Add zand, zor, zxor, znot, zbtest, zsplit, and the newly introduced ztrunc

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 56 insertions, 0 deletions

diff --git a/src/zxor.c b/src/zxor.c
new file mode 100644
index 0000000..4c68448
--- /dev/null
+++ b/src/zxor.c
@@ -0,0 +1,56 @@
+/* See LICENSE file for copyright and license details. */
+#include "internals"
+
+
+void
+zxor(z_t a, z_t b, z_t c)
+{
+	size_t n, m;
+
+	if (zzero(b)) {
+		if (zzero(c)) {
+			SET_SIGNUM(a, 0);
+		} else {
+			if (a != c)
+				zset(a, c);
+		}
+		return;
+	} else if (zzero(c)) {
+		if (a != b)
+			zset(a, b);
+		return;
+	}
+
+	m = b->used > c->used ? b->used : c->used;
+	n = b->used + c->used - m;
+
+	if (n == m && !memcmp(b->chars, c->chars, m * sizeof(*(b->chars)))) {
+		SET_SIGNUM(a, 0);
+		return;
+	}
+
+	if (a->alloced < m) {
+		a->alloced = m;
+		a->chars = realloc(a->chars, m * sizeof(*(a->chars)));
+	}
+
+	if (a == b) {
+		memcpy(a->chars + n, m == b->used ? b->chars : c->chars, (m - n) * sizeof(*(a->chars)));
+		while (n--)
+			a->chars[n] ^= c->chars[n];
+	} else if (a == c) {
+		memcpy(a->chars + n, m == b->used ? b->chars : c->chars, (m - n) * sizeof(*(a->chars)));
+		while (n--)
+			a->chars[n] ^= b->chars[n];
+	} else if (m == b->used) {
+		memcpy(a->chars, b->chars, m * sizeof(*(a->chars)));
+		while (n--)
+			a->chars[n] ^= c->chars[n];
+	} else {
+		memcpy(a->chars, c->chars, m * sizeof(*(a->chars)));
+		while (n--)
+			a->chars[n] ^= b->chars[n];
+	}
+
+	SET_SIGNUM(a, 1 - 2 * ((zsignum(b) ^ zsignum(c)) < 0);
+}