[Bug optimization/9059] unused arrays not optimized away when followed by external call

[Bug optimization/9059] unused arrays not optimized away when followed by external call

[pinskia@physics.uc.edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9059


pinskia@physics.uc.edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|0000-00-00 00:00:00         |2003-06-03 19:07:15
               date|                            |


------- Additional Comments From pinskia@physics.uc.edu  2003-06-03 19:07 -------
Simpler testcase:

f()
{
  int a[1024];
}

I think this is a duplicate but I cannot find the bug number.



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[Bug optimization/9059] unused arrays not optimized away

[pinskia@physics.uc.edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9059


pinskia@physics.uc.edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|unused arrays not optimized |unused arrays not optimized
                   |away when followed by       |away
                   |external call               |
   Target Milestone|3.4                         |---

[Bug optimization/9059] unused arrays not optimized away

[pinskia at physics dot uc dot edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9059


pinskia at physics dot uc dot edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement
             Status|NEW                         |SUSPENDED


------- Additional Comments From pinskia at physics dot uc dot edu  2003-07-21 02:54 -------
This problem is already fixed on the tree-ssa branch so suspending untill it merges into 
the mainline.

[Bug optimization/9059] unused arrays not optimized away

[pinskia at physics dot uc dot edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9059


pinskia at physics dot uc dot edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |tree-ssa

[Bug optimization/9059] unused arrays not optimized away

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2003-12-17 00:33 -------
Weird:
The testcase:
f()
{
  int a[1024];
}
is not optimized but the testcase is:
f()
{
  int a[1024];
  a[0]=0;
}

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|SUSPENDED                   |NEW
   Last reconfirmed|2003-12-04 09:07:42         |2003-12-17 00:33:25
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9059

[Bug optimization/9059] unused arrays not optimized away

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-03-03 07:18 -------
The problem here is that pass_remove_useless_vars is not being called for the last 
testcase, the one without any real code.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9059

[Bug tree-optimization/9059] unused arrays not optimized away

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2004-05-17 10:47 -------
Ehm, pass_remove_useless_vars _is_ called, but there is no variable annotation
for unused variables, so:

  /* Remove all unused, unaliased temporaries.  Also remove unused, unaliased
     local variables during highly optimizing compilations.  */
  ann = var_ann (var);
  if (ann
      && ! ann->may_aliases
      && ! ann->used
      && ! ann->has_hidden_use
      && ! TREE_ADDRESSABLE (var)

we already have (!ann).  Something like this should work:

+ if (!ann)
+   return false;
! else if (! ann->may_aliases
(etc.)

I'll make a patch and try if that works.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9059

[Bug tree-optimization/9059] unused arrays not optimized away

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-05-23 23:32 -------
Steven did your patch work?

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |steven at gcc dot gnu dot
                   |                            |org
   Target Milestone|3.5.0                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9059

[Bug tree-optimization/9059] unused arrays not optimized away

[stevenb at suse dot de]

------- Additional Comments From stevenb at suse dot de  2004-05-24 06:46 -------
Subject: Re:  unused arrays not optimized away

On Monday 24 May 2004 01:32, pinskia at gcc dot gnu dot org wrote:
> ------- Additional Comments From pinskia at gcc dot gnu dot org  2004-05-23
> 23:32 ------- Steven did your patch work?

no, but a modified one does. it's not pretty though, so i'm
looking for something else now.



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9059

[Bug tree-optimization/9059] unused arrays not optimized away

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-07-22 06:33 -------
Fixed for 3.5.0 by:
2004-07-21  Richard Henderson  <rth@redhat.com>

        * gimple-low.c (expand_var_p): Don't look at TREE_ADDRESSABLE,
        TREE_THIS_VOLATILE, may_aliases, or optimization level.
        (remove_useless_vars): Dump debugging info.
        (expand_used_vars): Move ...
        * cfgexpand.c (expand_used_vars): ... here.  Make static.
        * tree-flow-inline.h (set_is_used): New.
        (set_default_def): Use get_var_ann.
        * tree-flow.h: Update decls.
        * tree-ssa-live.c (mark_all_vars_used_1, mark_all_vars_used): New.
        (create_ssa_var_map): Use it.
        * tree-ssa.c (set_is_used): Remove.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |3.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9059