public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug tree-optimization/19831] New: Missing DSE/malloc/free optimization
@ 2005-02-09  7:20 pinskia at gcc dot gnu dot org
  2005-02-09  9:44 ` [Bug tree-optimization/19831] " dberlin at dberlin dot org
  2005-02-09 12:43 ` pinskia at gcc dot gnu dot org
  0 siblings, 2 replies; 3+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-02-09  7:20 UTC (permalink / raw)
  To: gcc-bugs

The following function really should be compiled to an empty function (DSE should first remove the 
store and then free of a malloc with no change inbetween and we should remove both calls).
void *malloc(__SIZE_TYPE__);
void free(void*);
int f(void)
{
  char *i = malloc(1);
  *i = 1;
  free (i);
}

This is something which is useful when we want to much higer level optimizations.

-- 
           Summary: Missing DSE/malloc/free optimization
           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=19831


^ permalink raw reply	[flat|nested] 3+ messages in thread
* [Bug tree-optimization/19831] Missing DSE/malloc/free optimization
  2005-02-09  7:20 [Bug tree-optimization/19831] New: Missing DSE/malloc/free optimization pinskia at gcc dot gnu dot org
@ 2005-02-09  9:44 ` dberlin at dberlin dot org
  2005-02-09 12:43 ` pinskia at gcc dot gnu dot org
  1 sibling, 0 replies; 3+ messages in thread
From: dberlin at dberlin dot org @ 2005-02-09  9:44 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From dberlin at gcc dot gnu dot org  2005-02-09 03:42 -------
Subject: Re:  New: Missing DSE/malloc/free
	optimization

> void *malloc(__SIZE_TYPE__);
> void free(void*);
> int f(void)
> {
>   char *i = malloc(1);
>   *i = 1;
>   free (i);
> }
> 
> This is something which is useful when we want to much higer level optimizations.

This would require an attribute free, which is on the tree-profiling
branch

Otherwise, you wouldn't know that free is really "free"



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19831


^ permalink raw reply	[flat|nested] 3+ messages in thread
* [Bug tree-optimization/19831] Missing DSE/malloc/free optimization
  2005-02-09  7:20 [Bug tree-optimization/19831] New: Missing DSE/malloc/free optimization pinskia at gcc dot gnu dot org
  2005-02-09  9:44 ` [Bug tree-optimization/19831] " dberlin at dberlin dot org
@ 2005-02-09 12:43 ` pinskia at gcc dot gnu dot org
  1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-02-09 12:43 UTC (permalink / raw)
  To: gcc-bugs



-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-02-09 06:51:15
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19831


^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2005-02-09  6:51 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2005-02-09  7:20 [Bug tree-optimization/19831] New: Missing DSE/malloc/free optimization pinskia at gcc dot gnu dot org
2005-02-09  9:44 ` [Bug tree-optimization/19831] " dberlin at dberlin dot org
2005-02-09 12:43 ` pinskia at gcc dot gnu dot org

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).