[Bug tree-optimization/38785] [4.3/4.4/4.5/4.6/4.7 Regression] huge performance regression on EEMBC bitmnp01

[Bug tree-optimization/38785] [4.3/4.4/4.5/4.6/4.7 Regression] huge performance regression on EEMBC bitmnp01

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.3.6                       |4.4.7

--- Comment #27 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-06-27 12:13:21 UTC ---
4.3 branch is being closed, moving to 4.4.7 target.

[Bug tree-optimization/38785] [4.4/4.5/4.6/4.7 Regression] huge performance regression on EEMBC bitmnp01

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

--- Comment #28 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-01-16 13:14:22 UTC ---
Re-confirmed.  Regular PRE has got some kind of a cost-model (restricting
insertion to the case where we eliminate a redundancy on a fast path).
Partial-insertion has not been updated in a similar manner.

[Bug tree-optimization/38785] [4.5/4.6/4.7/4.8 Regression] huge performance regression on EEMBC bitmnp01

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.4.7                       |4.5.4

--- Comment #29 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-13 12:46:14 UTC ---
4.4 branch is being closed, moving to 4.5.4 target.

[Bug tree-optimization/38785] [4.5/4.6/4.7/4.8 Regression] huge performance regression on EEMBC bitmnp01

[mkuvyrkov at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

--- Comment #30 from Maxim Kuvyrkov <mkuvyrkov at gcc dot gnu.org> 2012-04-28 01:56:59 UTC ---
Author: mkuvyrkov
Date: Sat Apr 28 01:56:54 2012
New Revision: 186928

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=186928
Log:
    PR tree-optimization/38785
    * common.opt (ftree-partial-pre): New option.
    * doc/invoke.texi: Document it.
    * opts.c (default_options_table): Initialize flag_tree_partial_pre.
    * tree-ssa-pre.c (do_partial_partial_insertion): Insert only if it will
    benefit speed path.
    (execute_pre): Use flag_tree_partial_pre.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/common.opt
    trunk/gcc/doc/invoke.texi
    trunk/gcc/opts.c
    trunk/gcc/tree-ssa-pre.c

[Bug tree-optimization/38785] [4.5/4.6/4.7/4.8 Regression] huge performance regression on EEMBC bitmnp01

[mkuvyrkov at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Maxim Kuvyrkov <mkuvyrkov at gcc dot gnu.org> changed:

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

--- Comment #31 from Maxim Kuvyrkov <mkuvyrkov at gcc dot gnu.org> 2012-04-28 02:09:38 UTC ---
Fixed by the above reworked version of Joern's and Steven's patches.

[Bug tree-optimization/38785] [4.5/4.6/4.7/4.8 Regression] huge performance regression on EEMBC bitmnp01

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.5.4                       |4.8.0

[Bug tree-optimization/38785] [4.5/4.6/4.7/4.8 Regression] huge performance regression on EEMBC bitmnp01

[hubicka at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Jan Hubicka <hubicka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |WAITING
                 CC|                            |hubicka at gcc dot gnu.org
         Resolution|FIXED                       |

--- Comment #32 from Jan Hubicka <hubicka at gcc dot gnu.org> 2012-11-16 17:50:28 UTC ---
Would be possible to double check if this problem is still fixed after the fix
to the tree-ssa-pre patch? I do not see any cold edges involved here, so
perhaps we will need better heuristic.

We now again find some partial redundancies.
Found partial redundancy for expression {mem_ref<0B>,_20}@.MEM_5 (0024)
Inserted pretmp_57 = *_20;
 in predecessor 6
Created phi prephitmp_56 = PHI <_24(20), pretmp_57(6)>
 in block 7
Found partial redundancy for expression {mem_ref<0B>,_20}@.MEM_6 (0029)
Inserted pretmp_55 = *_20;
 in predecessor 8
Created phi prephitmp_63 = PHI <_29(21), pretmp_55(8)>
 in block 9
Found partial redundancy for expression {mem_ref<0B>,_20}@.MEM_7 (0034)
Inserted pretmp_64 = *_20;
 in predecessor 10
Created phi prephitmp_65 = PHI <_34(22), pretmp_64(10)>
 in block 11
Found partial redundancy for expression {mem_ref<0B>,_20}@.MEM_8 (0039)
Inserted pretmp_66 = *_20;
 in predecessor 12
Created phi prephitmp_67 = PHI <_39(23), pretmp_66(12)>
 in block 13
Starting insert iteration 2
Replaced *_20 with prephitmp_56 in _29 = *_20;
Replaced *_20 with prephitmp_63 in _34 = *_20;
Replaced *_20 with prephitmp_65 in _39 = *_20;
Replaced *_20 with prephitmp_67 in _44 = *_20;

[Bug tree-optimization/38785] [4.5/4.6/4.7/4.8 Regression] huge performance regression on EEMBC bitmnp01

[hubicka at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

--- Comment #33 from Jan Hubicka <hubicka at gcc dot gnu.org> 2012-11-16 18:00:54 UTC ---
And at -O3 the testcase does not look really good indeed
  <bb 7>:
  # cstore_51 = PHI <0(5), 2147483647(6)>
  # prephitmp_82 = PHI <1073741823(5), 3221225470(6)>
  # prephitmp_83 = PHI <1789569705(5), 3937053352(6)>
  # prephitmp_84 = PHI <2326440616(5), 4473924263(6)>
  # prephitmp_85 = PHI <2755937345(5), 4903420992(6)>
  # prephitmp_86 = PHI <3113851286(5), 5261334933(6)>
  # prephitmp_87 = PHI <2684354557(5), 4831838204(6)>
  # prephitmp_88 = PHI <2219066434(5), 4366550081(6)>
  # prephitmp_89 = PHI <2576980375(5), 4724464022(6)>
  # prephitmp_90 = PHI <2147483646(5), 4294967293(6)>
  # prephitmp_91 = PHI <1610612734(5), 3758096381(6)>
  # prephitmp_92 = PHI <2040109463(5), 4187593110(6)>
  # prephitmp_93 = PHI <2398023404(5), 4545507051(6)>
  # prephitmp_94 = PHI <1968526675(5), 4116010322(6)>
  # prephitmp_95 = PHI <1503238552(5), 3650722199(6)>
  # prephitmp_96 = PHI <1861152493(5), 4008636140(6)>
  # prephitmp_97 = PHI <1431655764(5), 3579139411(6)>
  # prephitmp_98 = PHI <715827882(5), 2863311529(6)>
  # prephitmp_99 = PHI <1252698793(5), 3400182440(6)>
  # prephitmp_100 = PHI <1682195522(5), 3829679169(6)>
  # prephitmp_103 = PHI <1145324611(5), 3292808258(6)>
  # prephitmp_106 = PHI <536870911(5), 2684354558(6)>
  # prephitmp_107 = PHI <966367640(5), 3113851287(6)>
  # prephitmp_108 = PHI <1324281581(5), 3471765228(6)>
  # prephitmp_109 = PHI <894784852(5), 3042268499(6)>
  # prephitmp_110 = PHI <429496729(5), 2576980376(6)>
  # prephitmp_111 = PHI <787410670(5), 2934894317(6)>
  # prephitmp_112 = PHI <357913941(5), 2505397588(6)>
  *_18 = cstore_51;
  _24 = *_20;
  _25 = _24 << 2;
  if (_25 >= -14)
    goto <bb 8>;
  else
    goto <bb 9>;

The catch is that the patch disabled the partial PRE by an accident. No cold
edges are involved here since we predict all the branches quite even :(

[Bug tree-optimization/38785] [4.5/4.6/4.7/4.8 Regression] huge performance regression on EEMBC bitmnp01

[izamyatin at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

--- Comment #34 from Igor Zamyatin <izamyatin at gmail dot com> 2012-11-20 21:00:39 UTC ---
(In reply to comment #32)
> Would be possible to double check if this problem is still fixed after the fix
> to the tree-ssa-pre patch?

Unfortunately the regression happened after the fix...

[Bug tree-optimization/38785] [4.5/4.6/4.7/4.8 Regression] huge performance regression on EEMBC bitmnp01

[hubicka at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Jan Hubicka <hubicka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |REOPENED

--- Comment #35 from Jan Hubicka <hubicka at gcc dot gnu.org> 2012-11-21 17:56:04 UTC ---
Too bad, we really need to make some model on how many PHI copies we
introduce... I agree with Richard's comment that Joern's patch is rather bad in
respect to optimization oppurtunities.   This is more or less register pressure
problem. I will try think about it a bit more ;)

[Bug tree-optimization/38785] [4.5/4.6/4.7/4.8 Regression] huge performance regression on EEMBC bitmnp01

[amylaar at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

--- Comment #36 from Jorn Wolfgang Rennecke <amylaar at gcc dot gnu.org> 2012-11-21 17:59:10 UTC ---
(In reply to comment #35)
> Too bad, we really need to make some model on how many PHI copies we
> introduce... I agree with Richard's comment that Joern's patch is rather bad in
> respect to optimization oppurtunities.   This is more or less register pressure
> problem. I will try think about it a bit more ;)

This is not just register pressure, these constant loads and register-register
copies do not come free, either.

[Bug tree-optimization/38785] [4.5/4.6/4.7/4.8 Regression] huge performance regression on EEMBC bitmnp01

[hubicka at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Jan Hubicka <hubicka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |vmakarov at redhat dot com

--- Comment #37 from Jan Hubicka <hubicka at gcc dot gnu.org> 2012-11-22 09:50:52 UTC ---
Yes, agreed. It is overall problem of SSA form to assume that reg-reg copies in
PHIs will be optimized away by smart regalloc.  Moreover we assume the same for
constants.

This case is hard to fix later since the values are path sensitive...
Vladimir, I guess there is not much to do on regalloc side, right?

Why the problem do not reproduce on simplified testcase:
void
f (int i, long *a, long *b)
{
  int sum = 0;
  b[i] = 0;
#define PART(I) if (t()) sum++;
  PART (1);
  PART (2);
  PART (3);
  PART (4);
  PART (5);
  PART (6);
  tt (sum);
}
here we somehow do not consider the partial redundancies on sum...

[Bug tree-optimization/38785] [4.5/4.6/4.7/4.8 Regression] huge performance regression on EEMBC bitmnp01

[hubicka at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

--- Comment #38 from Jan Hubicka <hubicka at gcc dot gnu.org> 2012-11-22 13:05:38 UTC ---
yet another variant...
void
f (int i, long *a, long *b)
{
  int sum = 0;
  for (; --i >=  0; a++, b++)
    {
  b[i] = 0;
#define PART(I) if (t()) sum+=100+I;
  PART (1);
  PART (2);
  PART (3);
  PART (4);
  PART (5);
  PART (6);
  tt (sum);
    }
}
leads to...
Starting insert iteration 1
Could not find SSA_NAME representative for expression:{plus_expr,sum_8,101}
Created SSA_NAME representative pretmp_98 for expression:{plus_expr,sum_8,101}
Could not find SSA_NAME representative for expression:{plus_expr,pretmp_98,102}
Created SSA_NAME representative pretmp_99 for
expression:{plus_expr,pretmp_98,102}
Could not find SSA_NAME representative for expression:{plus_expr,pretmp_99,103}
Created SSA_NAME representative pretmp_100 for
expression:{plus_expr,pretmp_99,103}
Could not find SSA_NAME representative for
expression:{plus_expr,pretmp_100,104}
Created SSA_NAME representative pretmp_101 for
expression:{plus_expr,pretmp_100,104}
Could not find SSA_NAME representative for
expression:{plus_expr,pretmp_101,105}
Created SSA_NAME representative pretmp_102 for
expression:{plus_expr,pretmp_101,105}
Could not find SSA_NAME representative for
expression:{plus_expr,pretmp_100,105}
Created SSA_NAME representative pretmp_103 for
expression:{plus_expr,pretmp_100,105}
Could not find SSA_NAME representative for expression:{plus_expr,pretmp_99,104}
Created SSA_NAME representative pretmp_104 for
expression:{plus_expr,pretmp_99,104}
Could not find SSA_NAME representative for
expression:{plus_expr,pretmp_104,105}
Created SSA_NAME representative pretmp_105 for
expression:{plus_expr,pretmp_104,105}
Could not find SSA_NAME representative for expression:{plus_expr,pretmp_99,105}
Created SSA_NAME representative pretmp_106 for
expression:{plus_expr,pretmp_99,105}
Could not find SSA_NAME representative for expression:{plus_expr,pretmp_98,103}
Created SSA_NAME representative pretmp_107 for
expression:{plus_expr,pretmp_98,103}
Could not find SSA_NAME representative for
expression:{plus_expr,pretmp_107,104}
Created SSA_NAME representative pretmp_108 for
expression:{plus_expr,pretmp_107,104}
Could not find SSA_NAME representative for
expression:{plus_expr,pretmp_108,105}
Created SSA_NAME representative pretmp_109 for
expression:{plus_expr,pretmp_108,105}
Could not find SSA_NAME representative for
expression:{plus_expr,pretmp_107,105}
Created SSA_NAME representative pretmp_110 for
expression:{plus_expr,pretmp_107,105}
Could not find SSA_NAME representative for expression:{plus_expr,pretmp_98,104}
Created SSA_NAME representative pretmp_111 for
expression:{plus_expr,pretmp_98,104}
Could not find SSA_NAME representative for
expression:{plus_expr,pretmp_111,105}

that eventually leads to a lot of unused pretmp vars.

[Bug tree-optimization/38785] [4.5/4.6/4.7/4.8/4.9 Regression] huge performance regression on EEMBC bitmnp01

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.0                       |4.8.1

--- Comment #39 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-03-22 14:44:33 UTC ---
GCC 4.8.0 is being released, adjusting target milestone.

[Bug tree-optimization/38785] [4.5/4.7/4.8/4.9 Regression] huge performance regression on EEMBC bitmnp01

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.1                       |4.8.2

--- Comment #40 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.8.1 has been released.

[Bug tree-optimization/38785] [4.5/4.7/4.8/4.9 Regression] huge performance regression on EEMBC bitmnp01

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.2                       |4.8.3

--- Comment #41 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.8.2 has been released.

[Bug tree-optimization/38785] [4.5/4.7/4.8/4.9/4.10 Regression] huge performance regression on EEMBC bitmnp01

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.3                       |4.8.4

--- Comment #42 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 4.8.3 is being released, adjusting target milestone.

[Bug tree-optimization/38785] [4.8/4.9/5 Regression] huge performance regression on EEMBC bitmnp01

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.4                       |4.8.5

--- Comment #43 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.8.4 has been released.

[Bug tree-optimization/38785] [4.8/4.9/5/6 Regression] huge performance regression on EEMBC bitmnp01

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.5                       |4.9.3

--- Comment #44 from Richard Biener <rguenth at gcc dot gnu.org> ---
The gcc-4_8-branch is being closed, re-targeting regressions to 4.9.3.

[Bug tree-optimization/38785] [4.9/5/6 Regression] huge performance regression on EEMBC bitmnp01

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

--- Comment #45 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.9.3 has been released.

[Bug tree-optimization/38785] [4.9/5/6 Regression] huge performance regression on EEMBC bitmnp01

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.9.3                       |4.9.4

[Bug tree-optimization/38785] [8/9/10/11/12 Regression] huge performance regression on EEMBC bitmnp01

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED

[Bug tree-optimization/38785] [9/10/11/12 Regression] huge performance regression on EEMBC bitmnp01

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|8.5                         |9.4

--- Comment #54 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 8 branch is being closed.

[Bug tree-optimization/38785] [9/10/11/12 Regression] huge performance regression on EEMBC bitmnp01

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.4                         |9.5

--- Comment #55 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9.4 is being released, retargeting bugs to GCC 9.5.

[Bug tree-optimization/38785] [10/11/12/13 Regression] huge performance regression on EEMBC bitmnp01

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.5                         |10.4

--- Comment #56 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9 branch is being closed

[Bug tree-optimization/38785] [10/11/12/13 Regression] huge performance regression on EEMBC bitmnp01

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.4                        |10.5

--- Comment #57 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 10.4 is being released, retargeting bugs to GCC 10.5.

[Bug tree-optimization/38785] [11/12/13/14 Regression] huge performance regression on EEMBC bitmnp01

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.5                        |11.5

--- Comment #58 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 10 branch is being closed.