Add overflow and underflow prediction functions

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

1 files changed, 20 insertions, 4 deletions

diff --git a/libj2_j2u_sub_j2u.c b/libj2_j2u_sub_j2u.c
index 6727c71..bd645e2 100644
--- a/libj2_j2u_sub_j2u.c
+++ b/libj2_j2u_sub_j2u.c
@@ -56,13 +56,18 @@ check_(uintmax_t a_high, uintmax_t a_low, uintmax_t b_high, uintmax_t b_low,
 	EXPECT(libj2_j2u_eq_j2u(&b, &expected));
 	EXPECT(libj2_j2u_eq_j2u(&a, &a_saved));
 
-	r = (struct libj2_j2u){111, 222};
 	a = a_saved;
 	b = b_saved;
 	EXPECT(libj2_j2u_sub_j2u_overflow(&a, &b) == r_overflow);
 	EXPECT(libj2_j2u_eq_j2u(&a, &expected));
 	EXPECT(libj2_j2u_eq_j2u(&b, &b_saved));
 
+	a = a_saved;
+	b = b_saved;
+	EXPECT(libj2_j2u_sub_j2u_overflow_p((const struct libj2_j2u *)&a, (const struct libj2_j2u *)&b) == r_overflow);
+	EXPECT(libj2_j2u_eq_j2u(&a, &a_saved));
+	EXPECT(libj2_j2u_eq_j2u(&b, &b_saved));
+
 	r = (struct libj2_j2u){111, 222};
 	a = a_saved;
 	b = b_saved;
@@ -89,12 +94,17 @@ check_(uintmax_t a_high, uintmax_t a_low, uintmax_t b_high, uintmax_t b_low,
 	EXPECT(libj2_j2u_eq_j2u(&b, &expected));
 	EXPECT(libj2_j2u_eq_j2u(&a, &a_saved));
 
-	r = (struct libj2_j2u){111, 222};
 	a = a_saved;
 	b = b_saved;
 	EXPECT(libj2_j2u_rsub_j2u_overflow(&b, &a) == r_overflow);
 	EXPECT(libj2_j2u_eq_j2u(&b, &expected));
 	EXPECT(libj2_j2u_eq_j2u(&a, &a_saved));
+
+	a = a_saved;
+	b = b_saved;
+	EXPECT(libj2_j2u_rsub_j2u_overflow_p(&b, &a) == r_overflow);
+	EXPECT(libj2_j2u_eq_j2u(&b, &b_saved));
+	EXPECT(libj2_j2u_eq_j2u(&a, &a_saved));
 }
 
 
@@ -146,11 +156,14 @@ check_double(uintmax_t high, uintmax_t low)
 	libj2_j2u_sub_j2u_to_j2u(&a, &a, &a);
 	EXPECT(libj2_j2u_is_zero(&a));
 
-	r = (struct libj2_j2u){111, 222};
 	a = a_saved;
 	EXPECT(libj2_j2u_sub_j2u_overflow(&a, &a) == 0);
 	EXPECT(libj2_j2u_is_zero(&a));
 
+	a = a_saved;
+	EXPECT(libj2_j2u_sub_j2u_overflow_p((const struct libj2_j2u *)&a, (const struct libj2_j2u *)&a) == 0);
+	EXPECT(libj2_j2u_eq_j2u(&a, &a_saved));
+
 	r = (struct libj2_j2u){111, 222};
 	a = a_saved;
 	EXPECT(libj2_j2u_sub_j2u_to_j2u_overflow(&a, &a, &r) == 0);
@@ -165,10 +178,13 @@ check_double(uintmax_t high, uintmax_t low)
 	libj2_j2u_rsub_j2u(&a, &a);
 	EXPECT(libj2_j2u_is_zero(&a));
 
-	r = (struct libj2_j2u){111, 222};
 	a = a_saved;
 	EXPECT(libj2_j2u_rsub_j2u_overflow(&a, &a) == 0);
 	EXPECT(libj2_j2u_is_zero(&a));
+
+	a = a_saved;
+	EXPECT(libj2_j2u_rsub_j2u_overflow_p((const struct libj2_j2u *)&a, (const struct libj2_j2u *)&a) == 0);
+	EXPECT(libj2_j2u_eq_j2u(&a, &a_saved));
 }