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

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

7 files changed, 259 insertions, 0 deletions

diff --git a/src/zand.c b/src/zand.c
new file mode 100644
index 0000000..3156857
--- /dev/null
+++ b/src/zand.c
@@ -0,0 +1,42 @@
+/* See LICENSE file for copyright and license details. */
+#include "internals"
+
+#include <string.h>
+
+
+void
+zand(z_t a, z_t b, z_t c)
+{
+	size_t n;
+
+	if (zzero(b) || zzero(c)) {
+		SET_SIGNUM(a, 0);
+		return;
+	}
+
+	n = b->used < c->used ? b->used : c->used;
+	while (n--)
+		if (b->chars[n] & c->chars[n])
+			goto found_highest;
+	SET_SIGNUM(a, 0);
+	return;
+
+found_highest:
+	a->used = ++n;
+	if (a == b) {
+		while (n--)
+			a->chars[n] &= c->chars[n];
+	} else if (a == c) {
+		while (n--)
+			a->chars[n] &= b->chars[n];
+	} else {
+		if (a->alloced < a->used) {
+			a->alloced = a->used;
+			a->chars = realloc(a->chars, a->used * sizeof(*(a->chars)));
+		}
+		memcpy(a->chars, c->chars, a->used * sizeof(*(a->chars)));
+		while (n--)
+			a->chars[n] &= b->chars[n];
+	}
+	SET_SIGNUM(a, (zsignum(b) > 0 || zsignum(c) > 0) * 2 - 1);
+}
diff --git a/src/zbtest.c b/src/zbtest.c
new file mode 100644
index 0000000..8e9f8ff
--- /dev/null
+++ b/src/zbtest.c
@@ -0,0 +1,18 @@
+/* See LICENSE file for copyright and license details. */
+#include "internals"
+
+
+int
+zbtest(z_t a, size_t bit)
+{
+	size_t chars;
+	if (zzero(a))
+		return 0;
+
+	chars = bit >> LB_BITS_PER_CHAR;
+	if (chars >= a->used)
+		return 0;
+
+	bit &= BITS_PER_CHAR - 1;
+	return (a->chars[chars] >> bit) & 1;
+}
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);
+}
diff --git a/src/zor.c b/src/zor.c
new file mode 100644
index 0000000..0f17f8d
--- /dev/null
+++ b/src/zor.c
@@ -0,0 +1,51 @@
+/* See LICENSE file for copyright and license details. */
+#include "internals"
+
+
+void
+zor(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 (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, (zsignum(b) > 0 && zsignum(c) > 0) * 2 - 1);
+}
diff --git a/src/zsplit.c b/src/zsplit.c
new file mode 100644
index 0000000..40b3e54
--- /dev/null
+++ b/src/zsplit.c
@@ -0,0 +1,31 @@
+/* See LICENSE file for copyright and license details. */
+#include "internals"
+
+
+void
+zsplit(z_t high, z_t low, z_t a, size_t delim)
+{
+	size_t chars;
+
+	if (zzero(a)) {
+		SET_SIGNUM(high, 0);
+		SET_SIGNUM(low, 0);
+		return;
+	}
+
+	chars = delim >> LB_BITS_PER_CHAR;
+
+	if (high == a) {
+		if (a->used < chars)
+			SET_SIGNUM(low, 0);
+		else
+			ztrunc(low, a, delim);
+		zrsh(high, a, delim);
+	} else {
+		zrsh(high, a, delim);
+		if (a->used < chars)
+			SET_SIGNUM(low, 0);
+		else
+			ztrunc(low, a, delim);
+	}
+}
diff --git a/src/ztrunc.c b/src/ztrunc.c
new file mode 100644
index 0000000..d4c31de
--- /dev/null
+++ b/src/ztrunc.c
@@ -0,0 +1,31 @@
+/* See LICENSE file for copyright and license details. */
+#include "internals"
+
+#include <stdlib.h>
+#include <string.h>
+
+
+void
+ztrunc(z_t a, z_t b, size_t bits)
+{
+	zahl_char_t mask = 1;
+	size_t chars;
+	if (zzero(b)) {
+		SET_SIGNUM(a, 0);
+	} else {
+		chars = CEILING_BITS_TO_CHARS(bits);
+		a->sign = b->sign;
+		a->used = chars < b->used ? chars : b->used;
+		if (a->alloced < b->alloced) {
+			a->alloced = b->alloced;
+			a->chars = realloc(a->chars, b->alloced * sizeof(*(a->chars)));
+		}
+		memcpy(a->chars, b->chars, a->used * sizeof(*(a->chars)));
+		bits = BITS_IN_LAST_CHAR(bits);
+		if (bits) {
+			mask <<= bits;
+			mask -= 1;
+			a->chars[a->used - 1] &= mask;
+		}
+	}
+}
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);
+}