X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fana%2Firmemory.c;h=8f30cbd5d41ea335450fe6acb9dd15c30e5b92b1;hb=24be66840a207d58dd74a2e41086a652b301641c;hp=cedb972c1cebfb1a3d80d49a06910bc5d3f99480;hpb=4978d31d07612caa624bf72975ed415c872fced1;p=libfirm

diff --git a/ir/ana/irmemory.c b/ir/ana/irmemory.c
index cedb972c1..8f30cbd5d 100644
--- a/ir/ana/irmemory.c
+++ b/ir/ana/irmemory.c
@@ -1,23 +1,39 @@
 /*
- * Project:     libFIRM
- * File name:   ir/ana/irmemory.c
- * Purpose:     Memory disambiguator
- * Author:      Michael Beck
- * Modified by:
- * Created:     27.12.2006
- * CVS-ID:      $Id$
- * Copyright:   (c) 2006-2007 Universität Karlsruhe
- * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
+ * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
+ */
+
+/**
+ * @file
+ * @brief    Memory disambiguator
+ * @author   Michael Beck
+ * @date     27.12.2006
+ * @version  $Id$
  */
-#ifdef HAVE_CONFIG_H
 #include "config.h"
-#endif
 
 #include <stdlib.h>
+#include <stdbool.h>
 
+#include "adt/pmap.h"
 #include "irnode_t.h"
 #include "irgraph_t.h"
 #include "irprog_t.h"
+#include "irmemory_t.h"
 #include "irmemory.h"
 #include "irflag.h"
 #include "hashptr.h"
@@ -25,6 +41,14 @@
 #include "irouts.h"
 #include "irgwalk.h"
 #include "irprintf.h"
+#include "debug.h"
+#include "error.h"
+#include "typerep.h"
+#include "irpass.h"
+
+/** The debug handle. */
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
+DEBUG_ONLY(static firm_dbg_module_t *dbgcall = NULL;)
 
 /** The source language specific language disambiguator function. */
 static DISAMBIGUATOR_FUNC language_disambuigator = NULL;
@@ -32,8 +56,23 @@ static DISAMBIGUATOR_FUNC language_disambuigator = NULL;
 /** The global memory disambiguator options. */
 static unsigned global_mem_disamgig_opt = aa_opt_no_opt;
 
+/* Returns a human readable name for an alias relation. */
+const char *get_ir_alias_relation_name(ir_alias_relation rel)
+{
+#define X(a) case a: return #a
+	switch (rel) {
+	X(ir_no_alias);
+	X(ir_may_alias);
+	X(ir_sure_alias);
+	default:
+		panic("UNKNOWN alias relation");
+	}
+#undef X
+}
+
 /* Get the memory disambiguator options for a graph. */
-unsigned get_irg_memory_disambiguator_options(ir_graph *irg) {
+unsigned get_irg_memory_disambiguator_options(const ir_graph *irg)
+{
 	unsigned opt = irg->mem_disambig_opt;
 	if (opt & aa_opt_inherited)
 		return global_mem_disamgig_opt;
@@ -41,12 +80,14 @@ unsigned get_irg_memory_disambiguator_options(ir_graph *irg) {
 }  /* get_irg_memory_disambiguator_options */
 
 /*  Set the memory disambiguator options for a graph. */
-void set_irg_memory_disambiguator_options(ir_graph *irg, unsigned options) {
+void set_irg_memory_disambiguator_options(ir_graph *irg, unsigned options)
+{
 	irg->mem_disambig_opt = options & ~aa_opt_inherited;
 }  /* set_irg_memory_disambiguator_options */
 
 /* Set the global disambiguator options for all graphs not having local options. */
-void set_irp_memory_disambiguator_options(unsigned options) {
+void set_irp_memory_disambiguator_options(unsigned options)
+{
 	global_mem_disamgig_opt = options;
 }  /* set_irp_memory_disambiguator_options */
 
@@ -58,7 +99,8 @@ void set_irp_memory_disambiguator_options(unsigned options) {
  *
  * @return the base address.
  */
-static ir_node *find_base_adr(ir_node *sel, ir_entity **pEnt) {
+static ir_node *find_base_adr(const ir_node *sel, ir_entity **pEnt)
+{
 	ir_node *ptr = get_Sel_ptr(sel);
 
 	while (is_Sel(ptr)) {
@@ -70,15 +112,243 @@ static ir_node *find_base_adr(ir_node *sel, ir_entity **pEnt) {
 }  /* find_base_adr */
 
 /**
- * Two address expressions have the same base address,
- * check if there offsets are different.
+ * Check if a given Const node is greater or equal a given size.
+ *
+ * @param cns   a Const node
+ * @param size  a integer size
+ *
+ * @return ir_no_alias if the Const is greater, ir_may_alias else
+ */
+static ir_alias_relation check_const(const ir_node *cns, int size)
+{
+	tarval *tv = get_Const_tarval(cns);
+	tarval *tv_size;
+
+	if (size == 0)
+		return tarval_is_null(tv) ? ir_may_alias : ir_no_alias;
+	tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
+	return tarval_cmp(tv_size, tv) & (pn_Cmp_Eq|pn_Cmp_Lt) ? ir_no_alias : ir_may_alias;
+}  /* check_const */
+
+/**
+ * Treat idx1 and idx2 as integer indexes and check if they differ always more than size.
+ *
+ * @param idx1  a node representing the first index
+ * @param idx2  a node representing the second index
+ * @param size  an integer size
+ *
+ * @return ir_sure_alias iff idx1 == idx2
+ *         ir_no_alias iff they ALWAYS differ more than size
+ *         ir_may_alias else
+ */
+static ir_alias_relation different_index(const ir_node *idx1, const ir_node *idx2, int size)
+{
+	if (idx1 == idx2)
+		return ir_sure_alias;
+	if (is_Const(idx1) && is_Const(idx2)) {
+		/* both are const, we can compare them */
+		tarval *tv1 = get_Const_tarval(idx1);
+		tarval *tv2 = get_Const_tarval(idx2);
+		tarval *tv, *tv_size;
+		ir_mode *m1, *m2;
+
+		if (size == 0)
+			return tv1 == tv2 ? ir_sure_alias : ir_no_alias;
+
+		/* arg, modes may be different */
+		m1 = get_tarval_mode(tv1);
+		m2 = get_tarval_mode(tv2);
+		if (m1 != m2) {
+			int size = get_mode_size_bits(m1) - get_mode_size_bits(m2);
+
+			if (size < 0) {
+				/* m1 is a small mode, cast up */
+				m1 = mode_is_signed(m1) ? find_signed_mode(m2) : find_unsigned_mode(m2);
+				if (m1 == NULL) {
+					/* should NOT happen, but if it does we give up here */
+					return ir_may_alias;
+				}
+				tv1 = tarval_convert_to(tv1, m1);
+			} else if (size > 0) {
+				/* m2 is a small mode, cast up */
+				m2 = mode_is_signed(m2) ? find_signed_mode(m1) : find_unsigned_mode(m1);
+				if (m2 == NULL) {
+					/* should NOT happen, but if it does we give up here */
+					return ir_may_alias;
+				}
+				tv2 = tarval_convert_to(tv2, m2);
+			}
+			/* here the size should be identical, check for signed */
+			if (get_mode_sign(m1) != get_mode_sign(m2)) {
+				/* find the signed */
+				if (mode_is_signed(m2)) {
+					tarval *t = tv1;
+					ir_mode *tm = m1;
+					tv1 = tv2; m1 = m2;
+					tv2 = t;   m2 = tm;
+				}
+
+				/* m1 is now the signed one */
+				if (!tarval_is_negative(tv1)) {
+					/* tv1 is signed, but >= 0, simply cast into unsigned */
+					tv1 = tarval_convert_to(tv1, m2);
+				} else {
+					tv_size = new_tarval_from_long(size, m2);
+
+					if (tarval_cmp(tv2, tv_size) & (pn_Cmp_Eq|pn_Cmp_Gt)) {
+						/* tv1 is negative and tv2 >= tv_size, so the difference is bigger than size */
+						return ir_no_alias;
+					}
+					/* tv_size > tv2, so we can subtract without overflow */
+					tv2 = tarval_sub(tv_size, tv2, NULL);
+
+					/* tv1 is < 0, so we can negate it */
+					tv1 = tarval_neg(tv1);
+
+					/* cast it into unsigned. for two-complement it does the right thing for MIN_INT */
+					tv1 = tarval_convert_to(tv1, m2);
+
+					/* now we can compare without overflow */
+					return tarval_cmp(tv1, tv2) & (pn_Cmp_Eq|pn_Cmp_Gt) ? ir_no_alias : ir_may_alias;
+				}
+			}
+		}
+		if (tarval_cmp(tv1, tv2) == pn_Cmp_Gt) {
+			tarval *t = tv1;
+			tv1 = tv2;
+			tv2 = t;
+		}
+		/* tv1 is now the "smaller" one */
+		tv      = tarval_sub(tv2, tv1, NULL);
+		tv_size = new_tarval_from_long(size, get_tarval_mode(tv));
+		return tarval_cmp(tv_size, tv) & (pn_Cmp_Eq|pn_Cmp_Lt) ? ir_no_alias : ir_may_alias;
+	}
+
+	/* Note: we rely here on the fact that normalization puts constants on the RIGHT side */
+	if (is_Add(idx1)) {
+		ir_node *l1 = get_Add_left(idx1);
+		ir_node *r1 = get_Add_right(idx1);
+
+		if (l1 == idx2) {
+			/* x + c == y */
+			if (is_Const(r1))
+				return check_const(r1, size);
+		}
+		if (is_Add(idx2)) {
+			/* both are Adds, check if they are of x + a == x + b kind */
+			ir_node *l2 = get_Add_left(idx2);
+			ir_node *r2 = get_Add_right(idx2);
+
+			if (l1 == l2)
+				return different_index(r1, r2, size);
+			else if (l1 == r2)
+				return different_index(r1, l2, size);
+			else if (r1 == r2)
+				return different_index(l1, l2, size);
+			else if (r1 == l2)
+				return different_index(l1, r2, size);
+		}
+	}
+	if (is_Add(idx2)) {
+		ir_node *l2 = get_Add_left(idx2);
+		ir_node *r2 = get_Add_right(idx2);
+
+		if (l2 == idx1) {
+			/* x + c == y */
+			if (is_Const(r2))
+				return check_const(r2, size);
+		}
+	}
+
+	if (is_Sub(idx1)) {
+		ir_node *l1 = get_Sub_left(idx1);
+		ir_node *r1 = get_Sub_right(idx1);
+
+		if (l1 == idx2) {
+			/* x - c == y */
+			if (is_Const(r1))
+				return check_const(r1, size);
+		}
+
+		if (is_Sub(idx2)) {
+			/* both are Subs, check if they are of x - a == x - b kind */
+			ir_node *l2 = get_Sub_left(idx2);
+
+			if (l1 == l2) {
+				ir_node *r2 = get_Sub_right(idx2);
+				return different_index(r1, r2, size);
+			}
+		}
+	}
+	if (is_Sub(idx2)) {
+		ir_node *l2 = get_Sub_left(idx2);
+		ir_node *r2 = get_Sub_right(idx2);
+
+		if (l2 == idx1) {
+			/* x - c == y */
+			if (is_Const(r2))
+				return check_const(r2, size);
+		}
+
+	}
+	return ir_may_alias;
+}  /* different_index */
+
+/**
+ * Two Sel addresses have the same base address, check if there offsets are
+ * different.
  *
  * @param adr1  The first address.
  * @param adr2  The second address.
  */
-static ir_alias_relation different_offsets(ir_node *adr1, ir_node *adr2) {
-	return may_alias;
-}  /* different_offsets */
+static ir_alias_relation different_sel_offsets(const ir_node *sel1, const ir_node *sel2)
+{
+	/* seems to be broken */
+	(void) sel1;
+	(void) sel2;
+#if 0
+	ir_entity *ent1 = get_Sel_entity(sel1);
+	ir_entity *ent2 = get_Sel_entity(sel2);
+	int i, check_arr = 0;
+
+	if (ent1 == ent2)
+		check_arr = 1;
+	else {
+		ir_type *tp1 = get_entity_type(ent1);
+		ir_type *tp2 = get_entity_type(ent2);
+
+		if (tp1 == tp2)
+			check_arr = 1;
+		else if (get_type_state(tp1) == layout_fixed && get_type_state(tp2) == layout_fixed &&
+		         get_type_size_bits(tp1) == get_type_size_bits(tp2))
+			check_arr = 1;
+	}
+	if (check_arr) {
+		/* we select an entity of same size, check for indexes */
+		int n = get_Sel_n_indexs(sel1);
+		int have_no = 0;
+
+		if (n > 0 && n == get_Sel_n_indexs(sel2)) {
+			/* same non-zero number of indexes, an array access, check */
+			for (i = 0; i < n; ++i) {
+				ir_node *idx1 = get_Sel_index(sel1, i);
+				ir_node *idx2 = get_Sel_index(sel2, i);
+				ir_alias_relation res = different_index(idx1, idx2, 0); /* we can safely IGNORE the size here if it's at least >0 */
+
+				if (res == may_alias)
+					return may_alias;
+				else if (res == no_alias)
+					have_no = 1;
+			}
+			/* if we have at least one no_alias, there is no alias relation, else we have sure */
+			return have_no > 0 ? no_alias : sure_alias;
+		}
+	}
+#else
+	(void) different_index;
+#endif
+	return ir_may_alias;
+}  /* different_sel_offsets */
 
 /**
  * Determine the alias relation by checking if adr1 and adr2 are pointer
@@ -87,17 +357,17 @@ static ir_alias_relation different_offsets(ir_node *adr1, ir_node *adr2) {
  * @param adr1    The first address.
  * @param adr2    The second address.
  */
-static ir_alias_relation different_types(ir_node *adr1, ir_node *adr2)
+static ir_alias_relation different_types(const ir_node *adr1, const ir_node *adr2)
 {
 	ir_entity *ent1 = NULL, *ent2 = NULL;
 
-	if (is_SymConst(adr1) && get_SymConst_kind(adr1) == symconst_addr_ent)
-		ent1 = get_SymConst_entity(adr1);
+	if (is_Global(adr1))
+		ent1 = get_Global_entity(adr1);
 	else if (is_Sel(adr1))
 		ent1 = get_Sel_entity(adr1);
 
-	if (is_SymConst(adr2) && get_SymConst_kind(adr2) == symconst_addr_ent)
-		ent2 = get_SymConst_entity(adr2);
+	if (is_Global(adr2))
+		ent2 = get_Global_entity(adr2);
 	else if (is_Sel(adr2))
 		ent2 = get_Sel_entity(adr2);
 
@@ -106,235 +376,335 @@ static ir_alias_relation different_types(ir_node *adr1, ir_node *adr2)
 		ir_type *tp2 = get_entity_type(ent2);
 
 		if (tp1 != tp2) {
-			if (is_Pointer_type(tp1) && is_Pointer_type(tp2)) {
-				/* do deref until no pointer types are found */
-				do {
-					tp1 = get_pointer_points_to_type(tp1);
-					tp2 = get_pointer_points_to_type(tp2);
-				} while (is_Pointer_type(tp1) && is_Pointer_type(tp2));
+			/* do deref until no pointer types are found */
+			while (is_Pointer_type(tp1) && is_Pointer_type(tp2)) {
+				tp1 = get_pointer_points_to_type(tp1);
+				tp2 = get_pointer_points_to_type(tp2);
 			}
 
 			if (get_type_tpop(tp1) != get_type_tpop(tp2)) {
 				/* different type structure */
-				return no_alias;
+				return ir_no_alias;
 			}
 			if (is_Class_type(tp1)) {
 				/* check class hierarchy */
 				if (! is_SubClass_of(tp1, tp2) &&
 					! is_SubClass_of(tp2, tp1))
-					return no_alias;
+					return ir_no_alias;
 			} else {
 				/* different types */
-				return no_alias;
+				return ir_no_alias;
 			}
 		}
 	}
-	return may_alias;
+	return ir_may_alias;
 }  /* different_types */
 
 /**
- * Returns non-zero if a node is a routine parameter.
+ * Returns non-zero if a node is a result on a malloc-like routine.
  *
- * @param node  the node to test
+ * @param node  the Proj node to test
  */
-static int is_arg_Proj(ir_node *node) {
+static int is_malloc_Result(const ir_node *node)
+{
+	node = get_Proj_pred(node);
 	if (! is_Proj(node))
 		return 0;
 	node = get_Proj_pred(node);
-	if (! is_Proj(node))
+	if (! is_Call(node))
+		return 0;
+	node = get_Call_ptr(node);
+	if (is_Global(node)) {
+		ir_entity *ent = get_Global_entity(node);
+
+		if (get_entity_additional_properties(ent) & mtp_property_malloc)
+			return 1;
 		return 0;
-	return pn_Start_T_args == get_Proj_proj(node) && is_Start(get_Proj_pred(node));
-}  /* is_arg_Proj */
+	}
+	return 0;
+}  /* is_malloc_Result */
+
+/**
+ * Classify a base pointer.
+ *
+ * @param irg  the graph of the pointer
+ * @param irn  the node representing the base address
+ * @param ent  the base entity of the base address iff any
+ */
+ir_storage_class_class_t classify_pointer(const ir_graph *irg, const ir_node *irn, const ir_entity *ent)
+{
+	ir_storage_class_class_t res = ir_sc_pointer;
+	if (is_Global(irn)) {
+		ir_entity *entity = get_Global_entity(irn);
+		res = ir_sc_globalvar;
+		if (! (get_entity_usage(entity) & ir_usage_address_taken))
+			res |= ir_sc_modifier_nottaken;
+	} else if (irn == get_irg_frame(irg)) {
+		res = ir_sc_localvar;
+		if (ent != NULL && !(get_entity_usage(ent) & ir_usage_address_taken))
+			res |= ir_sc_modifier_nottaken;
+	} else if (irn == get_irg_tls(irg)) {
+		res = ir_sc_tls;
+		if (ent != NULL && !(get_entity_usage(ent) & ir_usage_address_taken))
+			res |= ir_sc_modifier_nottaken;
+	} else if (is_Proj(irn) && is_malloc_Result(irn)) {
+		return ir_sc_malloced;
+	} else if (is_Const(irn)) {
+		return ir_sc_globaladdr;
+	} else if (is_arg_Proj(irn)) {
+		res |= ir_sc_modifier_argument;
+	}
+
+	return res;
+}
+
+/**
+ * If adr represents a Bitfield Sel, skip it
+ */
+static const ir_node *skip_Bitfield_Sels(const ir_node *adr)
+{
+	if (is_Sel(adr)) {
+		ir_entity *ent     = get_Sel_entity(adr);
+		ir_type   *bf_type = get_entity_type(ent);
+
+		/* is it a bitfield type? */
+		if (is_Primitive_type(bf_type) && get_primitive_base_type(bf_type) != NULL)
+			adr = get_Sel_ptr(adr);
+	}
+	return adr;
+}
 
 /**
  * Determine the alias relation between two addresses.
+ *
+ * @param irg    the graph of both memory operations
+ * @param addr1  pointer address of the first memory operation
+ * @param mode1  the mode of the accessed data through addr1
+ * @param addr2  pointer address of the second memory operation
+ * @param mode2  the mode of the accessed data through addr2
+ *
+ * @return found memory relation
  */
 static ir_alias_relation _get_alias_relation(
-	ir_graph *irg,
-	ir_node *adr1, ir_mode *mode1,
-	ir_node *adr2, ir_mode *mode2)
+	const ir_graph *irg,
+	const ir_node *adr1, const ir_mode *mode1,
+	const ir_node *adr2, const ir_mode *mode2)
 {
-	ir_opcode op1, op2;
-	ir_entity *ent1, *ent2;
-	unsigned options;
+	ir_entity             *ent1, *ent2;
+	unsigned              options;
+	long                  offset1 = 0;
+	long                  offset2 = 0;
+	const ir_node         *base1;
+	const ir_node         *base2;
+	const ir_node         *orig_adr1 = adr1;
+	const ir_node         *orig_adr2 = adr2;
+	unsigned              mode_size;
+	ir_storage_class_class_t class1, class2, mod1, mod2;
+	int                   have_const_offsets;
 
 	if (! get_opt_alias_analysis())
-		return may_alias;
+		return ir_may_alias;
 
 	if (adr1 == adr2)
-		return sure_alias;
+		return ir_sure_alias;
 
 	options = get_irg_memory_disambiguator_options(irg);
 
 	/* The Armageddon switch */
 	if (options & aa_opt_no_alias)
-		return no_alias;
-
-	/* Two save some code, sort the addresses by its id's. Beware, this
-	   might break some things, so better check here. */
-	assert(iro_SymConst < iro_Sel && iro_Sel < iro_Proj && "Code dependence breaked");
-	op1 = get_irn_opcode(adr1);
-	op2 = get_irn_opcode(adr2);
-
-	if (op1 > op2) {
-		ir_node *t = adr1;
-		ir_mode *m = mode1;
-		adr1  = adr2;
-		mode1 = mode2;
-		adr2  = t;
-		mode2 = m;
-	}
-
-	if (is_SymConst(adr1) && get_SymConst_kind(adr1) == symconst_addr_ent) {
-		/* first address is a global variable */
-
-		if (is_SymConst(adr2) && get_SymConst_kind(adr2) == symconst_addr_ent) {
-			/* both addresses are global variables and we know
-			   they are different (R1 a) */
-			if (get_SymConst_entity(adr1) != get_SymConst_entity(adr2))
-				return no_alias;
-			else {
-				/* equal addresses */
-				return sure_alias;
-			}
+		return ir_no_alias;
+
+	/* do the addresses have constants offsets?
+	 *  Note: nodes are normalized to have constants at right inputs,
+	 *        sub X, C is normalized to add X, -C
+	 */
+	have_const_offsets = 1;
+	while (is_Add(adr1)) {
+		ir_node *add_right = get_Add_right(adr1);
+		if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
+			tarval *tv  = get_Const_tarval(add_right);
+			offset1    += get_tarval_long(tv);
+			adr1        = get_Add_left(adr1);
+		} else if (mode_is_reference(get_irn_mode(add_right))) {
+			adr1 = add_right;
+			have_const_offsets = 0;
+		} else {
+			adr1 = get_Add_left(adr1);
+			have_const_offsets = 0;
 		}
-		if (is_Sel(adr2)) {
-			ir_node *base = find_base_adr(adr2, &ent2);
-
-			if (is_SymConst(base) && get_SymConst_kind(base) == symconst_addr_ent) {
-				/* base address is a global var (R1 a) */
-				if (adr1 != base)
-					return no_alias;
-				if (base == adr1)
-					return different_offsets(adr1, adr2);
-			} else if (base == get_irg_frame(irg)) {
-				/* the second one is a local variable so they are always
-				   different (R1 b) */
-				return no_alias;
-			} else if (base == get_irg_tls(irg)) {
-				/* the second one is a TLS variable so they are always
-				   different (R1 c) */
-				return no_alias;
-			}
+	}
+	while (is_Add(adr2)) {
+		ir_node *add_right = get_Add_right(adr2);
+		if (is_Const(add_right) && !mode_is_reference(get_irn_mode(add_right))) {
+			tarval *tv  = get_Const_tarval(add_right);
+			offset2    += get_tarval_long(tv);
+			adr2        = get_Add_left(adr2);
+		} else if (mode_is_reference(get_irn_mode(add_right))) {
+			adr2 = add_right;
+			have_const_offsets = 0;
+		} else {
+			adr2 = get_Add_left(adr2);
+			have_const_offsets = 0;
 		}
+	}
+
+	mode_size = get_mode_size_bytes(mode1);
+	if (get_mode_size_bytes(mode2) > mode_size) {
+		mode_size = get_mode_size_bytes(mode2);
+	}
+
+	/* same base address -> compare offsets if possible.
+	 * FIXME: type long is not sufficient for this task ...
+	 */
+	if (adr1 == adr2 && have_const_offsets) {
+		if ((unsigned long)labs(offset2 - offset1) >= mode_size)
+			return ir_no_alias;
+		else
+			return ir_sure_alias;
+	}
 
-		/* Here we are: the first is a global var, the second some pointer. */
-		ent1 = get_SymConst_entity(adr1);
-		if (get_entity_address_taken(ent1) == ir_address_not_taken) {
-			/* The address of the global variable was never taken, so
-			   the pointer cannot match (R2). */
-			return no_alias;
+	/*
+	 * Bitfields can be constructed as Sels from its base address.
+	 * As they have different entities, the disambiguator would find that they are
+	 * alias free. While this is true for it's values, it is false for the addresses
+	 * (strictly speaking, the Sel's are NOT the addresses of the bitfields).
+	 * So, skip those bitfield selecting Sel's.
+	 */
+	adr1 = skip_Bitfield_Sels(adr1);
+	adr2 = skip_Bitfield_Sels(adr2);
+
+	/* skip Sels */
+	base1 = adr1;
+	base2 = adr2;
+	ent1  = NULL;
+	ent2  = NULL;
+	if (is_Sel(adr1)) {
+		base1 = find_base_adr(adr1, &ent1);
+	}
+	if (is_Sel(adr2)) {
+		base2 = find_base_adr(adr2, &ent2);
+	}
+
+	/* same base address -> compare Sel entities */
+	if (base1 == base2 && ent1 != NULL && ent2 != NULL) {
+		if (ent1 != ent2)
+			return ir_no_alias;
+		else if (have_const_offsets)
+			return different_sel_offsets(adr1, adr2);
+	}
+
+	mod1 = classify_pointer(irg, base1, ent1);
+	mod2 = classify_pointer(irg, base2, ent2);
+
+	class1 = GET_BASE_SC(mod1);
+	class2 = GET_BASE_SC(mod2);
+
+	if (class1 == ir_sc_pointer || class2 == ir_sc_pointer) {
+		/* swap pointer class to class1 */
+		if (class2 == ir_sc_pointer) {
+			ir_storage_class_class_t temp = mod1;
+			mod1 = mod2;
+			mod2 = temp;
+			class1 = GET_BASE_SC(mod1);
+			class2 = GET_BASE_SC(mod2);
 		}
-	} else if (is_Sel(adr1)) {
-		/* the first address is a Sel */
-		ir_node *base1 = find_base_adr(adr1, &ent1);
-
-		if (base1 == get_irg_frame(irg)) {
-			/* the first is a local variable */
-			if (is_Sel(adr2)) {
-				/* the second address is a Sel */
-				ir_node *base2 = find_base_adr(adr2, &ent2);
-
-				if (base2 == get_irg_frame(irg)) {
-					/* both addresses are local variables and we know
-					   they are different (R1 a) */
-					if (ent1 != ent2)
-						return no_alias;
-					else
-						return different_offsets(adr1, adr2);
-				} else if (base2 == get_irg_tls(irg)) {
-					/* the second one is a TLS variable so they are always
-				       different (R1 d) */
-					return no_alias;
-				} else if (is_arg_Proj(base2)) {
-					/* the second one is an offset from a parameter so they are
-					   always different (R1 e) */
-					return no_alias;
-				}
-			} else if (is_arg_Proj(adr2)) {
-				/* a local variable and a parameter are always different (R1 e) */
-				return no_alias;
-			}
-		} else if (base1 == get_irg_tls(irg)) {
-			/* the first is a TLS variable */
-			if (is_Sel(adr2)) {
-				/* the second address is a Sel */
-				ir_node *base2 = find_base_adr(adr2, &ent2);
-
-				if (base2 == get_irg_frame(irg)) {
-					/* the second one is a local variable so they are always
-				       different (R1 d) */
-					return no_alias;
-				} else if (base2 == get_irg_tls(irg)) {
-					/* both addresses are TLS variables and we know
-					   they are different (R1 a) */
-					if (ent1 != ent2)
-						return no_alias;
-					else
-						return different_offsets(adr1, adr2);
-				}
-			}
-		} else if (is_arg_Proj(base1)) {
-			/* the first one is an offset from a parameter */
-			if (is_Sel(adr2)) {
-				/* the second address is a Sel */
-				ir_node *base2 = find_base_adr(adr2, &ent2);
-
-				if (base2 == get_irg_frame(irg)) {
-					/* the second one is a local variable so they are always
-				       different (R1 e) */
-					return no_alias;
-				}
-			}
+		/* a pointer and an object whose address was never taken */
+		if (mod2 & ir_sc_modifier_nottaken) {
+			return ir_no_alias;
+		}
+		if (mod1 & ir_sc_modifier_argument) {
+			if ( (options & aa_opt_no_alias_args)
+					&& (mod2 & ir_sc_modifier_argument))
+				return ir_no_alias;
+			if ( (options & aa_opt_no_alias_args_global)
+					&& (class2 == ir_sc_globalvar
+						|| class2 == ir_sc_tls
+						|| class2 == ir_sc_globaladdr))
+				return ir_no_alias;
+		}
+	} else if (class1 != class2) {
+		/* two objects from different memory spaces */
+		return ir_no_alias;
+	} else {
+		/* both classes are equal */
+		if (class1 == ir_sc_globalvar) {
+			ir_entity *entity1 = get_SymConst_entity(base1);
+			ir_entity *entity2 = get_SymConst_entity(base2);
+			if (entity1 != entity2)
+				return ir_no_alias;
+
+			/* for some reason CSE didn't happen yet for the 2 SymConsts... */
+			return ir_may_alias;
+		} else if (class1 == ir_sc_globaladdr) {
+			tarval *tv  = get_Const_tarval(base1);
+			offset1    += get_tarval_long(tv);
+			tv          = get_Const_tarval(base2);
+			offset2    += get_tarval_long(tv);
+
+			if ((unsigned long)labs(offset2 - offset1) >= mode_size)
+				return ir_no_alias;
+			else
+				return ir_sure_alias;
 		}
 	}
 
-	if (options & aa_opt_type_based) { /* Type based alias analysis */
+	/* Type based alias analysis */
+	if (options & aa_opt_type_based) {
 		ir_alias_relation rel;
 
 		if (options & aa_opt_byte_type_may_alias) {
 			if (get_mode_size_bits(mode1) == 8 || get_mode_size_bits(mode2) == 8) {
-				/* One of the modes address a byte. Assume a may_alias and leave
+				/* One of the modes address a byte. Assume a ir_may_alias and leave
 				   the type based check. */
 				goto leave_type_based_alias;
 			}
 		}
 		/* cheap check: If the mode sizes did not match, the types MUST be different */
 		if (get_mode_size_bits(mode1) != get_mode_size_bits(mode2))
-			return no_alias;
+			return ir_no_alias;
+
+		/* cheap test: if only one is a reference mode, no alias */
+		if (mode_is_reference(mode1) != mode_is_reference(mode2))
+			return ir_no_alias;
+
+		/* cheap test: if arithmetic is different, no alias */
+		if (get_mode_arithmetic(mode1) != get_mode_arithmetic(mode2))
+			return ir_no_alias;
 
 		/* try rule R5 */
-		rel = different_types(adr1, adr2);
-		if (rel != may_alias)
+		rel = different_types(orig_adr1, orig_adr2);
+		if (rel != ir_may_alias)
 			return rel;
 leave_type_based_alias:;
 	}
 
 	/* do we have a language specific memory disambiguator? */
-	if (language_disambuigator) {
-		ir_alias_relation rel = (*language_disambuigator)(irg, adr1, mode1, adr2, mode2);
-		if (rel != may_alias)
+	if (language_disambuigator != NULL) {
+		ir_alias_relation rel = language_disambuigator(irg, orig_adr1, mode1, orig_adr2, mode2);
+		if (rel != ir_may_alias)
 			return rel;
 	}
 
 	/* access points-to information here */
-	return may_alias;
+	return ir_may_alias;
 }  /* _get_alias_relation */
 
 /*
  * Determine the alias relation between two addresses.
  */
 ir_alias_relation get_alias_relation(
-	ir_graph *irg,
-	ir_node *adr1, ir_mode *mode1,
-	ir_node *adr2, ir_mode *mode2)
+	const ir_graph *irg,
+	const ir_node *adr1, const ir_mode *mode1,
+	const ir_node *adr2, const ir_mode *mode2)
 {
 	ir_alias_relation rel = _get_alias_relation(irg, adr1, mode1, adr2, mode2);
+	DB((dbg, LEVEL_1, "alias(%+F, %+F) = %s\n", adr1, adr2, get_ir_alias_relation_name(rel)));
 	return rel;
 }  /* get_alias_relation */
 
 /* Set a source language specific memory disambiguator function. */
-void set_language_memory_disambiguator(DISAMBIGUATOR_FUNC func) {
+void set_language_memory_disambiguator(DISAMBIGUATOR_FUNC func)
+{
 	language_disambuigator = func;
 }  /* set_language_memory_disambiguator */
 
@@ -343,8 +713,10 @@ static set *result_cache = NULL;
 
 /** An entry in the relation cache. */
 typedef struct mem_disambig_entry {
-	ir_node	          *adr1;    /**< The first address. */
-	ir_node	          *adr2;    /**< The second address. */
+	const ir_node	  *adr1;    /**< The first address. */
+	const ir_mode	  *mode1;   /**< The first address mode. */
+	const ir_node	  *adr2;    /**< The second address. */
+	const ir_mode	  *mode2;   /**< The second address mode. */
 	ir_alias_relation result;   /**< The alias relation result. */
 } mem_disambig_entry;
 
@@ -353,17 +725,21 @@ typedef struct mem_disambig_entry {
 /**
  * Compare two relation cache entries.
  */
-static int cmp_mem_disambig_entry(const void *elt, const void *key, size_t size) {
+static int cmp_mem_disambig_entry(const void *elt, const void *key, size_t size)
+{
 	const mem_disambig_entry *p1 = elt;
 	const mem_disambig_entry *p2 = key;
+	(void) size;
 
-	return p1->adr1 == p2->adr1 && p1->adr2 == p2->adr2;
+	return p1->adr1 == p2->adr1 && p1->adr2 == p2->adr2 &&
+	       p1->mode1 == p2->mode1 && p1->mode2 == p2->mode2;
 }  /* cmp_mem_disambig_entry */
 
 /**
  * Initialize the relation cache.
  */
-void mem_disambig_init(void) {
+void mem_disambig_init(void)
+{
 	result_cache = new_set(cmp_mem_disambig_entry, 8);
 }  /* mem_disambig_init */
 
@@ -371,25 +747,29 @@ void mem_disambig_init(void) {
  * Determine the alias relation between two addresses.
  */
 ir_alias_relation get_alias_relation_ex(
-	ir_graph *irg,
-	ir_node *adr1, ir_mode *mode1,
-	ir_node *adr2, ir_mode *mode2)
+	const ir_graph *irg,
+	const ir_node *adr1, const ir_mode *mode1,
+	const ir_node *adr2, const ir_mode *mode2)
 {
 	mem_disambig_entry key, *entry;
 
+	ir_fprintf(stderr, "%+F <-> %+F\n", adr1, adr2);
+
 	if (! get_opt_alias_analysis())
-		return may_alias;
+		return ir_may_alias;
 
 	if (get_irn_opcode(adr1) > get_irn_opcode(adr2)) {
-		ir_node *t = adr1;
+		const ir_node *t = adr1;
 		adr1 = adr2;
 		adr2 = t;
 	}
 
-	key.adr1 = adr1;
-	key.adr2 = adr2;
+	key.adr1  = adr1;
+	key.adr2  = adr2;
+	key.mode1 = mode1;
+	key.mode2 = mode2;
 	entry = set_find(result_cache, &key, sizeof(key), HASH_ENTRY(adr1, adr2));
-	if (entry)
+	if (entry != NULL)
 		return entry->result;
 
 	key.result = get_alias_relation(irg, adr1, mode1, adr2, mode2);
@@ -399,8 +779,9 @@ ir_alias_relation get_alias_relation_ex(
 }  /* get_alias_relation_ex */
 
 /* Free the relation cache. */
-void mem_disambig_term(void) {
-	if (result_cache) {
+void mem_disambig_term(void)
+{
+	if (result_cache != NULL) {
 		del_set(result_cache);
 		result_cache = NULL;
 	}
@@ -425,90 +806,172 @@ void mem_disambig_term(void) {
  *
  * @return non-zero if the Load/Store is a hidden cast, zero else
  */
-static int is_hidden_cast(ir_mode *mode, ir_mode *ent_mode) {
+static int is_hidden_cast(const ir_mode *mode, const ir_mode *ent_mode)
+{
+	if (ent_mode == NULL)
+		return false;
+
 	if (ent_mode != mode) {
 		if (ent_mode == NULL ||
 			get_mode_size_bits(ent_mode) != get_mode_size_bits(mode) ||
 			get_mode_sort(ent_mode) != get_mode_sort(mode) ||
 			get_mode_arithmetic(ent_mode) != irma_twos_complement ||
 			get_mode_arithmetic(mode) != irma_twos_complement)
-			return 1;
+			return true;
 	}
-	return 0;
+	return false;
 }  /* is_hidden_cast */
 
 /**
- * Determine the address_taken state of a node (or it's successor Sels).
+ * Determine the usage state of a node (or its successor Sels).
  *
  * @param irn  the node
  */
-static ir_address_taken_state find_address_taken_state(ir_node *irn) {
-	int     i;
-	ir_mode *emode, *mode;
-	ir_node *value;
-	ir_entity *ent;
+static ir_entity_usage determine_entity_usage(const ir_node *irn, ir_entity *entity)
+{
+	int       i;
+	ir_mode   *emode, *mode;
+	ir_node   *value;
+	ir_type   *tp;
+	ir_entity_usage res = 0;
 
 	for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
 		ir_node *succ = get_irn_out(irn, i);
 
 		switch (get_irn_opcode(succ)) {
 		case iro_Load:
+			/* beware: irn might be a Id node here, so irn might be not
+			   equal to get_Load_ptr(succ) */
+			res |= ir_usage_read;
+
 			/* check if this load is not a hidden conversion */
-			mode = get_Load_mode(succ);
-			ent = is_SymConst(irn) ? get_SymConst_entity(irn) : get_Sel_entity(irn);
-			emode = get_type_mode(get_entity_type(ent));
+			mode  = get_Load_mode(succ);
+			emode = get_type_mode(get_entity_type(entity));
 			if (is_hidden_cast(mode, emode))
-				return ir_address_taken;
+				res |= ir_usage_reinterpret_cast;
 			break;
 
 		case iro_Store:
 			/* check that the node is not the Store's value */
-			value = get_Store_value(succ);
-			if (value == irn)
-				return ir_address_taken;
-			/* check if this Store is not a hidden conversion */
-			mode = get_irn_mode(value);
-			ent = is_SymConst(irn) ? get_SymConst_entity(irn) : get_Sel_entity(irn);
-			emode = get_type_mode(get_entity_type(ent));
-			if (is_hidden_cast(mode, emode))
-				return ir_address_taken;
+			if (irn == get_Store_value(succ)) {
+				res |= ir_usage_unknown;
+			}
+			if (irn == get_Store_ptr(succ)) {
+				res |= ir_usage_write;
+
+				/* check if this Store is not a hidden conversion */
+				value = get_Store_value(succ);
+				mode  = get_irn_mode(value);
+				emode = get_type_mode(get_entity_type(entity));
+				if (is_hidden_cast(mode, emode))
+					res |= ir_usage_reinterpret_cast;
+			}
+			assert(irn != get_Store_mem(succ));
 			break;
 
+		case iro_CopyB:
+			/* CopyB are like Loads/Stores */
+			tp  = get_entity_type(entity);
+			if (tp != get_CopyB_type(succ)) {
+				/* bad, different types, might be a hidden conversion */
+				res |= ir_usage_reinterpret_cast;
+			}
+			if (irn == get_CopyB_dst(succ)) {
+				res |= ir_usage_write;
+			} else {
+				assert(irn == get_CopyB_src(succ));
+				res |= ir_usage_read;
+			}
+			break;
+
+		case iro_Add:
+		case iro_Sub:
+			/* Check the successor of irn. */
+			res |= determine_entity_usage(succ, entity);
+			break;
 		case iro_Sel: {
+			ir_entity *entity = get_Sel_entity(succ);
+			/* this analysis can't handle unions correctly */
+			if (is_Union_type(get_entity_owner(entity))) {
+				res |= ir_usage_unknown;
+				break;
+			}
 			/* Check the successor of irn. */
-			ir_address_taken_state res = find_address_taken_state(succ);
-			if (res != ir_address_not_taken)
-				return res;
+			res |= determine_entity_usage(succ, entity);
 			break;
 		}
 
 		case iro_Call:
-			/* Only the call address is not an address taker but
-			   this is an uninteresting case, so we ignore it here. */
-			return ir_address_taken;
+			if (irn == get_Call_ptr(succ)) {
+				/* TODO: we could check for reinterpret casts here...
+				 * But I doubt anyone is interested in that bit for
+				 * function entities and I'm too lazy to write the code now.
+				 */
+				res |= ir_usage_read;
+			} else {
+				assert(irn != get_Call_mem(succ));
+				res |= ir_usage_unknown;
+			}
+			break;
+
+		/* skip identities */
+		case iro_Id:
+			res |= determine_entity_usage(succ, entity);
+			break;
+
+		/* skip tuples */
+		case iro_Tuple: {
+			int input_nr;
+			for (input_nr = get_Tuple_n_preds(succ) - 1; input_nr >= 0;
+					--input_nr) {
+				ir_node *pred = get_Tuple_pred(succ, input_nr);
+				if (pred == irn) {
+					int k;
+					/* we found one input */
+					for (k = get_irn_n_outs(succ) - 1; k >= 0; --k) {
+						ir_node *proj = get_irn_out(succ, k);
+
+						if (is_Proj(proj) && get_Proj_proj(proj) == input_nr) {
+							res |= determine_entity_usage(proj, entity);
+							break;
+						}
+					}
+				}
+			}
+			break;
+		}
 
 		default:
-			/* another op, the address may be taken */
-			return ir_address_taken_unknown;
+			/* another op, we don't know anything (we could do more advanced
+			 * things like a dataflow analysis here) */
+			res |= ir_usage_unknown;
+			break;
 		}
 	}
-	/* All successors finished, the address is not taken. */
-	return ir_address_not_taken;
-}  /* find_address_taken_state */
+
+	return res;
+}
 
 /**
- * Update the "address taken" flag of all frame entities.
+ * Update the usage flags of all frame entities.
  */
-static void analyse_irg_address_taken(ir_graph *irg) {
+static void analyse_irg_entity_usage(ir_graph *irg)
+{
 	ir_type *ft = get_irg_frame_type(irg);
 	ir_node *irg_frame;
-	int i;
+	int i, j, k, static_link_arg;
 
 	/* set initial state to not_taken, as this is the "smallest" state */
 	for (i = get_class_n_members(ft) - 1; i >= 0; --i) {
 		ir_entity *ent = get_class_member(ft, i);
 
-		set_entity_address_taken(ent, ir_address_not_taken);
+		/* methods can only be analyzed globally */
+		if (! is_method_entity(ent)) {
+			ir_entity_usage flags = 0;
+			if (get_entity_linkage(ent) & IR_LINKAGE_HIDDEN_USER)
+				flags = ir_usage_unknown;
+			set_entity_usage(ent, flags);
+		}
 	}
 
 	assure_irg_outs(irg);
@@ -516,108 +979,254 @@ static void analyse_irg_address_taken(ir_graph *irg) {
 	irg_frame = get_irg_frame(irg);
 
 	for (i = get_irn_n_outs(irg_frame) - 1; i >= 0; --i) {
-		ir_node *succ = get_irn_out(irg_frame, i);
-		ir_address_taken_state state;
+		ir_node        *succ = get_irn_out(irg_frame, i);
+		ir_entity      *entity;
+		ir_entity_usage flags;
 
-	    if (is_Sel(succ)) {
-			ir_entity *ent = get_Sel_entity(succ);
+		if (!is_Sel(succ))
+			continue;
 
-			if (get_entity_address_taken(ent) == ir_address_taken)
-				continue;
+		entity = get_Sel_entity(succ);
+		flags  = get_entity_usage(entity);
+		flags |= determine_entity_usage(succ, entity);
+		set_entity_usage(entity, flags);
+	}
+
+	/* check inner functions accessing outer frame */
+	static_link_arg = 0;
+	for (i = get_class_n_members(ft) - 1; i >= 0; --i) {
+		ir_entity *ent = get_class_member(ft, i);
+		ir_graph  *inner_irg;
+		ir_node   *args;
 
-			state = find_address_taken_state(succ);
-			if (state > get_entity_address_taken(ent))
-				set_entity_address_taken(ent, state);
+		if (! is_method_entity(ent))
+			continue;
+
+		inner_irg = get_entity_irg(ent);
+		if (inner_irg == NULL)
+			continue;
+
+		assure_irg_outs(inner_irg);
+		args = get_irg_args(inner_irg);
+		for (j = get_irn_n_outs(args) - 1; j >= 0; --j) {
+			ir_node *arg = get_irn_out(args, j);
+
+			if (get_Proj_proj(arg) == static_link_arg) {
+				for (k = get_irn_n_outs(arg) - 1; k >= 0; --k) {
+					ir_node *succ = get_irn_out(arg, k);
+
+					if (is_Sel(succ)) {
+						ir_entity *entity = get_Sel_entity(succ);
+
+						if (get_entity_owner(entity) == ft) {
+							/* found an access to the outer frame */
+							ir_entity_usage flags;
+
+							flags  = get_entity_usage(entity);
+							flags |= determine_entity_usage(succ, entity);
+							set_entity_usage(entity, flags);
+						}
+					}
+				}
+			}
 		}
 	}
+
+
 	/* now computed */
-	irg->adr_taken_state = ir_address_taken_computed;
-}  /* analyse_address_taken */
+	irg->entity_usage_state = ir_entity_usage_computed;
+}
 
-/* Returns the current address taken state of the graph. */
-ir_address_taken_computed_state get_irg_address_taken_state(const ir_graph *irg) {
-	return irg->adr_taken_state;
-}  /* get_irg_address_taken_state */
+ir_entity_usage_computed_state get_irg_entity_usage_state(const ir_graph *irg)
+{
+	return irg->entity_usage_state;
+}
 
-/* Sets the current address taken state of the graph. */
-void set_irg_address_taken_state(ir_graph *irg, ir_address_taken_computed_state state) {
-	irg->adr_taken_state = state;
-}  /* set_irg_address_taken_state */
+void set_irg_entity_usage_state(ir_graph *irg, ir_entity_usage_computed_state state)
+{
+	irg->entity_usage_state = state;
+}
+
+void assure_irg_entity_usage_computed(ir_graph *irg)
+{
+	if (irg->entity_usage_state != ir_entity_usage_not_computed)
+		return;
+
+	analyse_irg_entity_usage(irg);
+}
 
-/* Assure that the address taken flag is computed for the given graph. */
-void assure_irg_address_taken_computed(ir_graph *irg) {
-	if (irg->adr_taken_state == ir_address_taken_not_computed)
-		analyse_irg_address_taken(irg);
-}  /* assure_irg_address_taken_computed */
 
 /**
- * Initialize the address_taken flag for a global type like type.
+ * Initialize the entity_usage flag for a global type like type.
  */
-static void init_taken_flag(ir_type * tp) {
+static void init_entity_usage(ir_type *tp)
+{
 	int i;
 
-	/* All external visible entities are at least
-	   ir_address_taken_unknown. This is very conservative. */
+	/* We have to be conservative: All external visible entities are unknown */
 	for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
-		ir_entity *ent = get_compound_member(tp, i);
-		ir_address_taken_state state;
+		ir_entity       *ent  = get_compound_member(tp, i);
+		ir_entity_usage flags = ir_usage_none;
 
-		state = get_entity_visibility(ent) == visibility_external_visible ?
-				ir_address_taken_unknown : ir_address_not_taken ;
-		set_entity_address_taken(ent, state);
+		if (entity_is_externally_visible(ent)) {
+			flags |= ir_usage_unknown;
+		}
+		set_entity_usage(ent, flags);
 	}
-}  /* init_taken_flag */
+}
 
 /**
- * Print the address taken state of all entities of a given type for debugging.
+ * Mark all entities used in the initializer as unknown usage.
+ *
+ * @param initializer  the initializer to check
  */
-static void print_address_taken_state(ir_type *tp) {
+static void check_initializer_nodes(ir_initializer_t *initializer)
+{
+	unsigned i;
+	ir_node  *n;
+
+	switch (initializer->kind) {
+	case IR_INITIALIZER_CONST:
+		/* let's check if it's an address */
+		n = initializer->consti.value;
+		if (is_Global(n)) {
+			ir_entity *ent = get_Global_entity(n);
+			set_entity_usage(ent, ir_usage_unknown);
+		}
+		return;
+	case IR_INITIALIZER_TARVAL:
+	case IR_INITIALIZER_NULL:
+		return;
+	case IR_INITIALIZER_COMPOUND:
+		for (i = 0; i < initializer->compound.n_initializers; ++i) {
+			ir_initializer_t *sub_initializer
+				= initializer->compound.initializers[i];
+			check_initializer_nodes(sub_initializer);
+		}
+		return;
+	}
+	panic("invalid initializer found");
+}  /* check_initializer_nodes */
+
+/**
+ * Mark all entities used in the initializer for the given entity as unknown
+ * usage.
+ *
+ * @param ent  the entity
+ */
+static void check_initializer(ir_entity *ent)
+{
+	ir_node *n;
 	int i;
+
+	/* Beware: Methods are always initialized with "themself". This does not
+	 * count as a taken address.
+	 * TODO: this initialisation with "themself" is wrong and should be removed
+	 */
+	if (is_Method_type(get_entity_type(ent)))
+		return;
+
+	if (ent->initializer != NULL) {
+		check_initializer_nodes(ent->initializer);
+	} else if (entity_has_compound_ent_values(ent)) {
+		for (i = get_compound_ent_n_values(ent) - 1; i >= 0; --i) {
+			n = get_compound_ent_value(ent, i);
+
+			/* let's check if it's an address */
+			if (is_Global(n)) {
+				ir_entity *ent = get_Global_entity(n);
+				set_entity_usage(ent, ir_usage_unknown);
+			}
+		}
+	}
+}
+
+
+/**
+ * Mark all entities used in initializers as unknown usage.
+ *
+ * @param tp  a compound type
+ */
+static void check_initializers(ir_type *tp)
+{
+	int i;
+
 	for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
 		ir_entity *ent = get_compound_member(tp, i);
-		ir_address_taken_state state = get_entity_address_taken(ent);
 
-		if (state != ir_address_not_taken) {
-			assert(ir_address_not_taken <= state && state <= ir_address_taken);
-			ir_printf("%+F: %s\n", ent, get_address_taken_state_name(state));
-		}
+		check_initializer(ent);
+	}
+}  /* check_initializers */
+
+#ifdef DEBUG_libfirm
+/**
+ * Print the entity usage flags of all entities of a given type for debugging.
+ *
+ * @param tp  a compound type
+ */
+static void print_entity_usage_flags(ir_type *tp)
+{
+	int i;
+	for (i = get_compound_n_members(tp) - 1; i >= 0; --i) {
+		ir_entity *ent = get_compound_member(tp, i);
+		ir_entity_usage flags = get_entity_usage(ent);
+
+		if (flags == 0)
+			continue;
+		ir_printf("%+F:", ent);
+		if (flags & ir_usage_address_taken)
+			printf(" address_taken");
+		if (flags & ir_usage_read)
+			printf(" read");
+		if (flags & ir_usage_write)
+			printf(" write");
+		if (flags & ir_usage_reinterpret_cast)
+			printf(" reinterp_cast");
+		printf("\n");
 	}
-}  /* print_address_taken_state */
+}
+#endif /* DEBUG_libfirm */
 
 /**
  * Post-walker: check for global entity address
  */
-static void check_global_address(ir_node *irn, void *env) {
+static void check_global_address(ir_node *irn, void *env)
+{
 	ir_node *tls = env;
 	ir_entity *ent;
-	ir_address_taken_state state;
+	ir_entity_usage flags;
 
-	if (is_SymConst(irn) && get_SymConst_kind(irn) == symconst_addr_ent) {
+	if (is_Global(irn)) {
 		/* A global. */
-		ent = get_SymConst_entity(irn);
+		ent = get_Global_entity(irn);
 	} else if (is_Sel(irn) && get_Sel_ptr(irn) == tls) {
 		/* A TLS variable. */
-		ent = get_SymConst_entity(irn);
+		ent = get_Sel_entity(irn);
 	} else
 		return;
 
-	if (get_entity_address_taken(ent) == ir_address_not_taken) {
-		/* Already at the maximum. */
-		return;
-	}
-	state = find_address_taken_state(irn);
-	if (state > get_entity_address_taken(ent))
-		set_entity_address_taken(ent, state);
+	flags = get_entity_usage(ent);
+	flags |= determine_entity_usage(irn, ent);
+	set_entity_usage(ent, flags);
 }  /* check_global_address */
 
 /**
- * Update the "address taken" flag of all global entities.
+ * Update the entity usage flags of all global entities.
  */
-static void analyse_irp_globals_address_taken(void) {
+static void analyse_irp_globals_entity_usage(void)
+{
 	int i;
+	ir_segment_t s;
 
-	init_taken_flag(get_glob_type());
-	init_taken_flag(get_tls_type());
+	for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
+		ir_type *type = get_segment_type(s);
+		init_entity_usage(type);
+	}
+
+	for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
+		ir_type *type = get_segment_type(s);
+		check_initializers(type);
+	}
 
 	for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
 		ir_graph *irg = get_irp_irg(i);
@@ -625,25 +1234,137 @@ static void analyse_irp_globals_address_taken(void) {
 		assure_irg_outs(irg);
 		irg_walk_graph(irg, NULL, check_global_address, get_irg_tls(irg));
 	}
-	//print_address_taken_state(get_glob_type());
-	//print_address_taken_state(get_tls_type());
+
+#ifdef DEBUG_libfirm
+	if (firm_dbg_get_mask(dbg) & LEVEL_1) {
+		ir_segment_t s;
+		for (s = IR_SEGMENT_FIRST; s <= IR_SEGMENT_LAST; ++s) {
+			print_entity_usage_flags(get_segment_type(s));
+		}
+	}
+#endif /* DEBUG_libfirm */
 
 	/* now computed */
-	irp->globals_adr_taken_state = ir_address_taken_computed;
-}  /* analyse_irp_globals_address_taken */
+	irp->globals_entity_usage_state = ir_entity_usage_computed;
+}
 
 /* Returns the current address taken state of the globals. */
-ir_address_taken_computed_state get_irp_globals_address_taken_state(void) {
-	return irp->globals_adr_taken_state;
-}  /* get_irp_globals_address_taken_state */
+ir_entity_usage_computed_state get_irp_globals_entity_usage_state(void)
+{
+	return irp->globals_entity_usage_state;
+}
 
 /* Sets the current address taken state of the graph. */
-void set_irp_globals_address_taken_state(ir_address_taken_computed_state state) {
-	irp->globals_adr_taken_state = state;
-}  /* set_irg_address_taken_state */
+void set_irp_globals_entity_usage_state(ir_entity_usage_computed_state state)
+{
+	irp->globals_entity_usage_state = state;
+}
 
 /* Assure that the address taken flag is computed for the globals. */
-void assure_irp_globals_address_taken_computed(void) {
-	if (irp->globals_adr_taken_state == ir_address_taken_not_computed)
-		analyse_irp_globals_address_taken();
-}  /* assure_irp_globals_address_taken_computed */
+void assure_irp_globals_entity_usage_computed(void)
+{
+	if (irp->globals_entity_usage_state != ir_entity_usage_not_computed)
+		return;
+
+	analyse_irp_globals_entity_usage();
+}
+
+void firm_init_memory_disambiguator(void)
+{
+	FIRM_DBG_REGISTER(dbg, "firm.ana.irmemory");
+	FIRM_DBG_REGISTER(dbgcall, "firm.opt.cc");
+}
+
+
+/** Maps method types to cloned method types. */
+static pmap *mtp_map;
+
+/**
+ * Clone a method type if not already cloned.
+ *
+ * @param tp  the type to clone
+ */
+static ir_type *clone_type_and_cache(ir_type *tp)
+{
+	ir_type *res;
+	pmap_entry *e = pmap_find(mtp_map, tp);
+
+	if (e)
+		return e->value;
+
+	res = clone_type_method(tp);
+	pmap_insert(mtp_map, tp, res);
+
+	return res;
+}  /* clone_type_and_cache */
+
+/**
+ * Walker: clone all call types of Calls to methods having the
+ * mtp_property_private property set.
+ */
+static void update_calls_to_private(ir_node *call, void *env)
+{
+	(void) env;
+	if (is_Call(call)) {
+		ir_node *ptr = get_Call_ptr(call);
+
+		if (is_SymConst(ptr)) {
+			ir_entity *ent = get_SymConst_entity(ptr);
+			ir_type *ctp = get_Call_type(call);
+
+			if (get_entity_additional_properties(ent) & mtp_property_private) {
+				if ((get_method_additional_properties(ctp) & mtp_property_private) == 0) {
+					ctp = clone_type_and_cache(ctp);
+					set_method_additional_property(ctp, mtp_property_private);
+					set_Call_type(call, ctp);
+					DB((dbgcall, LEVEL_1, "changed call to private method %+F using cloned type %+F\n", ent, ctp));
+				}
+			}
+		}
+	}
+}  /* update_calls_to_private */
+
+/* Mark all private methods, i.e. those of which all call sites are known. */
+void mark_private_methods(void)
+{
+	int i;
+	int changed = 0;
+
+	assure_irp_globals_entity_usage_computed();
+
+	mtp_map = pmap_create();
+
+	/* first step: change the calling conventions of the local non-escaped entities */
+	for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
+		ir_graph        *irg   = get_irp_irg(i);
+		ir_entity       *ent   = get_irg_entity(irg);
+		ir_entity_usage  flags = get_entity_usage(ent);
+
+		if (!entity_is_externally_visible(ent) &&
+		    !(flags & ir_usage_address_taken)) {
+			ir_type *mtp = get_entity_type(ent);
+
+			set_entity_additional_property(ent, mtp_property_private);
+			DB((dbgcall, LEVEL_1, "found private method %+F\n", ent));
+			if ((get_method_additional_properties(mtp) & mtp_property_private) == 0) {
+				/* need a new type */
+				mtp = clone_type_and_cache(mtp);
+				set_method_additional_property(mtp, mtp_property_private);
+				set_entity_type(ent, mtp);
+				DB((dbgcall, LEVEL_2, "changed entity type of %+F to %+F\n", ent, mtp));
+				changed = 1;
+			}
+		}
+	}
+
+	if (changed)
+		all_irg_walk(NULL, update_calls_to_private, NULL);
+
+	pmap_destroy(mtp_map);
+}  /* mark_private_methods */
+
+/* create a pass for mark_private_methods() */
+ir_prog_pass_t *mark_private_methods_pass(const char *name)
+{
+	return def_prog_pass(name ? name : "mark_private_methods", mark_private_methods);
+}  /* mark_private_methods_pass */