PR middle-end/41360

        * cfgbuild.c (find_bb_boundaries): Re-instate 2009-09-02 barrier fix.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@151759 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 10 insertions, 2 deletions

diff --git a/gcc/cfgbuild.c b/gcc/cfgbuild.c
index b5ddadd2ac9..5744108b5d4 100644
--- a/gcc/cfgbuild.c
+++ b/gcc/cfgbuild.c
@@ -477,9 +477,17 @@ find_bb_boundaries (basic_block bb)
 	  if (code == CODE_LABEL && LABEL_ALT_ENTRY_P (insn))
 	    make_edge (ENTRY_BLOCK_PTR, bb, 0);
 	}
-
-      if (control_flow_insn_p (insn))
+      else if (code == BARRIER)
+	{
+	  /* __builtin_unreachable () may cause a barrier to be emitted in
+	     the middle of a BB.  We need to split it in the same manner as
+	     if the barrier were preceded by a control_flow_insn_p insn.  */
+	  if (!flow_transfer_insn)
+	    flow_transfer_insn = prev_nonnote_insn_bb (insn);
+	}
+      else if (control_flow_insn_p (insn))
 	flow_transfer_insn = insn;
+
       if (insn == end)
 	break;
       insn = NEXT_INSN (insn);