X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fir%2Firmode.c;h=49c14ac13804881a01f05395b15f9302aacbbc74;hb=202b43933e0cc0b71cc7fbe2b092b94efb7fd30e;hp=50000697d0cd86de2f7b49230ccbaa05322c3f12;hpb=eb08138c6b80c169945568e4414f491a9bc20388;p=libfirm

diff --git a/ir/ir/irmode.c b/ir/ir/irmode.c
index 50000697d..49c14ac13 100644
--- a/ir/ir/irmode.c
+++ b/ir/ir/irmode.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
+ * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
  *
  * This file is part of libFirm.
  *
@@ -17,51 +17,53 @@
  * PURPOSE.
  */
 
-/*
- * Project:     libFIRM
- * File name:   ir/ir/irmode.c
- * Purpose:     Data modes of operations.
- * Author:      Martin Trapp, Christian Schaefer
- * Modified by: Goetz Lindenmaier, Mathias Heil
- * Created:
- * CVS-ID:      $Id$
- * Copyright:   (c) 1998-2003 Universität Karlsruhe
+/**
+ * @file
+ * @brief    Data modes of operations.
+ * @author   Martin Trapp, Christian Schaefer, Goetz Lindenmaier, Mathias Heil
+ * @version  $Id$
  */
-#ifdef HAVE_CONFIG_H
-# include "config.h"
-#endif
+#include "config.h"
 
-#ifdef HAVE_STDLIB_H
-# include <stdlib.h>
-#endif
-#ifdef HAVE_STRING_H
-# include <string.h>
-#endif
+#include <stdlib.h>
+#include <string.h>
 
-# include <stddef.h>
+#include <stddef.h>
 
-# include "irprog_t.h"
-# include "irmode_t.h"
-# include "ident.h"
-# include "tv_t.h"
-# include "obst.h"
-# include "irhooks.h"
-# include "irtools.h"
+#include "irprog_t.h"
+#include "irmode_t.h"
+#include "ident.h"
+#include "tv_t.h"
+#include "obst.h"
+#include "irhooks.h"
+#include "irtools.h"
+#include "array.h"
+#include "error.h"
 
-/* * *
- * local values
- * * */
-
-
-/** dynamic array to hold all modes */
+/** Obstack to hold all modes. */
 static struct obstack modes;
 
-/** number of defined modes */
-static int num_modes;
+/** Number of defined modes. */
+static int num_modes = 0;
 
-/* * *
- * local functions
- * * */
+/** The list of all currently existing modes. */
+static ir_mode **mode_list;
+
+const char *get_mode_arithmetic_name(ir_mode_arithmetic ari)
+{
+#define X(a)    case a: return #a
+	switch (ari) {
+		X(irma_uninitialized);
+		X(irma_none);
+		X(irma_twos_complement);
+		X(irma_ones_complement);
+		X(irma_int_BCD);
+		X(irma_ieee754);
+		X(irma_float_BCD);
+		default: return "<unknown>";
+	}
+#undef X
+}
 
 /**
  * Compare modes that don't need to have their code field
@@ -69,7 +71,7 @@ static int num_modes;
  *
  * TODO: Add other fields
  **/
-INLINE static int modes_are_equal(const ir_mode *m, const ir_mode *n) {
+static inline int modes_are_equal(const ir_mode *m, const ir_mode *n) {
 	if (m == n) return 1;
 	if (m->sort         == n->sort &&
 		m->arithmetic   == n->arithmetic &&
@@ -82,61 +84,47 @@ INLINE static int modes_are_equal(const ir_mode *m, const ir_mode *n) {
 	return 0;
 }
 
-/*
- * calculates the next obstack address
- */
-static void *next_obstack_adr(struct obstack *o, void *p, size_t s) {
-	PTR_INT_TYPE adr = PTR_TO_INT((char *)p);
-	int mask = obstack_alignment_mask(o);
-
-	adr += s + mask;
-
-	return INT_TO_PTR(adr & ~mask);
-}
-
 /**
  * searches the modes obstack for the given mode and returns
  * a pointer on an equal mode already in the array, NULL if
  * none found
  */
 static ir_mode *find_mode(const ir_mode *m) {
-	ir_mode *n, *nn;
-	struct _obstack_chunk	*p;
-
-	p  = modes.chunk;
-	n  = (ir_mode *)p->contents;
-	nn = next_obstack_adr(&modes, n, sizeof(*n));
-	for (; (char *)nn <= modes.next_free;) {
-		assert(is_mode(n));
+	int i;
+	for (i = ARR_LEN(mode_list) - 1; i >= 0; --i) {
+		ir_mode *n = mode_list[i];
 		if (modes_are_equal(n, m))
 			return n;
-
-		n  = nn;
-		nn = next_obstack_adr(&modes, n, sizeof(*n));
 	}
+	return NULL;
+}
 
-	for (p = p->prev; p; p = p->prev) {
-		n  = (ir_mode *)p->contents;
-		nn = next_obstack_adr(&modes, n, sizeof(*n));
-		for (; (char *)nn < p->limit;) {
-			assert(is_mode(n));
-			if (modes_are_equal(n, m))
-				return n;
-
-			n  = nn;
-			nn = next_obstack_adr(&modes, n, sizeof(*n));
-		}
+#ifdef FIRM_STATISTICS
+/* return the mode index, only needed for statistics */
+int stat_find_mode_index(const ir_mode *m) {
+	int i;
+	for (i = ARR_LEN(mode_list) - 1; i >= 0; --i) {
+		ir_mode *n = mode_list[i];
+		if (modes_are_equal(n, m))
+			return i;
 	}
+	return -1;
+}
 
+/* return the mode for a given index, only needed for statistics */
+ir_mode *stat_mode_for_index(int idx) {
+	if (0 <= idx  && idx < ARR_LEN(mode_list))
+		return mode_list[idx];
 	return NULL;
 }
+#endif
 
 /**
  * sets special values of modes
  */
 static void set_mode_values(ir_mode* mode) {
 	switch (get_mode_sort(mode))    {
-	case irms_character:
+	case irms_reference:
 	case irms_int_number:
 	case irms_float_number:
 		mode->min  = get_tarval_min(mode);
@@ -144,6 +132,11 @@ static void set_mode_values(ir_mode* mode) {
 		mode->null = get_tarval_null(mode);
 		mode->one  = get_tarval_one(mode);
 		mode->minus_one = get_tarval_minus_one(mode);
+		if(get_mode_sort(mode) != irms_float_number) {
+			mode->all_one = get_tarval_all_one(mode);
+		} else {
+			mode->all_one = tarval_bad;
+		}
 		break;
 
 	case irms_internal_boolean:
@@ -152,14 +145,7 @@ static void set_mode_values(ir_mode* mode) {
 		mode->null = tarval_b_false;
 		mode->one  = tarval_b_true;
 		mode->minus_one = tarval_bad;
-		break;
-
-	case irms_reference:
-		mode->min  = tarval_bad;
-		mode->max  = tarval_bad;
-		mode->null = get_tarval_null(mode);
-		mode->one  = tarval_bad;
-		mode->minus_one = tarval_bad;
+		mode->all_one = tarval_b_true;
 		break;
 
 	case irms_auxiliary:
@@ -204,8 +190,6 @@ ir_mode *mode_Lu;
 ir_mode *mode_LLs;  /* 128 bit */
 ir_mode *mode_LLu;
 
-ir_mode *mode_C;
-ir_mode *mode_U;
 ir_mode *mode_b;
 ir_mode *mode_P;
 
@@ -232,8 +216,6 @@ ir_mode *get_modeLs(void) { return mode_Ls; }
 ir_mode *get_modeLu(void) { return mode_Lu; }
 ir_mode *get_modeLLs(void){ return mode_LLs; }
 ir_mode *get_modeLLu(void){ return mode_LLu; }
-ir_mode *get_modeC(void) { return mode_C; }
-ir_mode *get_modeU(void) { return mode_U; }
 ir_mode *get_modeb(void) { return mode_b; }
 ir_mode *get_modeP(void) { return mode_P; }
 ir_mode *get_modeX(void) { return mode_X; }
@@ -273,10 +255,13 @@ static ir_mode *register_mode(const ir_mode *new_mode) {
 
 	/* copy mode struct to modes array */
 	mode = (ir_mode *)obstack_copy(&modes, new_mode, sizeof(*mode));
+	ARR_APP1(ir_mode*, mode_list, mode);
 
 	mode->kind = k_ir_mode;
-	if (num_modes >= irm_max) mode->code = num_modes;
-		num_modes++;
+	if (num_modes >= irm_max)  {
+		mode->code = num_modes;
+	}
+	num_modes++;
 
 	/* add the new mode to the irp list of modes */
 	add_irp_mode(mode);
@@ -290,8 +275,8 @@ static ir_mode *register_mode(const ir_mode *new_mode) {
 /*
  * Creates a new mode.
  */
-ir_mode *new_ir_mode(const char *name, mode_sort sort, int bit_size, int sign,
-                     mode_arithmetic arithmetic, unsigned int modulo_shift)
+ir_mode *new_ir_mode(const char *name, ir_mode_sort sort, int bit_size, int sign,
+                     ir_mode_arithmetic arithmetic, unsigned int modulo_shift)
 {
 	ir_mode mode_tmpl;
 	ir_mode *mode = NULL;
@@ -318,23 +303,23 @@ ir_mode *new_ir_mode(const char *name, mode_sort sort, int bit_size, int sign,
 	case irms_control_flow:
 	case irms_memory:
 	case irms_internal_boolean:
-		assert(0 && "internal modes cannot be user defined");
-		break;
+		panic("internal modes cannot be user defined");
 
 	case irms_float_number:
 	case irms_int_number:
 	case irms_reference:
-	case irms_character:
 		mode = register_mode(&mode_tmpl);
+		break;
 	}
+	assert(mode != NULL);
 	return mode;
 }
 
 /*
  * Creates a new vector mode.
  */
-ir_mode *new_ir_vector_mode(const char *name, mode_sort sort, int bit_size, unsigned num_of_elem, int sign,
-                            mode_arithmetic arithmetic, unsigned int modulo_shift)
+ir_mode *new_ir_vector_mode(const char *name, ir_mode_sort sort, int bit_size, unsigned num_of_elem, int sign,
+                            ir_mode_arithmetic arithmetic, unsigned int modulo_shift)
 {
 	ir_mode mode_tmpl;
 	ir_mode *mode = NULL;
@@ -366,62 +351,51 @@ ir_mode *new_ir_vector_mode(const char *name, mode_sort sort, int bit_size, unsi
 	case irms_control_flow:
 	case irms_memory:
 	case irms_internal_boolean:
-		assert(0 && "internal modes cannot be user defined");
-		break;
+		panic("internal modes cannot be user defined");
 
 	case irms_reference:
-	case irms_character:
-		assert(0 && "only integer and floating point modes can be vectorized");
-		break;
+		panic("only integer and floating point modes can be vectorized");
 
 	case irms_float_number:
-		assert(0 && "not yet implemented");
-		break;
+		panic("not yet implemented");
 
 	case irms_int_number:
 		mode = register_mode(&mode_tmpl);
 	}
+	assert(mode != NULL);
 	return mode;
 }
 
 /* Functions for the direct access to all attributes of an ir_mode */
-modecode
-(get_mode_modecode)(const ir_mode *mode) {
+ir_modecode (get_mode_modecode)(const ir_mode *mode) {
 	return _get_mode_modecode(mode);
 }
 
-ident *
-(get_mode_ident)(const ir_mode *mode) {
+ident *(get_mode_ident)(const ir_mode *mode) {
 	return _get_mode_ident(mode);
 }
 
-const char *
-get_mode_name(const ir_mode *mode) {
+const char *get_mode_name(const ir_mode *mode) {
 	return get_id_str(mode->name);
 }
 
-mode_sort
-(get_mode_sort)(const ir_mode* mode) {
+ir_mode_sort (get_mode_sort)(const ir_mode* mode) {
 	return _get_mode_sort(mode);
 }
 
-int
-(get_mode_size_bits)(const ir_mode *mode) {
+unsigned (get_mode_size_bits)(const ir_mode *mode) {
 	return _get_mode_size_bits(mode);
 }
 
-int
-(get_mode_size_bytes)(const ir_mode *mode) {
+unsigned (get_mode_size_bytes)(const ir_mode *mode) {
 	return _get_mode_size_bytes(mode);
 }
 
-int
-(get_mode_sign)(const ir_mode *mode) {
+int (get_mode_sign)(const ir_mode *mode) {
 	return _get_mode_sign(mode);
 }
 
-int
-(get_mode_arithmetic)(const ir_mode *mode) {
+ir_mode_arithmetic (get_mode_arithmetic)(const ir_mode *mode) {
 	return get_mode_arithmetic(mode);
 }
 
@@ -430,160 +404,131 @@ int
  *  whether shift applies modulo to value of bits to shift.  Asserts
  *  if mode is not irms_int_number.
  */
-unsigned int
-(get_mode_modulo_shift)(const ir_mode *mode) {
+unsigned int (get_mode_modulo_shift)(const ir_mode *mode) {
 	return _get_mode_modulo_shift(mode);
 }
 
-unsigned int
-(get_mode_n_vector_elems)(const ir_mode *mode) {
+unsigned int (get_mode_n_vector_elems)(const ir_mode *mode) {
 	return _get_mode_vector_elems(mode);
 }
 
-void *
-(get_mode_link)(const ir_mode *mode) {
+void *(get_mode_link)(const ir_mode *mode) {
 	return _get_mode_link(mode);
 }
 
-void
-(set_mode_link)(ir_mode *mode, void *l) {
+void (set_mode_link)(ir_mode *mode, void *l) {
 	_set_mode_link(mode, l);
 }
 
-tarval *
-get_mode_min(ir_mode *mode) {
+tarval *get_mode_min(ir_mode *mode) {
 	assert(mode);
-	assert(get_mode_modecode(mode) < num_modes);
+	assert(get_mode_modecode(mode) < (ir_modecode) num_modes);
 	assert(mode_is_data(mode));
 
 	return mode->min;
 }
 
-tarval *
-get_mode_max(ir_mode *mode) {
+tarval *get_mode_max(ir_mode *mode) {
 	assert(mode);
-	assert(get_mode_modecode(mode) < num_modes);
+	assert(get_mode_modecode(mode) < (ir_modecode) num_modes);
 	assert(mode_is_data(mode));
 
 	return mode->max;
 }
 
-tarval *
-get_mode_null(ir_mode *mode) {
+tarval *get_mode_null(ir_mode *mode) {
 	assert(mode);
-	assert(get_mode_modecode(mode) < num_modes);
-	assert(mode_is_data(mode));
+	assert(get_mode_modecode(mode) < (ir_modecode) num_modes);
+	assert(mode_is_datab(mode));
 
 	return mode->null;
 }
 
-tarval *
-get_mode_one(ir_mode *mode) {
+tarval *get_mode_one(ir_mode *mode) {
 	assert(mode);
-	assert(get_mode_modecode(mode) < num_modes);
-	assert(mode_is_data(mode));
+	assert(get_mode_modecode(mode) < (ir_modecode) num_modes);
+	assert(mode_is_datab(mode));
 
 	return mode->one;
 }
 
-tarval *
-get_mode_minus_one(ir_mode *mode) {
+tarval *get_mode_minus_one(ir_mode *mode) {
 	assert(mode);
-	assert(get_mode_modecode(mode) < num_modes);
+	assert(get_mode_modecode(mode) < (ir_modecode) num_modes);
 	assert(mode_is_data(mode));
 
 	return mode->minus_one;
 }
 
-tarval *
-get_mode_infinite(ir_mode *mode) {
+tarval *get_mode_all_one(ir_mode *mode) {
+	assert(mode);
+	assert(get_mode_modecode(mode) < (ir_modecode) num_modes);
+	assert(mode_is_datab(mode));
+	return mode->all_one;
+}
+
+tarval *get_mode_infinite(ir_mode *mode) {
 	assert(mode);
-	assert(get_mode_modecode(mode) < num_modes);
+	assert(get_mode_modecode(mode) < (ir_modecode) num_modes);
 	assert(mode_is_float(mode));
 
 	return get_tarval_plus_inf(mode);
 }
 
-tarval *
-get_mode_NAN(ir_mode *mode) {
+tarval *get_mode_NAN(ir_mode *mode) {
 	assert(mode);
-	assert(get_mode_modecode(mode) < num_modes);
+	assert(get_mode_modecode(mode) < (ir_modecode) num_modes);
 	assert(mode_is_float(mode));
 
 	return get_tarval_nan(mode);
 }
 
-int
-is_mode(void *thing) {
-	if (get_kind(thing) == k_ir_mode)
-		return 1;
-	else
-		return 0;
+int is_mode(const void *thing) {
+	return get_kind(thing) == k_ir_mode;
 }
 
-int
-(mode_is_signed)(const ir_mode *mode) {
+int (mode_is_signed)(const ir_mode *mode) {
 	return _mode_is_signed(mode);
 }
 
-int
-(mode_is_float)(const ir_mode *mode) {
+int (mode_is_float)(const ir_mode *mode) {
 	return _mode_is_float(mode);
 }
 
-int
-(mode_is_int)(const ir_mode *mode) {
+int (mode_is_int)(const ir_mode *mode) {
 	return _mode_is_int(mode);
 }
 
-int
-(mode_is_character)(const ir_mode *mode) {
-	return _mode_is_character(mode);
-}
-
-int
-(mode_is_reference)(const ir_mode *mode) {
+int (mode_is_reference)(const ir_mode *mode) {
 	return _mode_is_reference(mode);
 }
 
-int
-(mode_is_num)(const ir_mode *mode) {
+int (mode_is_num)(const ir_mode *mode) {
 	return _mode_is_num(mode);
 }
 
-int
-(mode_is_numP)(const ir_mode *mode) {
-	return _mode_is_numP(mode);
-}
-
-int
-(mode_is_data)(const ir_mode *mode) {
+int (mode_is_data)(const ir_mode *mode) {
 	return _mode_is_data(mode);
 }
 
-int
-(mode_is_datab)(const ir_mode *mode) {
+int (mode_is_datab)(const ir_mode *mode) {
 	return _mode_is_datab(mode);
 }
 
-int
-(mode_is_dataM)(const ir_mode *mode) {
+int (mode_is_dataM)(const ir_mode *mode) {
 	return _mode_is_dataM(mode);
 }
 
-int
-(mode_is_float_vector)(const ir_mode *mode) {
+int (mode_is_float_vector)(const ir_mode *mode) {
 	return _mode_is_float_vector(mode);
 }
 
-int
-(mode_is_int_vector)(const ir_mode *mode) {
+int (mode_is_int_vector)(const ir_mode *mode) {
 	return _mode_is_int_vector(mode);
 }
 
 /* Returns true if sm can be converted to lm without loss. */
-int
-smaller_mode(const ir_mode *sm, const ir_mode *lm) {
+int smaller_mode(const ir_mode *sm, const ir_mode *lm) {
 	int sm_bits, lm_bits;
 
 	assert(sm);
@@ -598,23 +543,27 @@ smaller_mode(const ir_mode *sm, const ir_mode *lm) {
 	case irms_int_number:
 		switch (get_mode_sort(lm)) {
 		case irms_int_number:
+			if (get_mode_arithmetic(sm) != get_mode_arithmetic(lm))
+				return 0;
+
+			/* only two complement implemented */
+			assert(get_mode_arithmetic(sm) == irma_twos_complement);
+
 			/* integers are convertable if
 			 *   - both have the same sign and lm is the larger one
 			 *   - lm is the signed one and is at least two bits larger
 			 *     (one for the sign, one for the highest bit of sm)
 			 *   - sm & lm are two_complement and lm has greater or equal number of bits
 			 */
-			if (   get_mode_arithmetic(sm) == get_mode_arithmetic(lm)
-				&& get_mode_arithmetic(sm) == irma_twos_complement) {
-				return lm_bits >= sm_bits;
-			} else if (mode_is_signed(sm)) {
-				if ( mode_is_signed(lm) && (lm_bits >= sm_bits) )
-					return 1;
-			} else if (mode_is_signed(lm)) {
-				if (lm_bits > sm_bits + 1)
-					return 1;
-			} else if (lm_bits >= sm_bits) {
-				return 1;
+			if (mode_is_signed(sm)) {
+				if (!mode_is_signed(lm))
+					return 0;
+				return sm_bits <= lm_bits;
+			} else {
+				if (mode_is_signed(lm)) {
+					return sm_bits < lm_bits;
+				}
+				return sm_bits <= lm_bits;
 			}
 			break;
 
@@ -636,9 +585,12 @@ smaller_mode(const ir_mode *sm, const ir_mode *lm) {
 		break;
 
 	case irms_reference:
-		/* do exist machines out there with different pointer lenghts ?*/
+		/* do exist machines out there with different pointer lengths ?*/
 		return 0;
 
+	case irms_internal_boolean:
+		return mode_is_int(lm);
+
 	default:
 		break;
 	}
@@ -647,6 +599,37 @@ smaller_mode(const ir_mode *sm, const ir_mode *lm) {
 	return 0;
 }
 
+/* Returns true if a value of mode sm can be converted into mode lm
+   and backwards without loss. */
+int values_in_mode(const ir_mode *sm, const ir_mode *lm) {
+	int sm_bits, lm_bits;
+	ir_mode_arithmetic arith;
+
+	assert(sm);
+	assert(lm);
+
+	if (sm == lm) return 1;
+
+	if (sm == mode_b)
+		return mode_is_int(lm);
+
+	sm_bits = get_mode_size_bits(sm);
+	lm_bits = get_mode_size_bits(lm);
+
+	arith = get_mode_arithmetic(sm);
+	if (arith != get_mode_arithmetic(lm))
+		return 0;
+
+	switch (arith) {
+		case irma_twos_complement:
+		case irma_ieee754:
+			return get_mode_size_bits(sm) <= get_mode_size_bits(lm);
+
+		default:
+			return 0;
+	}
+}
+
 /* Return the signed integer equivalent mode for an reference mode. */
 ir_mode *get_reference_mode_signed_eq(ir_mode *mode) {
 	assert(mode_is_reference(mode));
@@ -674,11 +657,11 @@ void set_reference_mode_unsigned_eq(ir_mode *ref_mode, ir_mode *int_mode) {
 }
 
 /* initialization, build the default modes */
-void
-init_mode (void) {
+void init_mode(void) {
 	ir_mode newmode;
 
 	obstack_init(&modes);
+	mode_list = NEW_ARR_F(ir_mode*, 0);
 
 	num_modes  =  0;
 	/* initialize predefined modes */
@@ -775,7 +758,9 @@ init_mode (void) {
 	newmode.name    = new_id_from_chars("E", 1);
 	newmode.code    = irm_E;
 	newmode.sign    = 1;
-	newmode.size    = 80;
+	/* note that the tarval module is calculating with 80 bits, but we use
+	 * 96 bits, as that is what will be stored to memory by most hardware */
+	newmode.size    = 96;
 
 	mode_E = register_mode(&newmode);
 
@@ -874,29 +859,8 @@ init_mode (void) {
 
 	mode_LLu = register_mode(&newmode);
 
-	/* Character Modes */
-	newmode.sort         = irms_character;
-	newmode.arithmetic   = irma_twos_complement;
-	newmode.modulo_shift = 0;
-
-	/* Character */
-	newmode.name         = new_id_from_chars("C", 1);
-	newmode.code         = irm_C;
-	newmode.sign         = 0;
-	newmode.size         = 8;
-
-	mode_C = register_mode(&newmode);
-
-	/* Unicode character */
-	newmode.name         = new_id_from_chars("U", 1);
-	newmode.code         = irm_U;
-	newmode.sign         = 0;
-	newmode.size         = 16;
-
-	mode_U = register_mode(&newmode);
-
-	/* Reference Modes */
-	newmode.sort    = irms_reference;
+	/* Reference Mode */
+	newmode.sort       = irms_reference;
 	newmode.arithmetic = irma_twos_complement;
 
 	/* pointer */
@@ -919,7 +883,11 @@ init_mode (void) {
 ir_mode *find_unsigned_mode(const ir_mode *mode) {
 	ir_mode n = *mode;
 
-	assert(mode->sort == irms_int_number);
+	/* allowed for reference mode */
+	if (mode->sort == irms_reference)
+		n.sort = irms_int_number;
+
+	assert(n.sort == irms_int_number);
 	n.sign = 0;
 	return find_mode(&n);
 }
@@ -979,8 +947,28 @@ int mode_wrap_around(const ir_mode *mode) {
 	return mode_is_int(mode);
 }
 
+/*
+ * Returns non-zero if the cast from mode src to mode dst is a
+ * reinterpret cast (ie. only the bit pattern is reinterpreted,
+ * no conversion is done)
+ */
+int is_reinterpret_cast(const ir_mode *src, const ir_mode *dst) {
+	ir_mode_arithmetic ma;
+
+	if (src == dst)
+		return 1;
+	if (get_mode_size_bits(src) != get_mode_size_bits(dst))
+		return 0;
+	ma = get_mode_arithmetic(src);
+	if (ma != get_mode_arithmetic(dst))
+		return 0;
+
+	return ma == irma_twos_complement || ma == irma_ones_complement;
+}
+
 void finish_mode(void) {
 	obstack_free(&modes, 0);
+	DEL_ARR_F(mode_list);
 
 	mode_T   = NULL;
 	mode_X   = NULL;
@@ -1002,11 +990,9 @@ void finish_mode(void) {
 	mode_Ls  = NULL;
 	mode_Lu  = NULL;
 
-	mode_C   = NULL;
-	mode_U   = NULL;
 	mode_b   = NULL;
-	mode_P   = NULL;
 
+	mode_P      = NULL;
 	mode_P_code = NULL;
 	mode_P_data = NULL;
 }