[Bug tree-optimization/27799] adding unused char field inhibits optimization

[dann at godzilla dot ics dot uci dot edu]

------- Comment #7 from dann at godzilla dot ics dot uci dot edu  2008-03-04 21:32 -------
(In reply to comment #6)
> Actually RTL alias is just using the same routines.
Might be, but the RTL level code that optimizes away the abort() in both
testcases (if I remember well nonoverlapping_component_refs_p). 

> 
>   # SMT.4_6 = VDEF <SMT.4_4(D)>
>   # SMT.5_7 = VDEF <SMT.5_5(D)>
>   x_1(D)->x = 0;
>   # SMT.5_8 = VDEF <SMT.5_7>
>   y_2(D)->y = 1;
> 
> vs.
> 
>   # SMT.18_5 = VDEF <SMT.18_4(D)>
>   x_1(D)->x = 0;
>   # SMT.19_7 = VDEF <SMT.19_6(D)>
>   y_2(D)->y = 1;

That is for this testcase, but what about the impact on .final_cleanup for
something big like combine.c? 


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27799