[Bug rtl-optimization/30643] New: CSE regression

[Bug rtl-optimization/30643] New: CSE regression

[dann at godzilla dot ics dot uci dot edu]

CSE used to eliminate all the "if"s in the code below at least in gcc-3.x (and
probably even earlier). Now in SVN HEAD it does not do it anymore. 4.1 still
does it. 

struct s {  int a;  int b;};
void bar (struct s *ps,  int *p, int *__restrict__ rp, int *__restrict__ rq)
{
  ps->a = 0;
  ps->b = 1;
  if (ps->a != 0)    abort ();
  p[0] = 0;
  p[1] = 1;
  if (p[0] != 0)     abort ();
  rp[0] = 0;
  rq[0] = 1;
  if (rp[0] != 0)     abort();
}

-O2 assembly for SVN HEAD:
bar:
        subl    $12, %esp
        movl    16(%esp), %eax
        movl    20(%esp), %edx
        movl    24(%esp), %ecx
        movl    $0, (%eax)
        movl    $1, 4(%eax)
        movl    (%eax), %eax
        testl   %eax, %eax
        jne     .L20
        movl    $0, (%edx)
        movl    (%edx), %eax
        movl    $1, 4(%edx)
        testl   %eax, %eax
        jne     .L20
        movl    $0, (%ecx)
        movl    (%ecx), %ecx
        movl    28(%esp), %eax
        testl   %ecx, %ecx
        movl    $1, (%eax)
        jne     .L20
        addl    $12, %esp
        ret
.L20:
        call    abort


-O2 assembly for 4.1.1
bar:
        movl    4(%esp), %eax
        movl    8(%esp), %edx
        movl    $0, (%eax)
        movl    $1, 4(%eax)
        movl    12(%esp), %eax
        movl    $0, (%edx)
        movl    $1, 4(%edx)
        movl    $0, (%eax)
        movl    16(%esp), %eax
        movl    $1, (%eax)
        ret


-- 
           Summary: CSE regression
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dann at godzilla dot ics dot uci dot edu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] CSE regression

[janis at gcc dot gnu dot org]

------- Comment #1 from janis at gcc dot gnu dot org  2007-02-13 20:37 -------
Dan requested a regression hunt for this.  An i686-linux cross compiler starts
failing with this mainline patch:

    http://gcc.gnu.org/viewcvs?view=rev&rev=115614

    r115614 | pbrook | 2006-07-20 13:57:31 +0000 (Thu, 20 Jul 2006)

For powerpc-linux there are no calls to abort.


-- 

janis at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pbrook at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.2/4.3 Regression] CSE regression

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2007-02-20 22:31 -------
Confirmed.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |alias, missed-optimization
   Last reconfirmed|0000-00-00 00:00:00         |2007-02-20 22:31:02
               date|                            |
            Summary|CSE regression              |[4.2/4.3 Regression] CSE
                   |                            |regression
   Target Milestone|---                         |4.2.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.1/4.2/4.3 Regression] CSE regression

[jakub at gcc dot gnu dot org]

------- Comment #3 from jakub at gcc dot gnu dot org  2007-02-21 20:49 -------
4.1.2 behaves the same way as 4.2/4.3, the PR27363 patch that caused this
is got committed even there, see
http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=115620
Reverting that patch on gcc-4_1-branch restores the previous behavior.


-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |4.1.2 4.2.0 4.3.0
      Known to work|                            |4.1.1
            Summary|[4.2/4.3 Regression] CSE    |[4.1/4.2/4.3 Regression] CSE
                   |regression                  |regression
   Target Milestone|4.2.0                       |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.1/4.2/4.3 Regression] CSE regression

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.1/4.2/4.3 Regression] CSE regression

[ebotcazou at gcc dot gnu dot org]

------- Comment #4 from ebotcazou at gcc dot gnu dot org  2007-03-05 07:22 -------
Investigating.


-- 

ebotcazou at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |ebotcazou at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2007-02-20 22:31:02         |2007-03-05 07:22:17
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.1/4.2/4.3 regression] CSE pessimization

[aoliva at gcc dot gnu dot org]

------- Comment #5 from aoliva at gcc dot gnu dot org  2007-03-08 09:05 -------
I have a patch for the 4.1 branch that I'm bootstrap-testing now.  It doesn't
look like reverting the mentioned patch will fix the problem in mainline,
though, at least for an x86_64-linux-gnu native.


-- 

aoliva at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |aoliva at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.1/4.2/4.3 regression] CSE pessimization

[aoliva at gcc dot gnu dot org]

------- Comment #6 from aoliva at gcc dot gnu dot org  2007-03-08 10:23 -------
It was the fwprop merge that further disabled the optimization in the trunk. 
http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=118475


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.1/4.2/4.3 regression] CSE pessimization

[ebotcazou at gcc dot gnu dot org]

------- Comment #7 from ebotcazou at gcc dot gnu dot org  2007-03-08 11:39 -------
> I have a patch for the 4.1 branch that I'm bootstrap-testing now.

OK, reassigning to you, thanks.

> It doesn't look like reverting the mentioned patch will fix the problem in
> mainline, though, at least for an x86_64-linux-gnu native.

I presume it works on the 4.2 branch though?


-- 

ebotcazou at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|aoliva at gcc dot gnu dot   |ebotcazou at gcc dot gnu dot
                   |org                         |org
         AssignedTo|ebotcazou at gcc dot gnu dot|aoliva at gcc dot gnu dot
                   |org                         |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.1/4.2/4.3 regression] CSE pessimization

[patchapp at dberlin dot org]

------- Comment #8 from patchapp at dberlin dot org  2007-03-09 06:50 -------
Subject: Bug number PR30643

A patch for this bug has been added to the patch tracker.
The mailing list url for the patch is
http://gcc.gnu.org/ml/gcc-patches/2007-03/msg00525.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.1/4.2/4.3 regression] CSE pessimization

[bonzini at gnu dot org]

------- Comment #9 from bonzini at gnu dot org  2007-03-09 08:44 -------
Zdenek, any chance that your aliasing oracle can be used to fix these?


-- 

bonzini at gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rakdver at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.1/4.2/4.3 regression] CSE pessimization

[rakdver at gcc dot gnu dot org]

------- Comment #10 from rakdver at gcc dot gnu dot org  2007-03-09 08:54 -------
Alias oracle could be used for this; but my patch only uses it in loop
optimizers.  So some changes to make ccp use it would be necessary.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.1/4.2/4.3 regression] CSE pessimization

[patchapp at dberlin dot org]

------- Comment #11 from patchapp at dberlin dot org  2007-03-09 12:40 -------
Subject: Bug number PR30643

A patch for this bug has been added to the patch tracker.
The mailing list url for the patch is
http://gcc.gnu.org/ml/gcc-patches/2007-03/msg00545.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.1/4.2/4.3 regression] CSE pessimization

[aoliva at gcc dot gnu dot org]

------- Comment #12 from aoliva at gcc dot gnu dot org  2007-03-09 20:13 -------
Subject: Bug 30643

Author: aoliva
Date: Fri Mar  9 20:13:10 2007
New Revision: 122760

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=122760
Log:
gcc/ChangeLog:
PR rtl-optimization/30643
* cse.c (cse_insn): Recompute dest_hash after insert_regs for
(fold_rtx): Recurse, like before 2006-11-03.
gcc/testsuite/ChangeLog:
PR rtl-optimization/30643
* gcc.dg/pr30643.c: New.

Added:
    trunk/gcc/testsuite/gcc.dg/pr30643.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/cse.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.1/4.2/4.3 regression] CSE pessimization

[aoliva at gcc dot gnu dot org]

------- Comment #13 from aoliva at gcc dot gnu dot org  2007-03-09 23:30 -------
Subject: Bug 30643

Author: aoliva
Date: Fri Mar  9 23:29:51 2007
New Revision: 122771

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=122771
Log:
gcc/ChangeLog:
PR rtl-optimization/30643
* cse.c (cse_insn): Recompute dest_hash after insert_regs for
dest_addr_elt.
gcc/testsuite/ChangeLog:
PR rtl-optimization/30643
* gcc.dg/pr30643.c: New.

Added:
    branches/gcc-4_2-branch/gcc/testsuite/gcc.dg/pr30643.c
Modified:
    branches/gcc-4_2-branch/gcc/ChangeLog
    branches/gcc-4_2-branch/gcc/cse.c
    branches/gcc-4_2-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.1/4.2/4.3 regression] CSE pessimization

[aoliva at gcc dot gnu dot org]

------- Comment #14 from aoliva at gcc dot gnu dot org  2007-03-09 23:30 -------
Subject: Bug 30643

Author: aoliva
Date: Fri Mar  9 23:30:16 2007
New Revision: 122772

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=122772
Log:
gcc/ChangeLog:
PR rtl-optimization/30643
* cse.c (cse_insn): Recompute dest_hash after insert_regs for
dest_addr_elt.
gcc/testsuite/ChangeLog:
PR rtl-optimization/30643
* gcc.dg/pr30643.c: New.

Added:
    branches/gcc-4_1-branch/gcc/testsuite/gcc.dg/pr30643.c
Modified:
    branches/gcc-4_1-branch/gcc/ChangeLog
    branches/gcc-4_1-branch/gcc/cse.c
    branches/gcc-4_1-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.1/4.2/4.3 regression] CSE pessimization

[aoliva at gcc dot gnu dot org]

------- Comment #15 from aoliva at gcc dot gnu dot org  2007-03-09 23:36 -------
Should be fixed now, but H-P Nilsson says on IRC that there is a new ICE in
cse.c that could be related.  No details yet.  I suppose it's mainline, because
the patches for the branches are so much more trivial.  We'll see.


-- 

aoliva at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643

[Bug rtl-optimization/30643] [4.1/4.2/4.3 regression] CSE pessimization

[patchapp at dberlin dot org]

------- Comment #16 from patchapp at dberlin dot org  2007-03-13 07:30 -------
Subject: Bug number PR30643

A patch for this bug has been added to the patch tracker.
The mailing list url for the patch is
http://gcc.gnu.org/ml/gcc-patches/2007-03/msg00815.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30643