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-rw-r--r--libj2_j2u_add_ju.c301
1 files changed, 301 insertions, 0 deletions
diff --git a/libj2_j2u_add_ju.c b/libj2_j2u_add_ju.c
new file mode 100644
index 0000000..8592662
--- /dev/null
+++ b/libj2_j2u_add_ju.c
@@ -0,0 +1,301 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+extern inline void libj2_j2u_add_ju(struct libj2_j2u *a, uintmax_t b);
+/* TODO Add man page */
+
+
+#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;
+}
+
+
+static void
+check_zero_low(uintmax_t high, uintmax_t low)
+{
+ struct libj2_j2u a, r;
+
+ a = (struct libj2_j2u){.high = high, .low = 0};
+ libj2_j2u_add_ju(&a, low);
+ EXPECT(a.high == high);
+ EXPECT(a.low == low);
+
+ a = (struct libj2_j2u){.high = high, .low = 0};
+ EXPECT(libj2_j2u_add_ju_overflow(&a, low) == 0);
+ EXPECT(a.high == high);
+ EXPECT(a.low == low);
+
+ r = (struct libj2_j2u){111, 222};
+ a = (struct libj2_j2u){.high = high, .low = 0};
+ libj2_j2u_add_ju_to_j2u(&a, low, &r);
+ EXPECT(a.high == high);
+ EXPECT(a.low == 0);
+ EXPECT(r.high == high);
+ EXPECT(r.low == low);
+
+ a = (struct libj2_j2u){.high = high, .low = 0};
+ libj2_j2u_add_ju_to_j2u(&a, low, &a);
+ EXPECT(a.high == high);
+ EXPECT(a.low == low);
+
+ r = (struct libj2_j2u){111, 222};
+ a = (struct libj2_j2u){.high = high, .low = 0};
+ EXPECT(libj2_j2u_add_ju_to_j2u_overflow(&a, low, &r) == 0);
+ EXPECT(a.high == high);
+ EXPECT(a.low == 0);
+ EXPECT(r.high == high);
+ EXPECT(r.low == low);
+
+ a = (struct libj2_j2u){.high = high, .low = 0};
+ EXPECT(libj2_j2u_add_ju_to_j2u_overflow(&a, low, &a) == 0);
+ EXPECT(a.high == high);
+ EXPECT(a.low == low);
+
+ r = (struct libj2_j2u){111, 222};
+ a = (struct libj2_j2u){.high = high, .low = 0};
+ libj2_ju_add_j2u_to_j2u(low, &a, &r);
+ EXPECT(a.high == high);
+ EXPECT(a.low == 0);
+ EXPECT(r.high == high);
+ EXPECT(r.low == low);
+
+ a = (struct libj2_j2u){.high = high, .low = 0};
+ libj2_ju_add_j2u_to_j2u(low, &a, &a);
+ EXPECT(a.high == high);
+ EXPECT(a.low == low);
+
+ r = (struct libj2_j2u){111, 222};
+ a = (struct libj2_j2u){.high = high, .low = 0};
+ EXPECT(libj2_ju_add_j2u_to_j2u_overflow(low, &a, &r) == 0);
+ EXPECT(a.high == high);
+ EXPECT(a.low == 0);
+ EXPECT(r.high == high);
+ EXPECT(r.low == low);
+
+ a = (struct libj2_j2u){.high = high, .low = 0};
+ EXPECT(libj2_ju_add_j2u_to_j2u_overflow(low, &a, &a) == 0);
+ EXPECT(a.high == high);
+ EXPECT(a.low == low);
+}
+
+
+static void
+check_max_low(uintmax_t high, uintmax_t low)
+{
+ struct libj2_j2u a, r;
+ uintmax_t expected_high = high + (uintmax_t)!!low;
+ uintmax_t expected_low = low - 1U;
+ int expected_overflow = high == UINTMAX_MAX && low;
+
+ a = (struct libj2_j2u){.high = high, .low = UINTMAX_MAX};
+ libj2_j2u_add_ju(&a, low);
+ EXPECT(a.high == expected_high);
+ EXPECT(a.low == expected_low);
+
+ a = (struct libj2_j2u){.high = high, .low = UINTMAX_MAX};
+ EXPECT(libj2_j2u_add_ju_overflow(&a, low) == expected_overflow);
+ EXPECT(a.high == expected_high);
+ EXPECT(a.low == expected_low);
+
+ r = (struct libj2_j2u){111, 222};
+ a = (struct libj2_j2u){.high = high, .low = UINTMAX_MAX};
+ libj2_j2u_add_ju_to_j2u(&a, low, &r);
+ EXPECT(a.high == high);
+ EXPECT(a.low == UINTMAX_MAX);
+ EXPECT(r.high == expected_high);
+ EXPECT(r.low == expected_low);
+
+ a = (struct libj2_j2u){.high = high, .low = UINTMAX_MAX};
+ libj2_j2u_add_ju_to_j2u(&a, low, &a);
+ EXPECT(a.high == expected_high);
+ EXPECT(a.low == expected_low);
+
+ r = (struct libj2_j2u){111, 222};
+ a = (struct libj2_j2u){.high = high, .low = UINTMAX_MAX};
+ EXPECT(libj2_j2u_add_ju_to_j2u_overflow(&a, low, &r) == expected_overflow);
+ EXPECT(a.high == high);
+ EXPECT(a.low == UINTMAX_MAX);
+ EXPECT(r.high == expected_high);
+ EXPECT(r.low == expected_low);
+
+ a = (struct libj2_j2u){.high = high, .low = UINTMAX_MAX};
+ EXPECT(libj2_j2u_add_ju_to_j2u_overflow(&a, low, &a) == expected_overflow);
+ EXPECT(a.high == expected_high);
+ EXPECT(a.low == expected_low);
+
+ r = (struct libj2_j2u){111, 222};
+ a = (struct libj2_j2u){.high = high, .low = UINTMAX_MAX};
+ libj2_ju_add_j2u_to_j2u(low, &a, &r);
+ EXPECT(a.high == high);
+ EXPECT(a.low == UINTMAX_MAX);
+ EXPECT(r.high == expected_high);
+ EXPECT(r.low == expected_low);
+
+ a = (struct libj2_j2u){.high = high, .low = UINTMAX_MAX};
+ libj2_ju_add_j2u_to_j2u(low, &a, &a);
+ EXPECT(a.high == expected_high);
+ EXPECT(a.low == expected_low);
+
+ r = (struct libj2_j2u){111, 222};
+ a = (struct libj2_j2u){.high = high, .low = UINTMAX_MAX};
+ EXPECT(libj2_ju_add_j2u_to_j2u_overflow(low, &a, &r) == expected_overflow);
+ EXPECT(a.high == high);
+ EXPECT(a.low == UINTMAX_MAX);
+ EXPECT(r.high == expected_high);
+ EXPECT(r.low == expected_low);
+
+ a = (struct libj2_j2u){.high = high, .low = UINTMAX_MAX};
+ EXPECT(libj2_ju_add_j2u_to_j2u_overflow(low, &a, &a) == expected_overflow);
+ EXPECT(a.high == expected_high);
+ EXPECT(a.low == expected_low);
+}
+
+
+static void
+self_check(uintmax_t a_high, uintmax_t a_low, uintmax_t b_high, uintmax_t b_low,
+ uintmax_t r_high, uintmax_t r_low, int r_overflow)
+{
+ uintmax_t carry = 0;
+ unsigned i;
+
+ for (i = 0; i < LIBJ2_JU_BIT; i++) {
+ carry += (a_low >> i) & 1U;
+ carry += (b_low >> i) & 1U;
+ EXPECT((carry & 1U) == ((r_low >> i) & 1U));
+ carry >>= 1;
+ }
+
+ for (i = 0; i < LIBJ2_JU_BIT; i++) {
+ carry += (a_high >> i) & 1U;
+ carry += (b_high >> i) & 1U;
+ EXPECT((carry & 1U) == ((r_high >> i) & 1U));
+ carry >>= 1;
+ }
+
+ EXPECT((uintmax_t)r_overflow == carry);
+}
+
+
+static void
+check(uintmax_t a_high, uintmax_t a_low, uintmax_t b)
+{
+ struct libj2_j2u a, r;
+ uintmax_t expected_high = a_high + (uintmax_t)(a_low > UINTMAX_MAX - b);
+ uintmax_t expected_low = a_low + b;
+ int expected_overflow = a_high && !expected_high;
+
+ self_check(a_high, a_low, 0, b, expected_high, expected_low, expected_overflow);
+
+ a = (struct libj2_j2u){.high = a_high, .low = a_low};
+ libj2_j2u_add_ju(&a, b);
+ EXPECT(a.high == expected_high);
+ EXPECT(a.low == expected_low);
+
+ a = (struct libj2_j2u){.high = a_high, .low = a_low};
+ EXPECT(libj2_j2u_add_ju_overflow(&a, b) == expected_overflow);
+ EXPECT(a.high == expected_high);
+ EXPECT(a.low == expected_low);
+
+ r = (struct libj2_j2u){111, 222};
+ a = (struct libj2_j2u){.high = a_high, .low = a_low};
+ libj2_j2u_add_ju_to_j2u(&a, b, &r);
+ EXPECT(a.high == a_high);
+ EXPECT(a.low == a_low);
+ EXPECT(r.high == expected_high);
+ EXPECT(r.low == expected_low);
+
+ a = (struct libj2_j2u){.high = a_high, .low = a_low};
+ libj2_j2u_add_ju_to_j2u(&a, b, &a);
+ EXPECT(a.high == expected_high);
+ EXPECT(a.low == expected_low);
+
+ r = (struct libj2_j2u){111, 222};
+ a = (struct libj2_j2u){.high = a_high, .low = a_low};
+ EXPECT(libj2_j2u_add_ju_to_j2u_overflow(&a, b, &r) == expected_overflow);
+ EXPECT(a.high == a_high);
+ EXPECT(a.low == a_low);
+ EXPECT(r.high == expected_high);
+ EXPECT(r.low == expected_low);
+
+ a = (struct libj2_j2u){.high = a_high, .low = a_low};
+ EXPECT(libj2_j2u_add_ju_to_j2u_overflow(&a, b, &a) == expected_overflow);
+ EXPECT(a.high == expected_high);
+ EXPECT(a.low == expected_low);
+
+ r = (struct libj2_j2u){111, 222};
+ a = (struct libj2_j2u){.high = a_high, .low = a_low};
+ libj2_ju_add_j2u_to_j2u(b, &a, &r);
+ EXPECT(a.high == a_high);
+ EXPECT(a.low == a_low);
+ EXPECT(r.high == expected_high);
+ EXPECT(r.low == expected_low);
+
+ a = (struct libj2_j2u){.high = a_high, .low = a_low};
+ libj2_ju_add_j2u_to_j2u(b, &a, &a);
+ EXPECT(a.high == expected_high);
+ EXPECT(a.low == expected_low);
+
+ r = (struct libj2_j2u){111, 222};
+ a = (struct libj2_j2u){.high = a_high, .low = a_low};
+ EXPECT(libj2_ju_add_j2u_to_j2u_overflow(b, &a, &r) == expected_overflow);
+ EXPECT(a.high == a_high);
+ EXPECT(a.low == a_low);
+ EXPECT(r.high == expected_high);
+ EXPECT(r.low == expected_low);
+
+ a = (struct libj2_j2u){.high = a_high, .low = a_low};
+ EXPECT(libj2_ju_add_j2u_to_j2u_overflow(b, &a, &a) == expected_overflow);
+ EXPECT(a.high == expected_high);
+ EXPECT(a.low == expected_low);
+}
+
+
+int
+main(void)
+{
+ unsigned i;
+
+ srand((unsigned)time(NULL));
+
+ check_zero_low(0, 0);
+ check_zero_low(0, UINTMAX_MAX);
+ check_zero_low(UINTMAX_MAX, 0);
+ check_zero_low(UINTMAX_MAX, UINTMAX_MAX);
+ for (i = 0; i < 256; i++) {
+ check_zero_low(0, random_ju());
+ check_zero_low(random_ju(), 0);
+ check_zero_low(random_ju(), random_ju());
+ check_zero_low(random_ju(), UINTMAX_MAX);
+ check_zero_low(UINTMAX_MAX, random_ju());
+ }
+
+ check_max_low(0, 0);
+ check_max_low(0, UINTMAX_MAX);
+ check_max_low(UINTMAX_MAX, 0);
+ check_max_low(UINTMAX_MAX, UINTMAX_MAX);
+ for (i = 0; i < 256; i++) {
+ check_max_low(0, random_ju());
+ check_max_low(random_ju(), 0);
+ check_max_low(random_ju(), 1);
+ check_max_low(random_ju(), random_ju());
+ check_max_low(random_ju(), UINTMAX_MAX);
+ check_max_low(UINTMAX_MAX, random_ju());
+ }
+
+ for (i = 0; i < 256; i++)
+ check(random_ju(), random_ju(), random_ju());
+
+ return 0;
+}
+
+#endif
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