Add subtraction and addition with carry/borrow and add abs_diff1.2

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

1 files changed, 89 insertions, 0 deletions

diff --git a/libj2_ju_abs_diff_ji_to_j2u.c b/libj2_ju_abs_diff_ji_to_j2u.c
new file mode 100644
index 0000000..f3a2d50
--- /dev/null
+++ b/libj2_ju_abs_diff_ji_to_j2u.c
@@ -0,0 +1,89 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+extern inline void libj2_ju_abs_diff_ji_to_j2u(uintmax_t a, intmax_t b, struct libj2_j2u *res);
+
+
+#else
+
+static uintmax_t
+random_ju(void)
+{
+	size_t n = LIBJ2_JU_BIT;
+	uintmax_t r = 0;
+	while (n--)
+		if (rand() < rand())
+			r |= (uintmax_t)1 << n;
+	return r;
+}
+
+
+int
+main(void)
+{
+	struct libj2_j2u r, expected;
+	uintmax_t a;
+	intmax_t b;
+	unsigned i;
+
+	srand((unsigned)time(NULL));
+
+	r = (struct libj2_j2u){111, 222};
+	libj2_ju_abs_diff_ji_to_j2u(0, 0, &r);
+	EXPECT(libj2_j2u_eq_ju(&r, 0));
+
+	r = (struct libj2_j2u){111, 222};
+	libj2_ju_abs_diff_ji_to_j2u(UINTMAX_MAX, 0, &r);
+	EXPECT(libj2_j2u_eq_ju(&r, UINTMAX_MAX));
+
+	r = (struct libj2_j2u){111, 222};
+	libj2_ju_abs_diff_ji_to_j2u(0, INTMAX_MAX, &r);
+	EXPECT(libj2_j2u_eq_ji(&r, INTMAX_MAX));
+
+	r = (struct libj2_j2u){111, 222};
+	libj2_ju_abs_diff_ji_to_j2u(0, -INTMAX_MAX, &r);
+	EXPECT(libj2_j2u_eq_ju(&r, INTMAX_MAX));
+
+	r = (struct libj2_j2u){111, 222};
+	libj2_ju_abs_diff_ji_to_j2u(UINTMAX_MAX, INTMAX_MAX, &r);
+	EXPECT(libj2_j2u_eq_ju(&r, (uintmax_t)INTMAX_MAX + 1U));
+
+	r = (struct libj2_j2u){111, 222};
+	libj2_ju_abs_diff_ji_to_j2u(UINTMAX_MAX, -INTMAX_MAX, &r);
+	libj2_ju_to_j2u(UINTMAX_MAX, &expected);
+	libj2_j2u_add_ju(&expected, (uintmax_t)INTMAX_MAX);
+	EXPECT(libj2_j2u_eq_j2u(&r, &expected));
+
+	for (i = 0; i < 256U; i++) {
+		a = random_ju();
+		b = (intmax_t)(random_ju() >> 1);
+
+		r = (struct libj2_j2u){111, 222};
+		libj2_ju_abs_diff_ji_to_j2u(a, -b, &r);
+		libj2_ju_to_j2u(a, &expected);
+		libj2_j2u_add_ju(&expected, (uintmax_t)b);
+		EXPECT(libj2_j2u_eq_j2u(&r, &expected));
+
+		r = (struct libj2_j2u){111, 222};
+		libj2_ju_abs_diff_ji_to_j2u(a, b, &r);
+		if ((uintmax_t)b < a) {
+			libj2_ju_to_j2u(a, &expected);
+			libj2_j2u_sub_ju(&expected, (uintmax_t)b);
+		} else {
+			libj2_ju_to_j2u((uintmax_t)b, &expected);
+			libj2_j2u_sub_ju(&expected, a);
+		}
+		EXPECT(libj2_j2u_eq_j2u(&r, &expected));
+
+		if (a <= (uintmax_t)INTMAX_MAX) {
+			r = (struct libj2_j2u){111, 222};
+			libj2_ju_abs_diff_ji_to_j2u((uintmax_t)b, (intmax_t)a, &r);
+			EXPECT(libj2_j2u_eq_j2u(&r, &expected));
+		}
+	}
+
+	return 0;
+}
+
+#endif