[Bug rtl-optimization/37516] New: ~(-2 - a) is not being optimized into a + 1

pinskia at gcc dot gnu dot org gcc-bugzilla@gcc.gnu.org
Sun Sep 14 03:37:00 GMT 2008


I noticed this when looking into PR 34087 with connection of a patch I wrote
for loop-doloop.c which is supposed to reduce the number of instructions.
Anyways the following two functions are equivalent but are not optimized that
way:
int f(int a)
{
  a = -2 - a;
  return -(a+1);
}

int f1(int a)
{
  return a + 1;
}


-- 
           Summary: ~(-2 - a) is not being optimized into a + 1
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37516



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