public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug middle-end/14784] New: Tree-ssa alias analysis deficiency
@ 2004-03-30 16:03 rakdver at gcc dot gnu dot org
  2004-05-24 23:30 ` [Bug tree-optimization/14784] [Tree-ssa] " pinskia at gcc dot gnu dot org
                   ` (2 more replies)
  0 siblings, 3 replies; 21+ messages in thread
From: rakdver at gcc dot gnu dot org @ 2004-03-30 16:03 UTC (permalink / raw)
  To: gcc-bugs

Tree-ssa alias analysis does not take information about structure
fields into account.  Consequently head->using_obstack and bitmap_free
accesses in the following testcase are believed to alias, which prevents
further optimizations (load motion, unswitching) on tree level.

typedef struct bitmap_element_def
{
  unsigned int indx;
} bitmap_element;

typedef struct bitmap_head_def {
  bitmap_element *first;
  int using_obstack;
} bitmap_head;
typedef struct bitmap_head_def *bitmap;

bitmap_element *bitmap_free;

void foo (bitmap head, bitmap_element *elt)
{
  while (1)
    {
      if (head->using_obstack)
        bitmap_free = elt;
    }
}

-- 
           Summary: Tree-ssa alias analysis deficiency
           Product: gcc
           Version: tree-ssa
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rakdver at gcc dot gnu dot org
                CC: dnovillo at redhat dot com,gcc-bugs at gcc dot gnu dot
                    org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14784


^ permalink raw reply	[flat|nested] 21+ messages in thread
end of thread, other threads:[~2006-12-13  7:37 UTC | newest]

Thread overview: 21+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <bug-14784-5077@http.gcc.gnu.org/bugzilla/>
2006-02-16 21:40 ` [Bug tree-optimization/14784] [Tree-ssa] alias analysis deficiency pinskia at gcc dot gnu dot org
2006-02-17  1:04   ` Daniel Berlin
2006-02-17  1:04 ` dberlin at dberlin dot org
2006-10-23  9:23 ` rakdver at gcc dot gnu dot org
2006-10-24  0:12 ` rakdver at gcc dot gnu dot org
2006-10-26 13:00 ` pinskia at gcc dot gnu dot org
2006-10-31 15:00 ` hjl at lucon dot org
2006-10-31 15:02 ` hjl at lucon dot org
2006-10-31 15:05   ` Daniel Berlin
2006-10-31 15:05 ` dberlin at dberlin dot org
2006-10-31 21:49 ` hjl at lucon dot org
2006-10-31 22:22 ` hjl at lucon dot org
2006-11-13 12:38 ` rakdver at gcc dot gnu dot org
2006-11-13 13:54 ` pinskia at gcc dot gnu dot org
2006-11-20  2:37 ` pinskia at gcc dot gnu dot org
2006-12-01  1:09 ` chaoyingfu at gcc dot gnu dot org
2006-12-05 18:26 ` rakdver at gcc dot gnu dot org
2006-12-13  7:37 ` pinskia at gcc dot gnu dot org
2004-03-30 16:03 [Bug middle-end/14784] New: Tree-ssa " rakdver at gcc dot gnu dot org
2004-05-24 23:30 ` [Bug tree-optimization/14784] [Tree-ssa] " pinskia at gcc dot gnu dot org
2005-01-13  1:02 ` pinskia at gcc dot gnu dot org
2005-01-20 21:38 ` dberlin 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).