[Bug tree-optimization/26135] New: store copyprop not effective

[Bug tree-optimization/26135] New: store copyprop not effective

[rguenth at gcc dot gnu dot org]

For (-O2 -fno-tree-dominator-opts -fno-tree-salias -fno-tree-sra)

int foo(int i)
{
  struct { int i; int j; } a;
  a.i = i;
  return a.i;
}

store copyprop does not propagate i to the return stmt.


-- 
           Summary: store copyprop not effective
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rguenth at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26135

[Bug tree-optimization/26135] store copyprop not effective

[rguenth at gcc dot gnu dot org]

------- Comment #1 from rguenth at gcc dot gnu dot org  2006-02-06 17:36 -------
And I have a patch.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dnovillo at redhat dot com
         AssignedTo|unassigned at gcc dot gnu   |rguenth at gcc dot gnu dot
                   |dot org                     |org
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-02-06 17:36:39
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26135

[Bug tree-optimization/26135] store copyprop not effective

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2006-02-07 15:46 -------
Patch posted.  As DOM nearly handles all store copyprop I wonder if (this late)
store copyprop is worth it.  If not going to copyprop on steroids which I'm
going to clean up again and re-submit.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2006-
                   |                            |02/msg00559.html
           Keywords|                            |patch


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26135

[Bug tree-optimization/26135] store copyprop not effective

[steven at gcc dot gnu dot org]

------- Comment #3 from steven at gcc dot gnu dot org  2006-02-07 16:35 -------
In fact DOM should probably not be doing store copyprop, and store copyprop is
simply broken.  It never worked quite the way it should, so if you want to
implement a better one, great!


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26135

[Bug tree-optimization/26135] store copyprop not effective

[rguenth at gcc dot gnu dot org]

------- Comment #4 from rguenth at gcc dot gnu dot org  2006-02-08 13:18 -------
And the alternative store copyprop implementation was posted here:
http://gcc.gnu.org/ml/gcc-patches/2006-02/msg00669.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26135

[Bug tree-optimization/26135] store copyprop not effective

[rguenth at gcc dot gnu dot org]

------- Comment #5 from rguenth at gcc dot gnu dot org  2006-04-07 08:04 -------
Subject: Bug 26135

Author: rguenth
Date: Fri Apr  7 08:04:26 2006
New Revision: 112749

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=112749
Log:
2006-04-07  Richard Guenther  <rguenther@suse.de>

        PR tree-optimization/26135
        * tree-ssa-copy.c (stmt_may_generate_copy): Handle memory
        loads for store copy-prop.
        (copy_prop_visit_stmt): Likewise.

        * gcc.dg/tree-ssa/ssa-copyprop-1.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-copyprop-1.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-copy.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26135

[Bug tree-optimization/26135] store copyprop not effective

[rguenth at gcc dot gnu dot org]

------- Comment #6 from rguenth at gcc dot gnu dot org  2006-04-07 08:05 -------
Fixed.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.2.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26135