X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbechordal.c;h=ad144c4885f400908f0a55e74aa3e744ff30eea4;hb=63bea6c02bc23bdd1f63f2847bc180bdaeecb461;hp=c14d635aa34155a74e4e074750bb6bcf81933a53;hpb=00566a003ee9974894b55838f6db0065df770561;p=libfirm

diff --git a/ir/be/bechordal.c b/ir/be/bechordal.c
index c14d635aa..ad144c488 100644
--- a/ir/be/bechordal.c
+++ b/ir/be/bechordal.c
@@ -1,7 +1,11 @@
 /**
  * Chordal register allocation.
  * @author Sebastian Hack
- * @date 8.12.2004
+ * @date   8.12.2004
+ * @cvs-id $Id$
+ *
+ * Copyright (C) Universitaet Karlsruhe
+ * Released under the GPL
  */
 #ifdef HAVE_CONFIG_H
 #include "config.h"
@@ -10,9 +14,13 @@
 #include <ctype.h>
 
 #include "obst.h"
+#include "pset.h"
 #include "list.h"
 #include "bitset.h"
+#include "raw_bitset.h"
 #include "iterator.h"
+#include "bipartite.h"
+#include "hungarian.h"
 
 #include "irmode_t.h"
 #include "irgraph_t.h"
@@ -20,210 +28,65 @@
 #include "irgwalk.h"
 #include "irdump.h"
 #include "irdom.h"
+#include "irtools.h"
 #include "debug.h"
 #include "xmalloc.h"
 
 #include "beutil.h"
 #include "besched.h"
-#include "bera_t.h"
-#include "benumb_t.h"
 #include "besched_t.h"
 #include "belive_t.h"
+#include "benode_t.h"
+#include "bearch.h"
+#include "beirgmod.h"
+#include "beifg.h"
+#include "beinsn_t.h"
+#include "bestatevent.h"
+#include "beirg_t.h"
+
 #include "bechordal_t.h"
+#include "bechordal_draw.h"
 
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
 
+#define NO_COLOR (-1)
 
-#undef DUMP_INTERVALS
-#undef DUMP_PRESSURE
-#define DUMP_IFG
+#define DUMP_INTERVALS
 
-#define BUILD_GRAPH
+typedef struct _be_chordal_alloc_env_t {
+	be_chordal_env_t *chordal_env;
 
-#ifdef USE_OLD_PHI_INTERFERENCE
-#undef BUILD_GRAPH
-#define BUILD_GRAPH
-#endif
+	pset *pre_colored;              /**< Set of precolored nodes. */
+	bitset_t *live;				    /**< A liveness bitset. */
+	bitset_t *tmp_colors;           /**< An auxiliary bitset which is as long as the number of colors in the class. */
+	bitset_t *colors;			    /**< The color mask. */
+	bitset_t *in_colors;            /**< Colors used by live in values. */
+	int colors_n;                   /**< The number of colors. */
+} be_chordal_alloc_env_t;
 
-#ifdef DEBUG_libfirm
 #include "fourcc.h"
 
 /* Make a fourcc for border checking. */
 #define BORDER_FOURCC				FOURCC('B', 'O', 'R', 'D')
 
-#endif /* DEBUG_libfirm */
-
-#define TEST_COLORS 2048
-
-static firm_dbg_module_t *dbg;
-
-/**
- * Environment for each of the chordal register allocator phases
- */
-typedef struct _env_t {
-	struct obstack obst;	/**< An obstack for temporary storage. */
-#ifdef BUILD_GRAPH
-	set *graph;						/**< The interference graph. */
-#endif
-
-	bitset_t *live;				/**< A liveness bitset. */
-	bitset_t *colors;			/**< The color mask. */
-	bitset_t *in_colors;	/**< Colors used by live in values. */
-	int colors_n;					/**< The number of colors. */
-} env_t;
-
-
-typedef struct _be_chordal_dump_params_t {
-	int x_dist;
-	int y_dist;
-	double font_scale;
-} be_chordal_dump_params_t;
-
-static const be_chordal_dump_params_t dump_params = {
-	30,
-	10,
-	4
-};
-
-static void draw_interval_graphs(ir_node *block,
-		struct list_head *border_head,
-		const be_chordal_dump_params_t *params)
-{
-	int i;
-	int x_dist = params->x_dist;
-	int y_dist = params->y_dist;
-	ir_graph *irg = get_irn_irg(block);
-
-	FILE *f;
-	char buf[1024];
-
-	ir_snprintf(buf, sizeof(buf), "intv_%s_bl%N.eps",
-			get_entity_name(get_irg_entity(irg)), block);
-
-	if((f = fopen(buf, "wt")) != NULL) {
-		border_t *b;
-		int *seen = xcalloc(get_graph_node_count(irg), sizeof(seen[0]));
-		int last_pos = list_empty(border_head) ? 0 : list_entry(border_head->prev, border_t, list)->step;
-		int max_col = 0;
-
-		list_for_each_entry_reverse(border_t, b, border_head, list) {
-			const ir_node *irn = b->irn;
-			int col = get_irn_color(irn);
-			max_col = max_col > col ? max_col : col;
-		}
-
-		fprintf(f, "%%!PS-Adobe-2.0\n");
-		fprintf(f, "%%%%BoundingBox: -10 -10 %d %d\n",
-				x_dist * last_pos + x_dist, y_dist * max_col + y_dist);
-		fprintf(f, "/mainfont /Courier findfont %f scalefont def\n", params->font_scale);
-		fprintf(f, "mainfont setfont\n");
-		fprintf(f, "0.2 setlinewidth\n");
-
-		for(i = 0; i <= last_pos; ++i) {
-			fprintf(f, "0 0 0 setrgbcolor\n");
-			fprintf(f, "%d %d moveto\n", i * x_dist, -2);
-			fprintf(f, "%d %d lineto\n", i * x_dist, max_col * y_dist + 2);
-			fprintf(f, "stroke\n");
-		}
-		fprintf(f, "0.5 setlinewidth\n");
-
-		list_for_each_entry_reverse(border_t, b, border_head, list) {
-			const ir_node *irn = b->irn;
-			int nr = get_irn_graph_nr(irn);
-
-			if(b->is_def)
-				seen[nr] = b->step;
-			else {
-				int col = get_irn_color(irn);
-
-				int pos = last_pos - seen[nr];
-				int end_pos = last_pos - b->step;
-				int live_in = is_live_in(block, irn);
-				int live_end = is_live_end(block, irn);
-				int y_val = y_dist * col;
-
-				int red = 0;
-				int green = live_end;
-				int blue = live_in;
-
-				fprintf(f, "0 0 0 setrgbcolor\n");
-				fprintf(f, "%d %d moveto\n", x_dist * pos + 2, y_val + 2);
-				ir_fprintf(f, "(%n/%d%s) show\n", irn, nr, is_phi_operand(irn) ? "*" : "");
-				fprintf(f, "%d %d %d setrgbcolor\n", red, green, blue);
-				fprintf(f, "%d %d moveto\n", x_dist * pos, y_val);
-				fprintf(f, "%d %d lineto\n", (x_dist * end_pos) - 5, y_val);
-				fprintf(f, "stroke\n");
-			}
-		}
-
-		free(seen);
-		fclose(f);
-	}
-}
-
-#ifdef BUILD_GRAPH
-
-typedef struct _if_edge_t {
-	int src, tgt;
-} if_edge_t;
-
-#define IF_EDGE_HASH(e) ((e)->src)
-
-static int if_edge_cmp(const void *p1, const void *p2, size_t size)
-{
-	const if_edge_t *e1 = p1;
-	const if_edge_t *e2 = p2;
-
-	return !(e1->src == e2->src && e1->tgt == e2->tgt);
-}
-
-static INLINE if_edge_t *edge_init(if_edge_t *edge, int src, int tgt)
-{
-	/* Bring the smaller entry to src. */
-	if(src > tgt) {
-		edge->src = tgt;
-		edge->tgt = src;
-	} else {
-		edge->src = src;
-		edge->tgt = tgt;
-	}
-
-	return edge;
-}
-
-static INLINE void add_if(const env_t *env, int src, int tgt)
+#if 0
+static void check_border_list(struct list_head *head)
 {
-	if_edge_t edge;
-	edge_init(&edge, src, tgt);
-	set_insert(env->graph, &edge, sizeof(edge), IF_EDGE_HASH(&edge));
+  border_t *x;
+  list_for_each_entry(border_t, x, head, list) {
+    assert(x->magic == BORDER_FOURCC);
+  }
 }
 
-static INLINE int are_connected(const env_t *env, int src, int tgt)
+static void check_heads(be_chordal_env_t *env)
 {
-	if_edge_t edge;
-	edge_init(&edge, src, tgt);
-	return set_find(env->graph, &edge, sizeof(edge), IF_EDGE_HASH(&edge)) != NULL;
+  pmap_entry *ent;
+  for(ent = pmap_first(env->border_heads); ent; ent = pmap_next(env->border_heads)) {
+    /* ir_printf("checking border list of block %+F\n", ent->key); */
+    check_border_list(ent->value);
+  }
 }
-
-static void dump_ifg(set *edges, const char *filename)
-{
-	FILE *f;
-
-	if((f = fopen(filename, "wt")) != NULL) {
-		if_edge_t *edge;
-
-		fprintf(f, "graph G {\n");
-
-		for(edge = set_first(edges); edge; edge = set_next(edges)) {
-			fprintf(f, "i\tn%d -- n%d\n", edge->src, edge->tgt);
-		}
-
-		fprintf(f, "}\n");
-		fclose(f);
-	}
-
-}
-
-#endif /* BUILD_GRAPH */
+#endif
 
 /**
  * Add an interval border to the list of a block's list
@@ -237,7 +100,7 @@ static void dump_ifg(set *edges, const char *filename)
  * @param is_def Is the border a use or a def.
  * @return The created border.
  */
-static INLINE border_t *border_add(env_t *env, struct list_head *head,
+static INLINE border_t *border_add(be_chordal_env_t *env, struct list_head *head,
 			ir_node *irn, unsigned step, unsigned pressure,
 			unsigned is_def, unsigned is_real)
 {
@@ -250,6 +113,7 @@ static INLINE border_t *border_add(env_t *env, struct list_head *head,
 
 		/* also allocate the def and tie it to the use. */
 		def = obstack_alloc(&env->obst, sizeof(*def));
+		memset(def, 0, sizeof(*def));
 		b->other_end = def;
 		def->other_end = b;
 
@@ -260,10 +124,8 @@ static INLINE border_t *border_add(env_t *env, struct list_head *head,
 		 */
 		set_irn_link(irn, def);
 
-#ifdef DEBUG_libfirm
-		b->magic = BORDER_FOURCC;
-		def->magic = BORDER_FOURCC;
-#endif
+		DEBUG_ONLY(b->magic = BORDER_FOURCC);
+		DEBUG_ONLY(def->magic = BORDER_FOURCC);
 	}
 
 	/*
@@ -274,23 +136,561 @@ static INLINE border_t *border_add(env_t *env, struct list_head *head,
 	else {
 		b = get_irn_link(irn);
 
-#ifdef DEBUG_libfirm
 		assert(b && b->magic == BORDER_FOURCC && "Illegal border encountered");
-#endif
 	}
 
-
+	b->pressure = pressure;
 	b->is_def = is_def;
 	b->is_real = is_real;
 	b->irn = irn;
 	b->step = step;
 	list_add_tail(&b->list, head);
-	DBG((dbg, LEVEL_5, "\t\t%s adding %n, step: %d\n",
-				is_def ? "def" : "use", irn, step));
+	DBG((env->dbg, LEVEL_5, "\t\t%s adding %+F, step: %d\n", is_def ? "def" : "use", irn, step));
+
 
 	return b;
 }
 
+/**
+ * Check, if an irn is of the register class currently under processing.
+ * @param env The chordal environment.
+ * @param irn The node.
+ * @return 1, if the node is of that register class, 0 if not.
+ */
+static INLINE int has_reg_class(const be_chordal_env_t *env, const ir_node *irn)
+{
+	return arch_irn_has_reg_class(env->birg->main_env->arch_env, irn, -1, env->cls);
+	// return arch_irn_consider_in_reg_alloc(env->birg->main_env->arch_env, env->cls, irn);
+}
+
+#define has_limited_constr(req, irn) \
+	(arch_get_register_req(arch_env, (req), irn, -1) && (req)->type == arch_register_req_type_limited)
+
+static int get_next_free_reg(const be_chordal_alloc_env_t *alloc_env, bitset_t *colors)
+{
+	bitset_t *tmp = alloc_env->tmp_colors;
+	bitset_copy(tmp, colors);
+	bitset_or(tmp, alloc_env->chordal_env->ignore_colors);
+	return bitset_next_clear(tmp, 0);
+}
+
+static bitset_t *get_decisive_partner_regs(bitset_t *bs, const be_operand_t *o1, const be_operand_t *o2)
+{
+	bitset_t *res = bs;
+
+	if(!o1) {
+		bitset_copy(bs, o2->regs);
+		return bs;
+	}
+
+	if(!o2) {
+		bitset_copy(bs, o1->regs);
+		return bs;
+	}
+
+	assert(o1->req->cls == o2->req->cls || ! o1->req->cls || ! o2->req->cls);
+
+	if(bitset_contains(o1->regs, o2->regs))
+		bitset_copy(bs, o1->regs);
+	else if(bitset_contains(o2->regs, o1->regs))
+		bitset_copy(bs, o2->regs);
+	else
+		res = NULL;
+
+	return res;
+}
+
+static be_insn_t *chordal_scan_insn(be_chordal_env_t *env, ir_node *irn)
+{
+	be_insn_env_t ie;
+
+	ie.ignore_colors = env->ignore_colors;
+	ie.aenv          = env->birg->main_env->arch_env;
+	ie.obst          = &env->obst;
+	ie.cls           = env->cls;
+	return be_scan_insn(&ie, irn);
+}
+
+static ir_node *prepare_constr_insn(be_chordal_env_t *env, ir_node *irn)
+{
+	const arch_env_t *aenv = env->birg->main_env->arch_env;
+	bitset_t *tmp          = bitset_alloca(env->cls->n_regs);
+	bitset_t *def_constr   = bitset_alloca(env->cls->n_regs);
+	ir_node *bl            = get_nodes_block(irn);
+	be_lv_t *lv            = env->birg->lv;
+
+	be_insn_t *insn;
+	int i, j;
+
+	for (i = get_irn_arity(irn) - 1; i >= 0; --i) {
+		ir_node *op = get_irn_n(irn, i);
+		ir_node *copy;
+		const arch_register_t *reg;
+		const arch_register_req_t *req;
+
+		if (arch_get_irn_reg_class(aenv, irn, i) != env->cls)
+			continue;
+
+		reg = arch_get_irn_register(aenv, op);
+
+		if (reg == NULL || !arch_register_type_is(reg, ignore))
+			continue;
+		if(arch_register_type_is(reg, joker))
+			continue;
+
+		req = arch_get_register_req(aenv, irn, i);
+		if (!arch_register_req_is(req, limited))
+			continue;
+
+		if (rbitset_is_set(req->limited, reg->index))
+			continue;
+
+		copy = be_new_Copy(env->cls, env->irg, bl, op);
+		be_stat_ev("constr_copy", 1);
+
+		sched_add_before(irn, copy);
+		set_irn_n(irn, i, copy);
+		DBG((env->dbg, LEVEL_3, "inserting ignore arg copy %+F for %+F pos %d\n", copy, irn, i));
+	}
+
+    insn = chordal_scan_insn(env, irn);
+
+	if(!insn->has_constraints)
+		goto end;
+
+	/* insert copies for nodes that occur constrained more than once. */
+	for(i = insn->use_start; i < insn->n_ops; ++i) {
+		be_operand_t *op = &insn->ops[i];
+
+		if(!op->has_constraints)
+			continue;
+
+		for(j = i + 1; j < insn->n_ops; ++j) {
+			ir_node *copy;
+			be_operand_t *a_op = &insn->ops[j];
+
+			if(a_op->carrier != op->carrier || !a_op->has_constraints)
+				continue;
+
+			copy = be_new_Copy(env->cls, env->irg, bl, op->carrier);
+			be_stat_ev("constr_copy", 1);
+
+			sched_add_before(insn->irn, copy);
+			set_irn_n(insn->irn, a_op->pos, copy);
+			DBG((env->dbg, LEVEL_3, "inserting multiple constr copy %+F for %+F pos %d\n", copy, insn->irn, a_op->pos));
+		}
+	}
+
+	/* collect all registers occuring in out constraints. */
+	for(i = 0; i < insn->use_start; ++i) {
+		be_operand_t *op = &insn->ops[i];
+		if(op->has_constraints)
+			bitset_or(def_constr, op->regs);
+	}
+
+	/*
+		insert copies for all constrained arguments living through the node
+		and being constrained to a register which also occurs in out constraints.
+	*/
+	for(i = insn->use_start; i < insn->n_ops; ++i) {
+		ir_node *copy;
+		be_operand_t *op = &insn->ops[i];
+
+		bitset_copy(tmp, op->regs);
+		bitset_and(tmp, def_constr);
+
+		/*
+			Check, if
+			1) the operand is constrained.
+			2) lives through the node.
+			3) is constrained to a register occuring in out constraints.
+		*/
+		if(!op->has_constraints ||
+				!values_interfere(lv, insn->irn, op->carrier) ||
+				bitset_popcnt(tmp) == 0)
+			continue;
+
+		/*
+		   only create the copy if the operand is no copy.
+		   this is necessary since the assure constraints phase inserts
+		   Copies and Keeps for operands which must be different from the results.
+		   Additional copies here would destroy this.
+		 */
+		if(be_is_Copy(op->carrier))
+			continue;
+
+		copy = be_new_Copy(env->cls, env->irg, bl, op->carrier);
+
+		sched_add_before(insn->irn, copy);
+		set_irn_n(insn->irn, op->pos, copy);
+		DBG((env->dbg, LEVEL_3, "inserting constr copy %+F for %+F pos %d\n", copy, insn->irn, op->pos));
+		be_liveness_update(lv, op->carrier);
+	}
+
+end:
+	obstack_free(&env->obst, insn);
+	return insn->next_insn;
+}
+
+static void pre_spill_prepare_constr_walker(ir_node *bl, void *data)
+{
+	be_chordal_env_t *env = data;
+	ir_node *irn;
+	for(irn = sched_first(bl); !sched_is_end(irn);) {
+		irn = prepare_constr_insn(env, irn);
+	}
+}
+
+void be_pre_spill_prepare_constr(be_chordal_env_t *cenv) {
+	irg_block_walk_graph(cenv->irg, pre_spill_prepare_constr_walker, NULL, (void *) cenv);
+}
+
+static void pair_up_operands(const be_chordal_alloc_env_t *alloc_env, be_insn_t *insn)
+{
+	const be_chordal_env_t *env = alloc_env->chordal_env;
+
+	int n_uses   = be_insn_n_uses(insn);
+	int n_defs   = be_insn_n_defs(insn);
+	bitset_t *bs = bitset_alloca(env->cls->n_regs);
+	int *pairing = alloca(MAX(n_defs, n_uses) * sizeof(pairing[0]));
+	be_lv_t *lv  = env->birg->lv;
+
+	int i, j;
+
+	/*
+		For each out operand, try to find an in operand which can be assigned the
+		same register as the out operand.
+	*/
+	for (j = 0; j < insn->use_start; ++j) {
+		int smallest         = -1;
+		int smallest_n_regs  = 2 * env->cls->n_regs + 1;
+		be_operand_t *out_op = &insn->ops[j];
+
+		/* Try to find an in operand which has ... */
+		for(i = insn->use_start; i < insn->n_ops; ++i) {
+			int n_total;
+			const be_operand_t *op = &insn->ops[i];
+
+			if (op->partner != NULL)
+				continue;
+			if (values_interfere(lv, op->irn, op->carrier))
+				continue;
+
+			bitset_clear_all(bs);
+			bitset_copy(bs, op->regs);
+			bitset_and(bs, out_op->regs);
+			n_total = bitset_popcnt(op->regs) + bitset_popcnt(out_op->regs);
+
+			if (bitset_popcnt(bs) > 0 && n_total < smallest_n_regs) {
+				smallest = i;
+				smallest_n_regs = n_total;
+			}
+		}
+
+		if (smallest >= 0) {
+			be_operand_t *partner = &insn->ops[smallest];
+			out_op->partner  = partner;
+			partner->partner = out_op;
+		}
+	}
+}
+
+
+static ir_node *pre_process_constraints(be_chordal_alloc_env_t *alloc_env,
+                                        be_insn_t **the_insn)
+{
+	be_chordal_env_t *env       = alloc_env->chordal_env;
+	const arch_env_t *aenv      = env->birg->main_env->arch_env;
+	be_insn_t *insn             = *the_insn;
+	ir_node *perm               = NULL;
+	bitset_t *out_constr        = bitset_alloca(env->cls->n_regs);
+	const ir_edge_t *edge;
+	int i;
+
+	assert(insn->has_constraints && "only do this for constrained nodes");
+
+	/*
+		Collect all registers that occur in output constraints.
+		This is necessary, since if the insn has one of these as an input constraint
+		and the corresponding operand interferes with the insn, the operand must
+		be copied.
+	*/
+	for(i = 0; i < insn->use_start; ++i) {
+		be_operand_t *op = &insn->ops[i];
+		if(op->has_constraints)
+			bitset_or(out_constr, op->regs);
+	}
+
+	/*
+		Make the Perm, recompute liveness and re-scan the insn since the
+		in operands are now the Projs of the Perm.
+	*/
+	perm = insert_Perm_after(env->birg, env->cls, sched_prev(insn->irn));
+
+	/* Registers are propagated by insert_Perm_after(). Clean them here! */
+	if(perm == NULL)
+		return NULL;
+
+	be_stat_ev("constr_perm", get_irn_arity(perm));
+	foreach_out_edge(perm, edge) {
+		ir_node *proj = get_edge_src_irn(edge);
+		arch_set_irn_register(aenv, proj, NULL);
+	}
+
+	/*
+		We also have to re-build the insn since the input operands are now the Projs of
+		the Perm. Recomputing liveness is also a good idea if a Perm is inserted, since
+		the live sets may change.
+	*/
+	// be_liveness_recompute(lv);
+	obstack_free(&env->obst, insn);
+	*the_insn = insn = chordal_scan_insn(env, insn->irn);
+
+	/*
+		Copy the input constraints of the insn to the Perm as output
+		constraints. Succeeding phases (coalescing) will need that.
+	*/
+	for(i = insn->use_start; i < insn->n_ops; ++i) {
+		be_operand_t *op = &insn->ops[i];
+		ir_node *proj = op->carrier;
+		/*
+			Note that the predecessor must not be a Proj of the Perm,
+			since ignore-nodes are not Perm'ed.
+		*/
+		if(op->has_constraints &&  is_Proj(proj) && get_Proj_pred(proj) == perm) {
+			be_set_constr_limited(perm, BE_OUT_POS(get_Proj_proj(proj)), op->req);
+		}
+	}
+
+	return perm;
+}
+
+static ir_node *handle_constraints(be_chordal_alloc_env_t *alloc_env, ir_node *irn, int *silent)
+{
+	const arch_env_t *aenv;
+	int n_regs;
+	bitset_t *bs;
+	ir_node **alloc_nodes;
+	hungarian_problem_t *bp;
+	int *assignment;
+	pmap *partners;
+	int i, n_alloc;
+	long col;
+	const ir_edge_t *edge;
+	ir_node *perm = NULL;
+	int match_res, cost;
+	be_chordal_env_t *env  = alloc_env->chordal_env;
+	void *base             = obstack_base(&env->obst);
+	be_insn_t *insn        = chordal_scan_insn(env, irn);
+	ir_node *res           = insn->next_insn;
+	int be_silent          = *silent;
+	be_lv_t *lv            = env->birg->lv;
+
+	if(insn->pre_colored) {
+		int i;
+		for(i = 0; i < insn->use_start; ++i)
+			pset_insert_ptr(alloc_env->pre_colored, insn->ops[i].carrier);
+	}
+
+	/*
+		If the current node is a barrier toggle the silent flag.
+		If we are in the start block, we are ought to be silent at the beginning,
+		so the toggling activates the constraint handling but skips the barrier.
+		If we are in the end block we handle the in requirements of the barrier
+		and set the rest to silent.
+	*/
+	if(be_is_Barrier(irn))
+		*silent = !*silent;
+
+	if(be_silent)
+		goto end;
+
+	/*
+		Perms inserted before the constraint handling phase are considered to be
+		correctly precolored. These Perms arise during the ABI handling phase.
+	*/
+	if(!insn->has_constraints)
+		goto end;
+
+	aenv        = env->birg->main_env->arch_env;
+	n_regs      = env->cls->n_regs;
+	bs          = bitset_alloca(n_regs);
+	alloc_nodes = alloca(n_regs * sizeof(alloc_nodes[0]));
+	bp          = hungarian_new(n_regs, n_regs, 2, HUNGARIAN_MATCH_PERFECT);
+	// bipartite_t *bp        = bipartite_new(n_regs, n_regs);
+	assignment  = alloca(n_regs * sizeof(assignment[0]));
+	partners    = pmap_create();
+
+	/*
+		prepare the constraint handling of this node.
+		Perms are constructed and Copies are created for constrained values
+		interfering with the instruction.
+	*/
+	perm = pre_process_constraints(alloc_env, &insn);
+
+	/* find suitable in operands to the out operands of the node. */
+	pair_up_operands(alloc_env, insn);
+
+	/*
+		look at the in/out operands and add each operand (and its possible partner)
+		to a bipartite graph (left: nodes with partners, right: admissible colors).
+	*/
+	for(i = 0, n_alloc = 0; i < insn->n_ops; ++i) {
+		be_operand_t *op = &insn->ops[i];
+
+		/*
+			If the operand has no partner or the partner has not been marked
+			for allocation, determine the admissible registers and mark it
+			for allocation by associating the node and its partner with the
+			set of admissible registers via a bipartite graph.
+		*/
+		if(!op->partner || !pmap_contains(partners, op->partner->carrier)) {
+
+			pmap_insert(partners, op->carrier, op->partner ? op->partner->carrier : NULL);
+			alloc_nodes[n_alloc] = op->carrier;
+
+			DBG((dbg, LEVEL_2, "\tassociating %+F and %+F\n", op->carrier, op->partner ? op->partner->carrier : NULL));
+
+			bitset_clear_all(bs);
+			get_decisive_partner_regs(bs, op, op->partner);
+
+			DBG((dbg, LEVEL_2, "\tallowed registers for %+F: %B\n", op->carrier, bs));
+
+			bitset_foreach(bs, col) {
+				hungarian_add(bp, n_alloc, col, 1);
+				// bipartite_add(bp, n_alloc, col);
+			}
+
+			n_alloc++;
+		}
+	}
+
+	/*
+		Put all nodes which live through the constrained instruction also to the
+		allocation bipartite graph. They are considered unconstrained.
+	*/
+	if(perm != NULL) {
+		foreach_out_edge(perm, edge) {
+			ir_node *proj = get_edge_src_irn(edge);
+
+			assert(is_Proj(proj));
+
+			if(!values_interfere(lv, proj, irn) || pmap_contains(partners, proj))
+				continue;
+
+			assert(n_alloc < n_regs);
+			alloc_nodes[n_alloc] = proj;
+			pmap_insert(partners, proj, NULL);
+
+			bitset_clear_all(bs);
+			arch_put_non_ignore_regs(aenv, env->cls, bs);
+			bitset_andnot(bs, env->ignore_colors);
+			bitset_foreach(bs, col) {
+				hungarian_add(bp, n_alloc, col, 1);
+				// bipartite_add(bp, n_alloc, col);
+			}
+
+			n_alloc++;
+		}
+	}
+
+	/* Compute a valid register allocation. */
+	hungarian_prepare_cost_matrix(bp, HUNGARIAN_MODE_MAXIMIZE_UTIL);
+	match_res = hungarian_solve(bp, assignment, &cost, 1);
+	assert(match_res == 0 && "matching failed");
+	//bipartite_matching(bp, assignment);
+
+	/* Assign colors obtained from the matching. */
+	for(i = 0; i < n_alloc; ++i) {
+		const arch_register_t *reg;
+		ir_node *nodes[2];
+		int j;
+
+		assert(assignment[i] >= 0 && "there must have been a register assigned");
+		reg = arch_register_for_index(env->cls, assignment[i]);
+
+		nodes[0] = alloc_nodes[i];
+		nodes[1] = pmap_get(partners, alloc_nodes[i]);
+
+		for(j = 0; j < 2; ++j) {
+			if(!nodes[j])
+				continue;
+
+			arch_set_irn_register(aenv, nodes[j], reg);
+			(void) pset_hinsert_ptr(alloc_env->pre_colored, nodes[j]);
+			DBG((dbg, LEVEL_2, "\tsetting %+F to register %s\n", nodes[j], reg->name));
+		}
+	}
+
+	/* Allocate the non-constrained Projs of the Perm. */
+	if(perm != NULL) {
+		bitset_clear_all(bs);
+
+		/* Put the colors of all Projs in a bitset. */
+		foreach_out_edge(perm, edge) {
+			ir_node *proj              = get_edge_src_irn(edge);
+			const arch_register_t *reg = arch_get_irn_register(aenv, proj);
+
+			if(reg != NULL)
+				bitset_set(bs, reg->index);
+		}
+
+		/* Assign the not yet assigned Projs of the Perm a suitable color. */
+		foreach_out_edge(perm, edge) {
+			ir_node *proj              = get_edge_src_irn(edge);
+			const arch_register_t *reg = arch_get_irn_register(aenv, proj);
+
+			DBG((dbg, LEVEL_2, "\tchecking reg of %+F: %s\n", proj, reg ? reg->name : "<none>"));
+
+			if(reg == NULL) {
+				col = get_next_free_reg(alloc_env, bs);
+				reg = arch_register_for_index(env->cls, col);
+				bitset_set(bs, reg->index);
+				arch_set_irn_register(aenv, proj, reg);
+				pset_insert_ptr(alloc_env->pre_colored, proj);
+				DBG((dbg, LEVEL_2, "\tsetting %+F to register %s\n", proj, reg->name));
+			}
+		}
+	}
+
+	//bipartite_free(bp);
+	hungarian_free(bp);
+	pmap_destroy(partners);
+
+end:
+	obstack_free(&env->obst, base);
+	return res;
+}
+
+/**
+ * Handle constraint nodes in each basic block.
+ * handle_constraints() inserts Perm nodes which perm
+ * over all values live at the constrained node right in front
+ * of the constrained node. These Perms signal a constrained node.
+ * For further comments, refer to handle_constraints().
+ */
+static void constraints(ir_node *bl, void *data)
+{
+	be_chordal_alloc_env_t *env = data;
+
+	/*
+		Start silent in the start block.
+		The silence remains until the first barrier is seen.
+		Each other block is begun loud.
+	*/
+	int silent                  = bl == get_irg_start_block(get_irn_irg(bl));
+	ir_node *irn;
+
+	/*
+		If the block is the start block search the barrier and
+		start handling constraints from there.
+	*/
+
+	for(irn = sched_first(bl); !sched_is_end(irn);) {
+		irn = handle_constraints(env, irn, &silent);
+	}
+}
+
 /**
  * Annotate the register pressure to the nodes and compute
  * the liveness intervals.
@@ -307,35 +707,39 @@ static void pressure(ir_node *block, void *env_ptr)
 #define border_use(irn, step, real) \
 	border_add(env, head, irn, step, ++pressure, 0, real)
 
-	env_t *env = env_ptr;
-	bitset_t *live = env->live;
+	be_chordal_alloc_env_t *alloc_env = env_ptr;
+	be_chordal_env_t *env             = alloc_env->chordal_env;
+	bitset_t *live                    = alloc_env->live;
 	ir_node *irn;
+	be_lv_t *lv                       = env->birg->lv;
 
 	int i, n;
 	unsigned step = 0;
 	unsigned pressure = 0;
 	struct list_head *head;
-	pset *live_in = get_live_in(block);
-	pset *live_end = get_live_end(block);
+	pset *live_in  = be_lv_pset_put_in(lv, block, pset_new_ptr_default());
+	pset *live_end = be_lv_pset_put_end(lv, block, pset_new_ptr_default());
 
-	DBG((dbg, LEVEL_1, "Computing pressure in block %n\n", block));
+	DBG((dbg, LEVEL_1, "Computing pressure in block %+F\n", block));
 	bitset_clear_all(live);
 
 	/* Set up the border list in the block info */
-	head = &get_ra_block_info(block)->border_head;
+	head = obstack_alloc(&env->obst, sizeof(*head));
 	INIT_LIST_HEAD(head);
+	assert(pmap_get(env->border_heads, block) == NULL);
+	pmap_insert(env->border_heads, block, head);
 
 	/*
 	 * Make final uses of all values live out of the block.
-	 * They are neccessary to build up real intervals.
+	 * They are necessary to build up real intervals.
 	 */
-	for(irn = pset_first(live_end); irn; irn = pset_next(live_end)) {
-		DBG((dbg, LEVEL_3, "\tMaking live: %n/%d\n", irn, get_irn_graph_nr(irn)));
-		bitset_set(live, get_irn_graph_nr(irn));
-		if(is_allocatable_irn(irn))
+	foreach_pset(live_end, irn) {
+		if(has_reg_class(env, irn)) {
+			DBG((dbg, LEVEL_3, "\tMaking live: %+F/%d\n", irn, get_irn_idx(irn)));
+			bitset_set(live, get_irn_idx(irn));
 			border_use(irn, step, 0);
+		}
 	}
-
 	++step;
 
 	/*
@@ -343,31 +747,18 @@ static void pressure(ir_node *block, void *env_ptr)
 	 * relevant for the interval borders.
 	 */
 	sched_foreach_reverse(block, irn) {
-		DBG((dbg, LEVEL_1, "\tinsn: %n, pressure: %d\n", irn, pressure));
-		DBG((dbg, LEVEL_2, "\tlive: %b\n", live));
-
-		/* Erase the color of each node encountered. */
-		set_irn_color(irn, NO_COLOR);
+		DBG((dbg, LEVEL_1, "\tinsn: %+F, pressure: %d\n", irn, pressure));
+		DBG((dbg, LEVEL_2, "\tlive: %B\n", live));
 
 		/*
-		 * If the node defines a datab value, i.e. something, registers must
-		 * be allocated for, add a new def border to the border list.
+		 * If the node defines some value, which can put into a
+		 * register of the current class, make a border for it.
 		 */
-		if(is_allocatable_irn(irn)) {
-			int nr = get_irn_graph_nr(irn);
+		if(has_reg_class(env, irn)) {
+			int nr = get_irn_idx(irn);
 
 			bitset_clear(live, nr);
 			border_def(irn, step, 1);
-
-#ifdef BUILD_GRAPH
-			{
-				unsigned long elm;
-				bitset_foreach(live, elm) {
-					int live_nr = (int) elm;
-					add_if(env, nr, live_nr);
-				}
-			}
-#endif
 		}
 
 		/*
@@ -377,66 +768,65 @@ static void pressure(ir_node *block, void *env_ptr)
 			for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
 				ir_node *op = get_irn_n(irn, i);
 
-				if(is_allocatable_irn(op)) {
-					int nr = get_irn_graph_nr(op);
-
-					DBG((dbg, LEVEL_4, "\t\tpos: %d, use: %n\n", i, op));
+				if(has_reg_class(env, op)) {
+					int nr = get_irn_idx(op);
+					const char *msg = "-";
 
 					if(!bitset_is_set(live, nr)) {
 						border_use(op, step, 1);
 						bitset_set(live, nr);
+						msg = "X";
 					}
+
+					DBG((dbg, LEVEL_4, "\t\t%s pos: %d, use: %+F\n", msg, i, op));
 				}
 			}
 		}
-
 		++step;
 	}
 
 	/*
 	 * Add initial defs for all values live in.
 	 */
-	for(irn = pset_first(live_in); irn; irn = pset_next(live_in)) {
-		if(is_allocatable_irn(irn)) {
+	foreach_pset(live_in, irn) {
+		if(has_reg_class(env, irn)) {
 
 			/* Mark the value live in. */
-			bitset_set(live, get_irn_graph_nr(irn));
+			bitset_set(live, get_irn_idx(irn));
 
 			/* Add the def */
 			border_def(irn, step, 0);
 		}
 	}
+
+	del_pset(live_in);
+	del_pset(live_end);
 }
 
 static void assign(ir_node *block, void *env_ptr)
 {
-	env_t *env = env_ptr;
-	struct obstack *obst = &env->obst;
-	bitset_t *live = env->live;
-	bitset_t *colors = env->colors;
-	bitset_t *in_colors = env->in_colors;
-
-	/* The used colors will remain on the obstack. */
-	bitset_t *used_colors = bitset_obstack_alloc(obst, env->colors_n);
-
-	/* Mark the obstack level and allocate the temporary tmp_colors */
-	void *obstack_level = obstack_base(obst);
-	bitset_t *tmp_colors = bitset_obstack_alloc(obst, env->colors_n);
+	be_chordal_alloc_env_t *alloc_env = env_ptr;
+	be_chordal_env_t *env       = alloc_env->chordal_env;
+	bitset_t *live              = alloc_env->live;
+	bitset_t *colors            = alloc_env->colors;
+	bitset_t *in_colors         = alloc_env->in_colors;
+	const arch_env_t *arch_env  = env->birg->main_env->arch_env;
+	struct list_head *head      = get_block_border_head(env, block);
+	be_lv_t *lv                 = env->birg->lv;
+	pset *live_in               = be_lv_pset_put_in(lv, block, pset_new_ptr_default());
 
 	const ir_node *irn;
 	border_t *b;
-	struct list_head *head = &get_ra_block_info(block)->border_head;
-	pset *live_in = get_live_in(block);
 
-	bitset_clear_all(live);
 	bitset_clear_all(colors);
+	bitset_clear_all(live);
 	bitset_clear_all(in_colors);
 
-	DBG((dbg, LEVEL_4, "Assigning colors for block %n\n", block));
+	DBG((dbg, LEVEL_4, "Assigning colors for block %+F\n", block));
 	DBG((dbg, LEVEL_4, "\tusedef chain for block\n"));
 	list_for_each_entry(border_t, b, head, list) {
-		DBG((dbg, LEVEL_4, "\t%s %n/%d\n", b->is_def ? "def" : "use",
-					b->irn, get_irn_graph_nr(b->irn)));
+		DBG((dbg, LEVEL_4, "\t%s %+F/%d\n", b->is_def ? "def" : "use",
+					b->irn, get_irn_idx(b->irn)));
 	}
 
 	/*
@@ -444,18 +834,22 @@ static void assign(ir_node *block, void *env_ptr)
 	 * Since their colors have already been assigned (The dominators were
 	 * allocated before), we have to mark their colors as used also.
 	 */
-	for(irn = pset_first(live_in); irn; irn = pset_next(live_in)) {
-		if(is_allocatable_irn(irn)) {
-			int col = get_irn_color(irn);
+	foreach_pset(live_in, irn) {
+		if(has_reg_class(env, irn)) {
+			const arch_register_t *reg = arch_get_irn_register(arch_env, irn);
+			int col;
+
+			assert(reg && "Node must have been assigned a register");
+			col = arch_register_get_index(reg);
+
+			DBG((dbg, LEVEL_4, "%+F has reg %s\n", irn, reg->name));
 
 			/* Mark the color of the live in value as used. */
-			assert(is_color(col) && "Node must have been assigned a color.");
 			bitset_set(colors, col);
 			bitset_set(in_colors, col);
-			bitset_set(used_colors, col);
 
 			/* Mark the value live in. */
-			bitset_set(live, get_irn_graph_nr(irn));
+			bitset_set(live, get_irn_idx(irn));
 		}
 	}
 
@@ -465,167 +859,117 @@ static void assign(ir_node *block, void *env_ptr)
 	 * will work.
 	 */
 	list_for_each_entry_reverse(border_t, b, head, list) {
-		const ir_node *irn = b->irn;
-		int nr = get_irn_graph_nr(irn);
+		ir_node *irn = b->irn;
+		int nr       = get_irn_idx(irn);
+		int ignore   = arch_irn_is(arch_env, irn, ignore);
 
 		/*
 		 * Assign a color, if it is a local def. Global defs already have a
 		 * color.
 		 */
-		if(b->is_def && !is_live_in(block, irn)) {
-			ra_node_info_t *ri = get_ra_node_info(irn);
+		if(b->is_def && !be_is_live_in(lv, block, irn)) {
+			const arch_register_t *reg;
 			int col = NO_COLOR;
 
-			DBG((dbg, LEVEL_4, "\tcolors in use: %b\n", colors));
-
-			/*
-			 * Try to assign live out values colors which are not used by live
-			 * in values.
-			 */
-#if 0
-			if(is_live_out(block, irn)) {
-				int next_clear;
-
-				bitset_copy(tmp_colors, colors);
-				bitset_or(tmp_colors, in_colors);
-				next_clear = bitset_next_clear(tmp_colors, 0);
-				col = next_clear != -1 ? next_clear : NO_COLOR;
-
-				DBG((dbg, LEVEL_5, "next clear in only outs %b: %d\n", tmp_colors, col));
+			if(ignore || pset_find_ptr(alloc_env->pre_colored, irn)) {
+				reg = arch_get_irn_register(arch_env, irn);
+				col = reg->index;
+				assert(!bitset_is_set(colors, col) && "pre-colored register must be free");
+			} else {
+				col = get_next_free_reg(alloc_env, colors);
+				reg = arch_register_for_index(env->cls, col);
+				assert(arch_get_irn_register(arch_env, irn) == NULL && "This node must not have been assigned a register yet");
+				assert(!arch_register_type_is(reg, ignore) && "Must not assign ignore register");
 			}
-#endif
-
-			/* If a color is not yet assigned, do it now. */
-			if(!is_color(col))
-				col = bitset_next_clear(colors, 0);
-
-			assert(!is_color(get_irn_color(irn)) && "Color must not have assigned");
-			assert(!bitset_is_set(live, nr) && "Value def must not have been encountered");
 
 			bitset_set(colors, col);
-			bitset_set(used_colors, col);
-			bitset_set(live, nr);
+			arch_set_irn_register(arch_env, irn, reg);
 
-			ri->color = col;
+			DBG((dbg, LEVEL_1, "\tassigning register %s(%d) to %+F\n", arch_register_get_name(reg), col, irn));
 
-			DBG((dbg, LEVEL_1, "\tassigning color %d to %n\n", col, irn));
+			assert(!bitset_is_set(live, nr) && "Value's definition must not have been encountered");
+			bitset_set(live, nr);
 		}
 
 		/* Clear the color upon a use. */
 		else if(!b->is_def) {
-			int col = get_irn_color(irn);
+			const arch_register_t *reg = arch_get_irn_register(arch_env, irn);
+			int col;
 
-			assert(bitset_is_set(live, nr) && "Cannot have a non live use");
-			assert(is_color(col) && "A color must have been assigned");
+			assert(reg && "Register must have been assigned");
 
-			bitset_clear(colors, col);
-			bitset_clear(live, nr);
-		}
-	}
-
-#ifdef DUMP_INTERVALS
-	draw_interval_graphs(block, head, &dump_params);
+			col = arch_register_get_index(reg);
+#ifndef NDEBUG
+			if(!arch_register_type_is(reg, ignore)) {
+				assert(bitset_is_set(live, nr) && "Cannot have a non live use");
+			}
 #endif
 
-#ifdef DUMP_PRESSURE
-	{
-		char buf[128];
-		FILE *f;
-
-		ir_snprintf(buf, sizeof(buf), "pres_%s_bl_%N.txt",
-				get_entity_name(get_irg_entity(irg)), block);
-
-		if((f = fopen(buf, "wt")) != NULL) {
-			sched_foreach_reverse(block, irn) {
-				if(is_allocatable_irn(irn))
-					ir_fprintf(f, "\"%n\" %d %d\n", irn, sched_get_time_step(irn),
-							get_ra_node_info(irn)->pressure);
-
-			}
-			fclose(f);
+			bitset_clear(colors, col);
+			bitset_clear(live, nr);
 		}
 	}
-#endif
-
-
-	/*
-	 * Allocate the used colors array in the blocks ra info structure and
-	 * fill it.
-	 */
-	get_ra_block_info(block)->used_colors = used_colors;
-
-	/* Free the auxillary data on the obstack. */
-	obstack_free(obst, obstack_level);
-}
 
-void be_ra_chordal_init(void)
-{
-	dbg = firm_dbg_register(DBG_BERA);
-	/* firm_dbg_set_mask(dbg, -1);  */
+	del_pset(live_in);
 }
 
-void be_ra_chordal(ir_graph *irg)
+void be_ra_chordal_color(be_chordal_env_t *chordal_env)
 {
-	int node_count = get_graph_node_count(irg);
-	env_t *env = malloc(sizeof(*env));
-
-	if(get_irg_dom_state(irg) != dom_consistent)
-		compute_doms(irg);
-
-	obstack_init(&env->obst);
-
-#ifdef BUILD_GRAPH
-	env->graph = new_set(if_edge_cmp, node_count);
-#endif
+	be_chordal_alloc_env_t env;
+	char buf[256];
+	be_irg_t *birg = chordal_env->birg;
+	const arch_register_class_t *cls = chordal_env->cls;
+
+	int colors_n          = arch_register_class_n_regs(cls);
+	ir_graph *irg         = chordal_env->irg;
+	int allocatable_regs  = colors_n - be_put_ignore_regs(birg, cls, NULL);
+
+	/* some special classes contain only ignore regs, no work to be done */
+	if(allocatable_regs == 0)
+		return;
+
+	be_assure_dom_front(birg);
+	be_assure_liveness(birg);
+	assure_doms(irg);
+
+	env.chordal_env   = chordal_env;
+	env.colors_n      = colors_n;
+	env.colors        = bitset_alloca(colors_n);
+	env.tmp_colors    = bitset_alloca(colors_n);
+	env.in_colors     = bitset_alloca(colors_n);
+	env.pre_colored   = pset_new_ptr_default();
+
+	/* Handle register targeting constraints */
+	dom_tree_walk_irg(irg, constraints, NULL, &env);
+
+	if(chordal_env->opts->dump_flags & BE_CH_DUMP_CONSTR) {
+		snprintf(buf, sizeof(buf), "-%s-constr", chordal_env->cls->name);
+		be_dump(chordal_env->irg, buf, dump_ir_block_graph_sched);
+	}
 
-	env->live = bitset_obstack_alloc(&env->obst, node_count);
-	env->colors = bitset_obstack_alloc(&env->obst, TEST_COLORS);
-	env->in_colors = bitset_obstack_alloc(&env->obst, TEST_COLORS);
-	env->colors_n = TEST_COLORS;
+	env.live = bitset_malloc(get_irg_last_idx(chordal_env->irg));
 
 	/* First, determine the pressure */
-	dom_tree_walk_irg(irg, pressure, NULL, env);
-
-	/* Insert probable spills */
-	be_ra_chordal_spill(irg);
+	dom_tree_walk_irg(irg, pressure, NULL, &env);
 
 	/* Assign the colors */
-	dom_tree_walk_irg(irg, assign, NULL, env);
-
-#ifdef DUMP_IFG
-	{
-		char buf[128];
-
-		ir_snprintf(buf, sizeof(buf), "ifg_%s.dot", get_entity_name(get_irg_entity(irg)));
-		dump_ifg(env->graph, buf);
+	dom_tree_walk_irg(irg, assign, NULL, &env);
+
+	if(chordal_env->opts->dump_flags & BE_CH_DUMP_TREE_INTV) {
+		plotter_t *plotter;
+		ir_snprintf(buf, sizeof(buf), "ifg_%s_%F.eps", chordal_env->cls->name, irg);
+		plotter = new_plotter_ps(buf);
+		draw_interval_tree(&draw_chordal_def_opts, chordal_env, plotter);
+		plotter_free(plotter);
 	}
-#endif
 
-	set_irg_ra_link(irg, env);
+	bitset_free(env.live);
+	del_pset(env.pre_colored);
 }
 
-void be_ra_chordal_done(ir_graph *irg)
+void be_init_chordal(void)
 {
-	env_t *env = get_irg_ra_link(irg);
-
-#ifdef BUILD_GRAPH
-	free(env->graph);
-#endif
-
-	obstack_free(&env->obst, NULL);
-	free(env);
+	FIRM_DBG_REGISTER(dbg, "firm.be.chordal.constr");
 }
 
-int phi_ops_interfere(const ir_node *a, const ir_node *b)
-{
-#ifdef BUILD_GRAPH
-	ir_graph *irg = get_irn_irg(a);
-	env_t *env = get_irg_ra_link(irg);
-
-	assert(irg == get_irn_irg(b) && "Both nodes must be in the same graph");
-
-	return are_connected(env, get_irn_graph_nr(a), get_irn_graph_nr(b));
-#else
-	return values_interfere(a, b);
-#endif /* BUILD_GRAPH */
-}
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_chordal);