[Bug tree-optimization/101653] [9/10/11/12 Regression] Bad code generated when optimizing nested for loops

2021-07-27 Thread pinskia at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101653

Andrew Pinski  changed:

   What|Removed |Added

 Status|NEW |RESOLVED
 Resolution|--- |DUPLICATE

--- Comment #3 from Andrew Pinski  ---
So the loop of PR 100740 is same as this one so marking as a dup.

That is both have a double loop and the inner one has loop exit which is bound
by comparing of the induction variable that is counting how many times inside
the loop it has happened and comparing it against in the inner loop induction
variable.

*** This bug has been marked as a duplicate of bug 100740 ***

[Bug tree-optimization/101653] [9/10/11/12 Regression] Bad code generated when optimizing nested for loops

2021-07-27 Thread pinskia at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101653

--- Comment #2 from Andrew Pinski  ---
Confirmed,
ivcannon is turning the loops into:
   [local count: 79093198]:
  goto ; [100.00%]

   [local count: 357878150]:
  a_8 = a_11 + 1;
  c_14 = c_3 + 2;
  goto ; [100.00%]

   [local count: 79093198]:
  # _5 = PHI <123(6)>
  return _5;

   [local count: 375401868]:
  # c_3 = PHI <1(2), c_14(4)>
  # a_11 = PHI <0(2), a_8(4)>
  # ivtmp_20 = PHI <2(2), ivtmp_1(4)>
  c_6 = c_3 + 1;
  ivtmp_1 = ivtmp_20 - 1;
  if (ivtmp_1 == 0)
goto ; [5.50%]
  else
goto ; [94.50%]

Removing all of the if conditions on c < a and turning it into true ...

[Bug tree-optimization/101653] [9/10/11/12 Regression] Bad code generated when optimizing nested for loops

2021-07-27 Thread jakub at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101653

Jakub Jelinek  changed:

   What|Removed |Added

 CC||jakub at gcc dot gnu.org
   Last reconfirmed||2021-07-27
 Status|UNCONFIRMED |NEW
 Ever confirmed|0   |1

--- Comment #1 from Jakub Jelinek  ---
Started with r9-4145-ga81e2c6240655f60a49c16e0d8bbfd2ba40bba51
So possibly related or the same as PR101508 or PR100740

[Bug tree-optimization/101653] [9/10/11/12 Regression] Bad code generated when optimizing nested for loops

2021-07-27 Thread pinskia at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101653

Andrew Pinski  changed:

   What|Removed |Added

   Keywords||wrong-code
Summary|Bad code generated when |[9/10/11/12 Regression] Bad
   |optimizing nested for loops |code generated when
   ||optimizing nested for loops
  Component|c   |tree-optimization
   Target Milestone|--- |9.5