Add saturated arithmetic operations

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

1 files changed, 46 insertions, 1 deletions

diff --git a/libj2_j2u_sub_ju.c b/libj2_j2u_sub_ju.c
index 0cd0343..651cd1c 100644
--- a/libj2_j2u_sub_ju.c
+++ b/libj2_j2u_sub_ju.c
@@ -42,6 +42,10 @@ check(uintmax_t a_high, uintmax_t a_low, uintmax_t b)
 	EXPECT(libj2_j2u_eq_j2u(&a, &expected));
 
 	a = (struct libj2_j2u){.high = a_high, .low = a_low};
+	libj2_j2u_sat_sub_ju(&a, b);
+	EXPECT(expected_overflow ? libj2_j2u_is_zero(&a) : libj2_j2u_eq_j2u(&a, &expected));
+
+	a = (struct libj2_j2u){.high = a_high, .low = a_low};
 	EXPECT(libj2_j2u_sub_ju_overflow_p((const struct libj2_j2u *)&a, b) == expected_overflow);
 	EXPECT(a.high == a_high);
 	EXPECT(a.low == a_low);
@@ -70,6 +74,17 @@ check(uintmax_t a_high, uintmax_t a_low, uintmax_t b)
 
 	r = (struct libj2_j2u){111, 222};
 	a = (struct libj2_j2u){.high = a_high, .low = a_low};
+	libj2_j2u_sat_sub_ju_to_j2u(&a, b, &r);
+	EXPECT(a.high == a_high);
+	EXPECT(a.low == a_low);
+	EXPECT(expected_overflow ? libj2_j2u_is_zero(&r) : libj2_j2u_eq_j2u(&r, &expected));
+
+	a = (struct libj2_j2u){.high = a_high, .low = a_low};
+	libj2_j2u_sat_sub_ju_to_j2u(&a, b, &a);
+	EXPECT(expected_overflow ? libj2_j2u_is_zero(&a) : libj2_j2u_eq_j2u(&a, &expected));
+
+	r = (struct libj2_j2u){111, 222};
+	a = (struct libj2_j2u){.high = a_high, .low = a_low};
 	libj2_ju_sub_j2u_to_j2u(b, &a, &r);
 	EXPECT(a.high == a_high);
 	EXPECT(a.low == a_low);
@@ -92,6 +107,15 @@ check(uintmax_t a_high, uintmax_t a_low, uintmax_t b)
 	EXPECT(libj2_j2u_eq_j2u(&a, &expected));
 
 	a = (struct libj2_j2u){.high = a_high, .low = a_low};
+	libj2_j2u_sat_rsub_ju(&a, b);
+	if (expected_roverflow) {
+		EXPECT(libj2_j2u_is_zero(&a));
+	} else {
+		libj2_minus_j2u(&a);
+		EXPECT(libj2_j2u_eq_j2u(&a, &expected));
+	}
+
+	a = (struct libj2_j2u){.high = a_high, .low = a_low};
 	EXPECT(libj2_j2u_rsub_ju_overflow_p((const struct libj2_j2u *)&a, b) == expected_roverflow);
 	EXPECT(a.high == a_high);
 	EXPECT(a.low == a_low);
@@ -107,7 +131,28 @@ check(uintmax_t a_high, uintmax_t a_low, uintmax_t b)
 	a = (struct libj2_j2u){.high = a_high, .low = a_low};
 	EXPECT(libj2_ju_sub_j2u_to_j2u_overflow(b, &a, &a) == expected_roverflow);
 	libj2_minus_j2u(&a);
-	EXPECT(libj2_j2u_eq_j2u(&a, &expected));;
+	EXPECT(libj2_j2u_eq_j2u(&a, &expected));
+
+	r = (struct libj2_j2u){111, 222};
+	a = (struct libj2_j2u){.high = a_high, .low = a_low};
+	libj2_ju_sat_sub_j2u_to_j2u(b, &a, &r);
+	EXPECT(a.high == a_high);
+	EXPECT(a.low == a_low);
+	if (expected_roverflow) {
+		EXPECT(libj2_j2u_is_zero(&r));
+	} else {
+		libj2_minus_j2u(&r);
+		EXPECT(libj2_j2u_eq_j2u(&r, &expected));
+	}
+
+	a = (struct libj2_j2u){.high = a_high, .low = a_low};
+	libj2_ju_sat_sub_j2u_to_j2u(b, &a, &a);
+	if (expected_roverflow) {
+		EXPECT(libj2_j2u_is_zero(&a));
+	} else {
+		libj2_minus_j2u(&a);
+		EXPECT(libj2_j2u_eq_j2u(&a, &expected));
+	}
 
 	a = (struct libj2_j2u){.high = a_high, .low = a_low};
 	EXPECT(libj2_ju_sub_j2u_overflow_p(b, (const struct libj2_j2u *)&a) == expected_roverflow);