X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fir%2Firmode.c;h=75b02bcb73f097abb44caae59bf6edd74e67a447;hb=bb5c6d5ce2e35c4074900017f8c8e1a4935054d0;hp=55108bbea22429309914366061558393f770a2bf;hpb=1e7ccff032250868e233a0e9c843ba0be9c763fa;p=libfirm

diff --git a/ir/ir/irmode.c b/ir/ir/irmode.c
index 55108bbea..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));