[Bug tree-optimization/56049] [4.8 Regression] Simplification to constants not done

2013-02-12 Thread rguenther at suse dot de 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56049



--- Comment #6 from rguenther at suse dot de rguenther at suse dot de 
2013-02-12 11:06:23 UTC ---

On Mon, 11 Feb 2013, hubicka at gcc dot gnu.org wrote:



 

 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56049

 

 --- Comment #5 from Jan Hubicka hubicka at gcc dot gnu.org 2013-02-11 
 22:55:44 UTC ---

 Well, I think we should try to toamn fantasy of our optimizers here.  What

 unroller sees at -O3 -fno-tree-vectorize is quite ugly:

 

   bb 2:

   a = {};

 

   bb 3:

   # i_1 = PHI 1(2), i_7(7)

   # prephitmp_99 = PHI 0(2), pretmp_98(7)

   # prephitmp_102 = PHI 0(2), pretmp_101(7)

   # prephitmp_105 = PHI 0(2), pretmp_104(7)

   # prephitmp_108 = PHI 0(2), pretmp_107(7)

   # prephitmp_111 = PHI 0(2), pretmp_110(7)

   # prephitmp_114 = PHI 0(2), pretmp_113(7)

   # prephitmp_117 = PHI 0(2), pretmp_116(7)

   # prephitmp_120 = PHI 0(2), pretmp_119(7)

   # ivtmp_57 = PHI 1000(2), ivtmp_64(7)

 

   bb 4:

   # S.0_90 = PHI S.0_36(5), 1(3)

   # prephitmp_126 = PHI pretmp_125(5), prephitmp_99(3)

   # prephitmp_129 = PHI pretmp_128(5), prephitmp_102(3)

   # prephitmp_132 = PHI pretmp_131(5), prephitmp_105(3)

   # prephitmp_135 = PHI pretmp_134(5), prephitmp_108(3)

   # prephitmp_138 = PHI pretmp_137(5), prephitmp_111(3)

   # prephitmp_141 = PHI pretmp_140(5), prephitmp_114(3)

   # prephitmp_144 = PHI pretmp_143(5), prephitmp_117(3)

   # prephitmp_147 = PHI pretmp_146(5), prephitmp_120(3)

   # ivtmp_43 = PHI ivtmp_50(5), 8(3)

   _29 = S.0_90 * 8;

   _42 = _29 + -8;

   _44 = prephitmp_126 + 1;

   b[_42] = _44;

   _49 = _29 + -7;

   _51 = prephitmp_129 + 1;

   b[_49] = _51;

   _56 = _29 + -6;

   _58 = prephitmp_132 + 1;

   b[_56] = _58;

   _63 = _29 + -5;

   _65 = prephitmp_135 + 1;

   b[_63] = _65;

   _70 = _29 + -4;

   b[_63] = _65;

   _70 = _29 + -4;

   _72 = prephitmp_138 + 1;

   b[_70] = _72;

   _77 = _29 + -3;

   _79 = prephitmp_141 + 1;

   b[_77] = _79;

   _84 = _29 + -2;

   _86 = prephitmp_144 + 1;

   b[_84] = _86;

   _91 = _29 + -1;

   _93 = prephitmp_147 + 1;

   b[_91] = _93;

   S.0_36 = S.0_90 + 1;

   ivtmp_50 = ivtmp_43 - 1;

   if (ivtmp_50 == 0)

 goto bb 6;

   else

 goto bb 5;

 

   bb 5:

   pretmp_122 = S.0_36 * 8;

   pretmp_124 = pretmp_122 + -8;

   pretmp_125 = a[pretmp_124];

   pretmp_127 = pretmp_122 + -7;

   pretmp_128 = a[pretmp_127];

   pretmp_130 = pretmp_122 + -6;

   pretmp_131 = a[pretmp_130];

   pretmp_133 = pretmp_122 + -5;

   pretmp_134 = a[pretmp_133];

   pretmp_136 = pretmp_122 + -4;

   pretmp_137 = a[pretmp_136];

   pretmp_139 = pretmp_122 + -3;

   pretmp_140 = a[pretmp_139];

   pretmp_142 = pretmp_122 + -2;

   pretmp_143 = a[pretmp_142];

   pretmp_145 = pretmp_122 + -1;

   pretmp_146 = a[pretmp_145];

   goto bb 4;

 

 With vectorization we actually unroll the inner loop but the outer one gets so

 ugly that we don't do much about it...

 

 So what about keeping it as enhancement request? I will try to poke about it,

 but htere is but about PR overactivity of this type already, right?



Not that I know of (well there is some about PRE over-activity creating

lots of PHI nodes like this).  Yes, keep it as enhancement request

I suppose.



Does the unroller even look at PHI nodes for costs?

[Bug tree-optimization/56049] [4.8 Regression] Simplification to constants not done

2013-02-12 Thread aldyh at gcc dot gnu.org 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56049



Aldy Hernandez aldyh at gcc dot gnu.org changed:



   What|Removed |Added



   Severity|normal  |enhancement

[Bug tree-optimization/56049] [4.8 Regression] Simplification to constants not done

2013-02-12 Thread jakub at gcc dot gnu.org 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56049



Jakub Jelinek jakub at gcc dot gnu.org changed:



   What|Removed |Added



   Priority|P1  |P2



--- Comment #7 from Jakub Jelinek jakub at gcc dot gnu.org 2013-02-12 
14:28:15 UTC ---

Enhancement shouldn't be P1.

[Bug tree-optimization/56049] [4.8 Regression] Simplification to constants not done

2013-02-11 Thread aldyh at gcc dot gnu.org 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56049



Aldy Hernandez aldyh at gcc dot gnu.org changed:



   What|Removed |Added



 CC||aldyh at gcc dot gnu.org



--- Comment #4 from Aldy Hernandez aldyh at gcc dot gnu.org 2013-02-11 
22:02:02 UTC ---

Honza.  Are you interested in investigating this as Richard suggests, or can we

close this as WONTFIX?

[Bug tree-optimization/56049] [4.8 Regression] Simplification to constants not done

2013-02-11 Thread hubicka at gcc dot gnu.org 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56049



--- Comment #5 from Jan Hubicka hubicka at gcc dot gnu.org 2013-02-11 
22:55:44 UTC ---

Well, I think we should try to toamn fantasy of our optimizers here.  What

unroller sees at -O3 -fno-tree-vectorize is quite ugly:



  bb 2:

  a = {};



  bb 3:

  # i_1 = PHI 1(2), i_7(7)

  # prephitmp_99 = PHI 0(2), pretmp_98(7)

  # prephitmp_102 = PHI 0(2), pretmp_101(7)

  # prephitmp_105 = PHI 0(2), pretmp_104(7)

  # prephitmp_108 = PHI 0(2), pretmp_107(7)

  # prephitmp_111 = PHI 0(2), pretmp_110(7)

  # prephitmp_114 = PHI 0(2), pretmp_113(7)

  # prephitmp_117 = PHI 0(2), pretmp_116(7)

  # prephitmp_120 = PHI 0(2), pretmp_119(7)

  # ivtmp_57 = PHI 1000(2), ivtmp_64(7)



  bb 4:

  # S.0_90 = PHI S.0_36(5), 1(3)

  # prephitmp_126 = PHI pretmp_125(5), prephitmp_99(3)

  # prephitmp_129 = PHI pretmp_128(5), prephitmp_102(3)

  # prephitmp_132 = PHI pretmp_131(5), prephitmp_105(3)

  # prephitmp_135 = PHI pretmp_134(5), prephitmp_108(3)

  # prephitmp_138 = PHI pretmp_137(5), prephitmp_111(3)

  # prephitmp_141 = PHI pretmp_140(5), prephitmp_114(3)

  # prephitmp_144 = PHI pretmp_143(5), prephitmp_117(3)

  # prephitmp_147 = PHI pretmp_146(5), prephitmp_120(3)

  # ivtmp_43 = PHI ivtmp_50(5), 8(3)

  _29 = S.0_90 * 8;

  _42 = _29 + -8;

  _44 = prephitmp_126 + 1;

  b[_42] = _44;

  _49 = _29 + -7;

  _51 = prephitmp_129 + 1;

  b[_49] = _51;

  _56 = _29 + -6;

  _58 = prephitmp_132 + 1;

  b[_56] = _58;

  _63 = _29 + -5;

  _65 = prephitmp_135 + 1;

  b[_63] = _65;

  _70 = _29 + -4;

  b[_63] = _65;

  _70 = _29 + -4;

  _72 = prephitmp_138 + 1;

  b[_70] = _72;

  _77 = _29 + -3;

  _79 = prephitmp_141 + 1;

  b[_77] = _79;

  _84 = _29 + -2;

  _86 = prephitmp_144 + 1;

  b[_84] = _86;

  _91 = _29 + -1;

  _93 = prephitmp_147 + 1;

  b[_91] = _93;

  S.0_36 = S.0_90 + 1;

  ivtmp_50 = ivtmp_43 - 1;

  if (ivtmp_50 == 0)

goto bb 6;

  else

goto bb 5;



  bb 5:

  pretmp_122 = S.0_36 * 8;

  pretmp_124 = pretmp_122 + -8;

  pretmp_125 = a[pretmp_124];

  pretmp_127 = pretmp_122 + -7;

  pretmp_128 = a[pretmp_127];

  pretmp_130 = pretmp_122 + -6;

  pretmp_131 = a[pretmp_130];

  pretmp_133 = pretmp_122 + -5;

  pretmp_134 = a[pretmp_133];

  pretmp_136 = pretmp_122 + -4;

  pretmp_137 = a[pretmp_136];

  pretmp_139 = pretmp_122 + -3;

  pretmp_140 = a[pretmp_139];

  pretmp_142 = pretmp_122 + -2;

  pretmp_143 = a[pretmp_142];

  pretmp_145 = pretmp_122 + -1;

  pretmp_146 = a[pretmp_145];

  goto bb 4;



With vectorization we actually unroll the inner loop but the outer one gets so

ugly that we don't do much about it...



So what about keeping it as enhancement request? I will try to poke about it,

but htere is but about PR overactivity of this type already, right?

[Bug tree-optimization/56049] [4.8 Regression] Simplification to constants not done

2013-02-08 Thread rguenth at gcc dot gnu.org 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56049



Richard Biener rguenth at gcc dot gnu.org changed:



   What|Removed |Added



   Priority|P3  |P1

[Bug tree-optimization/56049] [4.8 Regression] Simplification to constants not done

2013-01-21 Thread rguenth at gcc dot gnu.org 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56049



Richard Biener rguenth at gcc dot gnu.org changed:



   What|Removed |Added



 Status|UNCONFIRMED |NEW

   Last reconfirmed||2013-01-21

 Ever Confirmed|0   |1



--- Comment #3 from Richard Biener rguenth at gcc dot gnu.org 2013-01-21 
13:30:00 UTC ---

Programs optimizing to a constant are artifical enough to mark this WONTFIX.

The lowering was deliberate to not grow object size too much.



Maybe Honza want's to investigate why heuristics do not detect the

all-constant outcome.

[Bug tree-optimization/56049] [4.8 Regression] Simplification to constants not done

2013-01-20 Thread tkoenig at gcc dot gnu.org 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56049



Thomas Koenig tkoenig at gcc dot gnu.org changed:



   What|Removed |Added



 CC||rguenth at gcc dot gnu.org

   Target Milestone|--- |4.8.0

[Bug tree-optimization/56049] [4.8 Regression] Simplification to constants not done

2013-01-20 Thread dominiq at lps dot ens.fr 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56049



--- Comment #1 from Dominique d'Humieres dominiq at lps dot ens.fr 2013-01-20 
10:32:18 UTC ---

This occurred between revisions 193542 (2012-11-15) and 193573 (2012-11-16).

[Bug tree-optimization/56049] [4.8 Regression] Simplification to constants not done

2013-01-20 Thread jakub at gcc dot gnu.org 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56049



Jakub Jelinek jakub at gcc dot gnu.org changed:



   What|Removed |Added



 CC||hubicka at gcc dot gnu.org,

   ||jakub at gcc dot gnu.org



--- Comment #2 from Jakub Jelinek jakub at gcc dot gnu.org 2013-01-20 
17:42:30 UTC ---

Since http://gcc.gnu.org/viewcvs?root=gccview=revrev=193570 you need:

--param max-completely-peeled-insns=129

to make this happen, as the defaults were lowered from 400 to 100.