangeLog.lto
    branches/lto/gcc/testsuite/ChangeLog.lto
    branches/lto/gcc/testsuite/g++.dg/lto/20080908-1.C
    branches/lto/gcc/testsuite/g++.dg/lto/20080908-3.C
    branches/lto/gcc/testsuite/g++.dg/lto/lto.exp
    branches/lto/gcc/testsuite/gcc.dg/lto/lto.exp
    branches/lto/gcc/tree-ssa-pre.c
    branches/lto/gcc/tree-ssa-sccvn.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37421