Hello,
I am using cgraph_function_versioning() to create a duplicate
function, e.g. a clone. This usually has worked well for me in the
past, but I have run into an interesting case where the
tree_function_versioning() code is performing a split_edge() on the
successor of the entry basic block. What I am left with is a gimple
dump of:
go.foo_package.NewThing2.cloned.0 ()
{
struct T * D.562;
struct T * $ret1;
struct T * t;
<bb 4>:
<bb 2>:
$ret1_1 = 0B;
t_2 = __go_new (16);
foo_package.NewMember.pN16_go.foo_package.T (t_2);
foo_package.setID (t_2, 1);
$ret1_3 = t_2;
D.562_4 = $ret1_3;
<L0>:
return D.562_4;
}
The code is just a test routine I am using for testing how my plugin
for region-based memory handles packages. Anyways, the important part
(I think) is that <bb 4> is the result of the split_edge call
mentioned earlier when I clone NewThing2, and that BB is just empty, a
fall-thru. When the gimple_cfg_expand() pass kicks-in
find_bb_boundaries() is called in find_many_sub_basic_blocks() and <bb
5>'s loop father is referenced. Well, that loop_father instance is
NULL. And gcc is dying in add_bb_to_loop(). I think I can avoid this
if I were to remove <bb 4> But I am not entirely sure. I am not even
sure why BB5 is even created as 0 is the Entry and 1 is the exit
block. I am running gcc 4.7.1 and am a bit lost as to what to do.
-Matt
