[Bug middle-end/18908] Missed folding opportunities with bools

["pinskia at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #12 from pinskia at gcc dot gnu dot org  2008-04-30 20:00 -------
(In reply to comment #11)
> Still f4 looks weird (wrong-code?!) as we fold *p = ~*p to *p = (int) *p != -1;
> I'll open a PR for this.

We decided this was the correct thing as we start out with ~((int)*p) != 0
which then gets folded into (int)*p != -1 and then VRP comes around and says
(int)*p can only be [0,1] so it gets folded into 1.

Chris said the same thing in comment #2.

So f4 is now fixed.

In summary, we still have some issues though:
f1: not fixed (at least on PPC):
        lbz 3,0(3)
        rlwinm 3,3,0,31,31
        blr
That mask should not be there.
f2: fixed:
f2:
        lbz 3,0(3)
        blr
f3: fixed
f3:
        lbz 0,0(3)
        xori 0,0,1
        stb 0,0(3)
        blr

f4: fixed, only a store of 1.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18908