wtf?

[libfirm] / ir / ana / irdom.c

diff --git a/ir/ana/irdom.c b/ir/ana/irdom.c
index a66d209..9ff0b12 100644 (file)
--- a/ir/ana/irdom.c
+++ b/ir/ana/irdom.c
@@ -1,13 +1,18 @@
-/* Copyright (C) 2002 by Universitaet Karlsruhe
-** All rights reserved.
-**
-** Authors:  Goetz Lindenmaier
-**
-** irdom.c --- Dominator tree.
-**
-*/
-
-/* $Id$ */
+/*
+ * Project:     libFIRM
+ * File name:   ir/ana/irdom.c
+ * Purpose:     Construct and access dominator tree.
+ * Author:      Goetz Lindenmaier
+ * Modified by:
+ * Created:     2.2002
+ * CVS-ID:      $Id$
+ * Copyright:   (c) 2002-2003 Universität Karlsruhe
+ * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
 
 #include "irouts.h"
 
@@ -15,13 +20,18 @@
 #include "irdom_t.h"
 #include "irgraph_t.h"   /* To access state field. */
 #include "irnode_t.h"
+#include "ircons_t.h"
 
-/**********************************************************************/
-/** Accessing the dominator datastructures                           **/
-/**********************************************************************/
+/*--------------------------------------------------------------------*/
+/** Accessing the dominator data structures                          **/
+/*--------------------------------------------------------------------*/
 
 ir_node *get_Block_idom(ir_node *bl) {
   assert(get_irn_op(bl) == op_Block);
+  if (get_Block_dom_depth(bl) == -1) {
+    /* This block is not reachable from Start */
+    return new_Bad();
+  }
   return bl->attr.block.dom.idom;
 }
 
@@ -52,25 +62,11 @@ void set_Block_dom_depth(ir_node *bl, int depth) {
 
 
 
-/**********************************************************************/
-/** Building and Removing the dominator datasturcture                **/
-/**                                                                  **/
-/**  **/
-/**  **/
-/**  **/
-/**  **/
-/**  **/
-/**  **/
-/** .**/
-/**  **/
-/**  **/
-/**  **/
-/**  **/
-/**  **/
-/**  **/
-/**********************************************************************/
-
-void count_and_init_blocks(ir_node *bl, void *env) {
+/*--------------------------------------------------------------------*/
+/*  Building and Removing the dominator datastructure                 */
+/*--------------------------------------------------------------------*/
+
+static void count_and_init_blocks(ir_node *bl, void *env) {
   int *n_blocks = (int *) env;
   (*n_blocks) ++;
 
@@ -107,8 +103,8 @@ typedef struct {
 
 /* Walks Blocks along the out datastructure.  If recursion started with
    Start block misses control dead blocks. */
-void init_tmp_dom_info(ir_node *bl, tmp_dom_info *parent,
-                      tmp_dom_info *tdi_list, int* used) {
+static void init_tmp_dom_info(ir_node *bl, tmp_dom_info *parent,
+                             tmp_dom_info *tdi_list, int* used) {
   tmp_dom_info *tdi;
   int i;
 
@@ -191,9 +187,8 @@ void compute_doms(ir_graph *irg) {
   if (current_ir_graph->outs_state != outs_consistent)
     compute_outs(current_ir_graph);
 
-  /** Initialize the temporary information, add link to parent.  We don't do
-      this with a standard walker as passing the parent to the sons isn't
-      simple. **/
+  /* this with a standard walker as passing the parent to the sons isn't
+     simple. */
   used = 0;
   inc_irg_block_visited(current_ir_graph);
   init_tmp_dom_info(get_irg_start_block(current_ir_graph), NULL, tdi_list, &used);
@@ -204,15 +199,18 @@ void compute_doms(ir_graph *irg) {
 
 
   for (i = n_blocks-1; i > 0; i--) {  /* Don't iterate the root, it's done. */
+    int irn_arity;
     tmp_dom_info *w = &tdi_list[i];
     tmp_dom_info *v;
 
     /* Step 2 */
-    for (j = 0;  j < get_irn_arity(w->block);  j++) {
-      ir_node *pred = get_nodes_Block(get_Block_cfgpred(w->block, j));
+    irn_arity = get_irn_arity(w->block);
+    for (j = 0;  j < irn_arity;  j++) {
+      ir_node *cf_op = get_Block_cfgpred(w->block, j);
+      ir_node *pred  = get_nodes_block(cf_op);
       tmp_dom_info *u;
 
-      if ((is_Bad(get_Block_cfgpred(w->block, j))) ||
+      if ((is_Bad(cf_op)) || (is_Bad(pred)) ||
          (get_Block_pre_num (pred) == -1))
        continue;       /* control-dead */
 
@@ -254,14 +252,14 @@ void compute_doms(ir_graph *irg) {
   }
 
   /* clean up */
-  /*  free(tdi_list); @@@ doew not work !!?? */
+  /*  free(tdi_list); @@@ does not work !!?? */
   current_ir_graph = rem;
 }
 
 void free_dom_and_peace(ir_graph *irg) {
   /* Update graph state */
   assert(get_irg_phase_state(current_ir_graph) != phase_building);
-  current_ir_graph->dom_state = no_dom;
+  current_ir_graph->dom_state = dom_none;
 
   /* With the implementation right now there is nothing to free,
      but better call it anyways... */