tarval_ieee754_get_mantissa_size() implemented

[r21772]

include/libfirm/tv.h

@@ -788,6 +788,12 @@ unsigned tarval_ieee754_set_immediate_precision(unsigned bits);
  */
 unsigned tarval_ieee754_get_exact(void);
 
+/**
+ * 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);
+
 /**
  * Enable/Disable floating point constant folding.
  */

ir/ir/iropt.c

@@ -1262,14 +1262,8 @@ restart:
 			if (mode_is_int(n_mode) && mode_is_float(a_mode)) {
 				/* ConvI(ConvF(I)) -> I, iff float mantissa >= int mode */
 				size_t int_mantissa = get_mode_size_bits(n_mode) - (mode_is_signed(n_mode) ? 1 : 0);
-				size_t float_mantissa;
-				/* FIXME There is no way to get the mantissa size of a mode */
-				switch (get_mode_size_bits(a_mode)) {
-					case 32: float_mantissa = 23 + 1; break; // + 1 for implicit 1
-					case 64: float_mantissa = 52 + 1; break;
-					case 80: float_mantissa = 64;     break;
-					default: float_mantissa = 0;      break;
-				}
+				size_t float_mantissa = tarval_ieee754_get_mantissa_size(a_mode);
+
 				if (float_mantissa >= int_mantissa) {
 					n = b;
 					DBG_OPT_ALGSIM1(oldn, a, b, n, FS_OPT_CONV);

ir/tv/tv.c

@@ -176,17 +176,17 @@ 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;
@@ -1696,6 +1696,17 @@ 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))