re PR tree-optimization/15654 (ICE in calculate_live_on_entry with -O2 -fno-tree-dominator-opts)

	PR tree-optimization/15654
	* tree-tailcall.c (eliminate_tail_call): Remove unreachable code.

From-SVN: r84527

1 files changed, 16 insertions, 0 deletions

diff --git a/gcc/tree-tailcall.c b/gcc/tree-tailcall.c
index 323c239cece..fdd010f160c 100644
--- a/gcc/tree-tailcall.c
+++ b/gcc/tree-tailcall.c
@@ -647,6 +647,7 @@ eliminate_tail_call (struct tailcall *t)
   stmt_ann_t ann;
   v_may_def_optype v_may_defs;
   unsigned i;
+  block_stmt_iterator bsi;
 
   stmt = bsi_stmt (t->call_bsi);
   get_stmt_operands (stmt);
@@ -666,6 +667,21 @@ eliminate_tail_call (struct tailcall *t)
 
   first = ENTRY_BLOCK_PTR->succ->dest;
 
+  /* Remove the code after call_bsi that will become unreachable.  The
+     possibly unreachable code in other blocks is removed later in
+     cfg cleanup.  */
+  bsi = t->call_bsi;
+  bsi_next (&bsi);
+  while (!bsi_end_p (bsi))
+    {
+      /* Do not remove the return statement, so that redirect_edge_and_branch
+	 sees how the block ends.  */
+      if (TREE_CODE (bsi_stmt (bsi)) == RETURN_EXPR)
+	break;
+
+      bsi_remove (&bsi);
+    }
+
   /* Replace the call by a jump to the start of function.  */
   e = redirect_edge_and_branch (t->call_block->succ, first);
   if (!e)