diff --git a/test/Transforms/LCSSA/2006-10-31-UnreachableBlock-2.ll b/test/Transforms/LCSSA/2006-10-31-UnreachableBlock-2.ll
new file mode 100644
index 00000000000..55c233a07da
--- /dev/null
+++ b/test/Transforms/LCSSA/2006-10-31-UnreachableBlock-2.ll
@@ -0,0 +1,210 @@
+; RUN: llvm-as < %s | opt -lcssa -disable-output
+; PR977
+
+declare int %opost_block()
+
+void %write_chan() {
+entry:
+	br bool false, label %shortcirc_next.0, label %shortcirc_done.0
+
+shortcirc_next.0:		; preds = %entry
+	br label %shortcirc_done.0
+
+shortcirc_done.0:		; preds = %shortcirc_next.0, %entry
+	br bool false, label %shortcirc_next.1, label %shortcirc_done.1
+
+shortcirc_next.1:		; preds = %shortcirc_done.0
+	br label %shortcirc_done.1
+
+shortcirc_done.1:		; preds = %shortcirc_next.1, %shortcirc_done.0
+	br bool false, label %then.0, label %endif.0
+
+then.0:		; preds = %shortcirc_done.1
+	br bool false, label %then.1, label %endif.1
+
+then.1:		; preds = %then.0
+	br label %return
+
+after_ret.0:		; No predecessors!
+	br label %endif.1
+
+endif.1:		; preds = %after_ret.0, %then.0
+	br label %endif.0
+
+endif.0:		; preds = %endif.1, %shortcirc_done.1
+	br label %loopentry.0
+
+loopentry.0:		; preds = %endif.12, %endif.0
+	br bool false, label %then.2, label %endif.2
+
+then.2:		; preds = %loopentry.0
+	br label %loopexit.0
+
+dead_block_after_break.0:		; No predecessors!
+	br label %endif.2
+
+endif.2:		; preds = %dead_block_after_break.0, %loopentry.0
+	br bool false, label %shortcirc_done.2, label %shortcirc_next.2
+
+shortcirc_next.2:		; preds = %endif.2
+	br bool false, label %shortcirc_next.3, label %shortcirc_done.3
+
+shortcirc_next.3:		; preds = %shortcirc_next.2
+	br label %shortcirc_done.3
+
+shortcirc_done.3:		; preds = %shortcirc_next.3, %shortcirc_next.2
+	br label %shortcirc_done.2
+
+shortcirc_done.2:		; preds = %shortcirc_done.3, %endif.2
+	br bool false, label %then.3, label %endif.3
+
+then.3:		; preds = %shortcirc_done.2
+	br label %loopexit.0
+
+dead_block_after_break.1:		; No predecessors!
+	br label %endif.3
+
+endif.3:		; preds = %dead_block_after_break.1, %shortcirc_done.2
+	br bool false, label %shortcirc_next.4, label %shortcirc_done.4
+
+shortcirc_next.4:		; preds = %endif.3
+	br label %shortcirc_done.4
+
+shortcirc_done.4:		; preds = %shortcirc_next.4, %endif.3
+	br bool false, label %then.4, label %else
+
+then.4:		; preds = %shortcirc_done.4
+	br label %loopentry.1
+
+loopentry.1:		; preds = %endif.8, %then.4
+	br bool false, label %no_exit, label %loopexit.1
+
+no_exit:		; preds = %loopentry.1
+	%tmp.94 = call int %opost_block( )		; <int> [#uses=1]
+	br bool false, label %then.5, label %endif.5
+
+then.5:		; preds = %no_exit
+	br bool false, label %then.6, label %endif.6
+
+then.6:		; preds = %then.5
+	br label %loopexit.1
+
+dead_block_after_break.2:		; No predecessors!
+	br label %endif.6
+
+endif.6:		; preds = %dead_block_after_break.2, %then.5
+	br label %break_out
+
+dead_block_after_goto.0:		; No predecessors!
+	br label %endif.5
+
+endif.5:		; preds = %dead_block_after_goto.0, %no_exit
+	br bool false, label %then.7, label %endif.7
+
+then.7:		; preds = %endif.5
+	br label %loopexit.1
+
+dead_block_after_break.3:		; No predecessors!
+	br label %endif.7
+
+endif.7:		; preds = %dead_block_after_break.3, %endif.5
+	switch uint 1, label %switchexit [
+		 uint 4, label %label.2
+		 uint 2, label %label.1
+		 uint 1, label %label.0
+	]
+
+label.0:		; preds = %endif.7
+	br label %switchexit
+
+dead_block_after_break.4:		; No predecessors!
+	br label %label.1
+
+label.1:		; preds = %dead_block_after_break.4, %endif.7
+	br label %switchexit
+
+dead_block_after_break.5:		; No predecessors!
+	br label %label.2
+
+label.2:		; preds = %dead_block_after_break.5, %endif.7
+	br label %switchexit
+
+dead_block_after_break.6:		; No predecessors!
+	br label %switchexit
+
+switchexit:		; preds = %dead_block_after_break.6, %label.2, %label.1, %label.0, %endif.7
+	br bool false, label %then.8, label %endif.8
+
+then.8:		; preds = %switchexit
+	br label %loopexit.1
+
+dead_block_after_break.7:		; No predecessors!
+	br label %endif.8
+
+endif.8:		; preds = %dead_block_after_break.7, %switchexit
+	br label %loopentry.1
+
+loopexit.1:		; preds = %then.8, %then.7, %then.6, %loopentry.1
+	br bool false, label %then.9, label %endif.9
+
+then.9:		; preds = %loopexit.1
+	br label %endif.9
+
+endif.9:		; preds = %then.9, %loopexit.1
+	br label %endif.4
+
+else:		; preds = %shortcirc_done.4
+	br bool false, label %then.10, label %endif.10
+
+then.10:		; preds = %else
+	br label %break_out
+
+dead_block_after_goto.1:		; No predecessors!
+	br label %endif.10
+
+endif.10:		; preds = %dead_block_after_goto.1, %else
+	br label %endif.4
+
+endif.4:		; preds = %endif.10, %endif.9
+	br bool false, label %then.11, label %endif.11
+
+then.11:		; preds = %endif.4
+	br label %loopexit.0
+
+dead_block_after_break.8:		; No predecessors!
+	br label %endif.11
+
+endif.11:		; preds = %dead_block_after_break.8, %endif.4
+	br bool false, label %then.12, label %endif.12
+
+then.12:		; preds = %endif.11
+	br label %loopexit.0
+
+dead_block_after_break.9:		; No predecessors!
+	br label %endif.12
+
+endif.12:		; preds = %dead_block_after_break.9, %endif.11
+	br label %loopentry.0
+
+loopexit.0:		; preds = %then.12, %then.11, %then.3, %then.2
+	br label %break_out
+
+break_out:		; preds = %loopexit.0, %then.10, %endif.6
+	%retval.3 = phi int [ 0, %loopexit.0 ], [ %tmp.94, %endif.6 ], [ 0, %then.10 ]		; <int> [#uses=0]
+	br bool false, label %cond_true, label %cond_false
+
+cond_true:		; preds = %break_out
+	br label %cond_continue
+
+cond_false:		; preds = %break_out
+	br label %cond_continue
+
+cond_continue:		; preds = %cond_false, %cond_true
+	br label %return
+
+after_ret.1:		; No predecessors!
+	br label %return
+
+return:		; preds = %after_ret.1, %cond_continue, %then.1
+	ret void
+}