[Bug tree-optimization/18529] New: When the lower bound of a loop is non-constant we cannot find the number of iterations

[Bug tree-optimization/18529] New: When the lower bound of a loop is non-constant we cannot find the number of iterations

[pinskia at gcc dot gnu dot org]

long *a;

void f(int start, int end)
{
  int i;
  for (i = start; i <end ; i++)
    a[i] = 0;
}

Some anylsis of the problem here: <http://gcc.gnu.org/ml/gcc/2004-08/msg01315.html>.

I filed this to keep track of it.

-- 
           Summary: When the lower bound of a loop is non-constant we cannot
                    find the number of iterations
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18529

[Bug tree-optimization/18529] When the lower bound of a loop is non-constant we cannot find the number of iterations

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-11-17 15:44 -------
Note this is like PR 18527 but a different problem (I don't know how offten this shows up in SPEC but I 
found this when I was working on my loops to memset pass).

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rakdver at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-11-17 15:44:58
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18529

[Bug tree-optimization/18529] When the lower bound of a loop is non-constant we cannot find the number of iterations

[rakdver at gcc dot gnu dot org]

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18529

[Bug tree-optimization/18529] When the lower bound of a loop is non-constant we cannot find the number of iterations

[rakdver at gcc dot gnu dot org]

------- Additional Comments From rakdver at gcc dot gnu dot org  2004-11-18 21:54 -------
Patch:

http://gcc.gnu.org/ml/gcc-patches/2004-11/msg01516.html

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18529

[Bug tree-optimization/18529] When the lower bound of a loop is non-constant we cannot find the number of iterations

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-11-22 21:33 -------
Subject: Bug 18529

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	rakdver@gcc.gnu.org	2004-11-22 21:33:48

Modified files:
	gcc            : ChangeLog fold-const.c tree-ssa-loop-niter.c 

Log message:
	PR tree-optimization/18529
	* fold-const.c (fold_to_nonsharp_ineq_using_bound): New function.
	(simple_operand_p): Use STRIP_NOPS.  Consider SSA names simple.
	(fold): Call fold_to_nonsharp_ineq_using_bound.
	* tree-ssa-loop-niter.c (simplify_replace_tree): New function.
	(number_of_iterations_cond): Fold the expressions before futher
	processing.
	(tree_simplify_using_condition): Handle case when cond or expr is
	an EQ_EXPR specially.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.6459&r2=2.6460
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/fold-const.c.diff?cvsroot=gcc&r1=1.475&r2=1.476
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-ssa-loop-niter.c.diff?cvsroot=gcc&r1=2.16&r2=2.17



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18529

[Bug tree-optimization/18529] When the lower bound of a loop is non-constant we cannot find the number of iterations

[rakdver at gcc dot gnu dot org]

------- Additional Comments From rakdver at gcc dot gnu dot org  2004-11-22 21:34 -------
Fixed.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18529

[Bug tree-optimization/18529] When the lower bound of a loop is non-constant we cannot find the number of iterations

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18529