X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Ftv%2Ftv.c;h=e0b51c18b735148b618076a36f1d4be70cb81014;hb=80cebecbcc1cfcc311c781f112da1712b25d4fca;hp=88b4c9348d25bf5b64449623dd496dbe47164577;hpb=946ac143432f37cbbadcd039b9c9892e21884ff5;p=libfirm

diff --git a/ir/tv/tv.c b/ir/tv/tv.c
index 88b4c9348..e0b51c18b 100644
--- a/ir/tv/tv.c
+++ b/ir/tv/tv.c
@@ -94,16 +94,29 @@ enum float_to_int_mode {
 
 #define fail_verify(a) _fail_verify((a), __FILE__, __LINE__)
 
-/****************************************************************************
- *   private variables
- ****************************************************************************/
-static struct set *tarvals = NULL;   /* container for tarval structs */
-static struct set *values = NULL;    /* container for values */
+/** A set containing all existing tarvals. */
+static struct set *tarvals = NULL;
+/** A set containing all existing values. */
+static struct set *values = NULL;
+
+/** The integer overflow mode. */
 static tarval_int_overflow_mode_t int_overflow_mode = TV_OVERFLOW_WRAP;
 
 /** if this is set non-zero, the constant folding for floating point is OFF */
 static int no_float = 0;
 
+/** IEEE-754r half precision */
+static const ieee_descriptor_t half_desc     = {  5,  10, 0, NORMAL };
+/** IEEE-754 single precision */
+static const ieee_descriptor_t single_desc   = {  8,  23, 0, NORMAL };
+/** IEEE-754 double precision */
+static const ieee_descriptor_t double_desc   = { 11,  52, 0, NORMAL };
+/** Intel x87 extended precision */
+static const ieee_descriptor_t extended_desc = { 15,  63, 1, NORMAL };
+
+/** IEEE-754r quad precision */
+static const ieee_descriptor_t quad_desc     = { 15, 112, 0, NORMAL };
+
 /****************************************************************************
  *   private functions
  ****************************************************************************/
@@ -114,10 +127,9 @@ static void _fail_verify(tarval *tv, const char* file, int line)
 {
 	/* print a memory image of the tarval and throw an assertion */
 	if (tv)
-		printf("%s:%d: Invalid tarval:\n  mode: %s\n value: [%p]\n", file, line, get_mode_name(tv->mode), tv->value);
+		panic("%s:%d: Invalid tarval: mode: %F\n value: [%p]", file, line, tv->mode, tv->value);
 	else
-		printf("%s:%d: Invalid tarval (null)", file, line);
-	assert(0);
+		panic("%s:%d: Invalid tarval (null)", file, line);
 }
 #ifdef __GNUC__
 INLINE static void tarval_verify(tarval *tv) __attribute__ ((unused));
@@ -134,8 +146,6 @@ INLINE static void tarval_verify(tarval *tv)
 
 	if (!FIND_TARVAL(tv)) fail_verify(tv);
 	if (tv->length > 0 && !FIND_VALUE(tv->value, tv->length)) fail_verify(tv);
-
-	return;
 }
 #endif /* NDEBUG */
 
@@ -165,17 +175,17 @@ static int cmp_tv(const void *p1, const void *p2, size_t n) {
 
 	assert(tv1->kind == k_tarval);
 	assert(tv2->kind == k_tarval);
-	if(tv1->mode < tv2->mode)
+	if (tv1->mode < tv2->mode)
 		return -1;
-	if(tv1->mode > tv2->mode)
+	if (tv1->mode > tv2->mode)
 		return 1;
-	if(tv1->length < tv2->length)
+	if (tv1->length < tv2->length)
 		return -1;
-	if(tv1->length > tv2->length)
+	if (tv1->length > tv2->length)
 		return 1;
-	if(tv1->value < tv2->value)
+	if (tv1->value < tv2->value)
 		return -1;
-	if(tv1->value > tv2->value)
+	if (tv1->value > tv2->value)
 		return 1;
 
 	return 0;
@@ -288,6 +298,23 @@ tarval *tarval_undefined   = &reserved_tv[3];
 tarval *tarval_reachable   = &reserved_tv[4];
 tarval *tarval_unreachable = &reserved_tv[5];
 
+/**
+ * get the float descriptor for given mode.
+ */
+static const ieee_descriptor_t *get_descriptor(const ir_mode *mode) {
+	switch (get_mode_size_bits(mode)) {
+	case 16:  return &half_desc;
+	case 32:  return &single_desc;
+	case 64:  return &double_desc;
+	case 80:
+	case 96:  return &extended_desc;
+	case 128: return &quad_desc;
+	default:
+		panic("Unsupported mode in get_descriptor()");
+		return NULL;
+	}
+}
+
 /*
  *   public functions declared in tv.h
  */
@@ -297,6 +324,8 @@ tarval *tarval_unreachable = &reserved_tv[5];
  */
 tarval *new_tarval_from_str(const char *str, size_t len, ir_mode *mode)
 {
+	const ieee_descriptor_t *desc;
+
 	assert(str);
 	assert(len);
 	assert(mode);
@@ -305,8 +334,7 @@ tarval *new_tarval_from_str(const char *str, size_t len, ir_mode *mode)
 	case irms_control_flow:
 	case irms_memory:
 	case irms_auxiliary:
-		assert(0);
-		break;
+		panic("Unsupported tarval creation with mode %F", mode);
 
 	case irms_internal_boolean:
 		/* match [tT][rR][uU][eE]|[fF][aA][lL][sS][eE] */
@@ -319,20 +347,8 @@ tarval *new_tarval_from_str(const char *str, size_t len, ir_mode *mode)
 			return atoi(str) ? tarval_b_true : tarval_b_false;
 
 	case irms_float_number:
-		switch (get_mode_size_bits(mode)) {
-		case 32:
-			fc_val_from_str(str, len, 8, 23, NULL);
-			break;
-		case 64:
-			fc_val_from_str(str, len, 11, 52, NULL);
-			break;
-		case 80:
-		case 96:
-			fc_val_from_str(str, len, 15, 64, NULL);
-			break;
-		default:
-			panic("Unsupported mode in new_tarval_from_str()");
-		}
+		desc = get_descriptor(mode);
+		fc_val_from_str(str, len, desc, NULL);
 		return get_tarval(fc_get_buffer(), fc_get_buffer_length(), mode);
 
 	case irms_reference:
@@ -341,9 +357,7 @@ tarval *new_tarval_from_str(const char *str, size_t len, ir_mode *mode)
 		sc_val_from_str(str, len, NULL, mode);
 		return get_tarval(sc_get_buffer(), sc_get_buffer_length(), mode);
 	}
-
-	assert(0);  /* can't be reached, can it? */
-	return NULL;
+	panic("Unsupported tarval creation with mode %F", mode);
 }
 
 /*
@@ -396,22 +410,11 @@ long get_tarval_long(tarval* tv) {
 }
 
 tarval *new_tarval_from_double(long double d, ir_mode *mode) {
-	assert(mode && (get_mode_sort(mode) == irms_float_number));
+	const ieee_descriptor_t *desc;
 
-	switch (get_mode_size_bits(mode)) {
-	case 32:
-		fc_val_from_ieee754(d, 8, 23, NULL);
-		break;
-	case 64:
-		fc_val_from_ieee754(d, 11, 52, NULL);
-		break;
-	case 80:
-	case 96:
-		fc_val_from_ieee754(d, 15, 64, NULL);
-		break;
-	default:
-		panic("Unsupported mode in new_tarval_from_double()");
-	}
+	assert(mode && (get_mode_sort(mode) == irms_float_number));
+	desc = get_descriptor(mode);
+	fc_val_from_ieee754(d, desc, NULL);
 	return get_tarval(fc_get_buffer(), fc_get_buffer_length(), mode);
 }
 
@@ -473,38 +476,26 @@ tarval *(get_tarval_unreachable)(void) {
 }
 
 tarval *get_tarval_max(ir_mode *mode) {
-	assert(mode);
+	const ieee_descriptor_t *desc;
 
+	assert(mode);
 	if (get_mode_n_vector_elems(mode) > 1) {
 		/* vector arithmetic not implemented yet */
 		return tarval_bad;
 	}
 
-	switch(get_mode_sort(mode)) {
+	switch (get_mode_sort(mode)) {
 	case irms_control_flow:
 	case irms_memory:
 	case irms_auxiliary:
-		assert(0);
-		break;
+		panic("mode %F does not support maximum value", mode);
 
 	case irms_internal_boolean:
 		return tarval_b_true;
 
 	case irms_float_number:
-		switch(get_mode_size_bits(mode)) {
-		case 32:
-			fc_get_max(8, 23, NULL);
-			break;
-		case 64:
-			fc_get_max(11, 52, NULL);
-			break;
-		case 80:
-		case 96:
-			fc_get_max(15, 64, NULL);
-			break;
-		default:
-			panic("Unsupported mode in get_tarval_max()");
-		}
+		desc = get_descriptor(mode);
+		fc_get_max(desc, NULL);
 		return get_tarval(fc_get_buffer(), fc_get_buffer_length(), mode);
 
 	case irms_reference:
@@ -516,38 +507,26 @@ tarval *get_tarval_max(ir_mode *mode) {
 }
 
 tarval *get_tarval_min(ir_mode *mode) {
-	assert(mode);
+	const ieee_descriptor_t *desc;
 
+	assert(mode);
 	if (get_mode_n_vector_elems(mode) > 1) {
 		/* vector arithmetic not implemented yet */
 		return tarval_bad;
 	}
 
-	switch(get_mode_sort(mode)) {
+	switch (get_mode_sort(mode)) {
 	case irms_control_flow:
 	case irms_memory:
 	case irms_auxiliary:
-		assert(0);
-		break;
+		panic("mode %F does not support minimum value", mode);
 
 	case irms_internal_boolean:
 		return tarval_b_false;
 
 	case irms_float_number:
-		switch(get_mode_size_bits(mode)) {
-		case 32:
-			fc_get_min(8, 23, NULL);
-			break;
-		case 64:
-			fc_get_min(11, 52, NULL);
-			break;
-		case 80:
-		case 96:
-			fc_get_min(15, 64, NULL);
-			break;
-		default:
-			panic("Unsupported mode in get_tarval_min()");
-		}
+		desc = get_descriptor(mode);
+		fc_get_min(desc, NULL);
 		return get_tarval(fc_get_buffer(), fc_get_buffer_length(), mode);
 
 	case irms_reference:
@@ -569,12 +548,11 @@ tarval *get_tarval_null(ir_mode *mode) {
 		return tarval_bad;
 	}
 
-	switch(get_mode_sort(mode)) {
+	switch (get_mode_sort(mode)) {
 	case irms_control_flow:
 	case irms_memory:
 	case irms_auxiliary:
-		assert(0);
-		break;
+		panic("mode %F does not support null value", mode);
 
 	case irms_float_number:
 		return new_tarval_from_double(0.0, mode);
@@ -592,18 +570,14 @@ tarval *get_tarval_null(ir_mode *mode) {
 tarval *get_tarval_one(ir_mode *mode) {
 	assert(mode);
 
-	if (get_mode_n_vector_elems(mode) > 1) {
-		/* vector arithmetic not implemented yet */
-		assert(0);
-		return tarval_bad;
-	}
+	if (get_mode_n_vector_elems(mode) > 1)
+		panic("vector arithmetic not implemented yet");
 
-	switch(get_mode_sort(mode)) {
+	switch (get_mode_sort(mode)) {
 	case irms_control_flow:
 	case irms_memory:
 	case irms_auxiliary:
-		assert(0);
-		break;
+		panic("mode %F does not support one value", mode);
 
 	case irms_internal_boolean:
 		return tarval_b_true;
@@ -621,18 +595,14 @@ tarval *get_tarval_one(ir_mode *mode) {
 tarval *get_tarval_all_one(ir_mode *mode) {
 	assert(mode);
 
-	if (get_mode_n_vector_elems(mode) > 1) {
-		/* vector arithmetic not implemented yet */
-		assert(0);
-		return tarval_bad;
-	}
+	if (get_mode_n_vector_elems(mode) > 1)
+		panic("vector arithmetic not implemented yet");
 
-	switch(get_mode_sort(mode)) {
+	switch (get_mode_sort(mode)) {
 	case irms_control_flow:
 	case irms_memory:
 	case irms_auxiliary:
-		assert(0);
-		return tarval_bad;
+		panic("mode %F does not support all-one value", mode);
 
 	case irms_int_number:
 	case irms_internal_boolean:
@@ -657,18 +627,15 @@ int tarval_is_constant(tarval *tv) {
 tarval *get_tarval_minus_one(ir_mode *mode) {
 	assert(mode);
 
-	if (get_mode_n_vector_elems(mode) > 1) {
-		/* vector arithmetic not implemented yet */
-		return tarval_bad;
-	}
+	if (get_mode_n_vector_elems(mode) > 1)
+		panic("vector arithmetic not implemented yet");
 
-	switch(get_mode_sort(mode)) {
+	switch (get_mode_sort(mode)) {
 	case irms_control_flow:
 	case irms_memory:
 	case irms_auxiliary:
 	case irms_internal_boolean:
-		assert(0);
-		break;
+		panic("mode %F does not support minus one value", mode);
 
 	case irms_reference:
 		return tarval_bad;
@@ -683,97 +650,49 @@ tarval *get_tarval_minus_one(ir_mode *mode) {
 }
 
 tarval *get_tarval_nan(ir_mode *mode) {
-	assert(mode);
+	const ieee_descriptor_t *desc;
 
-	if (get_mode_n_vector_elems(mode) > 1) {
-		/* vector arithmetic not implemented yet */
-		return tarval_bad;
-	}
+	assert(mode);
+	if (get_mode_n_vector_elems(mode) > 1)
+		panic("vector arithmetic not implemented yet");
 
 	if (get_mode_sort(mode) == irms_float_number) {
-		switch(get_mode_size_bits(mode)) {
-		case 32:
-			fc_get_qnan(8, 23, NULL);
-			break;
-		case 64:
-			fc_get_qnan(11, 52, NULL);
-			break;
-		case 80:
-		case 96:
-			fc_get_qnan(15, 64, NULL);
-			break;
-		default:
-			panic("Unsupported mode in get_tarval_nan()");
-		}
+		desc = get_descriptor(mode);
+		fc_get_qnan(desc, NULL);
 		return get_tarval(fc_get_buffer(), fc_get_buffer_length(), mode);
-	} else {
-		assert(0 && "tarval is not floating point");
-		return tarval_bad;
-	}
+	} else
+		panic("mode %F does not support NaN value", mode);
 }
 
 tarval *get_tarval_plus_inf(ir_mode *mode) {
 	assert(mode);
-
-	if (get_mode_n_vector_elems(mode) > 1) {
-		/* vector arithmetic not implemented yet */
-		return tarval_bad;
-	}
+	if (get_mode_n_vector_elems(mode) > 1)
+		panic("vector arithmetic not implemented yet");
 
 	if (get_mode_sort(mode) == irms_float_number) {
-		switch(get_mode_size_bits(mode)) {
-		case 32:
-			fc_get_plusinf(8, 23, NULL);
-			break;
-		case 64:
-			fc_get_plusinf(11, 52, NULL);
-			break;
-		case 80:
-		case 96:
-			fc_get_plusinf(15, 64, NULL);
-			break;
-		default:
-			panic("Unsupported mode in get_tarval_plus_inf()");
-		}
+		const ieee_descriptor_t *desc = get_descriptor(mode);
+		fc_get_plusinf(desc, NULL);
 		return get_tarval(fc_get_buffer(), fc_get_buffer_length(), mode);
-	} else {
-		assert(0 && "tarval is not floating point");
-		return tarval_bad;
-	}
+	} else
+		panic("mode %F does not support +inf value", mode);
 }
 
 tarval *get_tarval_minus_inf(ir_mode *mode) {
 	assert(mode);
 
-	if (get_mode_n_vector_elems(mode) > 1) {
-		/* vector arithmetic not implemented yet */
-		return tarval_bad;
-	}
+	if (get_mode_n_vector_elems(mode) > 1)
+		panic("vector arithmetic not implemented yet");
 
 	if (get_mode_sort(mode) == irms_float_number) {
-		switch(get_mode_size_bits(mode)) {
-		case 32:
-			fc_get_minusinf(8, 23, NULL);
-			break;
-		case 64:
-			fc_get_minusinf(11, 52, NULL);
-			break;
-		case 80:
-		case 96:
-			fc_get_minusinf(15, 64, NULL);
-			break;
-		default:
-			panic("Unsupported mode in get_tarval_minus_inf()");
-		}
+		const ieee_descriptor_t *desc = get_descriptor(mode);
+		fc_get_minusinf(desc, NULL);
 		return get_tarval(fc_get_buffer(), fc_get_buffer_length(), mode);
-	} else {
-		assert(0 && "tarval is not floating point");
-		return tarval_bad;
-	}
+	} else
+		panic("mode %F does not support -inf value", mode);
 }
 
 /*
- * Arithmethic operations on tarvals ========================================
+ * Arithmetic operations on tarvals ========================================
  */
 
 /*
@@ -782,11 +701,8 @@ tarval *get_tarval_minus_inf(ir_mode *mode) {
 int tarval_is_negative(tarval *a) {
 	assert(a);
 
-	if (get_mode_n_vector_elems(a->mode) > 1) {
-		/* vector arithmetic not implemented yet */
-		assert(0 && "tarval_is_negative is not allowed for vector modes");
-		return 0;
-	}
+	if (get_mode_n_vector_elems(a->mode) > 1)
+		panic("vector arithmetic not implemented yet");
 
 	switch (get_mode_sort(a->mode)) {
 	case irms_int_number:
@@ -798,8 +714,7 @@ int tarval_is_negative(tarval *a) {
 		return fc_is_negative(a->value);
 
 	default:
-		assert(0 && "not implemented");
-		return 0;
+		panic("mode %F does not support negation value", a->mode);
 	}
 }
 
@@ -844,7 +759,7 @@ pn_Cmp tarval_cmp(tarval *a, tarval *b) {
 	assert(b);
 
 	if (a == tarval_bad || b == tarval_bad) {
-		assert(0 && "Comparison with tarval_bad");
+		panic("Comparison with tarval_bad");
 		return pn_Cmp_False;
 	}
 
@@ -901,8 +816,9 @@ pn_Cmp tarval_cmp(tarval *a, tarval *b) {
  * convert to other mode
  */
 tarval *tarval_convert_to(tarval *src, ir_mode *dst_mode) {
-	char *buffer;
-	fp_value *res;
+	char                    *buffer;
+	fp_value                *res;
+	const ieee_descriptor_t *desc;
 
 	assert(src);
 	assert(dst_mode);
@@ -925,20 +841,8 @@ tarval *tarval_convert_to(tarval *src, ir_mode *dst_mode) {
 	case irms_float_number:
 		switch (get_mode_sort(dst_mode)) {
 		case irms_float_number:
-			switch (get_mode_size_bits(dst_mode)) {
-			case 32:
-				fc_cast(src->value, 8, 23, NULL);
-				break;
-			case 64:
-				fc_cast(src->value, 11, 52, NULL);
-				break;
-			case 80:
-			case 96:
-				fc_cast(src->value, 15, 64, NULL);
-				break;
-			default:
-				panic("Unsupported mode in tarval_convert_to()");
-			}
+			desc = get_descriptor(dst_mode);
+			fc_cast(src->value, desc, NULL);
 			return get_tarval(fc_get_buffer(), fc_get_buffer_length(), dst_mode);
 
 		case irms_int_number:
@@ -990,20 +894,8 @@ tarval *tarval_convert_to(tarval *src, ir_mode *dst_mode) {
 			snprintf(buffer, 100, "%s",
 				sc_print(src->value, get_mode_size_bits(src->mode), SC_DEC, mode_is_signed(src->mode)));
 			buffer[100 - 1] = '\0';
-			switch (get_mode_size_bits(dst_mode)) {
-			case 32:
-				fc_val_from_str(buffer, 0, 8, 23, NULL);
-				break;
-			case 64:
-				fc_val_from_str(buffer, 0, 11, 52, NULL);
-				break;
-			case 80:
-			case 96:
-				fc_val_from_str(buffer, 0, 15, 64, NULL);
-				break;
-			default:
-				panic("Unsupported mode in tarval_convert_to()");
-			}
+			desc = get_descriptor(dst_mode);
+			fc_val_from_str(buffer, 0, desc, NULL);
 			return get_tarval(fc_get_buffer(), fc_get_buffer_length(), dst_mode);
 
 		default:
@@ -1099,9 +991,7 @@ tarval *tarval_neg(tarval *a) {
  * addition
  */
 tarval *tarval_add(tarval *a, tarval *b) {
-	tarval  *res;
-	char    *buffer;
-	ir_mode *dst_mode, *src_mode = NULL;
+	char *buffer;
 
 	assert(a);
 	assert(b);
@@ -1111,60 +1001,39 @@ tarval *tarval_add(tarval *a, tarval *b) {
 		return tarval_bad;
 	}
 
-	if (mode_is_reference(a->mode)) {
-		src_mode = a->mode;
-		dst_mode = find_unsigned_mode(a->mode);
-
-		if (dst_mode == NULL)
-			return tarval_bad;
-
-		a = tarval_convert_to(a, dst_mode);
-		b = tarval_convert_to(b, dst_mode);
-	}
-	if (mode_is_reference(b->mode)) {
-		src_mode = b->mode;
-		dst_mode = find_unsigned_mode(b->mode);
-
-		if (dst_mode == 0)
-			return tarval_bad;
-
-		a = tarval_convert_to(a, dst_mode);
-		b = tarval_convert_to(b, dst_mode);
+	if (mode_is_reference(a->mode) && a->mode != b->mode) {
+		b = tarval_convert_to(b, a->mode);
+	} else if (mode_is_reference(b->mode) && b->mode != a->mode) {
+		a = tarval_convert_to(a, b->mode);
 	}
 
 	assert(a->mode == b->mode);
 
 	switch (get_mode_sort(a->mode)) {
+	case irms_reference:
 	case irms_int_number:
 		/* modes of a,b are equal, so result has mode of a as this might be the character */
 		buffer = alloca(sc_get_buffer_length());
 		sc_add(a->value, b->value, buffer);
-		res = get_tarval_overflow(buffer, a->length, a->mode);
-		break;
+		return get_tarval_overflow(buffer, a->length, a->mode);
 
 	case irms_float_number:
 		if (no_float)
 			return tarval_bad;
 
 		fc_add(a->value, b->value, NULL);
-		res = get_tarval_overflow(fc_get_buffer(), fc_get_buffer_length(), a->mode);
-		break;
+		return get_tarval_overflow(fc_get_buffer(), fc_get_buffer_length(), a->mode);
 
 	default:
 		return tarval_bad;
 	}
-	if (src_mode != NULL)
-		return tarval_convert_to(res, src_mode);
-	return res;
 }
 
 /*
  * subtraction
  */
-tarval *tarval_sub(tarval *a, tarval *b) {
-	tarval  *res;
+tarval *tarval_sub(tarval *a, tarval *b, ir_mode *dst_mode) {
 	char    *buffer;
-	ir_mode *dst_mode, *src_mode = NULL;
 
 	assert(a);
 	assert(b);
@@ -1173,49 +1042,33 @@ tarval *tarval_sub(tarval *a, tarval *b) {
 		/* vector arithmetic not implemented yet */
 		return tarval_bad;
 	}
-	if (mode_is_reference(a->mode)) {
-		src_mode = a->mode;
-		dst_mode = find_unsigned_mode(a->mode);
-
-		if (dst_mode == NULL)
-			return tarval_bad;
 
-		a = tarval_convert_to(a, dst_mode);
-		b = tarval_convert_to(b, dst_mode);
+	if (dst_mode != NULL) {
+		if (a->mode != dst_mode)
+			a = tarval_convert_to(a, dst_mode);
+		if (b->mode != dst_mode)
+			b = tarval_convert_to(b, dst_mode);
 	}
-	if (mode_is_reference(b->mode)) {
-		src_mode = b->mode;
-		dst_mode = find_unsigned_mode(b->mode);
-
-		if (dst_mode == 0)
-			return tarval_bad;
-
-		a = tarval_convert_to(a, dst_mode);
-		b = tarval_convert_to(b, dst_mode);
-	}
-
 	assert(a->mode == b->mode);
 
 	switch (get_mode_sort(a->mode)) {
+	case irms_reference:
 	case irms_int_number:
 		/* modes of a,b are equal, so result has mode of a as this might be the character */
 		buffer = alloca(sc_get_buffer_length());
 		sc_sub(a->value, b->value, buffer);
-		res = get_tarval_overflow(buffer, a->length, a->mode);
+		return get_tarval_overflow(buffer, a->length, a->mode);
 
 	case irms_float_number:
 		if (no_float)
 			return tarval_bad;
 
 		fc_sub(a->value, b->value, NULL);
-		res = get_tarval_overflow(fc_get_buffer(), fc_get_buffer_length(), a->mode);
+		return get_tarval_overflow(fc_get_buffer(), fc_get_buffer_length(), a->mode);
 
 	default:
 		return tarval_bad;
 	}
-	if (src_mode != NULL)
-		return tarval_convert_to(res, src_mode);
-	return res;
 }
 
 /*
@@ -1391,7 +1244,7 @@ tarval *tarval_and(tarval *a, tarval *b) {
 
 	/* works even for vector modes */
 
-	switch(get_mode_sort(a->mode)) {
+	switch (get_mode_sort(a->mode)) {
 	case irms_internal_boolean:
 		return (a == tarval_b_false) ? a : b;
 
@@ -1672,7 +1525,7 @@ char *get_tarval_bitpattern(tarval *tv) {
 	int i, j, pos = 0;
 	int n = get_mode_size_bits(tv->mode);
 	int bytes = (n + 7) / 8;
-	char *res = xmalloc((n + 1) * sizeof(char));
+	char *res = XMALLOCN(char, n + 1);
 	unsigned char byte;
 
 	for(i = 0; i < bytes; i++) {
@@ -1772,23 +1625,8 @@ int tarval_ieee754_get_exponent(tarval *tv) {
  * precision loss.
  */
 int tarval_ieee754_can_conv_lossless(tarval *tv, ir_mode *mode) {
-	char exp_size, mant_size;
-	switch (get_mode_size_bits(mode)) {
-	case 32:
-		exp_size = 8; mant_size = 23;
-		break;
-	case 64:
-		exp_size = 11; mant_size = 52;
-		break;
-	case 80:
-	case 96:
-		exp_size = 15; mant_size = 64;
-		break;
-	default:
-		panic("Unsupported mode in tarval_ieee754_can_conv_lossless()");
-		return 0;
-	}
-	return fc_can_lossless_conv_to(tv->value, exp_size, mant_size);
+	const ieee_descriptor_t *desc = get_descriptor(mode);
+	return fc_can_lossless_conv_to(tv->value, desc);
 }
 
 /* Set the immediate precision for IEEE-754 results. */
@@ -1801,6 +1639,17 @@ unsigned tarval_ieee754_get_exact(void) {
 	return fc_is_exact();
 }
 
+/* Return the size of the mantissa in bits (including possible
+   implicit bits) for the given mode. */
+unsigned tarval_ieee754_get_mantissa_size(const ir_mode *mode) {
+	const ieee_descriptor_t *desc;
+
+	assert(get_mode_arithmetic(mode) == irma_ieee754);
+	desc = get_descriptor(mode);
+
+	return desc->mantissa_size + desc->explicit_one;
+}
+
 /* check if its the a floating point NaN */
 int tarval_is_NaN(tarval *tv) {
 	if (! mode_is_float(tv->mode))
@@ -1861,7 +1710,7 @@ static const tarval_mode_info hex_output = {
 /*
  * Initialization of the tarval module: called before init_mode()
  */
-void init_tarval_1(long null_value) {
+void init_tarval_1(long null_value, int support_quad_precision) {
 	/* if these assertion fail, tarval_is_constant() will follow ... */
 	assert(tarval_b_false == &reserved_tv[0] && "b_false MUST be the first reserved tarval!");
 	assert(tarval_b_true  == &reserved_tv[1] && "b_true MUST be the second reserved tarval!");
@@ -1872,10 +1721,8 @@ void init_tarval_1(long null_value) {
 	 * an initial size, which is the expected number of constants */
 	tarvals = new_set(cmp_tv, N_CONSTANTS);
 	values  = new_set(memcmp, N_CONSTANTS);
-	/* init strcalc with precision of 68 to support floating point values with 64
-	 * bit mantissa (needs extra bits for rounding and overflow) */
-	init_strcalc(68);
-	init_fltcalc(0);
+	/* calls init_strcalc() with needed size */
+	init_fltcalc(support_quad_precision ? 112 : 64);
 }
 
 /*