http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18908
--- Comment #15 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-07-19
08:33:23 UTC ---
On x86_64 we have
f3:
.LFB2:
.cfi_startproc
xorb $1, (%rdi)
andb $1, (%rdi)
ret
already, thus only a truncation to bitfield precision is left.
As we expand ~*p as *p ^ 1 folding on the tree level isn't strictly necessary
so this is a missed opt on RTL or expand.
