rework add_irn_dep, add delete_irn_dep

- Setting dep edges to NULL is illegal now
- add_irn_dep is simpler but does not check for duplicates anymore

include/libfirm/irnode.h

@@ -89,16 +89,12 @@ FIRM_API ir_node *get_irn_n(const ir_node *node, int n);
 FIRM_API void set_irn_in(ir_node *node, int arity, ir_node *in[]);
 
 /**
- * Add a artificial dependency to the node.
- * The dependency is only inserted if it is not there already.
- * This is only allowed in phase_backend!
+ * Add an artificial dependency to the node.
  *
  * @param node The node.
  * @param dep  The dependency target.
- *
- * @return The index in the array (get_irn_dep with that index returns @p dep).
  */
-FIRM_API int add_irn_dep(ir_node *node, ir_node *dep);
+FIRM_API void add_irn_dep(ir_node *node, ir_node *dep);
 
 /**
  * Copy all dependencies from a node to another.
@@ -132,6 +128,15 @@ FIRM_API ir_node *get_irn_dep(const ir_node *node, int pos);
  */
 FIRM_API void set_irn_dep(ir_node *node, int pos, ir_node *dep);
 
+/**
+ * Deletes the entry of the dependency array, that points to dep. Does nothing
+ * if no dependency exists.
+ *
+ * @param node the node to delete the dependency at
+ * @param dep the target of the dependency to delete
+ */
+FIRM_API void delete_irn_dep(ir_node *node, ir_node *dep);
+
 /** Replaces the n-th predecessor of a node with a new one. */
 FIRM_API void set_irn_n(ir_node *node, int n, ir_node *in);
 /**

ir/ir/irnode.c

@@ -309,39 +309,32 @@ void (set_irn_dep)(ir_node *node, int pos, ir_node *dep)
 	set_irn_dep_(node, pos, dep);
 }
 
-int add_irn_dep(ir_node *node, ir_node *dep)
+void add_irn_dep(ir_node *node, ir_node *dep)
 {
-	int res = 0;
-
-	/* DEP edges are only allowed in backend phase */
-	assert(get_irg_phase_state(get_irn_irg(node)) == phase_backend);
+	assert(dep != NULL);
 	if (node->deps == NULL) {
-		node->deps = NEW_ARR_F(ir_node *, 1);
-		node->deps[0] = dep;
-	} else {
-		int i, n;
-		int first_zero = -1;
-
-		for (i = 0, n = ARR_LEN(node->deps); i < n; ++i) {
-			if (node->deps[i] == NULL)
-				first_zero = i;
+		node->deps = NEW_ARR_F(ir_node *, 0);
+	}
+	ARR_APP1(ir_node*, node->deps, dep);
+	edges_notify_edge_kind(node, ARR_LEN(node->deps)-1, dep, NULL, EDGE_KIND_DEP, get_irn_irg(node));
+}
 
-			if (node->deps[i] == dep)
-				return i;
-		}
+void delete_irn_dep(ir_node *node, ir_node *dep)
+{
+	size_t i;
+	size_t n_deps;
+	if (node->deps == NULL)
+		return;
 
-		if (first_zero >= 0) {
-			node->deps[first_zero] = dep;
-			res = first_zero;
-		} else {
-			ARR_APP1(ir_node *, node->deps, dep);
-			res = n;
+	n_deps = ARR_LEN(node->deps);
+	for (i = 0; i < n_deps; ++i) {
+		if (node->deps[i] == dep) {
+			set_irn_dep(node, i, node->deps[n_deps-1]);
+			edges_notify_edge(node, i, NULL, dep, get_irn_irg(node));
+			ARR_SHRINKLEN(node->deps, n_deps-1);
+			break;
 		}
 	}
-
-	edges_notify_edge_kind(node, res, dep, NULL, EDGE_KIND_DEP, get_irn_irg(node));
-
-	return res;
 }
 
 void add_irn_deps(ir_node *tgt, ir_node *src)

ir/ir/irnode_t.h

@@ -159,6 +159,7 @@ static inline void set_irn_dep_(ir_node *node, int pos, ir_node *dep)
 
 	assert(node->deps && "dependency array node yet allocated. use add_irn_dep()");
 	assert(pos >= 0 && pos < (int)ARR_LEN(node->deps) && "dependency index out of range");
+	assert(dep != NULL);
 	old = node->deps[pos];
 	node->deps[pos] = dep;
 	edges_notify_edge_kind(node, pos, dep, old, EDGE_KIND_DEP, get_irn_irg(node));