[Bug tree-optimization/55110] New: Internal compiler error in vectorizable_reduction, at tree-vect-loop.c:4633

[Bug tree-optimization/55110] New: Internal compiler error in vectorizable_reduction, at tree-vect-loop.c:4633

[antoine.balestrat at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55110

             Bug #: 55110
           Summary: Internal compiler error in vectorizable_reduction, at
                    tree-vect-loop.c:4633
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: antoine.balestrat@gmail.com


Hello !
The following testcase makes GCC 4.8.0 as of 20121021 crash with -O1
-ftree-vectorize.

$ cat vector.c
int a, b, c;

void f(void)
{
    for(; b; b++)
        for(c = 0; c < 2; c++)
            a /= 5;
}

$ xgcc -O1 -ftree-vectorize -w vector.c
vector.c: In function ‘f’:
vector.c:3:6: internal compiler error: in vectorizable_reduction, at
tree-vect-loop.c:4633
 void f(void)
      ^
linux-vdso.so.1: No such file or directory
0xa67b9c vectorizable_reduction(gimple_statement_d*, gimple_stmt_iterator*,
gimple_statement_d**, _slp_tree*)
    ../../srcdir/gcc/tree-vect-loop.c:4633
0xa58fa0 vect_analyze_stmt(gimple_statement_d*, bool*, _slp_tree*)
    ../../srcdir/gcc/tree-vect-stmts.c:5710
0xa58aca vect_analyze_stmt(gimple_statement_d*, bool*, _slp_tree*)
    ../../srcdir/gcc/tree-vect-stmts.c:5632
0xa6356d vect_analyze_loop_operations
    ../../srcdir/gcc/tree-vect-loop.c:1447
0xa6356d vect_analyze_loop_2
    ../../srcdir/gcc/tree-vect-loop.c:1725
0xa6356d vect_analyze_loop(loop*)
    ../../srcdir/gcc/tree-vect-loop.c:1778
0xa75f1c vectorize_loops()
    ../../srcdir/gcc/tree-vectorizer.c:114
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.

[Bug tree-optimization/55110] Internal compiler error in vectorizable_reduction, at tree-vect-loop.c:4633

[mpolacek at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55110

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-10-29
                 CC|                            |mpolacek at gcc dot
                   |                            |gnu.org, rth at gcc dot
                   |                            |gnu.org
     Ever Confirmed|0                           |1

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> 2012-10-29 12:14:19 UTC ---
Started with http://gcc.gnu.org/viewcvs?view=revision&revision=189006

[Bug tree-optimization/55110] [4.8 Regression] Internal compiler error in vectorizable_reduction, at tree-vect-loop.c:4633

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55110

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.8.0
            Summary|Internal compiler error in  |[4.8 Regression] Internal
                   |vectorizable_reduction, at  |compiler error in
                   |tree-vect-loop.c:4633       |vectorizable_reduction, at
                   |                            |tree-vect-loop.c:4633

[Bug tree-optimization/55110] [4.8 Regression] Internal compiler error in vectorizable_reduction, at tree-vect-loop.c:4633

[rth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55110

Richard Henderson <rth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
         AssignedTo|unassigned at gcc dot       |rth at gcc dot gnu.org
                   |gnu.org                     |

[Bug tree-optimization/55110] [4.8 Regression] Internal compiler error in vectorizable_reduction, at tree-vect-loop.c:4633

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55110

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-26 10:35:44 UTC ---
I'd say either we should nuke the bogus
  gcc_assert (STMT_VINFO_RELATED_STMT (orig_stmt_info) == stmt);
assertion, which predates the introduction of
STMT_VINFO_PATTERN_DEF_STMT (and later STMT_VINFO_PATTERN_DEF_SEQ) - both in
4.7 cycle, or just return false; if it isn't equal.
We won't successfully vectorize this anyway, orig_code is still TRUNC_DIV_EXPR
and that is not a handled reduction (and even if we'd handled it as the signed
MULT_HIGHPART_EXPR reduction, that isn't handled either).

So, I'd propose this (if we wanted to assert something, it would need to
walk the STMT_VINFO_PATTERN_DEF_SEQ sequence and checking whether stmt isn't in
there too):

2012-11-26  Jakub Jelinek  <jakub@redhat.com>

    PR tree-optimization/55110
    * tree-vect-loop.c (vectorizable_reduction): Don't assert
    that STMT_VINFO_RELATED_STMT of orig_stmt is stmt.

    * gcc.dg/pr55110.c: New test.

--- gcc/tree-vect-loop.c.jj    2012-11-21 16:00:12.000000000 +0100
+++ gcc/tree-vect-loop.c    2012-11-26 11:24:42.903995009 +0100
@@ -4624,7 +4624,6 @@ vectorizable_reduction (gimple stmt, gim
   if (orig_stmt)
     {
       orig_stmt_info = vinfo_for_stmt (orig_stmt);
-      gcc_assert (STMT_VINFO_RELATED_STMT (orig_stmt_info) == stmt);
       gcc_assert (STMT_VINFO_IN_PATTERN_P (orig_stmt_info));
       gcc_assert (!STMT_VINFO_IN_PATTERN_P (stmt_info));
     }
--- gcc/testsuite/gcc.dg/pr55110.c.jj    2012-11-26 11:31:32.008587313 +0100
+++ gcc/testsuite/gcc.dg/pr55110.c    2012-11-26 11:31:09.000000000 +0100
@@ -0,0 +1,13 @@
+/* PR tree-optimization/55110 */
+/* { dg-do compile } */
+/* { dg-options "-O1 -ftree-vectorize" } */
+
+int
+foo (int x)
+{
+  int a, b;
+  for (b = 0; b < 8; b++)
+    for (a = 0; a < 2; a++)
+      x /= 3;
+  return x;
+}

[Bug tree-optimization/55110] [4.8 Regression] Internal compiler error in vectorizable_reduction, at tree-vect-loop.c:4633

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55110

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-27 13:34:19 UTC ---
Author: jakub
Date: Tue Nov 27 13:34:11 2012
New Revision: 193845

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=193845
Log:
    PR tree-optimization/55110
    * tree-vect-loop.c (vectorizable_reduction): Don't assert
    that STMT_VINFO_RELATED_STMT of orig_stmt is stmt.

    * gcc.dg/pr55110.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/pr55110.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vect-loop.c

[Bug tree-optimization/55110] [4.8 Regression] Internal compiler error in vectorizable_reduction, at tree-vect-loop.c:4633

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55110

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

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

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-27 13:39:53 UTC ---
Fixed.

[Bug tree-optimization/55110] [4.8 Regression] Internal compiler error in vectorizable_reduction, at tree-vect-loop.c:4633

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55110

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-02-19 17:16:02 UTC ---
Author: jakub
Date: Tue Feb 19 17:15:53 2013
New Revision: 196140

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=196140
Log:
    Backported from mainline
    2012-11-27  Jakub Jelinek  <jakub@redhat.com>

    PR tree-optimization/55110
    * tree-vect-loop.c (vectorizable_reduction): Don't assert
    that STMT_VINFO_RELATED_STMT of orig_stmt is stmt.

    * gcc.dg/pr55110.c: New test.

Added:
    branches/gcc-4_7-branch/gcc/testsuite/gcc.dg/pr55110.c
Modified:
    branches/gcc-4_7-branch/gcc/ChangeLog
    branches/gcc-4_7-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_7-branch/gcc/tree-vect-loop.c