BugFix: works again for RAW with non twos-complement

[libfirm] / ir / ana / irdom.c

diff --git a/ir/ana/irdom.c b/ir/ana/irdom.c
index 789d8c3..a878a41 100644 (file)
--- a/ir/ana/irdom.c
+++ b/ir/ana/irdom.c
@@ -444,15 +444,13 @@ static void assign_tree_postdom_pre_order_max(ir_node *bl, void *data)
  * count the number of blocks and clears the post dominance info
  */
 static void count_and_init_blocks_pdom(ir_node *bl, void *env) {
-       if (is_Block(bl)) {
-               int *n_blocks = (int *) env;
-               (*n_blocks) ++;
-
-               memset(get_pdom_info(bl), 0, sizeof(ir_dom_info));
-               set_Block_ipostdom(bl, NULL);
-               set_Block_postdom_pre_num(bl, -1);
-               set_Block_postdom_depth(bl, -1);
-       }
+       int *n_blocks = (int *) env;
+       (*n_blocks) ++;
+
+       memset(get_pdom_info(bl), 0, sizeof(ir_dom_info));
+       set_Block_ipostdom(bl, NULL);
+       set_Block_postdom_pre_num(bl, -1);
+       set_Block_postdom_depth(bl, -1);
 }
 
 /** temporary type used while constructing the dominator / post dominator tree. */
@@ -596,15 +594,13 @@ INLINE static void dom_link(tmp_dom_info *v, tmp_dom_info *w) {
  * Walker: count the number of blocks and clears the dominance info
  */
 static void count_and_init_blocks_dom(ir_node *bl, void *env) {
-       if (is_Block(bl)) {
-               int *n_blocks = (int *) env;
-               (*n_blocks) ++;
-
-               memset(get_dom_info(bl), 0, sizeof(ir_dom_info));
-               set_Block_idom(bl, NULL);
-               set_Block_dom_pre_num(bl, -1);
-               set_Block_dom_depth(bl, -1);
-       }
+       int *n_blocks = (int *) env;
+       (*n_blocks) ++;
+
+       memset(get_dom_info(bl), 0, sizeof(ir_dom_info));
+       set_Block_idom(bl, NULL);
+       set_Block_dom_pre_num(bl, -1);
+       set_Block_dom_depth(bl, -1);
 }
 
 /**
@@ -612,21 +608,52 @@ static void count_and_init_blocks_dom(ir_node *bl, void *env) {
  *
  * - count the number of blocks
  * - clear the dominance info
+ * - remove Block-keepalives of live blocks to reduce
+ *   the number of "phantom" block edges
  *
  * @param irg  the graph
  * @param pre  a walker function that will be called for every block in the graph
  */
 static int init_construction(ir_graph *irg, irg_walk_func *pre) {
+       ir_graph *rem = current_ir_graph;
+       ir_node *end;
+       int arity;
        int n_blocks = 0;
 
-       /*
-        * Normally one would use irg_block_walk_graph() here, however, this does NOT
-        * guarantee that all UNREACHABLE blocks are visited.
-        * This could led to wrong dominance info in those blocks, causing
-        * the verifier to crash for instance.
-        * So, we visit EVERY node to ensure the info is updated.
-        */
-       irg_walk_graph(irg, pre, NULL, &n_blocks);
+       current_ir_graph = irg;
+
+       /* this visits only the reachable blocks */
+       irg_block_walk(get_irg_end_block(irg), pre, NULL, &n_blocks);
+
+       /* now visit the unreachable (from End) Blocks and remove unnecessary keep-alives */
+       end   = get_irg_end(irg);
+       arity = get_End_n_keepalives(end);
+       if (arity) {    /* we have keep-alives */
+               ir_node **in;
+               int i, j;
+
+               NEW_ARR_A(ir_node *, in, arity);
+               for (i = j = 0; i < arity; i++) {
+                       ir_node *pred = get_End_keepalive(end, i);
+
+                       if (is_Block(pred)) {
+                               if (Block_block_visited(pred))
+                                       continue;
+
+                               /* we found an endless loop */
+                               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 */
+                       set_End_keepalives(end, j, in);
+                       set_irg_outs_inconsistent(irg);
+               }
+       }
+
+       current_ir_graph = rem;
        return n_blocks;
 }