X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Fcombo.c;h=ad88f5ae868fe54c26d0bc88a995fbcb8afc1ceb;hb=bd019d8cd785c1a433c19dee44bf3f9e82397286;hp=3b71669f07fde9f7f5eb14a984a91e789e01c36a;hpb=16db5e53c1496b01c651d1ec347db4b267cc2af2;p=libfirm

diff --git a/ir/opt/combo.c b/ir/opt/combo.c
index 3b71669f0..ad88f5ae8 100644
--- a/ir/opt/combo.c
+++ b/ir/opt/combo.c
@@ -21,7 +21,6 @@
  * @file
  * @brief   Cliff Click's Combined Analysis/Optimization
  * @author  Michael Beck
- * @version $Id$
  *
  * This is a slightly enhanced version of Cliff Clicks combo algorithm
  * - support for commutative nodes is added, Add(a,b) and Add(b,a) ARE congruent
@@ -84,6 +83,7 @@
 #include "irpass.h"
 #include "tv_t.h"
 #include "irtools.h"
+#include "opt_manage.h"
 
 #include "irprintf.h"
 #include "irdump.h"
@@ -106,17 +106,7 @@ typedef void (*compute_func)(node_t *node);
  * An opcode map key.
  */
 struct opcode_key_t {
-	unsigned    code;   /**< The Firm opcode. */
-	ir_mode     *mode;  /**< The mode of all nodes in the partition. */
-	int         arity;  /**< The arity of this opcode (needed for Phi etc. */
-	union {
-		long      proj;   /**< For Proj nodes, its proj number */
-		ir_entity *ent;   /**< For Sel Nodes, its entity */
-		int       intVal; /**< For Conv/Div Nodes: strict/remainderless */
-		unsigned  uintVal;/**< for Builtin: the kind */
-		ir_node   *irn;   /**< for nodes that never be construent: the node itself */
-		void      *ptr;   /**< generic pointer for hash/cmp */
-	} u;
+	ir_node *irn;    /**< An IR node representing this opcode. */
 };
 
 /**
@@ -228,7 +218,7 @@ DEBUG_ONLY(static firm_dbg_module_t *dbg;)
 DEBUG_ONLY(static const char *what_reason;)
 
 /** Next partition number. */
-DEBUG_ONLY(static unsigned part_nr = 0);
+DEBUG_ONLY(static unsigned part_nr = 0;)
 
 /** The tarval returned by Unknown nodes: set to either tarval_bad OR tarval_top. */
 static ir_tarval *tarval_UNKNOWN;
@@ -236,6 +226,42 @@ static ir_tarval *tarval_UNKNOWN;
 /* forward */
 static node_t *identity(node_t *node);
 
+/**
+ * Compare two opcode representatives.
+ */
+static int cmp_irn_opcode(const ir_node *a, const ir_node *b)
+{
+	int arity;
+
+	if ((get_irn_op(a) != get_irn_op(b)) ||
+	    (get_irn_mode(a) != get_irn_mode(b)))
+		return 1;
+
+	/* compare if a's in and b's in are of equal length */
+	arity = get_irn_arity(a);
+	if (arity != get_irn_arity(b))
+		return 1;
+
+	if (is_Block(a)) {
+		/*
+		 * Some ugliness here: Two Blocks having the same
+		 * IJmp predecessor would be congruent, which of course is wrong.
+		 * We fix it by never letting blocks be congruent
+		 * which cannot be detected by combo either.
+		 */
+		return 1;
+	}
+
+	/*
+	 * here, we already know that the nodes are identical except their
+	 * attributes
+	 */
+	if (a->op->ops.node_cmp_attr)
+		return a->op->ops.node_cmp_attr(a, b);
+
+	return 0;
+}  /* cmp_irn_opcode */
+
 #ifdef CHECK_PARTITIONS
 /**
  * Check a partition.
@@ -260,94 +286,21 @@ static void check_partition(const partition_t *T)
 	}
 }  /* check_partition */
 
-/**
- * return the result mode of a node (part of combo's opcode).
- */
-static ir_mode *get_irn_resmode(const ir_node *irn)
-{
-	switch (get_irn_opcode(irn)) {
-	case iro_Load:
-		return get_Load_mode(irn);
-	case iro_Div:
-		return get_Div_resmode(irn);
-	case iro_Mod:
-		return get_Mod_resmode(irn);
-	default:
-		return get_irn_mode(irn);
-	}
-}  /* get_irn_resmode */
-
 /**
  * check that all leader nodes in the partition have the same opcode.
  */
 static void check_opcode(const partition_t *Z)
 {
-	node_t       *node;
-	opcode_key_t key;
-	int          first = 1;
+	node_t        *node;
+	const ir_node *repr = NULL;
 
 	list_for_each_entry(node_t, node, &Z->Leader, node_list) {
 		ir_node *irn = node->node;
 
-		if (first) {
-			key.code   = get_irn_opcode(irn);
-			key.mode   = get_irn_resmode(irn);
-			key.arity  = get_irn_arity(irn);
-			key.u.proj = 0;
-			key.u.ent  = NULL;
-
-			switch (get_irn_opcode(irn)) {
-			case iro_Proj:
-				key.u.proj = get_Proj_proj(irn);
-				break;
-			case iro_Sel:
-				key.u.ent = get_Sel_entity(irn);
-				break;
-			case iro_Conv:
-				key.u.intVal = get_Conv_strict(irn);
-				break;
-			case iro_Div:
-				key.u.intVal = get_Div_no_remainder(irn);
-				break;
-			case iro_Block:
-			case iro_ASM:
-				key.u.irn = irn;
-				break;
-			case iro_Builtin:
-				key.u.intVal = get_Builtin_kind(irn);
-				break;
-			default:
-				break;
-			}
-			first = 0;
+		if (repr == NULL) {
+			repr = irn;
 		} else {
-			assert((unsigned)key.code == get_irn_opcode(irn));
-			assert(key.mode  == get_irn_resmode(irn));
-			assert(key.arity == get_irn_arity(irn));
-
-			switch (get_irn_opcode(irn)) {
-			case iro_Proj:
-				assert(key.u.proj == get_Proj_proj(irn));
-				break;
-			case iro_Sel:
-				assert(key.u.ent == get_Sel_entity(irn));
-				break;
-			case iro_Conv:
-				assert(key.u.intVal == get_Conv_strict(irn));
-				break;
-			case iro_Div:
-				assert(key.u.intVal == get_Div_no_remainder(irn));
-				break;
-			case iro_Block:
-			case iro_ASM:
-				assert(key.u.irn == irn);
-				break;
-			case iro_Builtin:
-				assert(key.u.intVal == (int)get_Builtin_kind(irn));
-				break;
-			default:
-				break;
-			}
+			assert(cmp_irn_opcode(repr, irn) == 0);
 		}
 	}
 }  /* check_opcode */
@@ -610,7 +563,18 @@ static listmap_entry_t *listmap_find(listmap_t *map, void *id)
  */
 static unsigned opcode_hash(const opcode_key_t *entry)
 {
-	return (unsigned)(PTR_TO_INT(entry->mode) * 9 + entry->code + entry->u.proj * 3 + HASH_PTR(entry->u.ptr) + entry->arity);
+	/* we cannot use the ir ops hash function here, because it hashes the
+	 * predecessors. */
+	const ir_node *n = entry->irn;
+	ir_opcode code  = get_irn_opcode(n);
+	ir_mode   *mode = get_irn_mode(n);
+	unsigned hash = (unsigned)(PTR_TO_INT(mode) * 9 + code) + get_irn_arity(n);
+
+	if (code == iro_Const)
+		hash ^= (unsigned)HASH_PTR(get_Const_tarval(n));
+	else if (code == iro_Proj)
+		hash += (unsigned)get_Proj_proj(n);
+	return hash;
 }  /* opcode_hash */
 
 /**
@@ -622,11 +586,8 @@ static int cmp_opcode(const void *elt, const void *key, size_t size)
 	const opcode_key_t *o2 = (opcode_key_t*)key;
 
 	(void) size;
-	return o1->code != o2->code || o1->mode != o2->mode ||
-	       o1->arity != o2->arity ||
-	       o1->u.proj != o2->u.proj ||
-	       o1->u.intVal != o2->u.intVal || /* this already checks uIntVal */
-	       o1->u.ptr != o2->u.ptr;
+
+	return cmp_irn_opcode(o1->irn, o2->irn);
 }  /* cmp_opcode */
 
 /**
@@ -819,7 +780,8 @@ static void init_block_phis(ir_node *irn, void *ctx)
 	(void) ctx;
 
 	if (is_Phi(irn)) {
-		add_Block_phi(get_nodes_block(irn), irn);
+		ir_node *block = get_nodes_block(irn);
+		add_Block_phi(block, irn);
 	}
 }  /* init_block_phis */
 
@@ -864,9 +826,10 @@ static void add_to_cprop(node_t *y, environment_t *env)
 	if (y->on_cprop == 0) {
 		partition_t *Y = y->part;
 		ir_node *irn   = y->node;
+		ir_node *skipped = skip_Proj(irn);
 
 		/* place Conds and all its Projs on the cprop_X list */
-		if (is_Cond(skip_Proj(irn)))
+		if (is_Cond(skipped) || is_Switch(skipped))
 			list_add_tail(&y->cprop_list, &Y->cprop_X);
 		else
 			list_add_tail(&y->cprop_list, &Y->cprop);
@@ -884,7 +847,7 @@ static void add_to_cprop(node_t *y, environment_t *env)
 	irn = y->node;
 	if (get_irn_mode(irn) == mode_T) {
 		/* mode_T nodes always produce tarval_bottom, so we must explicitly
-		   add it's Proj's to get constant evaluation to work */
+		 * add its Projs to get constant evaluation to work */
 		int i;
 
 		for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
@@ -1737,52 +1700,8 @@ static void *lambda_type(const node_t *node, environment_t *env)
 static void *lambda_opcode(const node_t *node, environment_t *env)
 {
 	opcode_key_t key, *entry;
-	ir_node      *irn = node->node;
 
-	key.code   = get_irn_opcode(irn);
-	key.mode   = get_irn_resmode(irn);
-	key.arity  = get_irn_arity(irn);
-	key.u.proj = 0;
-	key.u.ent  = NULL;
-
-	switch (get_irn_opcode(irn)) {
-	case iro_Proj:
-		key.u.proj = get_Proj_proj(irn);
-		break;
-	case iro_Sel:
-		key.u.ent = get_Sel_entity(irn);
-		break;
-	case iro_Conv:
-		key.u.intVal = get_Conv_strict(irn);
-		break;
-	case iro_Div:
-		key.u.intVal = get_Div_no_remainder(irn);
-		break;
-	case iro_Block:
-		/*
-		 * Some ugliness here: Two Blocks having the same
-		 * IJmp predecessor would be congruent, which of course is wrong.
-		 * We fix it by never letting blocks be congruent
-		 * which cannot be detected by combo either.
-		 */
-		key.u.irn = irn;
-		break;
-	case iro_ASM:
-		/*
-		 * If is difficult to detect when two ASM nodes are congruent: even
-		 * if the assembler "text" is identical, the instruction might
-		 * have a side effect like flag toggle or function call.
-		 * So, do not even try it.
-		 *
-		 */
-		key.u.irn = irn;
-		break;
-	case iro_Builtin:
-		key.u.intVal = get_Builtin_kind(irn);
-		break;
-	default:
-		break;
-	}
+	key.irn = node->node;
 
 	entry = (opcode_key_t*)set_insert(env->opcode2id_map, &key, sizeof(key), opcode_hash(&key));
 	return entry;
@@ -1896,7 +1815,7 @@ static void split_by(partition_t *X, environment_t *env)
 	dump_partition("split_by", X);
 
 	if (X->n_leader == 1) {
-		/* we have only one leader, no need to split, just check it's type */
+		/* we have only one leader, no need to split, just check its type */
 		node_t *x = get_first_node(X);
 		X->type_is_T_or_C = x->type.tv == tarval_top || is_con(x->type);
 		return;
@@ -2010,7 +1929,7 @@ static void compute_Block(node_t *node)
 	int     i;
 	ir_node *block = node->node;
 
-	if (block == get_irg_start_block(current_ir_graph) || has_Block_entity(block)) {
+	if (block == get_irg_start_block(current_ir_graph) || get_Block_entity(block) != NULL) {
 		/* start block and labelled blocks are always reachable */
 		node->type.tv = tarval_reachable;
 		return;
@@ -2318,44 +2237,12 @@ static void compute_Eor(node_t *node)
  */
 static void compute_Cmp(node_t *node)
 {
-	ir_node        *cmp  = node->node;
-	node_t         *l    = get_irn_node(get_Cmp_left(cmp));
-	node_t         *r    = get_irn_node(get_Cmp_right(cmp));
-	lattice_elem_t a     = l->type;
-	lattice_elem_t b     = r->type;
-	ir_mode        *mode = get_irn_mode(get_Cmp_left(cmp));
-
-	if (a.tv == tarval_top || b.tv == tarval_top) {
-		node->type.tv = tarval_top;
-	} else if (r->part == l->part) {
-		/* both nodes congruent, we can probably do something */
-		if (mode_is_float(mode)) {
-			/* beware of NaN's */
-			node->type.tv = tarval_bottom;
-		} else {
-			node->type.tv = tarval_b_true;
-		}
-	} else if (is_con(a) && is_con(b)) {
-		node->type.tv = tarval_b_true;
-	} else {
-		node->type.tv = tarval_bottom;
-	}
-}  /* compute_Cmp */
-
-/**
- * (Re-)compute the type for a Proj(Cmp).
- *
- * @param node  the node
- * @param cond  the predecessor Cmp node
- */
-static void compute_Proj_Cmp(node_t *node, ir_node *cmp)
-{
-	ir_node        *proj = node->node;
-	node_t         *l    = get_irn_node(get_Cmp_left(cmp));
-	node_t         *r    = get_irn_node(get_Cmp_right(cmp));
-	lattice_elem_t a     = l->type;
-	lattice_elem_t b     = r->type;
-	pn_Cmp         pnc   = get_Proj_pn_cmp(proj);
+	ir_node        *cmp     = node->node;
+	node_t         *l       = get_irn_node(get_Cmp_left(cmp));
+	node_t         *r       = get_irn_node(get_Cmp_right(cmp));
+	lattice_elem_t a        = l->type;
+	lattice_elem_t b        = r->type;
+	ir_relation    relation = get_Cmp_relation(cmp);
 	ir_tarval      *tv;
 
 	if (a.tv == tarval_top || b.tv == tarval_top) {
@@ -2370,19 +2257,21 @@ static void compute_Proj_Cmp(node_t *node, ir_node *cmp)
 	 *  consistent with compute_Cmp, so don't do anything for floats)
 	 */
 	} else if (r->part == l->part && !mode_is_float(get_irn_mode(l->node))) {
-		tv = pnc & pn_Cmp_Eq ? tarval_b_true : tarval_b_false;
+		tv = relation & ir_relation_equal ? tarval_b_true : tarval_b_false;
 
-		/* if the node was ONCE evaluated by all constants, but now
+		/* if the node was ONCE evaluated to a constant, but now
 		   this breaks AND we get from the argument partitions a different
-		   result, switch to bottom.
+		   result, ensure monotony by fall to bottom.
 		   This happens because initially all nodes are in the same partition ... */
-		if (node->type.tv != tv)
+		if (node->type.tv == tarval_bottom)
+			tv = tarval_bottom;
+		else if (node->type.tv != tv && is_constant_type(node->type))
 			tv = tarval_bottom;
 		node->type.tv = tv;
 	} else {
 		node->type.tv = tarval_bottom;
 	}
-}  /* compute_Proj_Cmp */
+}
 
 /**
  * (Re-)compute the type for a Proj(Cond).
@@ -2449,90 +2338,105 @@ static void compute_Proj_Cond(node_t *node, ir_node *cond)
 	if (node->type.tv == tarval_reachable)
 		return;
 
-	if (get_irn_mode(sel) == mode_b) {
-		/* an IF */
-		if (pnc == pn_Cond_true) {
-			if (selector->type.tv == tarval_b_false) {
-				node->type.tv = tarval_unreachable;
-			} else if (selector->type.tv == tarval_b_true) {
-				node->type.tv = tarval_reachable;
-			} else if (selector->type.tv == tarval_bottom) {
-				node->type.tv = tarval_reachable;
-			} else {
-				assert(selector->type.tv == tarval_top);
-				if (tarval_UNKNOWN == tarval_top) {
-					/* any condition based on Top is "!=" */
-					node->type.tv = tarval_unreachable;
-				} else {
-					node->type.tv = tarval_unreachable;
-				}
-			}
+	if (pnc == pn_Cond_true) {
+		if (selector->type.tv == tarval_b_false) {
+			node->type.tv = tarval_unreachable;
+		} else if (selector->type.tv == tarval_b_true) {
+			node->type.tv = tarval_reachable;
+		} else if (selector->type.tv == tarval_bottom) {
+			node->type.tv = tarval_reachable;
 		} else {
-			assert(pnc == pn_Cond_false);
-
-			if (selector->type.tv == tarval_b_false) {
-				node->type.tv = tarval_reachable;
-			} else if (selector->type.tv == tarval_b_true) {
+			assert(selector->type.tv == tarval_top);
+			if (tarval_UNKNOWN == tarval_top) {
+				/* any condition based on Top is "!=" */
 				node->type.tv = tarval_unreachable;
-			} else if (selector->type.tv == tarval_bottom) {
-				node->type.tv = tarval_reachable;
 			} else {
-				assert(selector->type.tv == tarval_top);
-				if (tarval_UNKNOWN == tarval_top) {
-					/* any condition based on Top is "!=" */
-					node->type.tv = tarval_reachable;
-				} else {
-					node->type.tv = tarval_unreachable;
-				}
+				node->type.tv = tarval_unreachable;
 			}
 		}
 	} else {
-		/* an SWITCH */
-		if (selector->type.tv == tarval_bottom) {
+		assert(pnc == pn_Cond_false);
+
+		if (selector->type.tv == tarval_b_false) {
+			node->type.tv = tarval_reachable;
+		} else if (selector->type.tv == tarval_b_true) {
+			node->type.tv = tarval_unreachable;
+		} else if (selector->type.tv == tarval_bottom) {
 			node->type.tv = tarval_reachable;
-		} else if (selector->type.tv == tarval_top) {
-			if (tarval_UNKNOWN == tarval_top &&
-			    pnc == get_Cond_default_proj(cond)) {
-				/* a switch based of Top is always "default" */
+		} else {
+			assert(selector->type.tv == tarval_top);
+			if (tarval_UNKNOWN == tarval_top) {
+				/* any condition based on Top is "!=" */
 				node->type.tv = tarval_reachable;
 			} else {
 				node->type.tv = tarval_unreachable;
 			}
+		}
+	}
+}  /* compute_Proj_Cond */
+
+static void compute_Proj_Switch(node_t *node, ir_node *switchn)
+{
+	ir_node *proj     = node->node;
+	long     pnc      = get_Proj_proj(proj);
+	ir_node *sel      = get_Switch_selector(switchn);
+	node_t  *selector = get_irn_node(sel);
+
+	/* see long comment in compute_Proj_Cond */
+	if (node->type.tv == tarval_reachable)
+		return;
+
+	if (selector->type.tv == tarval_bottom) {
+		node->type.tv = tarval_reachable;
+	} else if (selector->type.tv == tarval_top) {
+		if (tarval_UNKNOWN == tarval_top && pnc == pn_Switch_default) {
+			/* a switch based of Top is always "default" */
+			node->type.tv = tarval_reachable;
 		} else {
-			long value = get_tarval_long(selector->type.tv);
-			if (pnc == get_Cond_default_proj(cond)) {
-				/* default switch, have to check ALL other cases */
-				int i;
-
-				for (i = get_irn_n_outs(cond) - 1; i >= 0; --i) {
-					ir_node *succ = get_irn_out(cond, i);
-
-					if (succ == proj)
-						continue;
-					if (value == get_Proj_proj(succ)) {
-						/* we found a match, will NOT take the default case */
-						node->type.tv = tarval_unreachable;
-						return;
-					}
+			node->type.tv = tarval_unreachable;
+		}
+	} else {
+		long                   value = get_tarval_long(selector->type.tv);
+		const ir_switch_table *table = get_Switch_table(switchn);
+		size_t                 n_entries = ir_switch_table_get_n_entries(table);
+		size_t                 e;
+
+		for (e = 0; e < n_entries; ++e) {
+			const ir_switch_table_entry *entry
+				= ir_switch_table_get_entry_const(table, e);
+			ir_tarval *min = entry->min;
+			ir_tarval *max = entry->max;
+			if (min == max) {
+				if (selector->type.tv == min) {
+					node->type.tv = entry->pn == pnc
+						? tarval_reachable : tarval_unreachable;
+					return;
 				}
-				/* all cases checked, no match, will take default case */
-				node->type.tv = tarval_reachable;
 			} else {
-				/* normal case */
-				node->type.tv = value == pnc ? tarval_reachable : tarval_unreachable;
+				long minval = get_tarval_long(min);
+				long maxval = get_tarval_long(max);
+				if (minval <= value && value <= maxval) {
+					node->type.tv = entry->pn == pnc
+						? tarval_reachable : tarval_unreachable;
+					return;
+				}
 			}
 		}
+
+		/* no entry matched: default */
+		node->type.tv
+			= pnc == pn_Switch_default ? tarval_reachable : tarval_unreachable;
 	}
-}  /* compute_Proj_Cond */
+}
 
 /**
- * (Re-)compute the type for a Proj-Node.
- *
- * @param node  the node
- */
+* (Re-)compute the type for a Proj-Node.
+*
+* @param node  the node
+*/
 static void compute_Proj(node_t *node)
 {
-	ir_node *proj = node->node;
+ir_node *proj = node->node;
 	ir_mode *mode = get_irn_mode(proj);
 	node_t  *block = get_irn_node(get_nodes_block(skip_Proj(proj)));
 	ir_node *pred  = get_Proj_pred(proj);
@@ -2542,7 +2446,7 @@ static void compute_Proj(node_t *node)
 		node->type.tv = tarval_top;
 		return;
 	}
-	if (get_irn_node(pred)->type.tv == tarval_top && !is_Cond(pred)) {
+	if (get_irn_node(pred)->type.tv == tarval_top && !is_Cond(pred) && !is_Switch(pred)) {
 		/* if the predecessor is Top, its Proj follow */
 		node->type.tv = tarval_top;
 		return;
@@ -2552,28 +2456,26 @@ static void compute_Proj(node_t *node)
 		/* mode M is always bottom */
 		node->type.tv = tarval_bottom;
 		return;
+	} else if (mode == mode_X) {
+		/* handle mode_X nodes */
+		switch (get_irn_opcode(pred)) {
+		case iro_Start:
+			/* the Proj_X from the Start is always reachable.
+			   However this is already handled at the top. */
+			node->type.tv = tarval_reachable;
+			return;
+		case iro_Cond:
+			compute_Proj_Cond(node, pred);
+			return;
+		case iro_Switch:
+			compute_Proj_Switch(node, pred);
+			return;
+		default:
+			break;
+		}
 	}
-	if (mode != mode_X) {
-		if (is_Cmp(pred))
-			compute_Proj_Cmp(node, pred);
-		else
-			default_compute(node);
-		return;
-	}
-	/* handle mode_X nodes */
 
-	switch (get_irn_opcode(pred)) {
-	case iro_Start:
-		/* the Proj_X from the Start is always reachable.
-		   However this is already handled at the top. */
-		node->type.tv = tarval_reachable;
-		break;
-	case iro_Cond:
-		compute_Proj_Cond(node, pred);
-		break;
-	default:
-		default_compute(node);
-	}
+	default_compute(node);
 }  /* compute_Proj */
 
 /**
@@ -2586,7 +2488,7 @@ static void compute_Confirm(node_t *node)
 	ir_node *confirm = node->node;
 	node_t  *pred = get_irn_node(get_Confirm_value(confirm));
 
-	if (get_Confirm_cmp(confirm) == pn_Cmp_Eq) {
+	if (get_Confirm_relation(confirm) == ir_relation_equal) {
 		node_t *bound = get_irn_node(get_Confirm_bound(confirm));
 
 		if (is_con(bound->type)) {
@@ -3088,10 +2990,15 @@ static int only_one_reachable_proj(ir_node *n)
  */
 static int can_exchange(ir_node *pred, ir_node *block)
 {
-	if (is_Start(pred) || has_Block_entity(block))
+	if (is_Start(pred) || get_Block_entity(block) != NULL)
 		return 0;
 	else if (is_Jmp(pred))
 		return 1;
+	else if (is_Raise(pred)) {
+		/* Raise is a tuple and usually has only one reachable ProjX,
+		 * but it must not be eliminated like a Jmp */
+		return 0;
+	}
 	else if (get_irn_mode(pred) == mode_T) {
 		/* if the predecessor block has more than one
 		   reachable outputs we cannot remove the block */
@@ -3121,31 +3028,29 @@ static void apply_cf(ir_node *block, void *ctx)
 			ir_node *pred = get_Block_cfgpred(block, i);
 
 			if (! is_Bad(pred)) {
-				node_t *pred_bl = get_irn_node(get_nodes_block(skip_Proj(pred)));
-
-				if (pred_bl->flagged == 0) {
-					pred_bl->flagged = 3;
-
-					if (pred_bl->type.tv == tarval_reachable) {
-						/*
-						 * We will remove an edge from block to its pred.
-						 * This might leave the pred block as an endless loop
-						 */
-						if (! is_backedge(block, i))
-							keep_alive(pred_bl->node);
+				ir_node *pred_block = get_nodes_block(skip_Proj(pred));
+				if (!is_Bad(pred_block)) {
+					node_t *pred_bl = get_irn_node(pred_block);
+
+					if (pred_bl->flagged == 0) {
+						pred_bl->flagged = 3;
+
+						if (pred_bl->type.tv == tarval_reachable) {
+							/*
+							 * We will remove an edge from block to its pred.
+							 * This might leave the pred block as an endless loop
+							 */
+							if (! is_backedge(block, i))
+								keep_alive(pred_bl->node);
+						}
 					}
 				}
 			}
 		}
 
-		/* the EndBlock is always reachable even if the analysis
-		   finds out the opposite :-) */
-		if (block != get_irg_end_block(current_ir_graph)) {
-			/* mark dead blocks */
-			set_Block_dead(block);
-			DB((dbg, LEVEL_1, "Removing dead %+F\n", block));
-		} else {
-			/* the endblock is unreachable */
+		if (block == get_irg_end_block(current_ir_graph)) {
+			/* Analysis found out that the end block is unreachable,
+			 * hence we remove all its control flow predecessors. */
 			set_irn_in(block, 0, NULL);
 		}
 		return;
@@ -3177,18 +3082,21 @@ static void apply_cf(ir_node *block, void *ctx)
 		} else {
 			DB((dbg, LEVEL_1, "Removing dead input %d from %+F (%+F)\n", i, block, pred));
 			if (! is_Bad(pred)) {
-				node_t *pred_bl = get_irn_node(get_nodes_block(skip_Proj(pred)));
-
-				if (pred_bl->flagged == 0) {
-					pred_bl->flagged = 3;
-
-					if (pred_bl->type.tv == tarval_reachable) {
-						/*
-						 * We will remove an edge from block to its pred.
-						 * This might leave the pred block as an endless loop
-						 */
-						if (! is_backedge(block, i))
-							keep_alive(pred_bl->node);
+				ir_node *pred_block = get_nodes_block(skip_Proj(pred));
+				if (!is_Bad(pred_block)) {
+					node_t *pred_bl = get_irn_node(pred_block);
+
+					if (!is_Bad(pred_bl->node) && pred_bl->flagged == 0) {
+						pred_bl->flagged = 3;
+
+						if (pred_bl->type.tv == tarval_reachable) {
+							/*
+							 * We will remove an edge from block to its pred.
+							 * This might leave the pred block as an endless loop
+							 */
+							if (! is_backedge(block, i))
+								keep_alive(pred_bl->node);
+						}
 					}
 				}
 			}
@@ -3362,7 +3270,9 @@ static void apply_result(ir_node *irn, void *ctx)
 		node_t *block = get_irn_node(get_nodes_block(irn));
 
 		if (block->type.tv == tarval_unreachable) {
-			ir_node *bad = get_irg_bad(current_ir_graph);
+			ir_graph *irg  = get_irn_irg(irn);
+			ir_mode  *mode = get_irn_mode(node->node);
+			ir_node  *bad  = new_r_Bad(irg, mode);
 
 			/* here, bad might already have a node, but this can be safely ignored
 			   as long as bad has at least ONE valid node */
@@ -3412,7 +3322,7 @@ static void apply_result(ir_node *irn, void *ctx)
 				/* leave or Jmp */
 				ir_node *cond = get_Proj_pred(irn);
 
-				if (is_Cond(cond)) {
+				if (is_Cond(cond) || is_Switch(cond)) {
 					if (only_one_reachable_proj(cond)) {
 						ir_node *jmp = new_r_Jmp(block->node);
 						set_irn_node(jmp, node);
@@ -3422,14 +3332,16 @@ static void apply_result(ir_node *irn, void *ctx)
 						exchange(irn, jmp);
 						env->modified = 1;
 					} else {
-						node_t    *sel = get_irn_node(get_Cond_selector(cond));
-						ir_tarval *tv  = sel->type.tv;
-
-						if (is_tarval(tv) && tarval_is_constant(tv)) {
-							/* The selector is a constant, but more
-							 * than one output is active: An unoptimized
-							 * case found. */
-							env->unopt_cf = 1;
+						if (is_Switch(cond)) {
+							node_t    *sel = get_irn_node(get_Switch_selector(cond));
+							ir_tarval *tv  = sel->type.tv;
+
+							if (is_tarval(tv) && tarval_is_constant(tv)) {
+								/* The selector is a constant, but more
+								 * than one output is active: An unoptimized
+								 * case found. */
+								env->unopt_cf = 1;
+							}
 						}
 					}
 				}
@@ -3517,13 +3429,22 @@ static void apply_end(ir_node *end, environment_t *env)
 
 	/* fix the keep alive */
 	for (i = j = 0; i < n; i++) {
-		ir_node *ka   = get_End_keepalive(end, i);
-		node_t  *node = get_irn_node(ka);
+		ir_node *ka = get_End_keepalive(end, i);
+		ir_node *block;
+		node_t  *node;
 
-		if (! is_Block(ka))
-			node = get_irn_node(get_nodes_block(ka));
+		if (is_Bad(ka))
+			continue;
+		if (!is_Block(ka)) {
+			block = get_nodes_block(ka);
+			if (is_Bad(block))
+				continue;
+		} else {
+			block = ka;
+		}
 
-		if (node->type.tv != tarval_unreachable && !is_Bad(ka))
+		node = get_irn_node(block);
+		if (node->type.tv != tarval_unreachable)
 			in[j++] = ka;
 	}
 	if (j != n) {
@@ -3591,7 +3512,7 @@ static void add_memory_keeps(ir_node **kept_memory, size_t len)
 	ir_nodeset_destroy(&set);
 }  /* add_memory_keeps */
 
-void combo(ir_graph *irg)
+static ir_graph_state_t do_combo(ir_graph *irg)
 {
 	environment_t env;
 	ir_node       *initial_bl;
@@ -3624,14 +3545,11 @@ void combo(ir_graph *irg)
 	env.commutative    = 1;
 	env.opt_unknown    = 1;
 
-	assure_irg_outs(irg);
-	assure_cf_loop(irg);
-
 	/* we have our own value_of function */
 	set_value_of_func(get_node_tarval);
 
 	set_compute_functions();
-	DEBUG_ONLY(part_nr = 0);
+	DEBUG_ONLY(part_nr = 0;)
 
 	ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_PHI_LIST);
 
@@ -3646,7 +3564,7 @@ void combo(ir_graph *irg)
 	irg_walk_graph(irg, create_initial_partitions, init_block_phis, &env);
 
 	/* set the hook: from now, every node has a partition and a type */
-	DEBUG_ONLY(set_dump_node_vcgattr_hook(dump_partition_hook));
+	DEBUG_ONLY(set_dump_node_vcgattr_hook(dump_partition_hook);)
 
 	/* all nodes on the initial partition have type Top */
 	env.initial->type_is_T_or_C = 1;
@@ -3691,19 +3609,10 @@ void combo(ir_graph *irg)
 		DB((dbg, LEVEL_1, "Unoptimized Control Flow left"));
 	}
 
-	if (env.modified) {
-		/* control flow might changed */
-		set_irg_outs_inconsistent(irg);
-		set_irg_extblk_inconsistent(irg);
-		set_irg_doms_inconsistent(irg);
-		set_irg_loopinfo_inconsistent(irg);
-		set_irg_entity_usage_state(irg, ir_entity_usage_not_computed);
-	}
-
 	ir_free_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_PHI_LIST);
 
 	/* remove the partition hook */
-	DEBUG_ONLY(set_dump_node_vcgattr_hook(NULL));
+	DEBUG_ONLY(set_dump_node_vcgattr_hook(NULL);)
 
 	DEL_ARR_F(env.kept_memory);
 	del_set(env.opcode2id_map);
@@ -3712,8 +3621,21 @@ void combo(ir_graph *irg)
 	/* restore value_of() default behavior */
 	set_value_of_func(NULL);
 	current_ir_graph = rem;
+
+	return 0; // cannot guarantee anything
 }  /* combo */
 
+static optdesc_t opt_combo = {
+	"combo",
+	IR_GRAPH_STATE_NO_BADS | IR_GRAPH_STATE_CONSISTENT_OUTS | IR_GRAPH_STATE_CONSISTENT_LOOPINFO,
+	do_combo,
+};
+
+void combo(ir_graph *irg)
+{
+	perform_irg_optimization(irg, &opt_combo);
+}
+
 /* Creates an ir_graph pass for combo. */
 ir_graph_pass_t *combo_pass(const char *name)
 {