[Bug tree-optimization/34016] New: ICE in execute_todo with -ftree-loop-linear for 454.calculix

[Bug tree-optimization/34016] New: ICE in execute_todo with -ftree-loop-linear for 454.calculix

[janis at gcc dot gnu dot org]

Test 454.calculix from SPEC CPU2006 fails to build on powerpc-linux using -O2
-ftree-loop-linear with an ICE in execute_todo at passes.c:983.  This minimized
test case demonstrates the problem:

      subroutine bug()
      implicit none
      integer i,j
      real*8 gr(6,6)
      do i=1,6
         do j=1,6
            gr(i,j)=0.d0
         enddo
         if(i.le.3) then
            gr(i,i)=1.d0
         endif
      enddo
      call foo(gr)
      return
      end

The failure starts with:

    http://gcc.gnu.org/viewcvs?view=rev&rev=129494
    r129494 | spop | 2007-10-19 19:01:58 +0000 (Fri, 19 Oct 2007)


-- 
           Summary: ICE in execute_todo with -ftree-loop-linear for
                    454.calculix
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: janis at gcc dot gnu dot org
GCC target triplet: powerpc-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34016

[Bug tree-optimization/34016] ICE in execute_todo with -ftree-loop-linear for 454.calculix

[spop at gcc dot gnu dot org]

------- Comment #1 from spop at gcc dot gnu dot org  2007-11-08 01:58 -------
Fails also on i686-linux.  I'm working on a fix.

Sebastian


-- 

spop at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-11-08 01:58:18
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34016

[Bug tree-optimization/34016] [4.3 Regression] ICE in execute_todo with -ftree-loop-linear for 454.calculix

[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 execute_todo with -  |[4.3 Regression] ICE in
                   |ftree-loop-linear for       |execute_todo with -ftree-
                   |454.calculix                |loop-linear for 454.calculix
   Target Milestone|---                         |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34016

[Bug tree-optimization/34016] [4.3 Regression] ICE in execute_todo with -ftree-loop-linear for 454.calculix

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34016

[Bug tree-optimization/34016] [4.3 Regression] ICE in execute_todo with -ftree-loop-linear for 454.calculix

[jakub at gcc dot gnu dot org]

------- Comment #2 from jakub at gcc dot gnu dot org  2007-11-27 12:31 -------
Testcase in C:
/* PR tree-optimization/34016 */
/* { dg-do compile } */
/* { dg-options "-O2 -ftree-loop-linear" } */

extern void bar (double *);

void foo (void)
{
  double gr[36];
  int i, j;
  for (i = 0; i <= 5; i++)
    {
      for (j = 0; j <= 5; j++)
        gr[i + j * 6] = 0.0;
      if (i <= 2)
        gr[i + i * 6] = 1.0;
    }
  bar (gr);
}

As perfect_nestify will call mark_syms_for_renaming, I believe the right fix is
to update todo flags of this pass either using:
--- tree-ssa-loop.c.jj6 2007-09-17 22:25:50.000000000 +0200
+++ tree-ssa-loop.c     2007-11-27 13:18:41.000000000 +0100
@@ -272,6 +272,7 @@ struct tree_opt_pass pass_linear_transfo
   0,                                   /* properties_destroyed */
   0,                                   /* todo_flags_start */
   TODO_dump_func | TODO_verify_loops
+    | TODO_update_ssa_only_virtuals
     | TODO_ggc_collect,                        /* todo_flags_finish */
   0                                    /* letter */
 };

or by returning TODO_update_ssa_only_virtuals from tree_linear_transform if
there wasn't already a perfect nest.  As update_ssa is a nop if
!need_ssa_update_p, I believe just adding | TODO_update_ssa_only_virtuals
to pass_linear_transform.todo_flags_finish is better.  Will test.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34016

[Bug tree-optimization/34016] [4.3 Regression] ICE in execute_todo with -ftree-loop-linear for 454.calculix

[jakub at gcc dot gnu dot org]

------- Comment #3 from jakub at gcc dot gnu dot org  2007-11-27 22:23 -------
Subject: Bug 34016

Author: jakub
Date: Tue Nov 27 22:23:29 2007
New Revision: 130476

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=130476
Log:
        PR tree-optimization/34016
        * tree-ssa-loop.c (pass_linear_transform): Add
        TODO_update_ssa_only_virtuals to todo_flags_finish.

        * gcc.dg/pr34016.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/pr34016.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-loop.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34016

[Bug tree-optimization/34016] [4.3 Regression] ICE in execute_todo with -ftree-loop-linear for 454.calculix

[jakub at gcc dot gnu dot org]

------- Comment #4 from jakub at gcc dot gnu dot org  2007-11-27 22:24 -------
Fixed.


-- 

jakub at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34016