http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47541
--- Comment #8 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-01-31 16:28:19 UTC --- Hmm. We have D.10321_19 = MEM[(const struct RefCount &)ptr_3(D) + 8].count_; MEM[(struct RefCount *)D.9717_8 + 8B].count_ = D.10321_19; D.10322_20 = MEM[(struct RefCount *)D.9717_8 + 8B].count_; ... MEM[(int *)D.10322_20] = D.10324_22; so _19 isn't used at this point (as in, dereferenced) directly. Constraints: PARM_NOALIAS.204.64+64 = NONLOCAL PARM_NOALIAS.204.128+64 = NONLOCAL ptr = &PARM_NOALIAS.204.64+64 D.10321_19 = *ptr + 128 *D.9717_8 + 128 = D.10321_19 D.10322_20 = *D.9717_8 + 128 D.10323_21 = *D.10322_20 Note the funny fact that no constraint is there for the subvar starting at 0. And we end up with # PT = nonlocal escaped D.10320_18 = MEM[(const struct RefCount &)ptr_3(D) + 8].ptr_; MEM[(struct RefCount *)D.9717_8 + 8B].ptr_ = D.10320_18; # PT = D.10321_19 = MEM[(const struct RefCount &)ptr_3(D) + 8].count_; MEM[(struct RefCount *)D.9717_8 + 8B].count_ = D.10321_19; # PT = nonlocal escaped D.10322_20 = MEM[(struct RefCount *)D.9717_8 + 8B].count_; which means that we think we access PARM_NOALIAS.204.196+64 when loading from count_. This looks like a type issue to me, related to pass-by-reference + restrict handling. Eventually related to how inheritance is represented.
