[Bug middle-end/23488] [4.1/4.2 Regression] GCSE load PRE does not work with non sets

[dann at godzilla dot ics dot uci dot edu]

------- Comment #18 from dann at godzilla dot ics dot uci dot edu  2006-03-03 02:14 -------
(In reply to comment #17)
> (In reply to comment #5)
> > It's strange that the load(*) does not get optimized, given that it's in the
> > same BB as the store that precedes it... 
> > 
> >            movl    %eax, result.1282   
> > (*)        movl    result.1282, %eax
> 
> This is because the copying of the trace is happening at the very end of the
> optimization phase so it does not optimized at all.

Right, the copying happens in .bbro (as shown in PR26537). 
gcc-4.0 did the same kind of copying in .bbro, but it did not generate the
redundant mov.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23488