[Bug middle-end/46885] New: [4.6 Regression] ICE: in gsi_insert_seq_nodes_after, at gimple-iterator.c:251 with -ftree-parallelize-loops -g

[Bug middle-end/46885] New: [4.6 Regression] ICE: in gsi_insert_seq_nodes_after, at gimple-iterator.c:251 with -ftree-parallelize-loops -g

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46885

           Summary: [4.6 Regression] ICE: in gsi_insert_seq_nodes_after,
                    at gimple-iterator.c:251 with -ftree-parallelize-loops
                    -g
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsojka@seznam.cz
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu


Created attachment 22706
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22706
reduced testcase

Compiler output:
$ gcc -O -ftree-parallelize-loops=4 -g -fno-tree-dominator-opts
-funswitch-loops pr46885.c 
pr46885.c: In function 'foo':
pr46885.c:8:1: internal compiler error: in gsi_insert_seq_nodes_after, at
gimple-iterator.c:251
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

Tested revisions:
r167643 - crash
r161659 - crash
r158095 - OK
4.5 r166509 - OK

[Bug middle-end/46885] [4.6 Regression] ICE: in gsi_insert_seq_nodes_after, at gimple-iterator.c:251 with -ftree-parallelize-loops -g

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46885

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2010.12.10 16:54:33
                 CC|                            |aoliva at gcc dot gnu.org
   Target Milestone|---                         |4.6.0
     Ever Confirmed|0                           |1

--- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> 2010-12-10 16:54:33 UTC ---
It is caused by revision 160762:

http://gcc.gnu.org/ml/gcc-cvs/2010-06/msg00677.html

[Bug middle-end/46885] [4.6 Regression] ICE: in gsi_insert_seq_nodes_after, at gimple-iterator.c:251 with -ftree-parallelize-loops -g

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46885

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

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

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-12-13 15:48:16 UTC ---
Created attachment 22742
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22742
gcc46-pr46885.patch

Untested fix.

When bumping in latch, create_iv inserts the new stmt after the given position
instead of before it, which ICEs if the bb contains just debug stmts.  When
inserting after the last stmt, we should just use gsi_last_bb.

[Bug middle-end/46885] [4.6 Regression] ICE: in gsi_insert_seq_nodes_after, at gimple-iterator.c:251 with -ftree-parallelize-loops -g

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46885

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-12-14 14:11:25 UTC ---
Author: jakub
Date: Tue Dec 14 14:11:16 2010
New Revision: 167801

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=167801
Log:
    PR debug/46885
    * tree-ssa-loop-manip.c (canonicalize_loop_ivs): Use gsi_last_bb
    instead of gsi_last_nondebug_bb if bump_in_latch.

    * gcc.dg/autopar/pr46885.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/autopar/pr46885.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-loop-manip.c

[Bug middle-end/46885] [4.6 Regression] ICE: in gsi_insert_seq_nodes_after, at gimple-iterator.c:251 with -ftree-parallelize-loops -g

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46885

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> 2010-12-14 14:39:38 UTC ---
Fixed.