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

[rjiejie at me dot com]

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

--- Comment #2 from jojo <rjiejie at me dot com> ---
(In reply to Richard Biener from comment #1)
> The analysis sounds a bit confused.  What is the transform that DOM cannot
> do after the transform that FRE does?  There's some older bug about
> out-of-SSA
> coalescing issues with loops and liveness of induction variables but it's
> not clear if this is related (the assembly doesn't show the loop exit block).
> 
> Can you name the loop in the source that is problematic?
> 

see this loop:

      for( i1 = 0 ; i1 < ( numXEntries - 1 ) ; i1++ )
        {
            if( ( loadValue < engLoad[i1+1] ) && ( loadValue >= engLoad[i1] ) )
            {
                break ;
            }
        }