[Bug tree-optimization/22117] New: VRP thinks <ptr type> + <ptr type> is always nonnull.

[Bug tree-optimization/22117] New: VRP thinks <ptr type> + <ptr type> is always nonnull.

[kazu at cs dot umass dot edu]

Consider:

void
foo (int *p, int q)
{
  if (p == 0)
    {
      if (q == 0)
	{
	  int *r = &p[q];
	  if (r != 0)
	    link_error ();
	}
    }
}

Note that the innermost "if" condition should be folded to false,
but VRP folds that to true.

Under "if (q == 0)", both p and q are known to be zero,
but VRP thinks that regardless of their values, p + q is always nonnull.

-- 
           Summary: VRP thinks <ptr type> + <ptr type> is always nonnull.
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kazu at cs dot umass dot edu
                CC: dnovillo at redhat dot com,gcc-bugs at gcc dot gnu dot
                    org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22117

[Bug tree-optimization/22117] [4.1 Regression] VRP thinks <ptr type> + <ptr type> is always nonnull.

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-06-19 13:15 -------
Confirmed.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-06-19 13:15:06
               date|                            |
            Summary|VRP thinks <ptr type> + <ptr|[4.1 Regression] VRP thinks
                   |type> is always nonnull.    |<ptr type> + <ptr type> is
                   |                            |always nonnull.
   Target Milestone|---                         |4.1.0
            Version|unknown                     |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22117

[Bug tree-optimization/22117] [4.1 Regression] VRP thinks <ptr type> + <ptr type> is always nonnull.

[kazu at cs dot umass dot edu]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |kazu at cs dot umass dot edu
                   |dot org                     |
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22117

[Bug tree-optimization/22117] [4.1 Regression] VRP thinks <ptr type> + <ptr type> is always nonnull.

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-06-23 16:04 -------
Subject: Bug 22117

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	kazu@gcc.gnu.org	2005-06-23 16:04:10

Modified files:
	gcc            : ChangeLog tree-vrp.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.dg/tree-ssa: pr22117.c 

Log message:
	gcc/
	PR tree-optimization/22117
	* tree-vrp.c (extract_range_from_binary_expr): Compute a
	correct range when adding two pointers.
	
	testsuite/
	PR tree-optimization/22117
	* gcc.dg/tree-ssa/pr22117.c: New.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.9212&r2=2.9213
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-vrp.c.diff?cvsroot=gcc&r1=2.32&r2=2.33
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.5674&r2=1.5675
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/pr22117.c.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22117

[Bug tree-optimization/22117] [4.1 Regression] VRP thinks <ptr type> + <ptr type> is always nonnull.

[kazu at cs dot umass dot edu]

------- Additional Comments From kazu at cs dot umass dot edu  2005-06-24 01:59 -------
Just checked in a patch.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22117

[Bug tree-optimization/22117] [4.1 Regression] VRP thinks <ptr type> + <ptr type> is always nonnull.

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-06-24 14:16 -------
Fixed.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22117