1 files changed, 30 insertions, 0 deletions
diff --git a/src/znot.c b/src/znot.c
new file mode 100644
index 0000000..7f2f021
--- /dev/null
+++ b/src/znot.c
@@ -0,0 +1,30 @@
+/* See LICENSE file for copyright and license details. */
+#include "internals"
+
+
+void
+znot(z_t a, z_t b)
+{
+	size_t bits, n;
+
+	if (zzero(b)) {
+		SET_SIGNUM(a, 0)
+		return;
+	}
+
+	bits = zbits(b);
+	if (a != b)
+		zset(a, b);
+	SET_SIGNUM(a, -zsignum(a));
+
+	for (n = a->used; n--;)
+		a->chars[n] = ~(a->chars[n]);
+	bits &= BITS_PER_CHAR - 1;
+	a->chars[a->used - 1] &= ((zahl_char_t)1 << bits) - 1;
+
+	while (; a->used; a->used--)
+		if (a->chars[a->used - 1])
+			break;
+	if (!a->used)
+		SET_SIGNUM(a, 0);
+}