- changed handling of block walks: we might reach a block through a kept node only ...

- this should fix the gigo_return problem

[r24502]

diff --git a/ir/ana/irdom.c b/ir/ana/irdom.c
index 829f36c..d9a4dc7 100644 (file)
--- a/ir/ana/irdom.c
+++ b/ir/ana/irdom.c
@@ -632,18 +632,19 @@ static int init_construction(ir_graph *irg, irg_walk_func *pre) {
                for (i = j = 0; i < arity; i++) {
                        ir_node *pred = get_End_keepalive(end, i);
 
-                       if (is_Block(pred)) {
-                               if (Block_block_visited(pred))
+                       if (!is_Block(pred)) {
+                               pred = get_nodes_block(pred);
+                               if (!is_Block(pred)) {
+                                       /* a node which has a bad block input: kill it */
                                        continue;
-
-                               /* we found an endless loop */
-                               dec_irg_block_visited(irg);
-                               irg_block_walk(pred, pre, NULL, &n_blocks);
+                               }
                        }
+                       dec_irg_block_visited(irg);
+                       irg_block_walk(pred, pre, NULL, &n_blocks);
                        in[j++] = pred;
                }
                if (j != arity) {
-                       /* we kill some Block keep-alives */
+                       /* we kill some keep-alives */
                        set_End_keepalives(end, j, in);
                        set_irg_outs_inconsistent(irg);
                }

diff --git a/ir/ir/irgwalk.c b/ir/ir/irgwalk.c
index 78daade..732ae4e 100644 (file)
--- a/ir/ir/irgwalk.c
+++ b/ir/ir/irgwalk.c
@@ -574,13 +574,13 @@ static void irg_block_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *p
        if (!Block_block_visited(node)) {
                mark_Block_block_visited(node);
 
-               if(pre) pre(node, env);
+               if (pre) pre(node, env);
 
                for(i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
                        /* find the corresponding predecessor block. */
                        ir_node *pred = get_cf_op(get_Block_cfgpred(node, i));
                        pred = get_nodes_block(pred);
-                       if(get_irn_opcode(pred) == iro_Block) {
+                       if (get_irn_opcode(pred) == iro_Block) {
                                /* recursion */
                                irg_block_walk_2(pred, pre, post, env);
                        }
@@ -589,7 +589,7 @@ static void irg_block_walk_2(ir_node *node, irg_walk_func *pre, irg_walk_func *p
                        }
                }
 
-               if(post) post(node, env);
+               if (post) post(node, env);
        }
 }
 
@@ -606,7 +606,7 @@ void irg_block_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void
 
        assert(node);
        assert(!get_interprocedural_view());   /* interprocedural_view not implemented, because it
-                                              * interleaves with irg_walk */
+                                               * interleaves with irg_walk */
        ir_reserve_resources(irg, IR_RESOURCE_BLOCK_VISITED);
        inc_irg_block_visited(irg);
        block = is_Block(node) ? node : get_nodes_block(node);
@@ -618,19 +618,16 @@ void irg_block_walk(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void
                int arity = get_irn_arity(node);
                for (i = 0; i < arity; i++) {
                        pred = get_irn_n(node, i);
-                       if (is_Block(pred))
-                               irg_block_walk_2(pred, pre, post, env);
-               }
-               /* Sometimes the blocks died, but are still reachable through Phis.
-               * Make sure the algorithms that try to remove these reach them. */
-               for (i = 0; i < arity; i++) {
-                       pred = get_irn_n(node, i);
-                       if (get_irn_op(pred) == op_Phi) {
-                               ir_node *block = get_nodes_block(pred);
-
-                               if (! is_Bad(block))
-                                       irg_block_walk_2(block, pre, post, env);
+                       if (!is_Block(pred)) {
+                               pred = get_nodes_block(pred);
+                               if (!is_Block(pred)) {
+                                       /* if rare cases a kept node might have a bad block input */
+                                       continue;
+                               }
                        }
+                       /* Sometimes the blocks died, but are still reachable through kept nodes.
+                        * Make sure the algorithms that try to remove these reach them. */
+                       irg_block_walk_2(pred, pre, post, env);
                }
        }