[Bug tree-optimization/98673] pass fre4 inhibit pass dom3 to create much more optimized code

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98673

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |8.4.0

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Please try simplifying the testcase, I've tried

long loadValue;
const long *engLoad;
float engLoadDelta1;
void foo()
{
  long i1, numXEntries = 50;
  for( i1 = 0 ; i1 < ( numXEntries - 1 ) ; i1++ )
    {
      if( ( loadValue < engLoad[i1+1] ) && ( loadValue >= engLoad[i1] ) )
        {
          break ;
        }
    }

  if( i1 == ( numXEntries - 1 ) )
    {
      loadValue = engLoad[i1] ;
    }

  engLoadDelta1 = (float)( loadValue - engLoad[i1] ) /
      (float)( engLoad[i1 + 1] - engLoad[i1] ) ;
}

which on x86 doesn't exhibit the issue (same code with GCC 8 and GCC 10).