https://gcc.gnu.org/bugzilla/show_bug.cgi?id=10050
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution|--- |INVALID
--- Comment #12 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #11)
> Note for func2 we get:
>
> if (flag.0_2 != 0)
> goto <bb 4>; [50.00%]
> else
> goto <bb 3>; [50.00%]
>
> <bb 3> [local count: 536870912]:
> pretmp_18 = *a_10(D);
> pretmp_20 = MEM[(int *)a_10(D) + 4B];
> goto <bb 5>; [100.00%]
>
> <bb 4> [local count: 536870913]:
> *a_10(D) = _9;
> MEM[(int *)a_10(D) + 4B] = _1;
>
> <bb 5> [local count: 1073741824]:
> # prephitmp_19 = PHI <pretmp_18(3), _9(4)>
> # prephitmp_21 = PHI <pretmp_20(3), _1(4)>
>
> the conditional stores are correct if not supplying -fallow-store-data-races
> . Now GCC does not optimize this even with -fallow-store-data-races but
> maybe it could.
So looking into this again, it can't because if a is pointing to read only
memory and doing a store to it when `!flag` would cause a crash.
So there is nothing to be done here so closing as invalid for func2
