This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Dealing with basic blocks
- From: pocmatos at gmail dot com (Paulo J. Matos)
- To: gcc at gcc dot gnu dot org
- Date: Tue, 14 Sep 2010 10:08:34 +0100
- Subject: Dealing with basic blocks
Hello all,
I am moving basic blocks around and currently the cfg is getting very,
very awkward. My guess is that I am doing something I shouldn't [as
usual].
For each SWITCH_EXPR I found on the code I generate a CFG which I have
to replace with the SWITCH_EXPR. The switch is always the last statement
on a basic block, so what I am doing is removing all the edges of the
current bb:
VEC_truncate (edge, bsi.bb->succs, 0);
Create a single edge from the current bb to the initial bb of the
generated cfg:
make_edge(bsi.bb, new, EDGE_FALLTHRU);
And finally remove the switch_expr we are pointing to:
bsi_remove(&bsi, true);
Is this the correct way to do it? I am quite concerned as to whether I
am removing all the edges from the basic block correctly and if I can
simply had a fallthru edge to the new cfg (given that after removing the
switch_expr, the original basic block will end on a statement that would
normally not require the basic block to end).
Cheers,
--
PMatos