X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fir%2Firmode.c;h=55108bbea22429309914366061558393f770a2bf;hb=52684e8ee70083c7ba5b25f51f33c6b5de78c7cf;hp=b59c13cd31829420978106a9d7c65d678c8b7fc9;hpb=946ac143432f37cbbadcd039b9c9892e21884ff5;p=libfirm

diff --git a/ir/ir/irmode.c b/ir/ir/irmode.c
index b59c13cd3..55108bbea 100644
--- a/ir/ir/irmode.c
+++ b/ir/ir/irmode.c
@@ -907,6 +907,25 @@ 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);