There is no need to avoid threading to a loop header, the threading
code can cope with this just fine. Noticed when working on PR72772.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2016-08-05 Richard Biener <rguent...@suse.de>
* tree-ssa-threadupdate.c (thread_block_1): Remove unnecessary
restriction on threading to a loop header.
Index: gcc/tree-ssa-threadupdate.c
===================================================================
--- gcc/tree-ssa-threadupdate.c (revision 239117)
+++ gcc/tree-ssa-threadupdate.c (working copy)
@@ -1531,10 +1531,8 @@ thread_block_1 (basic_block bb, bool nol
threading path that crosses loop boundaries. We do not try
and thread this elsewhere, so just cancel the jump threading
request by clearing the AUX field now. */
- if ((bb->loop_father != e2->src->loop_father
- && !loop_exit_edge_p (e2->src->loop_father, e2))
- || (e2->src->loop_father != e2->dest->loop_father
- && !loop_exit_edge_p (e2->src->loop_father, e2)))
+ if (bb->loop_father != e2->src->loop_father
+ && !loop_exit_edge_p (e2->src->loop_father, e2))
{
/* Since this case is not handled by our special code
to thread through a loop header, we must explicitly
