[Bug tree-optimization/21485] [4.0/4.1/4.2/4.3 Regression] codegen regression due to PRE increasing register pressure (missing load PRE really)

[pinskia at gcc dot gnu dot org]

--- Comment #22 from pinskia at gcc dot gnu dot org  2007-06-18 06:12 
---
This is basically fixed by the pointer_plus except we still have some
combinable code (though this is not PRE's fault); see
http://gcc.gnu.org/ml/gcc-patches/2007-05/msg01996.html for how to fix that
issue.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21485

[Bug tree-optimization/21485] [4.0/4.1/4.2/4.3 Regression] codegen regression due to PRE increasing register pressure (missing load PRE really)

[pinskia at gcc dot gnu dot org]

--- Comment #21 from pinskia at gcc dot gnu dot org  2007-05-28 07:06 
---
The missed load PRE for the testcase below is fixed on the pointer plus banch
as the addition is done in "unsigned int" for both the "++k" and the
array[k+1].  If we change "++k" into "k+=2" and array[k+1] into array[k+2], we
run into another missed PRE issue which can be shown by the following testcase
which we don't optimize currently:
int f(int a, int b)
{
  int c = a+2;
  int d = c*2;
  int e = a*2;
  int f = e+2;
  return d == f;
}

Which I will file seperately.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21485

[Bug tree-optimization/21485] [4.0/4.1/4.2/4.3 Regression] codegen regression due to PRE increasing register pressure (missing load PRE really)

[mmitchel at gcc dot gnu dot org]

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mmitchel at gcc dot gnu dot org changed:

   What|Removed |Added

   Target Milestone|4.1.2   |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21485