[Bug c/21582] New: (optimisation) VRP pass could/should use non-null function attribute

[Bug c/21582] New: (optimisation) VRP pass could/should use non-null function attribute

[arjanv at redhat dot com]

The nonnull function attribute specifies that certain pointer arguments to said
function are not allowed to be NULL. The VRP pass could put this in the possible
range for said variables, after which NULL pointer checks inside the function
body (or more likely, functions inlined into that function) can be optimized away.

-- 
           Summary: (optimisation) VRP pass could/should use non-null
                    function attribute
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: arjanv at redhat dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21582

[Bug tree-optimization/21582] (optimisation) VRP pass could/should use non-null function attribute

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-05-15 14:22 -------
Interesting idea.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dnovillo at gcc dot gnu dot
                   |                            |org
          Component|c                           |tree-optimization
           Keywords|                            |missed-optimization


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21582

[Bug tree-optimization/21582] (optimisation) VRP pass could/should use non-null function attribute

[kazu at cs dot umass dot edu]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |18373


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21582

[Bug tree-optimization/21582] (optimisation) VRP pass could/should use non-null function attribute

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-05-23 18:25 -------
Confirmed.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-05-23 18:25:00
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21582

[Bug tree-optimization/21582] (optimisation) VRP pass could/should use non-null function attribute

[arjanv at redhat dot com]

------- Additional Comments From arjanv at redhat dot com  2005-06-02 12:59 -------
simple test case:

#include <stdio.h>

static inline void do_thing(char *s)
{
        if (s)
                printf("do_thing: %s \n", s);
}

void __attribute__((nonnull)) do_other_thing(char *s)
{
        do_thing(s);
}



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21582

[Bug tree-optimization/21582] (optimisation) VRP pass could/should use non-null function attribute

[dnovillo at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |dnovillo at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2005-05-23 18:25:00         |2005-06-02 13:43:47
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21582

[Bug tree-optimization/21582] (optimisation) VRP pass could/should use non-null function attribute

[dnovillo at gcc dot gnu dot org]

------- Additional Comments From dnovillo at gcc dot gnu dot org  2005-06-02 18:26 -------

Fixed.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21582

[Bug tree-optimization/21582] (optimisation) VRP pass could/should use non-null function attribute

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-06-02 18:26 -------
Subject: Bug 21582

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	dnovillo@gcc.gnu.org	2005-06-02 18:26:08

Modified files:
	gcc            : ChangeLog tree-vrp.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.dg/tree-ssa: pr21582.c 

Log message:
	PR 21582
	* tree-vrp.c (nonnull_arg_p): New.
	(get_value_range): Call it.
	
	testsuite/ChangeLog
	
	PR 21582
	* gcc.dg/tree-ssa/pr21582.c: New test.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.9000&r2=2.9001
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-vrp.c.diff?cvsroot=gcc&r1=2.20&r2=2.21
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.5579&r2=1.5580
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/pr21582.c.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21582

[Bug tree-optimization/21582] (optimisation) VRP pass could/should use non-null function attribute

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21582

[Bug tree-optimization/21582] (optimisation) VRP pass could/should use non-null function attribute

[pinskia at gcc dot gnu dot org]

-- 
Bug 21582 depends on bug 18373, which changed state.

Bug 18373 Summary: [meta-bug] VRP Value Range Propagation
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18373

           What    |Old Value                   |New Value
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21582