[Bug tree-optimization/52324] New: [4.7 Regression] Store motion no longer performed

[Bug tree-optimization/52324] New: [4.7 Regression] Store motion no longer performed

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52324

             Bug #: 52324
           Summary: [4.7 Regression] Store motion no longer performed
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: rguenth@gcc.gnu.org


The following fails on trunk but works in 4.5 and 4.6.

/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-lim1-details" } */

int *l, *r;
int test_func(void)
{
  int i;
  int direction;
  static int pos;

  pos = 0;
  direction = 1;

  for ( i = 0; i <= 400; i++ )
    {
      if ( direction == 0 )
        pos = l[pos];
      else
        pos = r[pos];

      if ( pos == -1 )
        {
          pos = 0;
          direction = !direction;
        }
    }
  return i;
}

/* { dg-final { scan-tree-dump "Executing store motion of pos" "lim1" } } */
/* { dg-final { cleanup-tree-dump "lim1" } } */

[Bug tree-optimization/52324] [4.7 Regression] Store motion no longer performed

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52324

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2012-02-21
      Known to work|                            |4.5.3, 4.6.2
         AssignedTo|unassigned at gcc dot       |rguenth at gcc dot gnu.org
                   |gnu.org                     |
   Target Milestone|---                         |4.7.0
     Ever Confirmed|0                           |1
      Known to fail|                            |4.7.0

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-02-21 10:16:32 UTC ---
I have a patch.

[Bug tree-optimization/52324] [4.7 Regression] Store motion no longer performed

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52324

--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-02-21 12:37:37 UTC ---
Author: rguenth
Date: Tue Feb 21 12:37:33 2012
New Revision: 184435

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=184435
Log:
2012-02-21  Richard Guenther  <rguenther@suse.de>

    PR tree-optimization/52324
    * gimplify.c (gimplify_expr): When re-gimplifying expressions
    do not gimplify a MEM_REF address operand if it is already
    in suitable form.

    * gcc.dg/tree-ssa/ssa-lim-10.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-lim-10.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/gimplify.c
    trunk/gcc/testsuite/ChangeLog

[Bug tree-optimization/52324] [4.7 Regression] Store motion no longer performed

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52324

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

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

--- Comment #3 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-02-21 12:46:40 UTC ---
Fixed.