jump.c (cleanup_barriers): Handle case of no insns before a barrier.

2009-06-17  David Daney  <ddaney@caviumnetworks.com>

	* jump.c (cleanup_barriers): Handle case of no insns before a
	barrier.

2009-06-17  David Daney  <ddaney@caviumnetworks.com>

	* gcc.dg/builtin-unreachable-3.c: New test.

From-SVN: r148624

1 files changed, 2 insertions, 0 deletions

diff --git a/gcc/jump.c b/gcc/jump.c
index 350de16..7fe34f1 100644
--- a/gcc/jump.c
+++ b/gcc/jump.c
@@ -113,6 +113,8 @@ cleanup_barriers (void)
       if (BARRIER_P (insn))
 	{
 	  prev = prev_nonnote_insn (insn);
+	  if (!prev)
+	    continue;
 	  if (BARRIER_P (prev))
 	    delete_insn (insn);
 	  else if (prev != PREV_INSN (insn))