update gigo():

- add missing skip_Proj()
- do not kill control flow from a dead block WITHOUT setting this block to dead
- fixed warning

[r17339]

diff --git a/ir/ir/iropt.c b/ir/ir/iropt.c
index ce862ea..0318352 100644 (file)
--- a/ir/ir/iropt.c
+++ b/ir/ir/iropt.c
@@ -5151,8 +5151,8 @@ static ir_op_ops *firm_set_default_node_cmp_attr(ir_opcode code, ir_op_ops *ops)
  * nodes as parameters.  Returns 0 if the nodes are a Common Sub Expression.
  */
 int identities_cmp(const void *elt, const void *key) {
-       const ir_node *a = elt;
-       const ir_node *b = key;
+       ir_node *a = (ir_node *)elt;
+       ir_node *b = (ir_node *)key;
        int i, irn_arity_a;
 
        if (a == b) return 0;
@@ -5407,22 +5407,35 @@ static ir_node *gigo(ir_node *node) {
                ir_node *block = get_nodes_block(skip_Proj(node));
 
                /* Don't optimize nodes in immature blocks. */
-               if (!get_Block_matured(block)) return node;
+               if (!get_Block_matured(block))
+                       return node;
                /* Don't optimize End, may have Bads. */
                if (op == op_End) return node;
 
                if (is_Block(block)) {
-                       irn_arity = get_irn_arity(block);
-                       for (i = 0; i < irn_arity; i++) {
+                       if (is_Block_dead(block)) {
+                               /* control flow from dead block is dead */
+                               return new_Bad();
+                       }
+
+                       for (i = get_irn_arity(block) - 1; i >= 0; --i) {
                                if (!is_Bad(get_irn_n(block, i)))
                                        break;
                        }
-                       if (i == irn_arity) {
+                       if (i < 0) {
                                ir_graph *irg = get_irn_irg(block);
                                /* the start block is never dead */
                                if (block != get_irg_start_block(irg)
-                                       && block != get_irg_end_block(irg))
+                                       && block != get_irg_end_block(irg)) {
+                                       /*
+                                        * Do NOT kill control flow without setting
+                                        * the block to dead of bad things can happen:
+                                        * We get a Block that is not reachable be irg_block_walk()
+                                        * but can be found by irg_walk()!
+                                        */
+                                       set_Block_dead(block);
                                        return new_Bad();
+                               }
                        }
                }
        }
@@ -5436,7 +5449,7 @@ static ir_node *gigo(ir_node *node) {
                 * Beware: we can only read the block of a non-floating node.
                 */
                if (is_irn_pinned_in_irg(node) &&
-                       is_Block_dead(get_nodes_block(node)))
+                       is_Block_dead(get_nodes_block(skip_Proj(node))))
                        return new_Bad();
 
                for (i = 0; i < irn_arity; i++) {