X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fir%2Firmode.c;h=75b02bcb73f097abb44caae59bf6edd74e67a447;hb=afbbc0b1ccd684c4c24bfd43d0f994123245f39f;hp=b59c13cd31829420978106a9d7c65d678c8b7fc9;hpb=946ac143432f37cbbadcd039b9c9892e21884ff5;p=libfirm

diff --git a/ir/ir/irmode.c b/ir/ir/irmode.c
index b59c13cd3..75b02bcb7 100644
--- a/ir/ir/irmode.c
+++ b/ir/ir/irmode.c
@@ -592,6 +592,37 @@ int 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));
@@ -907,6 +938,25 @@ 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);