[Bug tree-optimization/21658] New: CCP does not propagate ADDR_EXPR far enough.

[Bug tree-optimization/21658] New: CCP does not propagate ADDR_EXPR far enough.

[kazu at cs dot umass dot edu]

Consider:

void
f (void)
{
  int *p, *q, *r;
  int a[10];
  p = &a[5];
  q = p - 1;
  r = q - 1;
  *r = 1;
}

Here is what I get from the first CCP.

f ()
{
  int a[10];
  int * r;
  int * q;
  int * p;

<bb 0>:
  p_1 = &a[5];
  q_2 = &a[4];
  r_3 = q_2 - 4B;
  *r_3 = 1;
  return;

}

Note that p_1 and q_2 are of the form &a[CST], but r_3 is not.

-- 
           Summary: CCP does not propagate ADDR_EXPR far enough.
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          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=21658

[Bug tree-optimization/21658] CCP does not propagate ADDR_EXPR far enough.

[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|UNCONFIRMED                 |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21658

[Bug tree-optimization/21658] CCP does not propagate ADDR_EXPR far enough.

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-05-27 16:31 -------
Subject: Bug 21658

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	kazu@gcc.gnu.org	2005-05-27 16:31:29

Modified files:
	gcc            : ChangeLog tree-ssa-ccp.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.dg/tree-ssa: pr21658.c 

Log message:
	gcc/
	PR tree-optimization/21658
	* tree-ssa-ccp.c (ccp_fold): Call fold_binary instead of
	fold_binary_to_constant.  Likewise, call fold_unary instead of
	fold_unary_to_constant.
	
	testsuite/
	PR tree-optimization/21658
	* gcc.dg/tree-ssa/pr21658.c: New.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.8920&r2=2.8921
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-ssa-ccp.c.diff?cvsroot=gcc&r1=2.72&r2=2.73
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.5546&r2=1.5547
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/pr21658.c.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21658

[Bug tree-optimization/21658] CCP does not propagate ADDR_EXPR far enough.

[kazu at cs dot umass dot edu]

------- Additional Comments From kazu at cs dot umass dot edu  2005-05-27 16:33 -------
Just checked in a patch.


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21658